ArticleLiterature Review

Oil spill impacts on mangroves: Recommendations for operational planning and action based on a global review

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Abstract

Mangrove tidal wetland habitats are recognized as highly vulnerable to large and chronic oil spills. This review of current literature and public databases covers the last 6 decades, summarising global data on oil spill incidents affecting, or likely to have affected, mangrove habitat. Over this period, there have been at least 238 notable oil spills along mangrove shorelines worldwide. In total, at least 5.5 million tonnes of oil has been released into mangrove-lined, coastal waters, oiling possibly up to around 1.94 million ha of mangrove habitat, and killing at least 126,000 ha of mangrove vegetation since 1958. However, there were assessment limitations with incomplete and unavailable data, as well as unequal coverage across world regions. To redress the gaps described here in reporting on oil spill impacts on mangroves and their recovery worldwide, a number of recommendations and suggestions are made for refreshing and updating standard operational procedures for responders, managers and researchers alike.

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... Pathways by which recovery (or loss) of undisturbed and oil impacted mangroves are outlined in Figure 7-9. Recovery of mangroves from heavy and persistent oiling often takes decades, while sublethal impacts may be followed by recovery in 1-10 years if there are live trees from which to recover a canopy (Duke 2016). Recovery following tree mortality requires much more time due to the need for seedling recruitment, establishment, and growth of trees, as long as 25-30 years for recovery of a mature forest (Duke 2016), if recovery occurs at all. ...
... Recovery of mangroves from heavy and persistent oiling often takes decades, while sublethal impacts may be followed by recovery in 1-10 years if there are live trees from which to recover a canopy (Duke 2016). Recovery following tree mortality requires much more time due to the need for seedling recruitment, establishment, and growth of trees, as long as 25-30 years for recovery of a mature forest (Duke 2016), if recovery occurs at all. ...
... Long recovery periods for mature mangrove forests appear inevitable if they are heavily impacted by an oil spill. The extent of mangrove loss and recovery can be measured using aerial photography, which has been used successfully for long-term monitoring (Duke 2016). This method can be used to differentiate between and track sublethal and lethal impacts and to monitor previously impacted mangroves that have not been tracked for many years. ...
... Les arbres les plus caractéristiques des mangroves sont les palétuviers avec leurs pneumatophores et leurs racines-échasses. Les palétuviers sont particulièrement sensibles aux altérations du substrat par les pollutions de type marée noire (Duke, 2016). Les changements climatiques qui causent des changements brutaux de la salinité et de l'équilibre hydrique au sein du milieu peuvent avoir un fort impact sur la survie des palétuviers (Spalding et al., 2010). ...
... Des travaux ont montrés que les éléments trace métalliques s'accumulent principalement dans les sédiments de la mangrove et dans les racines fines chez Avicennia marina (Chaudhuri et al., 2014;Kulkarni et al., 2018). De même les conséquences d'une pollution aux hydrocarbures (marée noire) sur le dépérissement des palétuviers a été abondamment décrit dans la littérature (Duke, 2016). Cependant ces études ont été réalisées à l'échelle de l'écosystème et seulement peu d'informations sont disponibles sur les phénomènes mis en place à l'échelle du palétuvier. ...
... Cependant, ces études portent sur le fonctionnement global de l'écosystème et ses altérations. Au niveau de l'arbre, les mécanismes de tolérance au sel ont été bien étudiés (Parida and Jha, 2010;Robert et al., 2009;Schmitz et al., 2007b) de même que ceux portant sur la résilience et la persistance des palétuvier après une marée noire (Duke, 2016). Naidoo and Naidoo, (2018) ont montré la non-accumulation des HAP dans le bois de Rhizophora mucronata. ...
... Studies of oil impacts to mature mangroves have reported leaf yellowing (chlorosis) and defoliation, mortality, stunted growth, leaf deformities, bark fissuring, epithelial scarring, lenticel expansion, reduced lenticel numbers, reduced leaf number, reduced pneumatophore density, limb loss, reduced water flux through roots, and genetic damage such as variegated leaves (NOAA, 2014;Tansel et al., 2015;Duke, 2016). In mangrove seedlings and juveniles, observed impacts include reduced germination/establishment, increased mutation rates, stunted/ deformed propagules, reduced plant height, reduced leaf number, reduced chlorophyll content, reduced root length and diameter, reduced relative root growth rate, and chlorophyll deficient propagules (Böer, 1993;Proffitt et al., 1995;Duke, 2016;Naidoo, 2016;Naidoo and Naidoo, 2017). ...
... Studies of oil impacts to mature mangroves have reported leaf yellowing (chlorosis) and defoliation, mortality, stunted growth, leaf deformities, bark fissuring, epithelial scarring, lenticel expansion, reduced lenticel numbers, reduced leaf number, reduced pneumatophore density, limb loss, reduced water flux through roots, and genetic damage such as variegated leaves (NOAA, 2014;Tansel et al., 2015;Duke, 2016). In mangrove seedlings and juveniles, observed impacts include reduced germination/establishment, increased mutation rates, stunted/ deformed propagules, reduced plant height, reduced leaf number, reduced chlorophyll content, reduced root length and diameter, reduced relative root growth rate, and chlorophyll deficient propagules (Böer, 1993;Proffitt et al., 1995;Duke, 2016;Naidoo, 2016;Naidoo and Naidoo, 2017). ...
... Initial acute effects are related to physical intrusion of oil into the mangrove forest environment, with death of associated animals, defoliation of adult trees, and loss of seedlings and juveniles (Burns et al., 1993;Mackey and Hodgkinson, 1996;Proffitt, 1997;Hensel et al., 2010;Lewis et al., 2011;Santos et al., 2011). Over time, mature trees are lost Michel and Rutherford, 2014;Duke, 2016). The effects of oil exposures in mangrove environments thus follow a pattern of short-term acute effects, with associated secondary and residual effects which ultimately lead to recovery or loss (Duke, 2016). ...
Article
The TRopical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment, conducted on the Caribbean coast of Panama, has become one of the most comprehensive field experiments examining the long-term impacts of oil and dispersed oil exposures in nearshore tropical marine environments. From the initial experiment through more than three decades of study and data collection visits, the intertidal and subtidal communities have exhibited significantly different impact and recovery regimes, depending on whether the sites were exposed to crude oil only or crude oil treated with a chemical dispersant. This review provides a synopsis of the original experiment and a cumulative summary of the results and observations, illustrating the environmental and ecosystem trade-offs of chemical dispersant use in mangrove, seagrass, and coral reef environments.
... For example, Zhang et al. (2008) reported an annual rate of 5 to 9 lightning "flashes" per square kilometer in mangroves of the Everglades National Park, United States. Furthermore, the distribution of mangroves along coastlines makes them highly exposed to humaninduced disturbances like offshore oil spills (Duke, 2016). Noticeable examples include the Deepwater Horizon platform failure in 2011, and vessel leakages along Brazilian and Mauritian coasts in 2019 and 2020, respectively (Magris & Giarrizzo, 2020;Nixon et al., 2016;Rajendran et al., 2021). ...
... On a broad scale, large mangrove dieback is sometimes observed in response to major disturbances such as extreme weather events (Abhik et al., 2021;Duke, 2016). However, a common consequence of disturbances is the onset of medium to large canopy gaps (10 to 1000 m 2 and more), which can be defined as round to elliptic discontinuities in mature canopies resulting from the death of several, neighboring mangrove trees (Amir & Duke, 2019). ...
... For example, gaps formed by cutting or wood-borer insects tend to be smaller in area than those caused by lightning strikes (Feller & McKee, 1999;Rasquinha & Mishra, 2021). Gaps resulting from oil spills may lead to permanent mangrove loss if seedling recruitment failsfor example, because of persistent pollution (Duke, 2016). Hence, mangroves may comprise a mosaic of canopy gaps from different stages, sizes, and shapes, which inform on the disturbances that occurred over the three last decades. ...
Article
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Mangroves are among the most ecologically valuable ecosystems of the globe. Reliable remote sensing solutions are required to assist their management and conservation at broad scale. Canopy gaps are part of forests' turnover and reju-venation, but yet no method has been proposed to map their occurrence and recovery in mangroves. Here, were propose an approach based on a deep learning framework called Mask R-CNN to achieve automatic detection and delin-eation of gaps using very-high-resolution satellite imagery (<1 m). The Mask R-CNN combines a series of neural network architectures to identify and delin-eate gaps, determine their recovery stage, and estimate their morphological attributes. The approach was tested on four mangroves from different regions of the globe with high concentration of gaps of various origins (lightning strikes, oil spills, cutting, pests). The Mask R-CNN performed well to detect gaps, and accurately delineated gap contours (F1-score of segmentation ≥0.89). The model also succeeded in distinguishing among five recovery stages of gaps, from their onset to closure (Overall Accuracy = 91.4, Kappa = 0.89). Accurate retrieval of gap area, eccentricity, and compactness-three relevant morphological attributes-were obtained (R 2 ≥ 0.83, NRMSE ≤10%). Several sources of confusion and misdelineation were identified. Our approach shows promising transferability to other mangrove sites and optical sensors and could help monitor canopy recovery in mangroves. It also opens promising perspectives for identifying the origin of gaps (natural or human-induced). It is intended to assist environmental managers and field experts in the management and conservation of these fragile ecosystems.
... Most deforested mangrove cover has been converted to aquaculture and agriculture (plantations), and then to urban land uses (Richards and Friess 2016;Friess et al. 2019). Approximately 62% of global mangrove covers were deforested and converted to aquaculture and agriculture in the period 2000-2016(Goldberg et al. 2020 while over 50% of the deforested mangroves in Southeast Asia became aquaculture and rice plantation in the past . In 2000-2012, mangrove deforestation in Southeast Asia had a declined loss to aquaculture down to approximately 30% but nearly 88% loss to rice plantation in Myanmar, 40% loss to oil palm plantation in Malaysia and Thailand, and 63% loss to urban land use in Vietnam (Richards and Friess 2016;Bryan-Brown et al. 2020). ...
... In 2000-2012, mangrove deforestation in Southeast Asia had a declined loss to aquaculture down to approximately 30% but nearly 88% loss to rice plantation in Myanmar, 40% loss to oil palm plantation in Malaysia and Thailand, and 63% loss to urban land use in Vietnam (Richards and Friess 2016;Bryan-Brown et al. 2020). Crude oil and gas production in coast also caused mangrove deforestation for drilling and infrastructure, and even worse during oil spill events while fuelwood and charcoal productions contributed to the early losses (Duke 2016;Friess et al. 2019). Comprehensive losses of socioeconomic benefits have been assessed for mangrove deforestations (Walters et al. 2008). ...
... Global mangrove cover changes over time were analyzed using a linear regression (Proc REG) for the combined databases in 1980-2005(Food and Agriculture Organization 20032007), the single database in 1990-2020 (Food and Agriculture Organization 2020), and the combined vector databases of NASA snapshot in 2000 (Giri et al. 2011) and GMW in 1996-2016(Bunting et al. 2018, respectively, as shown in Fig. 2. Interactive relationships of annual mangrove cover change with the socioeconomic indicators were conducted by Spearman correlation analysis for both the Table 1 Annual mangrove cover changes (%) in the globe and continents of the multi-databases (FAO and GMW in1990-2016 with 83 countries and territories) and the CGMFC-21 database (2001-2012 with 78 countries and territories) in relation to the socioeconomic-aquacultural indicators explored by Spearman correlation Note: GDP per capita was presented in current USD from the World Bank database. Urban population percentile (%) referred to the percentile of annual urban population in the annual national population from the World Bank database. ...
Article
Socioeconomic patterns beyond the land conversions of global mangrove cover changes were few discussed. This study integrated databases of global mangrove covers, i.e., a multi-database in 1980-2016 with a combination of FAO country-survey and the global mangrove watch, and a mangrove biome cover database in 2000-2012. Annual cover change (%) of each mangrove holding country or territory was incorporated with its socioeconomic indicators in the two periods to testify possible socioeconomic patterns beyond the mangrove deforestation. The socioeconomic indicators consisted of GDP per capita and urban population percentile, and aquacultural indicators (production per capita, sales value per capita, contribution to the national GDP, and product price). Results indicated that annual mangrove cover change was interactively driven by multi-factors of national economy measures, urbanization, and aquaculture. The multi-factor driven patterns of annual mangrove changes differed geographically among the continents. Temporal change of aquacultural product price was significantly and positively correlated to annual mangrove cover change (increase), especially in Asia and Oceania for both the periods, suggesting positive feedbacks of mangrove conservation and restoration in the two continents although the price was used to a motivator of mangrove deforestation, such as currently in Africa. These findings preliminarily bridge the knowledge gap between land conversion losses and socioeconomics of global mangrove cover changes and improve understandings on interactions between social and natural systems for the UN Decade of mangrove ecosystem conservation and restoration.
... Studies of oil impacts to mangroves are most commonly field studies of oil impacts, as well as laboratory studies. Observations have indicated a variety of acute and chronic effects (Duke 2016), and although interpretation is complicated by variability in methodology, species, and specific scenarios, there are a number of consistencies that allow some comparisons to be made. ...
... Initial acute impacts are related to physical intrusion of oil into the mangrove forest environment, with death of associated animals, defoliation of adult trees, and loss of seedlings and juveniles (Burns et al. 1993, Mackey and Hodgkinson 1996, Proffitt 1997Hensel et al. 2010, Lewis et al. 2011, Santos et al. 2011. Over time, mature trees are lost (Duke and Burns 1999, Michel and Rutherford 2014, Duke 2016. The effects of oil spills in mangrove environments thus follow a pattern of short-term acute effects, with associated secondary and residual effects which ultimately lead to recovery or loss (Duke 2016). ...
... Over time, mature trees are lost (Duke and Burns 1999, Michel and Rutherford 2014, Duke 2016. The effects of oil spills in mangrove environments thus follow a pattern of short-term acute effects, with associated secondary and residual effects which ultimately lead to recovery or loss (Duke 2016). This pattern was generally followed by Site O in the TROPICS experiment, where long term recovery appeared to track the delayed loss of detectable hydrocarbons in the substrate and maturation of colonizing juveniles; the time frame thus far for recovery is still within the 10-50 years suggested by Lewis (1983) although complete recovery is not yet evident. ...
Article
In 1984, the Tropical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment began in Bahia Almirante on the Caribbean coast of Panama. This study sought to compare the impacts of a severe, but realistic spill of untreated crude oil versus chemically treated (dispersed) crude oil on tropical marine reef, sea-grass, and mangrove ecosystems. The aim of the study was to identify and evaluate the environmental trade-offs of dispersant use in tropical marine and subtidal systems. As a result of continuing research at the site, the study became one of the most comprehensive field experiments examining the long-term impacts of oil and dispersed oil exposures in nearshore tropical communities. Consequently, TROPICS has been the foundational and seminal field study which served as the historical antecedent for Net Environmental Benefit Analysis (NEBA), as well as the basis for follow-on Spill Impact Mitigation Analysis (SIMA) and Comparative Risk Analysis (CRA) for oil spill planning, preparation, and response. From the initial experiment in 1984, through three decades of study and data collection visits, the coral reef, seagrass, and mangrove communities have exhibited significantly different damage and recovery regimes, depending on whether the sites were exposed to non-treated crude oil or dispersed crude oil. While this study does not definitively determine whether or not dispersants should be applied in tropical nearshore environments, it is illustrative of the environmental and ecosystem trade-offs between surface oil impacts to the shoreline, compared to water column exposure from chemically dispersed oil. This paper provides an overview of the results and observations reported in numerous previous TROPICS publications, as a progression of damage and recovery over time. With this perspective, planners and responders can use this study to predict what damages/recoveries may be expected from an oil spill incident in this environment. The results of the TROPICS experiment are examined within the context of this recent parallel research from the perspective of ongoing implications for oil spill preparedness and response.
... Oil behavior and persistence in marsh and mangrove habitats are influenced by the regional and local differences in wave energy, tidal frequency and amplitude, and vegetation described previously. Factors affecting the behavior and persistence of oil in marshes and mangroves are summarized below (Duke 2016;Hoff et al. 2014;Michel and Rutherford 2013). ...
... The number of spills reported to have adversely impacted mangroves far exceeds the number of studies documenting these impacts. The number of oil spills of 500-20,000 bbl known to have impacted mangroves from 1958 to 2016 includes 95 crude oil spills, two diesel spills, and one spill of condensate, based on data compiled by Duke (2016). Review of the literature on impacts from oil spills and response found data from five median-range size spills, one of which was experimental, were adequate for characterizing oil impacts to mangroves ( Table 7-2 and Figure 7 -8). ...
... Pathways by which recovery (or loss) of undisturbed and oil impacted mangroves are outlined in Figure 7-9. Recovery of mangroves from heavy and persistent oiling often takes decades, while sublethal impacts may be followed by recovery in 1-10 years if there are live trees from which to recover a canopy (Duke 2016;Duke and Burns 1999). Recovery following tree mortality requires much more time due to the need for seedling recruitment, establishment, and growth of trees, and as long as 25-30 years for recovery of a mature forest (Duke 2016), if recovery occurs at all. ...
... Nansingh and Jurawan (1999) have categorized mangrove ecosystems under the greatest index of environmental sensitivity relative to oil spills. The historical data for the major oil spill in the mangrove habitat as well as their adverse impact on the mangrove ecosystems has been documented (see review Lewis et al. 2011;Duke 2016). It is well known that PAHs are one of the major components of crude oil; for example, the PAHs proportion of light oil, heavy oil, intermediate fuel oil and bunker oil is 10-35%, 15-40%, 40-60% and 30-50%, respectively (e.g., Fingas 2014; Yoon et al. 2021). ...
... Several factors may affect the concentration of PAHs in coastal/mangrove water ways, including; • Concentration of PAHs in nearby industrial and urban effluents (Eduok et al. 2010); • Rate of atmospheric deposition and sedimentation in the region (Golomb et al. 2001); • Intensity of agricultural and industrial activities in the region (Zaghden et al. 2022); • River runoff (Herrmann and Hiibner 1982); • The occurrence of oil spills in the region, whether accidental or chronic (Duke 2016); and • Intensity of coal preparation and washing in nearby areas (e.g., Ambade et al. 2021). ...
Article
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Although coastal ecosystems such as mangroves have substantial productive and protective rules, this ecosystem is threatened due to inorganic and organic contaminants including polycyclic aromatic hydrocarbons (PAHs). PAHs are lipophilic, persistent, carcinogenic, mutagenic and considered as a global concern. We reviewed the occurrence, distribution and sources of PAHs in the mangrove ecosystem, providing a comprehensive discussion on this information and giving recommendations for future research. Through systematic literature search, this review considered existing studies on PAHs in the different compartments (water, sediment, aquatic fauna and plants) of mangrove system collected from field investigations. Little information is available for the levels and sources of PAHs in the water compartment of the mangrove systems. PAHs in the mangrove sediments are reported for 18 countries, and most of the levels of PAHs in mangrove sediments are considered as being low (0—100 ng g⁻¹ dry weight, DW) to moderate (100–1000 ng g⁻¹ DW). Different diagnostic ratios have been applied in order to determine the potential source of PAHs in the mangrove sediments, that are mainly attributed to mixed sources (pyrogenic and petrogenic). Studies have documented the biomonitoring of PAHs in mangrove systems, the majority of which use bivalves. Additionally, there are published studies for PAHs levels in 12 species of mangrove plants; showing a general tendency of residual PAHs accumulation in the leaves, if compared to root samples (leaves > roots). As a result of atmospheric PAH accumulation in leaf surfaces, leaves have higher concentrations of PAHs; implying that mangrove leaves can be used to monitor air quality relative to PAH pollution in coastal environments. This review has implications for future research in this field as well as coastal environmental management. Graphical abstract
... In addition, body surface penetration and inhalation has been linked to skin rashes and respiratory sicknesses, respectively, in local communities in the area (Whyte et al., 2020). Beyond this, the spill destroyed 1000 ha of mangroves, a key fish breeding and nursery habitat and high value carbon sink (Duke, 2016). ...
... It is anticipated that the operational model of the Ogoniland clean-up and restoration project would serve as a template for HYPREP to follow in undertaking remediation of other oil polluted parts of the Niger Delta, which is one of the most oil impacted regions in the world (UNEP, 2011;Duke, 2016;Zabbey and Uyi, 2014). This paper sets the context of oil pollution in the Niger Delta, appraises HYPREP's implementation of the Ogoniland clean-up, and flags identified deficiencies of the clean-up effort. ...
Article
Environmental contamination by hydrocarbons has negative effects on human health and other receptors including air, water and land resources. Following a United Nations Environment Programme report in 2011 which concluded that remediation strategies adopted in Nigeria did not meet international best practice, the Nigerian Government is attempting to develop a fit for purpose model of managing oil-contaminated land and wetlands. It has established the Hydrocarbon Pollution Remediation Project (HYPREP) to coordinate the environmental remediation and the restoration of livelihoods of local communities in the Niger Delta, starting with Ogoniland. HYPREP has been implementing the remediation process for more than five years with limited expected sustainable outcomes. It is now 11 years following UNEP’s recommendations for environmental and livelihood restoration in the region. The challenges of effective land remediation and restoration of traditional livelihoods are explored in the context of the Niger Delta, Nigeria’s hub of oil and gas production. The preliminary appraisal indicates that HYPREP operations are bureaucratic, suffering from capacity gaps and a weak stakeholder engagement strategy. Other extant challenges include the slow implementation of recommended emergency measures, corruption and the absence of infrastructure for hazardous materials management. Additionally, HYPREP has not optimized quality assurance by engaging internationally accredited laboratories for chemical analysis of environmental samples. Opportunities exist for HYPREP to learn lessons from other regimes for effective contaminated land management. Roles for different stakeholders working towards sustainable contaminated land management in Ogoniland and the wider Niger Delta are outlined. These recommendations would benefit regions with similar contexts and contaminated land issues.
... They are formed by dense forests, which shelter a wide diversity of living organisms and provide more than 20 ecological services and 45 natural products (Barbier, 2016;Hogarth, 2015;Lewis et al., 2011;Vo et al., 2012). Because they colonize the transition zone between terrestrial and marine environments, mangroves act as "coastal kidneys" by limiting land contaminant transport and as natural barriers against waves (Duke, 2016). More importantly, their carbon production rate (up to 700 Tg C.year − 1 ) equals that of tropical forests, making mangrove ecosystems one of the most valuable contributors to the global blue carbon pool (Alongi, 2012). ...
... In particular, humaninduced mangrove loss falls into four categories according to Makowski and Finkl (2018): resource exploitation (e.g., wood, oil, medicine), competition for space (aquacultural, urban, and industrial development), human modification (freshwater resource diversion) and pollution (oil spills, wastewater), and management failure (i.e., failures in planning policies and ecosystem evaluation). In addition, sea-level rise, global warming, genetic isolation, and pests are becoming severe threats to mangroves, which are now among the most preoccupying ecosystems worldwide even though they represent less than 0.5% of the global forest coverage (Duke, 2016;Krauss et al., 2014;Ward et al., 2016). Therefore, monitoring mangrove forests is critical to maintaining their invaluable services in the long term. ...
Article
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Mangrove forests are vulnerable ecosystems that require broad-scale monitoring. Various solutions based on satellite imagery have emerged for this purpose but still suffer from the lack of methods to accurately delineate individual tree crowns (ITCs). Within-stand variability in crown size and shape, crown clumping and fragmentation, and understory vegetation hamper the delineation in these ecosystems. To cope with these factors, the proposed method combines a deep learning-based enhancement of ITCs with a marker-controlled watershed segmentation algorithm. The MT-EDv3 neural network is employed to compute the normalized Euclidean distance of crown pixels to treetops and a Laplacian of Gaussian filter is applied to the resulting image to enhance crown borders before segmentation. The method was applied to WorldView imagery over four mangrove sites worldwide and compared to previously published methods using standardized metrics. Accurate detection (Overall Accuracy ≥ 0.93 and Kappa ≥ 0.87) and area estimation (R2 ≥ 0.66, NRMSE ≤ 12%) of crowns was achieved for all sites using either the panchromatic band or a combination of the pan-sharpened visible-near-infrared bands. Based on Precision, Recall, and F1-score, the proposed method outperformed previous watershed segmentation and software-based algorithms of crown delineation, as well as the Mask R-CNN segmentation framework. The viewing geometry of images and the forest heterogeneity were identified as important contributors to the delineation accuracy. This study is the first to achieve accurate delineation of ITCs in mangrove forests across sites, opening perspectives of applications to satellite-based monitoring. The method shows promising transferability to other very-high-resolution satellite sensors as well as to aerial and unmanned aerial vehicle imagery and could be improved by including more spectral information and LiDAR-derived canopy height models.
... Some mangrove estuaries are suppressed by the impact of leachate and overflow garbage from the nearby illegal landfills [22]. In addition, oil spills [23], and chemical waste are also affecting the mangroves and other coastal marine habitats. The mangrove ecosystem is increasingly threatened by anthropogenic human activities such as land use conversion for agriculture and aquaculture, deforestation, greenhouse gas emission, waste dumping and overpopulation. ...
... The sub-lethal impacts of oil spill incidents could cause reduction of forest canopies and partial loss of habitat. Oils spills tend to coat breathing surfaces of mangrove roots, seedlings, stems, surrounding sediments and fauna [23]. A massive oil spill could smother the leaves and aerial root system of mangroves leading to death of mangroves within weeks. ...
Article
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The feasibility of artificial intelligence (AI) as a predictive model for thorough efficacy analysis on environmental pollution applied on mangrove forests are discussed. Mangrove forests are among the most productive and biological diverse ecosystems on the planet. However, due to environmental pollution and climate change, mangrove forests are in serious decline. Despite crucial issues pertaining mangrove forests, the law enforcement on the ecosystem is still dubious due to the lack of evidence and data that could provide accurate analysis and prediction. The main highlight of this review elaborates on pollutant markers in soil, water, and air, by correlating these three aspects to the sustainability of mangrove ecosystem. The research gap identified from this review suggests the application of an integrated environmental prediction system for practical environmental insights. A predictive model for environmental decision-making could be developed by integrating meteorological, climatological, hydrological, atmospheric, and heavy metal concentration to understand the interaction between each factor for an efficient solution of pollutant reduction scheme involving mangrove ecosystems.
... Oil spills cause excessive harm to the aquatic fauna and seabirds. Globally, till now, around 238 notable incidents of the oil spill have been reported along the mangrove shorelines releasing a total of about 5.5 million tonnes of oil (Duke 2016). The oil spill, globally, has oiled around 1.94 million ha of mangrove ecosystems since 1958. ...
... This event triggered an extensive regulation that involved oil spill preparedness on offshore and onshore support activities (Arbo and Thủy 2016). About 54% of vessel incidents, 21% of pipelines, and 14% of shore tanks have already happened, but now the number of oil spill cases is decreasing, and their ill impact on mangrove ecosystem has also reduced in three decades of the twentieth century (Duke 2016). However, when past and current centenaries are compared, it must be seen that the frequency of occurrences (oil spills) has increased significantly, and the total mangrove area has been significantly reduced by these incidents (de Lacerda et al. 2019). ...
Chapter
The history of human civilization has witnessed a strong and rapid transformation pattern in the coastal environment. It harbors a prominent transition zone of land and sea that plays a significant part in the socioeconomic and environmental aspects. Due to tremendous pressure from anthropogenic perturbations manifested by coastal squeeze, it’s protection and conservation become substantial. 5.04% of the mangrove land has been converted to aquaculture land between 1988 and 2013. Present mangrove loss is 35% which is supposed to reach 60% by 2030. Human activities increase the chances of exposure of coastal waters to effluents (organic and inorganic) released from the industrial and urban components which accelerate the metals and nutrient pollution, eutrophication, and oxygen depletion. This tends to alter ecosystem dynamics and biogeochemical processes with serious impacts on the biota. Pichavaram shows an increase in nitrate from 5.9 mg/l in 1995 to 29.9 mg/l in 2006–2007. In Sundarbans it increases from 1.14 mg/l in 2001 to 3.69 mg/l in 2006 and in Godavari from 0.61 mg/l in 2001 to 2.25 mg/l in 2016. The phosphate values increase from 0.28 mg/l in 1995 to 6.6 mg/l in 2006 in Pichavaram mangroves. Manori creek, Mumbai, shows hike in phosphate in past 25 years. The value increases from 0.06 mg/l in 1982 to 2.19 mg/l in 2007. A consistent increase in heavy metal content has been observed in Sundarban, Pichavaram, and Goa mangroves. Thus, the resultant surge of heavy metals and nutrient pollutants indicates growth of fallow land, agricultural, and aquaculture activities and industrial pollution. This chapter has been constructed to discuss a holistic view of the major drivers of coastal mangrove ecosystem degradation by reviewing the case studies to highlight the past changes and present trends of human activities through industrialization and urbanization. We evaluate the impact of these human influences on the mangrove ecosystem, with an approach to emphasize the crucial role of mangroves, both in terms of quality and quantity, and the absolute need to conserve their future.
... Anthropogenic activities including coastal urbanization, port development, conversion to agricultural land and over exploitation of timber and aquaculture played a vital role in this decline. Growth in aquaculture resulted with 38% of mangrove loss globally [6,7,8]. The coastal belt of Pakistan is extended up t (700 km 2 ) [9]. ...
... Anthropogenic activities including coastal ort development, conversion to agricultural land and over exploitation of timber and aquaculture played a vital role in this decline. Growth in aquaculture resulted with 38% of mangrove loss globally [6,7,8]. The coastal belt of Pakistan is extended up to 1050 km 2 in Sindh (350 km 2 and Baluchistan ) [9]. ...
Article
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The coastline of Pakistan comprises of five significant sites including Indus Delta which contains extensive mangroves zones and termed as the largest arid mangrove found globally. This study evaluate the current extent of mangroves along the Western edge of Indus Delta and provide the most re mangroves. Moreover, this study identifies the changes occurred in forest cover from the years 2000 to 2020. Landsat 5 Thematic Mapper (TM), 8 Operational Land Imager (OLI) and Landsat 7 ETM data were used for mangroves mapp classification method. The results displayed that total area of mangrove forest cover was nearly 279.094km², 395.77km², 306.58km² in the years 2000, 2010 and 2020 respectively. This study indicates an increase in area of mangrove cov 2000 to 2010. Regeneration of mangrove mostly took place around the southern region of the Indus Delta. The mangrove specie has decreased from 41% to 31% from the year 2010 to 2020. The major causes of this reduction were u fishing in Indus delta, freshwater diversion for agriculture, and overharvesting of mangroves by the local communities, coastal erosion and sedimentation.
... Tumpahan minyak di area mangrove dapat menyebabkan daun menjadi kuning (yellowing), berbintik (spots), berjatuhan (defoliating), berlubang (perforation), memutar (twisting) dan memudar (fading); perubahan densitas dan distribusi vegetasi dan hewan (Getter et al, 1981;Kairo et al, 2005). Dalam jangka panjang, biasanya lebih dari 1 tahun, tumpahan minyak dapat menyebabkan kematian pada pohon (Duke, 2016). Pada pohon-pohon yang tidak mengalami kematian (lethal impact) maka biasanya akan menjadi organisme yang sangat rentan (sub-lethal impact) terhadap berbagai tekanan seperti polusi dan hama. ...
Article
Muara Gembong merupakan daerah yang mengalami tekanan antropogenik yang memberikan dampak signifikan bagi ekosistem pesisir di wilayah Teluk Jakarta. Riset ini bertujuan untuk menilai kondisi ekosistem mangrove, menghitung biomasa dan jumlah karbon yang tersimpan di dalam vegetasi mangrove per satuan luas (hektar) guna menentukan nilai moneternya. Riset dilakukan dengan pengamatan dan pengukuran mangrove untuk mengidentifikasi jenis mangrove, jumlah tegakan serta mengukur diameter batang pohon mangrove. Hasil riset menunjukkan bahwa rata-rata biomass dan karbon yang tersimpan di ekosistem mangrove Muara Gembong adalah sebesar 258,81 Mg/ha dan 119,97 Mg C/ha. Potensi kehilangan nilai ekonomi akibat kehilangan karbon ditaksirkan berkisar antara 1,15-2,84 x 1011 rupiah atau setara dengan 2,7-6,7 milyar per tahun. Kondisi kerusakan diperparah dengan adanya serangan hama, abrasi dan sampah. Dibutuhkan skenario rehabilitasi dengan memperhitungkan luasan area mangrove yang terdampak serta besarnya nilai kerugian moneter akibat kerusakan dan jasa ekosistem mangrove yang hilang.
... Mangrove area in Papua archipelago was rather to decline due to natural event than anthropogenic land use change such as aquaculture, reclamation and oil palm cultures [3]. Oil spill had also driven a massive damage of mangrove forest [45], but it was not found in this area. ...
Article
Full-text available
Indonesian mangrove declined significantly in the last two decades which has been considered to deliver a negative impact for adjacent communities in small islands. Mangrove quality monitoring was conducted during Nusa Manggala Expedition in 2018, which was aimed to analyze forest structure and healthiness using spatial-temporal investigation in Liki island, Papua. Field data were collected from 10m-×-10m quadratic plots which were distributed following stratified purposive sampling method. Spatial and temporal was implemented using Sentinel 2 imagery on this area from 2016 to 2021. The result of this field study had considered that mangrove in Liki island was in moderate healthiness since the MHI value was between 33.33%-66.67%. It was supported by remote sensing analysis in 2018 which showed that the moderate MHI area was dominant by approximately 42% compared to the excellent area in about 33%. Liki’s mangrove had experienced a declining trend of excellent category from 2016 and reached the lowest area of its category in 2018. In the last four-year observation, excellent areas gradually increased which was covering 57.68% of forest MHI. The dynamic of mangrove healthiness on this island tended to be delivered by natural events.
... The ecological impacts associated with offshore oil spills are numerous and severe, prompting a quick response from various private and national organisations to clean-up and remediate damages whenever an incident is detected. Evidence points to the fact that shoreline ecosystems across the world are impacted negatively by many offshore oil spills (Duke, 2016;Schiel et al., 2016). These impacts include; suppression of microbial activity and diversity of aerobes due to the displacement of soil air, and water by the infiltrating oil; the reduction in water infiltration capacity of the polluted soil; the poisoning of native soil macro-organism by toxic compounds in the oil; and the biomagnification of toxins along the food chain (Acosta-González et al., 2015;Levine, 2016). ...
Article
Full-text available
This study investigated the employment/use of H 2 O 2 and bio-stimulation in crude oil clean up in coastal soil. It identified the optimal percentage concentration of H 2 O 2 , needed to oxidise petroleum hydrocarbon contamination in coastal soil from the Ahanta West District of Ghana. The potential of enhancing the soil treatment process by bio-stimulating the pre-oxidised contaminated soil using chemical fertilizer was also evaluated. Pristine coastal soil from Cape Three Points in the Western Region of Ghana was contaminated with crude oil from the TEN oil field. Treatment with different concentrations of H 2 O 2 (at 6%, 30%, and 60%), as well as a combination of each H 2 O 2 concentration and a chemical fertiliser as bio-stimulant was undertaken. Laboratory tests were conducted on soil samples over a 24-day period on petroleum hydrocarbon (C9-C44) levels (GC-MS), polycyclic aromatic hydrocarbon levels (GC-MS), and nutrient levels (nitrogen, phosphorus and potassium). The study found that treatment of petroleum hydrocarbon contaminated coastal soil with 30% or 60% H 2 O 2 over a 3-day period was a very effective and timely remediation approach. The use of 6% H 2 O 2 was also effective but required a relatively long period of time (24 days). In addition, bio-stimulating the contaminated soil pretreated with hydrogen peroxide improved the efficiency of treating the contaminated soil.
... Petroleum hydrocarbon spillage is one of the common causes of vegetation loss contributing significantly to deforestation (Duke, 2016). Where farmlands are in the vicinity of an oil spill, crop plants are destroyed and the lands are rendered inoperable (Ani et al., 2015). ...
Article
Full-text available
Petroleum hydrocarbon contamination remains a major challenge confronting soil health, environmental sustainability, and food security in oil exploration areas. In this study, the effect of Bonny Light crude oil on cowpea (Vigna unguiculata L. Walp.) was investigated with a view to assessing its toxicity to plant growth and performance. Pristine soil samples were collected in different pots and contaminated with crude oil to achieve 0.0%, 2.5%, 5.0%, 7.5% and 10.0% v/w contamination levels. Viable seeds of cowpea were planted and monitored for the emergence and subsequent growth for a period of 12 weeks. Results showed that the crude oil extended the period of seed germination and delayed the emergence of sprouts by 2 days at a rate of 96.7%, 80.0%, 50.0%, 96.7%, and 73.3% emergence respectively. The plants’ shoots, roots, and leaves lengths were longer in control than in the contaminated soil. Phytotoxicity study showed that shoots, roots and leaves lengths of the plants were significantly reduced by ≥ 50% of the control. The relative plants' weights, chlorophyll, and the number of leaves were worst affected especially in plants grown in higher crude oil concentrations where fewer or absence of leaves was observed at the end of the experiments. No yield parameter was observed in all plants grown in contaminated soil as opposed to the control where flowers, fruits, and seeds were produced. The findings illustrated that the growth rate of V. unguiculata was severely affected due to hydrocarbon contamination in a concentration-dependent manner. It further demonstrated the imminent danger to food security especially in frontier basins with impending oil exploration activities. Therefore, there is a need to identify and integrate effective measures that minimize or prevent oil spillage in the course of oil exploration activities with a view to avoiding the repeat of persistent pollution problems disturbing host communities.
... Oil spills impact the marine environment and its biodiversity, they cause significant impacts on aquatic plants, micro and macro-algae, seagrasses, kelp forests, and shrubs (Singh et al., 2020;Duke, 2016). Exposure to hydrocarbons can smother the pneumatophores of the roots by covering them, decreasing the oxygen flow in the roots, which ultimately leads to starvation and death (Lewis et al., 2011). ...
Chapter
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The technical aspects of oil spill remote sensing are examined and the practical uses and drawbacks of each technology are given with a focus on emerging technology. The use of visible techniques is common, but limited to certain observational conditions and simple applications. Infrared cameras offer some potential as oil spill sensors but have several limitations. Both techniques, although limited in capability, are widely used because of their increasing economy. The laser fluorosensor uniquely detects oil on substrates that include shoreline, water, soil, plants, ice, and snow. New commercial units have come out in the last few years. Radar detects calm areas on water and thus, oil on water, because oil will reduce capillary waves on a water surface given moderate winds. Radar provides a unique option for wide area surveillance, all day or night and rainy/cloudy weather. Satellite-borne radars with their frequent overpass and high spatial resolution make these day-night and all-weather sensors essential for delineating both large spills and monitoring ship and platform oil discharges. Most strategic oil spill mapping is now being carried out using radar. Slick thickness measurements have been sought for many years. The operational sensor at this time is the passive microwave. New techniques for calibration and verification have made these instruments more reliable.
... Salt marshes are valuable habitats that provide a number of ecosystem services, including coastal erosion mitigation, carbon sequestration, water quality enhancement, and faunal support (Pennings and Bertness 2001; Barbier et al. 2011;Duke 2016;Gorman and Turra 2016;CPRA 2017). Vegetation in these salt marshes are subjected to a number of environmental stressors, including elevated ooding, anoxic soils, and increased salinity (Pennings and Bertness 2001;Alleman and Hester 2010;Lonard et al. 2017). ...
Preprint
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Oil spills are a significant stressor to coastal and maritime environments worldwide. The growth responses of Batis maritima and Avicennia germinans seedlings to weathered Deepwater Horizon oiling were assessed through a mesocosm study using a factorial arrangement of 4 soil oiling levels (0 L m ⁻² , 1 L m ⁻² , 2 L m ⁻² , 4 L ⁻ m ⁻² ) x 3 tissue oiling levels (0% of stem height, 50% of stem height, 100% of stem height). Overall, growth metrics of B. maritima displayed much greater sensitivity to both tissue and soil oiling than A. germinans , which exhibited a relatively high tolerance to both routes of oiling exposure. Batis maritima in the 4 L m ⁻² soil oiling treatment demonstrated significant reductions in cumulative stem height and leaf number, whereas no significant effects of soil oiling on A. germinans were detected. This was reflected in end of the study biomass partitioning, where total aboveground and live aboveground biomass were significantly reduced for B. maritima with 4 L m ⁻² soil oiling, but no impacts to A. germinans were found. Tissue oiling of 100% did appear to initially reduce B. maritima stem diameter , but no effect of tissue oiling was discerned on biomass partitioning, suggesting that there were no impacts to integrated growth. These findings suggest that B. maritima would be more severely affected by heavy soil oiling than A. germinans .
... Modificador área protegida k =1+ Vulnerabilidad hábitat k = (Vulnerabilidad costera k +vulnerabilidad fondo k ) * Modificador área protegida Los valores más altos de vulnerabilidad del hábitat se observaron en las regiones localizadas a lo largo de la zona costera, debido a la alta heterogeneidad de hábitats que incluye bosques de mangles, praderas o parches de pastos marinos y lagunas salinas (Figura 2). La alta vulnerabilidad observada se debe a que estos hábitats tienen un alto potencial de retención de petróleo por periodos largos a causa de las corrientes de marea y oleaje que se caracterizan por ser de baja intensidad y que, a su vez, ocasionan que se depositen y retengan sedimentos, con tiempos de residencia altos (Duke 2016, Kenworthy et al., 2017. A nivel regional, la región estuarina de la laguna Madre y plataforma de Tamaulipas (GM_1) y el área nerítica Tabasqueña (GM_3) son las que presentaron mayor vulnerabilidad a posibles derrames de petróleo. ...
Chapter
La evaluación de la vulnerabilidad se ha convertido en una necesidad clave para los sistemas sociales y ecológicos que enfrentan exposiciones cada vez mayores a amenazas de origen diverso (e.g., eutrofización, acidificación, contaminación petroquímica). A partir de esta necesidad, han surgido varias propuestas metodológicas, de diversas disciplinas (e.g. geografía, ecología, sociología) que han propuesto y probado aproximaciones conceptuales y numéricas con un objetivo principal: estimar la probabilidad de que un sistema sufra daños debido a la exposición a un peligro por la presencia de una perturbación antrópica o estresor ambiental (Adger 2016) y evaluar el estado del sistema en términos de vulnerabilidad.
... Modificador área protegida k =1+ Vulnerabilidad hábitat k = (Vulnerabilidad costera k +vulnerabilidad fondo k ) * Modificador área protegida Los valores más altos de vulnerabilidad del hábitat se observaron en las regiones localizadas a lo largo de la zona costera, debido a la alta heterogeneidad de hábitats que incluye bosques de mangles, praderas o parches de pastos marinos y lagunas salinas (Figura 2). La alta vulnerabilidad observada se debe a que estos hábitats tienen un alto potencial de retención de petróleo por periodos largos a causa de las corrientes de marea y oleaje que se caracterizan por ser de baja intensidad y que, a su vez, ocasionan que se depositen y retengan sedimentos, con tiempos de residencia altos (Duke 2016, Kenworthy et al., 2017. A nivel regional, la región estuarina de la laguna Madre y plataforma de Tamaulipas (GM_1) y el área nerítica Tabasqueña (GM_3) son las que presentaron mayor vulnerabilidad a posibles derrames de petróleo. ...
Chapter
Full-text available
Las comunidades planctónicas en el ambiente marino son potenciales indicadores que permiten evaluar el impacto de los hidrocarburos ante un derrame de petróleo. Esto se debe a la relación intrínseca entre bacterias y microalgas ya que estos grupos tienen un papel clave en los ciclos biogeoquímicos, en la productividad primaria y son la base de las redes tróficas (Lindh y Pinhassi, 2018; Shade et al., 2012; Zhu, Hong, Zada, Hu y Wang, 2018). Se conoce que la estructura y funcionamiento de las comunidades planctónicas cambia a lo largo del año (Niu et al., 2011; Salmerón-García, Zavala- Hidalgo, Mateos-Jasso y Romero-Centeno, 2011), por lo tanto se considera que su vulnerabilidad podría ser variable.
... Biological indicators were assessed in our study by incorporating valuation of regulating and supporting services. Salt marshes, wetlands, and estuaries are recognized as important economic and biological resources with a number of highly beneficial ESs, and they are the habitats most sensitive to coastal oil spills once the oil arrives at the shoreline (Duke, 2016). Previous studies have suggested that oil may lead to blade and shoot mortality when it has direct contact with plants (Fonseca et al., 2017). ...
Article
Coastal environment is one of the most important ecological and socioeconomic areas. However, increasing energy demand and economic development lead to a continuous gas and oil exploration, production, and traffics, which notably raise the risk of oil spill accidents in coastal areas. Sensitivity assessment aiming to determine the coastal features that would be severely impaired by spill incidents is a crucial part of the response planning. In this study, an innovative framework for coastal sensitivity mapping that incorporated ecosystem service (ES) valuation and multidimensional assessment was proposed. Sensitivity was computed by valuing physical, biological, and social-economical indicators from ES perspective and separating each indicator into specific coastal domains. For different ES typologies, provisioning services contributed most to the overall ES value followed by culture services, supporting services, and regulating services. For ES value in different coastal domains, the highest value was recorded in the water column followed by water surface, shoreline, and seabed. However, the shoreline ranked highest regarding the ES value per ha. Sensitivity assessment revealed that sensitive areas differed in different domains, both in distribution and extent. Compared with the scoring method, the ES valuation method showed more coincidence with Ecologically and Biologically Significant Areas (EBSA), representing a more precise and practical approach for sensitivity assessment. A three-dimensional (3D) oil spill model was also applied to generate maps of oil contamination probability in shoreline, water surface, and water column. The obtained results highlighted the significance of incorporating different coastal domains into oil spill responses, and the urgent demand to broaden and deepen our understanding of ecological processes across the vertical coastal zones.
... However, the spatial resolution of Sentinel-2 images (20 m, and originally 10 m for certain bands) showed important limits. Indeed, it was not possible to distinguish between the acute and chronic effects of the spill on the mangrove stands as described in other locations [8]. Acute effects result in gaps in mangrove canopies, which rarely exceed 20-m wide, so they remain very difficult to detect without metric spatial resolution. ...
Conference Paper
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In 2019, a mysterious oil spill occurred off the Brazilian coast. While the origin of the spill remains uncertain, huge amounts of oil reached the coastal ecosystem, especially mangroves. In that frame, this study provides the first assessment of changes in mangrove health from three to nine months after the spill occurred using satellite imaging. Vegetation indices were computed from Sentinel-2 images acquired over spilled sites. Following the spill, index values were significantly different from those observed before the spill, which might be caused by oil. The spatial distribution of index changes was contrasted among sites. In the line of this study, further research is needed to confirm whether the observed changes are due to oil-induced alterations in mangrove health, or if they come from natural interannual variations
... Bioremediation has been successfully Microbial bioremediation of petroleum hydrocarbon [27]. applied worldwide in environmental oil pollution mitigation, such as in the oil spills in Prince William Sound, Alaska, in 1989 [37] and the Gulf of Mexico in 2010 [38], and it is a promising strategy for environmental cleanup in contaminated mangrove sediments [28,39]. ...
Chapter
Anthropogenic activities introduce petroleum hydrocarbons into the environments, and the remediation of the polluted environments using conventional physicochemical, thermal, and electromagnetic technologies is a challenging task, laborious work, and expensive. The ecotoxicological effects and human health hazards posed by petroleum hydrocarbon pollutions gave rise to the call for “green technologies” to remove petroleum hydrocarbon contaminants from polluted environments. It is imperative to transition from the conventional physicochemical treatments methods that are expensive to more eco-friendly biological treatment technologies that reduce energy consumption, chemicals usage, cost of implementation and enables more sustainable risk-based approaches towards environmental reclamation. The chapter summarises and gives an overview of the various biological treatment technologies adapted to the remediation of hazardous petroleum hydrocarbon polluted sites. Biological treatment technologies include; bioremediation, biostimulation, bioaugmentation, bioattenuation, bioventing, biosparging, bioslurry, biopiling, biotransformation, landfarming, composting, windrow, vermiremediation, phytoremediation, mycoremediation, phycoremediation, electrobioremediation, nanoremediation, and trichoremediation. They are green technology approaches widely adopted, scientifically defensible, sustainable, non-invasive, ecofriendly, and cost-efficient in the remediation of petroleum hydrocarbons polluted environments compared to the physicochemical, thermal, and electromagnetic treatments technologies, which are rather destructive and expensive. The chapter provides detailed illustrations representing the various biological treatment technologies for a comprehensive understanding and successful implementation with their subsequent benefits and constraints.
... Bioremediation has been successfully Microbial bioremediation of petroleum hydrocarbon [27]. applied worldwide in environmental oil pollution mitigation, such as in the oil spills in Prince William Sound, Alaska, in 1989 [37] and the Gulf of Mexico in 2010 [38], and it is a promising strategy for environmental cleanup in contaminated mangrove sediments [28,39]. ...
Chapter
Anthropogenic activities introduce petroleum hydrocarbons into the environments, and the remediation of the polluted environments using conventional physicochemical, thermal, and electromagnetic technologies is a challenging task, laborious work, and expensive. The ecotoxicological effects and human health hazards posed by petroleum hydrocarbon pollutions gave rise to the call for “green technologies” to remove petroleum hydrocarbon contaminants from polluted environments. It is imperative to transition from the conventional physicochemical treatments methods that are expensive to more eco-friendly biological treatment technologies that reduce energy consumption, chemicals usage, cost of implementation and enables more sustainable risk-based approaches towards environmental reclamation. The chapter summarises and gives an overview of the various biological treatment technologies adapted to the remediation of hazardous petroleum hydrocarbon polluted sites. Biological treatment technologies include; bioremediation, biostimulation, bioaugmentation, bioattenuation, bioventing, biosparging, bioslurry, biopiling, biotransformation, landfarming, composting, windrow, vermiremediation, phytoremediation, mycoremediation, phycoremediation, electrobioremediation, nanoremediation, and trichoremediation. They are green technology approaches widely adopted, scientifically defensible, sustainable, non-invasive, ecofriendly, and cost-efficient in the remediation of petroleum hydrocarbons polluted environments compared to the physicochemical, thermal, and electromagnetic treatments technologies, which are rather destructive and expensive. The chapter provides detailed illustrations representing the various biological treatment technologies for a comprehensive understanding and successful implementation with their subsequent benefits and constraints.
... Stations have recently been established to develop research on how to minimize the negative impact of oil spills on these wetlands (Duke et al. 2000;Tansel et al. 2015;Duke 2016). One of the strategies used is biological restoration, which is aided by the use of microorganism-synthesized substances, called biosurfactants (Patel et al. 2015;Ojeda-Morales et al. 2016b;Geetha et al. 2018). ...
Preprint
Mangrove forests are ecosystems subject to contamination by oil spills. The objective of this study was to evaluate the development of Rhizophora mangle plants in soil contaminated with oil emulsified with surfactants. These ecosystems have diverse and economically valuable ecological functions. Mangrove soil and propagules were collected in southeastern Mexico. The propagules were sown under greenhouse conditions and the plants were grown for three months. Two bioassays were applied: 1) the soil was contaminated by oil emulsified with a biosurfactant synthesized by Azospirillum lipoferum, and 2) the soil was contaminated with oil emulsified with a surfactant based on pine essential oil. Emulsified oil was applied to the substrate in containers with three-month-old plants until several concentrations were reached (0, 30,000, 40,000, 50,000, 60,000 and 70,000 ppm). Subsequently, five plants for each treatment were randomly extracted every 30 days for 12 months, and the stem length and diameter, root length, leaf area and fresh and dry weights of the plants were evaluated. Plant development was evaluated through an analysis of variance and a test of means. At the end of the bioassay, the treatments with oil emulsified with pine oil yielded no surviving plants, while the treatments with oil emulsified with the biosurfactant yielded a 100% survival rate. Treatment with 30,000 ppm of oil emulsified with the biosurfactant yielded the greatest increases in the leaf area and total dry biomass. The heavy oil fraction concentration decreased by 93.9% with the 30,000 ppm treatment and by 82.64% with the 70,000 ppm treatment.
... Organic pollutants are the causative agents of severe environmental complications. Sometimes, they can be more calamitous than the inorganic pollutants because mangrove ecosystems are reported to be highly vulnerable to incidents like oil spill (Duke 2016). Therefore, the pollutants, irrespective of inorganic or organic origin, can create undeniable hazards to the ecosystems and their components, ultimately distorting ecosystem functions. ...
Article
Full-text available
Mangroves are among the world's most productive ecosystems and a part of the “blue carbon” sink. They act as a connection between the terrestrial and marine ecosystems, providing habitat to countless organisms. Among these, microorganisms (e.g., bacteria, archaea, fungi, phytoplankton, and protozoa) play a crucial role in this ecosystem. Microbial cycling of major nutrients (carbon, nitrogen, phosphorus, and sulfur) helps maintain the high productivity of this ecosystem. However, mangrove ecosystems are being disturbed by the increasing concentration of greenhouse gases within the atmosphere. Both the anthropogenic and natural factors contribute to the upsurge of greenhouse gas concentration, resulting in global warming. Changing climate due to global warming and the increasing rate of human interferences such as pollution and deforestation are significant concerns for the mangrove ecosystem. Mangroves are susceptible to such environmental perturbations. Global warming, human interventions, and its consequences are destroying the ecosystem, and the dreadful impacts are experienced worldwide. Therefore, the conservation of mangrove ecosystems is necessary for protecting them from the changing environment—a step toward preserving the globe for better living. This review highlights the importance of mangroves and their microbial components on a global scale and the degree of vulnerability of the ecosystems toward anthropic and climate change factors. The future scenario of the mangrove ecosystem and the resilience of plants and microbes have also been discussed.
... In addition to these natural conditions, mangroves are also challenging by human activities because of their vicinity with towns, industries, aquatic farms and harbours. Meiofauna is affected by direct contact with potential pollutants that may accumulate in mangrove sediments, including heavy metals, oil spills, organic compounds or sewage (Bartolini et al. 2011;Lewis et al. 2011;Molnar et al. 2013;Zhang et al. 2014;Duke, 2016). ...
Thesis
Mangroves are a challenging and extreme habitat. Since they are relevant for humans, different anthropogenic pressures affect them. In this study, the Kinorhyncha populations inhabiting a moderately impacted mangrove in Mayotte Archipelago (south-western Indian Ocean) are studied. Two species of the genus Echinoderes were found in the studied area, and their unique combination of morphological characters seems to indicate they are undescribed species. These species are characterized by having an enlarged sieve-plate (nephridiopore) consisting of an anterior, convex area with numerous pores and a posterior, concave region with a single pore. This feature, together with the fact of living in an intertidal environment affected by strong salinity fluctuations, suggest their affiliation to the so-called Echinoderes coulli-group. The studied Kinorhyncha populations seem not to be particularly affected by the sewage emissions from nearby towns. Evidence for significant differences in density or richness between the areas more impacted by this pollution and the less impacted areas was not found, but differences in the community species composition seem to be present. However, further analysis including more samples and quantitative ecological data are needed in order to confirm this assumption.
... Some studies have been carried out to evaluate the effects of oil spills on the structure and survival of mangrove plants (Rodrigues et al. 1999;Moreira et al. 2011;Camargo et al. 2013). In elsewhere published data (Touchette et al. 1992;Duke 2016), seedling germination was highly susceptible to oil exposure, representing more than 96% of deaths in Avicennia marina seedlings controls (Grant et al. 1993). ...
Article
The development of Rhizophora mangle and Avicennia schaueriana seedlings impacted by marine diesel oil (MDO) was evaluated in the presence or absence of a hydrocarbon-degrading bacterial consortium (HBC). The bioassays were conducted in a greenhouse during 6 months and consisted of three different treatments (control, MDO only and MDO + HBC). The bacterial consortium was mainly composed of Bacillus spp. (73%), but Rhizobium spp., Pseudomonas spp., Ochrobactrum spp., and Brevundimonas spp. were also present. After 6 months, A. schaueriana seedlings showed higher mortality compared to those of R. mangle; R. mangle exhibited 68% (control), 44% (MDO alone) and 50% (MDO + HBC) seedlings survivorship compared to 42% (control), 0% (MDO alone) and 4% (MDO + HBC) for A. schaueriana. This variability may be due to differences in species physiology. Stem growth, diameter and number of leaves remained constant during the 6 months of the experiment with marine diesel oil and hydrocarbon-degrading bacterial consortium (MDO + BBC). For both mangrove species, bacterial enzymatic activity in the sediments was sufficient to maintain cell counts of 107 cells cm-3 in the rhizospheric soil and possibly synthetize the extracellular polymeric substances (EPS) that may emulsify and solubilize oil products.
... The higher requirements were put forward for the corrosion resistance of engineering materials in the marine environment because that abundant offshore oily wastewater brought great challenges to environmental governance and equipment maintenance. The corrosion resistance tests were carried out in 3.50 wt% NaCl aqueous solution, simulating the seawater environment, which in order to evaluate the corrosion resistance of the material in seawater [48,49]. As a reference, the corrosion situation of SSM-LDA was also explored, and then the corrosion resistance of the two samples in the same conditions was evaluated. ...
Article
Full-text available
Preparing an efficient and durable separation material for solving the problem of oily wastewater treatment is of importance but difficult due to the restriction of complex process and secondary pollutants. Herein, the environmentally friendly and low damage waterjet-assisted laser ablation was developed to fabricate robust microstructure on 304 stainless steel mesh (SSM-WJALA) for oil/water separation. This underwater oil-repellent/underoil water-repellent SSM-WJALA realized the separation of light and heavy oil/water mixtures only under gravity, and exhibited high separation efficiency and great stability to various oil/water mixtures and cyclic separation tests. The detailed analysis of mechanical properties and durability of the material were carried out, which included the tests of friction coefficient, nanohardness, and electrochemical corrosion. The results showed that the surface hardness increased by more than 20%, the corrosion potential increased from -1.02 V to -0.49 V, and the corrosion current density decreased by more than two orders of magnitude, compared with SSM-LDA. The application of WJALA technology not only enhanced the properties of mechanical and corrosion resistance of oil-water separation materials but also reduced dust pollution and harm to the health of operators. Therefore, this environmentally friendly and cost-efficient SSM-WJALA provided an effective strategy to solve the problem of oily wastewater treatment especially in harsh conditions and opened an avenue for developing low-cost and facile technology for preparing functional materials.
... Mangrove vegetation is also adversely affected by oil pollution. Duke has reported that about 5.5 million tonnes of oil have killed at least 126,000 ha of mangrove vegetation by entering mangrovelined coastal waters since 1958 (Duke 2016). Because the accumulation of pollutants in animal and plant tissues can result in offspring mortality or mutation, hydrocarbon-contaminated soil causes significant harm to local ecosystems (Alvarez et al. 1991). ...
Article
Petrochemicals are important hydrocarbons, which are one of the major concerns when accidently escaped into the environment. On one hand, these cause soil and fresh water pollution on land due to their seepage and leakage from automobile and petrochemical industries. On the other hand, oil spills occur during the transport of crude oil or refined petroleum products in the oceans around the world. These hydrocarbon and petrochemical spills have not only posed a hazard to the environment and marine life, but also linked to numerous ailments like cancers and neural disorders. Therefore, it is very important to remove or degrade these pollutants before their hazardous effects deteriorate the environment. There are varieties of mechanical and chemical methods for removing hydrocarbons from polluted areas, but they are all ineffective and expensive. Bioremediation techniques provide an economical and eco-friendly mechanism for removing petrochemical and hydrocarbon residues from the affected sites. Bioremediation refers to the complete mineralization or transformation of complex organic pollutants into the simplest compounds by biological agents such as bacteria, fungi, etc. Many indigenous microbes present in nature are capable of detoxification of various hydrocarbons and their contaminants. This review presents an updated overview of recent advancements in various technologies used in the degradation and bioremediation of petroleum hydrocarbons, providing useful insights to manage such problems in an eco-friendly manner.
... Aquaculture and agriculture activities frequently cause high levels of nutrient contamination, which eventually make their way into marine water and disrupt ecosystem services. Shipbreaking-induced heavy metals, waste oil and oil spills from power-driven ships, trawlers and boats have devastating effects on human health, marine biotic communities and mangrove forests (Duke, 2016;Sarker et al., 2018). ...
Article
Full-text available
The southeastern coastline of Bangladesh where the longest natural sea beach Cox’s Bazar is located has experienced more pronounced changes due to human intervention compared to the changes due to storms, cyclones and flooding. Over the past 30 years, nature-dependent livelihood and economic activities have generated employment, income and shelter to people but has also enhanced exposure level and consequent vulnerability and risks to fast growing economic activities and human settlements to projected climate-induced natural disasters. Satellite imageries clearly show the changing land-use pattern due to human intervention. On the ground, questionnaire-based, face-to-face interview method has helped in understanding the key drivers behind the changing economic activities, occupation category-wise exposure and vulnerability of the people along the coast. Fishing, salt-shrimp practice, fish drying, agriculture, tourism, and related small trading business are now the main economic activities, and human settlement expansion has changed the coastal ecosystem. The vulnerability assessment suggests that the fast emergence of salt-shrimp farm-based employment and livelihood is one of the most sensitive to natural threats. As per anthropogenic threats, the hotel and restaurant industries are polluting the most fragile coastal ecosystem.
... Aquaculture and agriculture activities frequently cause high levels of nutrient contamination, which eventually make their way into marine water and disrupt ecosystem services. Shipbreaking-induced heavy metals, waste oil and oil spills from power-driven ships, trawlers and boats have devastating effects on human health, marine biotic communities and mangrove forests (Duke, 2016;Sarker et al., 2018). ...
... A recent project of the Indian Government for drilling in the Cauvery delta region for hydrocarbon and methane exploration threatened Pichavaram mangrove forest, Tamilnadu, which lies only 490 meters away from the exploration zone sheltering the inhabitants of Tamilnadu coast from natural calamities such as the 2004 tsunami [147]. Petroleum explorations, for example, in the Persian Gulf zone, resulted in oil spills from oil wells, oil refiners, and oil transports, which, in turn, led to pollution, driving substantial mangrove habitat loss [148]. These activities can also lead to accidents, for example, the Gulf of Mexico oil spill in 2010 affected 10% of the mangrove forests in the region, with a residue impact lasting for 10 years [149]. ...
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Globally, mangrove forests are substantially declining, and a globally synthesized database containing the drivers of deforestation and drivers’ interactions is scarce. Here, we synthesized the key social-ecological drivers of global mangrove deforestation by reviewing about two hundred published scientific studies over the last four decades (from 1980 to 2021). Our focus was on both natural and anthropogenic drivers with their gradual and abrupt impacts and on their geographic coverage of effects, and how these drivers interact. We also summarized the patterns of global mangrove coverage decline between 1990 and 2020 and identified the threatened mangrove species. Our consolidated studies reported an 8600 km2 decline in the global mangrove coverage between 1990 and 2020, with the highest decline occurring in South and Southeast Asia (3870 km2). We could identify 11 threatened mangrove species, two of which are critically endangered (Sonneratia griffithii and Bruguiera hainseii). Our reviewed studies pointed to aquaculture and agriculture as the predominant driver of global mangrove deforestation though their impacts varied across global regions. Gradual climate variations, i.e., sea-level rise, long-term precipitation, and temperature changes and driven coastline erosion, salinity intrusion and acidity at coasts, constitute the second major group of drivers. Our findings underline a strong interaction across natural and anthropogenic drivers, with the strongest interaction between the driver groups aquaculture and agriculture and industrialization and pollution. Our results suggest prioritizing globally coordinated empirical studies linking drivers and mangrove deforestation and global development of policies for mangrove conservation.
... Severe damage has been done to the aquatic environment as a result of artisanal refining which has led to the loss of the mangrove plants in the region (Plate 2 B, E, and G). Duke (2016) noted that a review of crude oil impact on mangroves shows that 37% of the global impact had occurred in the Niger Delta. Artisanal refining has caused pollution in many intertidal creeks which have left the mangroves denuded of leaves and stems, leaving roots coated in a bitumenlike substance sometimes 1cm or thicker. ...
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Crude oil is the major source of revenue in Nigeria with the vast majority of exploration from the Niger Delta. Illegal refining of stolen oil is a major cause of oil spills and comes with steep environmental, economic, and social costs in the region. Oil theft, artisanal refineries, and ecosystem pollution are simultaneously linked. Therefore, the review paper seeks to highlight the effect of illegal refineries on the region's ecosystems currently exacerbated by black soot pollution, the causes of increasing artisanal refineries, the implication of illegal oil destruction, and possible solutions. The review revealed that illegal crude oil refining has a denudating impact on flora and fauna, air, soil, aquatic ecosystems, and the mangroves. Causes of illegal refineries include poverty and low standard of living, the pragmatic collaboration between security authorities and other actors, the relatively low setup cost, and the lackadaisical attitude of oil companies towards the replacement damaged oil facilities. The common practice of burning recovered stolen crude further damages the ecosystem. The need for government agencies, laws, and policies for environmental protection to be active while creating synergy with security outfits to curb the menace and engaging in regular cleanups through phytoremediation are possible solutions. We recommend the following; shutdown of all illegal refineries, stakeholders' synergies to guard against oil pollution and biodiversity loss, environmental education, and youth empowerment through vocational training and cleaning, afforestation, and reforestation of degraded sites.
... Salt marshes are valuable habitats that provide a number of ecosystem services, including coastal erosion mitigation, carbon sequestration, water quality enhancement, and faunal support (Pennings and Bertness 2001;Barbier et al. 2011;Duke 2016;Gorman and Turra 2016;CPRA 2017). Vegetation in these salt marshes is subjected to a number of environmental stressors, including flooding, anoxic soils, and increased salinity (Pennings and Bertness 2001;Alleman and Hester 2010;Lonard et al. 2017). ...
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Oil spills are a significant stressor to coastal and maritime environments worldwide. The growth responses of Batis maritima and Avicennia germinans seedlings to weathered Deepwater Horizon oiling were assessed through a mesocosm study using a factorial arrangement of 4 soil oiling levels (0 L m⁻², 1 L m⁻², 2 L m⁻², 4 L ⁻m⁻²) × 3 tissue oiling levels (0% of stem height, 50% of stem height, 100% of stem height). Overall, growth metrics of B. maritima displayed much greater sensitivity to both tissue and soil oiling than A. germinans, which exhibited a relatively high tolerance to both routes of oiling exposure. Batis maritima in the 4 L m⁻² soil oiling treatment demonstrated significant reductions in cumulative stem height and leaf number, whereas no significant effects of soil oiling on A. germinans were detected. This was reflected in the end of the study biomass partitioning, where total aboveground and live aboveground biomass were significantly reduced for B. maritima with 4 L m⁻² soil oiling, but no impacts to A. germinans were found. Tissue oiling of 100% did appear to reduce B. maritima stem diameter, but no effect of tissue oiling was discerned on biomass partitioning, suggesting that there were no impacts to integrated growth. These findings suggest that B. maritima would be more severely affected by moderate soil oiling than A. germinans.
Chapter
Mangroves are one of the significant categories of coastal vegetation, distributed in the shorelines of tropical and subtropical regions and performing a dynamic role in coastal ecosystems. The recent developments of coastal cities, industrialization, unplanned recreational activities and expansion of aquaculture at mangrove areas in various regions of the world have generated a threat on such significant ecosystems. Nevertheless, the mangrove vegetation has some adaptive features to mitigate the pollution. These ecosystems act as physical, chemical and biological barriers for the transference of pollutants. They play a vital role in trapping sediments; assimilate the excess nutrients by phyto- or bioremediation of toxic substances. The earlier studies revealed that mangroves can act as possible phytoremediators. They absorb a considerable quantity of toxic metal ions and store them in various parts such as stems and roots, consequently evade the transmission of heavy metal ions. In addition, the mangrove associated microorganisms are responsible for remediation of numerous toxic contaminants present within the mangroves. In view of the above, the present chapter offers a comprehensive discussion on the role of mangrove vegetation on abatement of pollutants.
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Oil spills are of great concern because they impose a threat to the marine ecosystem, including shorelines. As oil spilled at sea is transported to the shoreline, and after its arrival, its behavior and physicochemical characteristics change because of natural weathering phenomena. Additionally, the fate of the oil depends on shoreline type, tidal energy, and environmental conditions. This paper critically overviews the vulnerability of shorelines to oil spill impact and the implication of seasonal variations with the natural attenuation of oil. A comprehensive review of various monitoring techniques, including GIS tools and remote sensing, is discussed for tracking, and mapping oil spills. A comparison of various remote sensors shows that laser fluorosensors can detect oil on various types of substrates, including snow and ice. Moreover, current methods to prevent oil from reaching the shoreline, including physical booms, sorbents, and dispersants, are examined. The advantages and limitations of various physical, chemical, and biological treatment methods and their application suitability for different shore types are discussed. The paper highlights some of the challenges faced while managing oil spills, including viewpoints on the lack of monitoring data, the need for integrated decision-making systems, and the development of rapid response strategies to optimize the protection of shorelines from oil spills.
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Mangroves are known to provide many ecosystem services, however there is little information on their potential role to cap and immobilise toxic levels of total petroleum hydrocarbons (TPH). Using an Australian case study, we investigated the capacity of planted mangroves (Avicennia marina) to immobilise TPH within a small embayment (Stony Creek, Victoria, Australia) subjected to minor oil spills throughout the 1980s. Mangroves were planted on the oil rich strata in 1984 to rehabilitate the site. Currently the area is covered with a dense mangrove forest. One-meter-long sediment cores revealed that mangroves have formed a thick (up to 30 cm) organic layer above the TPH-contaminated sediments, accumulating on average 6.6 mm of sediment per year. Mean TPH levels below this organic layer (30–50 cm) are extremely toxic (30,441.6 mg kg⁻¹), exceeding safety thresholds up to 220-fold which is eight times higher when compared to top layer (0–10 cm).
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Socioeconomic patterns beyond the land conversions of global mangrove cover changes were few discussed. This study integrated databases of global mangrove covers, i.e., a multi-database in 1980-2016 with a combination of FAO country-survey and the global mangrove watch, and a mangrove biome cover database in 2000-2012. Annual mangrove cover change (%) of each mangrove holding country or territory was incorporated with its socioeconomic indicators in the two periods to testify possible socioeconomic patterns beyond the mangrove deforestation. The socioeconomic indicators consisted of GDP per capita and urban population percentile, and aquacultural indicators (production per capita, sales value per capita, contribution to the national GDP, and product price). Results indicated that annual mangrove cover change was interactively driven by multi-factors of national economy measures, urbanization, and aquaculture, instead of aquacultural dominance or GDP per capita alone. The multi-factor driven patterns of annual mangrove changes differed geographically among the continents. Temporal change of aquacultural product price was significantly and positively correlated to annual mangrove cover change (increase), especially in Asia and Oceania for both the periods, suggesting positive feedbacks of mangrove conservation and restoration in the two continents although the price was used to a motivator of mangrove deforestation, such as currently in Africa. These findings preliminarily bridge the knowledge gap between land conversion losses and socioeconomics of global mangrove cover changes.
Chapter
Mangroves occur in coastal settings of estuaries, deltas, lagoons, open coasts and oceanic low islands. In these settings, mangrove attributes are influenced by physical factors of temperature, coastal typology, ocean currents and land barriers, wave action and sediment supply, river catchment discharge and sediment yield, and tidal range and inundation frequencies. Factors of gradients and tidal ranges control the lateral extent of mangroves through inundation frequency, and factors influencing accretion rates in the context of relative sea level change can shift or eliminate mangrove extents over time. Mangroves are however resilient systems within steady state equilibrium, that allows recovery from minor perturbations. Factors influencing mangroves can however exceed tipping points of tolerance, bringing a sudden change in ecosystem function and breakdown of equilibrium. Stressors that may cause critical reduction of mangrove resilience are the impacts from humans, climate becoming significantly drier, increased inundation, reduced sedimentation supply, and relative sea level rise. Rehabilitation can be successful if ecological guidance on mangrove restoration is followed, particularly topographic positioning with respect to tidal inundation frequency factors. Understanding of the physical factors that influence mangrove ecosystems that contribute to variation in processes, that result in spatial and temporal differences in mangrove attributes, is essential to effective management.
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Mangroves are one of the most potential tidal wetlands characterized by their hydrological, ecological, and geological features. They form the diversified and biologically productive ecosystem, populated with heterogeneous groups of plant taxonomy. The transboundary Sundarban mangrove wetland (89°02′ to 89°55′E and 21°30′ to 22°30′N) is situated on the Ganges–Brahmaputra–Meghna river network. This represents the largest continuous tract of mangrove forest in the world, spanning across Bangladesh (62%) and India (38%). The chapter gives an illustrative account of the diversity and distribution patterns of mangroves in India and other coastal regions across the world, along with their anomalous biogeographical patterns, mangrove landform classification and their morphological structure and adaptation strategies. In addition, the mangrove ecosystem goods and services, carbon storage efficiency and application of remote sensing for mangrove mapping have been discussed. A haven for rich biodiversity, Sundarban harbors several rare and globally threatened plants and animals. The overall common key threats for mangrove ecosystems are land-use changes, overexploitation of natural resources, chemical pollution from point and diffusive sources, reduced freshwater supply and silt deposition. Both India and Bangladesh should implement bilateral monitoring programs to resolve those emerging problems and formulate necessary management strategies to restore this diversified and iconic mangrove ecosystem.
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Recent ENSO-related, extreme low oscillations in mean sea level, referred to as 'Taimasa' in Samoa, have destabilised shoreline mangroves of tropical northern Australia, and possibly elsewhere. In 1982 and 2015, two catastrophic Taimasa each resulted in widespread mass dieback of~76 km 2 of shoreline mangroves along 2,000 km of Australia's Gulf of Car-pentaria. For the 2015 event, we determined that a temporary drop in sea level of~0.4 metres for up to six months duration caused upper zone shoreline mangroves across the region to die from severe moisture deficit and desiccation. The two dramatic collapse events revealed a previously unrecognised vulnerability of semi-arid tidal wetland habitats to more extreme ENSO influences on sea level. In addition, we also observed a relationship between annual sea level oscillations and mangrove forest productivity where seasonal oscillations in mean sea level were co-incident with regular annual mangrove leaf growth during months of higher sea levels (March-May), and leaf shedding during lower sea levels (September-November). The combination of these periodic fluctuations in sea level defined a mangrove 'Goldilocks' zone of seasonal productivity during median-scale oscillations, bracketed by critical threshold events when sea levels became unusually low, or high. On the two occasions reported here when sea levels were extremely low, upper zone mangrove vegetation died en masse in synchrony across northern Australia. Such extreme pulse impacts combined with localised stressors profoundly threaten the longer-term survival of mangrove ecosystems and their benefits, like minimisation of shoreline erosion with rising sea levels. These new insights into such critical influences of climate and sea level on mangrove forests offer further affirmation of the urgency for implementing well-considered miti-gation efforts for the protection of shoreline mangroves at risk, especially given predictions of future re-occurrences of extreme events affecting sea levels, combined with ongoing pressure of rapidly rising sea levels.
Article
Biosurfactant is one of the emerging compounds in the industrial sector that behaves similarly with their synthetic counterparts, as they can reduce surface and interfacial tension between two fluids. Their unique properties also enable biosurfactant molecules to be able to clump together to form micelles that can capture targeted molecules within a solution. Biosurfactants are compared with synthetic surfactants on various applications for which the results shows that biosurfactants are fully capable of replacing synthetic surfactants in applications including enhanced oil recovery and wastewater treatment applications. Biosurfactants are able to be used in different applications as well since they are less toxic than synthetic surfactants. These applications include bioremediation on oil spills in the marine environment and bioremediation for contaminated soil and water, as well as a different approach on the pharmaceutical applications. The future of biosurfactants in the pharmaceutical industry and petroleum industry as well as challenges faced for implementing biosurfactants into large-scale applications are also discussed at the end of this review.
Chapter
Despite their importance, the mangrove ecosystem is one of the highly vulnerable ecosystems in the Anthropocene era. Mangrove ecosystems lie in an intertidal zone of subtropics and tropics regions. They provide ecological and economic services to the coastal communities. Mangrove provides multifaceted advantages to the local ecosystem such as it reduces the severity of the hurricane, storm surge, cyclone, and tsunami, prepares a perfect bed for spawning marine fishes, and also plays a major role in carbon sequestration. Deterioration in global estimates of mangrove covers ~150,000 km² is the consequence of exponentially increasing urbanization and industrialization. These two major anthropogenic activities induce numerous problems such as an increment in the intensity of natural calamities, local inhabitant losing their livelihood, and many marine species standing on the verge of extinction. An integrated approach is required for the preservation and management of mangrove biotopes with an amalgamation of local inhabitants, researchers, and government. Conservation techniques include afforestation, legislation, policies, application of remote sensing and geoinformation system (GIS), and development of parks and reserves for protection. This chapter is a consolidated approach to study the sources and impact of anthropogenic threats on mangrove forests from a global and Indian perspective with holistic conservation strategies.
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Während der über 100-jährigen Präsenz der Ölindustrie in Louisiana wurde eine Regulierung von schädlichen Umwelteinflüssen bisher größtenteils untergraben und ein ökonomisches Abhängigkeitsverhältnis des Staates Louisiana zur Industrie geschaffen. Zu den ökologischen Folgen zählen unter anderem der Verlust von Feuchtgebieten. Zwar gibt es Projekte zur Wiederherstellung der Natur, wie nach dem Deepwater Horizon (DWH) Unglück im Jahr 2010, die aber größtenteils durch Schadensersatzzahlungen von der Industrie finanziert werden. Die vorliegende Forschungsarbeit untersucht den Diskurs um die ökologischen Auswirkungen der Ölindustrie in zwei Zeiträumen, vor und nach der DWH Katstrophe, und dessen Veränderung. Dazu werden statistische Auswertungsverfahren durchgeführt. Die Auswertung der Ergebnisse zeigt, dass es durchaus eine Veränderung im historischen Verlauf gibt, wenn man die Anzahl der publizierten Artikel betrachtet. Es lässt sich kein prägnantes Ergebnis bei der Art der Veränderung (kritischer, nicht kritischer) feststellen. Die den medialen Diskurs bestimmenden Ereignisse sind zu vielfältig, um ein Vorkommnis wie der Vorfall von DWH in einen kausalen Zusammenhang mit dem aus der Forschung resultierenden Endergebnis zu bringen.
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Mangrove, or bakau as it is known in Indonesia, is one of the vegetations commonly found along the shallow coasts, estuaries, deltas and protected coastal areas and are still influenced by rising tides. After the Aceh tsunami disaster, mangrove restoration was intensively conducted in coastal areas all over Indonesia and was made into a special conservation program by the government. Mangrove is distinguishable by its big, wooden stilt roots, sharpening tip in the form of supporting leaves. The roots of the mangrove tree are morphologically distinguishable into heart root which grows into the ground and the stilt root which appear to grabs onto the surface of the ground. Mangrove forests serve several important ecological roles: they act as filters which turns saline water into fresh water, buffer from seawater intrusion, prevent erosion and abrasion, hold sediments to form new habitats, feeding ground, nursery ground, and spawning ground for a number of aquatic wildlife. Mangrove forest also possess economical functions such as as source of income, industrial ingredients for the locals and as source of new mangrove seedlings. Mangunhardjo Village, Urban Community of Mangunhardjo, Mangkang Area, Kecamatan of Tugu, Semarang City, Indonesia was an area dotted with brackish water pond. However, the area had been suffering from the effects of climate change, being inundated by overflow of river and seawater intrusion (rob). These disasters caused decline in the productivity of the ponds in the area. In an effort to combat the adverse effect of environmental change in the area, the locals of Mangunhardjo village decided to shift their livelihood by restoring the surrounding mangrove forest. Mangrove conservation at Mangunhardjo Village was conducted through activities of the program such as mangrove planting, mangrove-based food production, and mangrove waste management by applications of bioactivator bacteria for mangrove composting and production of mangrove-based natural dye for batik fabric. Mangrove-based natural dye for batik fabric from Rhizopora mucronata mangrove waste is a quite promising product and increases people’s income.
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An innovative mid-infrared spectroscopic sensor system based on quantum cascade lasers has been developed. The system combines the versatility of substrate-integrated hollow waveguides (IHWGs) with the robustness of attenuated total reflection (ATR) crystals employed as internal reflection waveguides for evanescent field sensing. IHWGs are highly reflective metal structures that propagate infrared (IR) radiation and were used as light pipes for coupling radiation into the ATR waveguide. The combined IHWG-ATR device has been designed such that the utmost stability and robustness of the optical alignment were ensured. This novel assembly enables evanescent field absorption measurements at yet unprecedently harsh conditions, that is, high pressure and temperature. Combining these advantages, this innovative sensor assembly is perfectly suited for taking ATR spectroscopy into the field where the robustness of the assembly and optical alignment is essential.
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Mangroves are high-productive ecosystems and globally protected. Establishing nature reserves aimed at counteracting the negative effects of anthropogenic activities is one of the most pivotal approaches to conserve mangrove ecosystems. Evaluation of the conservation effectiveness for mangrove nature reserves is thus indispensable for making knowledge-based conservation policies and funding-decisions by government and managers. In this study, using composited Landsat images by the Google Earth Engine cloud platform and object-oriented deep learning classification method, the land cover maps of national mangrove nature reserves (NMNRs) in China were obtained from 1987 to 2019. The systematic evaluation of conservation effectiveness for each NMNR was conducted by landscape metrics and an entropy weight model. Combined with the dynamics in mangrove distribution, human interference intensity, and natural environment change, the driving force factors affecting the conservation effectiveness for NMNRs were investigated. The results show that the total mangrove area in all NMNRs increased 968.6 ha during the study period, a 21.8 % rate of increase. Except for one NMNR with a slight decline, the conservation of remaining NMNRs was considered effective with increase varied from 14.8 % to 87.5 % in the level of protective efficacy. The conservation effectiveness of NMNRs was affected by both anthropogenic and natural factors, while the improvement to the conservation effectiveness was largely attributed to the implementation of protection policies, such as reforestation engineering. Further direct or indirect challenges in mangrove conservation effectiveness, e.g., pollution, natural disasters, and exotic species invasion, still require close attention. This study provides an effective and efficient approach to quantify the conservation effectiveness of mangrove nature reserves, which would facilitate mangrove conservation and management in the future.
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Long-term monitoring of an oil spill carried out along the coast of São Paulo (Brazil). indicate that the forest was seriously damaged. Reduction of the basal area was 40%, and 24% for forest density. Loss of basal area was greatest for Avicennia, indicating that it was the most vulnerable mangrove species present. The three species showed a continuous increase of leaf area after the spill, which caused initial high rate of defoliation, 25,9% for R. mangle, 43,4% for L. racemosa, and 64,5% for A. schaueriana. There was a reduction of herbivory on all three species. Propagule density was reduced and accompanied by atrophy and malformations. The affected area was rapidly colonized by new seedlings but followed by a 100% mortality. Ten years after the pollution event, field observations indicate that the mangrove area under study is at the begining of the recovery stage. These results may be useful to develop a methodology for impact assessment of oil pollution in mangrove areas.
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Climate change with human direct pressures represent significant threats to the resilience of shoreline habitats like mangroves. A rapid, whole-of-system assessment strategy is needed to evaluate such threats, better linking innovative remote sensing with essential on-ground evaluations. Using the Shoreline Video Assessment Method, we surveyed around 190 km of the mostly mangrove-fringed (78%) coastline of Kien Giang Province, Vietnam. The aim was to identify anthropogenic drivers of degradation, establishing baseline for specific rehabilitation and protection strategies. Fish traps occupy at least 87% of shoreline mangroves, around which there were abundant human activities – like fishing, crabbing, farming, plus collecting firewood and foliage. Such livelihoods were associated with remnant, fringing mangrove that were largely degraded and threatened by erosion retreat, herbivory, and excessive cutting. Our assessment quantified associated threats to shoreline stability, along with previous rehabilitation intervention measures. The method offers key opportunities for effective conservation and management of vulnerable shoreline habitats.
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Exploration and exploitation of oil in Nigeria since the discovery of oil in the commercial quantities in 1958 have sustained the country economy and contributed greatly to the enhancement of its citizenries’ well-being. However, the negative impacts of the introduction of unwanted byproducts into the ecological system during oil exploration and exploitation by way of relentless flaring of gas and oil spillage cannot be ignored. This present study, therefore, reports the economics and environmental impacts of oil exploration and exploitation in Nigeria. Data were collected and analyzed on the volume of gas produced and flared in Nigeria between 1970 and 2010; also collected are the barrels of oil produced between 1970 and 2020 and the average price of barrel oil and gallon of gas between the said period. Results of analysis indicate that about $669 billion was generated from the sales of crude oil between 1970 and 2010. Analysis of the collected data also showed that, between 1999 and 2010, 742,983,000 m3 of gas was produced, equivalent to $192 billion if harnessed and 587,375,000 m3 flared, representing $151.3 billion loss of revenue. The exploitation and exploration of oil therefore not only are a source of revenue for the country but also contributed greatly to the pollution of the environment and the need to collect the gas for effective utilization.
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We build on previous work to construct a comprehensive database of shoreline oiling exposure from the Deepwater Horizon (DWH) spill by compiling field and remotely-sensed datasets to support oil exposure and injury quantification. We compiled a spatial database of shoreline segments with attributes summarizing habitat, oiling category and timeline. We present new simplified oil exposure classes for both beaches and coastal wetland habitats derived from this database integrating both intensity and persistence of oiling on the shoreline over time. We document oiling along 2113 km out of 9545 km of surveyed shoreline, an increase of 19% from previously published estimates and representing the largest marine oil spill in history by length of shoreline oiled. These data may be used to generate maps and calculate summary statistics to assist in quantifying and understanding the scope, extent, and spatial distribution of shoreline oil exposure as a result of the DWH incident.
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Mangrove forests are the dominant intertidal plant community along most low wave energy shorelines in the tropics (Macnae 1968; Lugo and Snedaker 1974). Their value as habitat and detrital food sources for marine organisms as well as their direct commercial value as lumber, firewood and tanning agents are well documented (Odum and Heald 1972; Chapman 1976).
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Recent field studies at five oil spill sites where mangroves were affected provide a broad base of information on the response of mangrove communities to oiling. Three study sites in Florida (two in the Florida Keys, one in Tampa Bay) and two in eastern Puerto Rico were visted in 1978, 1979, and 1980. At each site, impacts on mangroves were assessed by the compartmental method, which uses statistical comparisons of ecological parameters between impacted and comparison stations and produces an array of biological and geomorphic data sets that allows spill sites to be compared. Despite many differences in the size of the spills and the spill sites, the responses of the oiled-mangrove communities were similar in terms of tree mortality; leaf defoliation, deformation, and stunting; seedling deformation and mortality; lenticel expansion; adventitious growth of pneumatophores; and changes in the density and distribution of plants and animals. Each spill site differed mainly in the magnitude of the stress response. Observations of the spills showed that differences in the physical environment, such as the degree of exposure to waves and currents and geomorphic features like the terrain, greatly influence the distribution and persistence of oil within different mangrove forest types. From these studies, mangrove forest types can be ranked by their predicted sensitivity to oil. This differentiation in ranking increases the value of the Environmental Sensitivity Index, especially where it is desirable to assign priorities in a campaign to protect oil-sensitive habitats from oil spills along mangrove-dominated coastlines.
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This chapter provides an overview of mangrove management, assessment, and monitoring. It addresses the need for integrated planning and management, based on sound legal principles. The central part of the chapter covers mangrove conservation and planting. Conserving existing mangrove forest is often more effective than planting new forests. When a decision for planting has been made, one has to differentiate between planting on degraded and non-degraded sites and distinguish between replanting, rehabilitation, restoration, and afforestation. Emphasis is put on the need for careful selection of appropriate sites and species and on an ecosystem-based approach to mangrove planting and management which uses and supports natural regeneration and other natural processes. Since the primary intention with any rehabilitation intervention works is for improved protection of existing seedlings and forests from degradation or destruction, then planting should be undertaken only if absolutely necessary. Involving local communities in mangrove management is an effective way of maintaining and enhancing the protection function of the mangrove forest while providing livelihood for local people and contributing to better assessment and governance of natural resources. Assessment of the status of mangrove forests is essential for better conservation planning and management. This includes research and economic assessment and valuation. The last section highlights the importance of applied/participatory as well as academic and long-term monitoring (see also chapter “Mangroves: Unusual Forests at the Seas Edge”).
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Mangrove Coasts are shorelines fringed by mangrove and saltmarsh vegetation. They form a significant part of coastal tidal wetlands as distinctive habitats of tropic and temperate shorelines. Tidal wetlands have vegetation of varying complexities from forested mangrove woodlands, thick mangrove and saltmarsh shrubbery, low dense samphire plains, to microlagal covered saltpans (Tomlinson 1994). In the tropics, mangroves are often the dominant shoreline ecosystem comprised chiefly of flowering trees and shrubs uniquely adapted to coastal and estuarine tidal conditions (Duke 2011). They form distinctly vegetated and often densely structured habitat of verdant closed canopies cloaking coastal margins and tidal waterways of equatorial, tropical and subtropical regions of the world. Normally, but not exclusively, these vegetation assemblages grow in soft sediments above mean sea level in the intertidal zone of sheltered coastal environments and estuarine margins (Fig. 1). The plants of Mangrove Coasts are well-known for their morphological and physiological adaptations coping with salt, saturated anoxic soils and regular tidal inundation; notably with specialised attributes like: exposed air-breathing roots above ground; extra, above-ground stem support structures; salt-excreting leaves; low water potentials and high intracellular salt concentrations to maintain favorable water relations in saline environments; and viviparous water-dispersed propagules. With such attributes, these habitats have essential roles in coastal productivity and connectivity, often supporting high biodiversity and biomass not possible in upland vegetation, especially in more arid regions. Mangrove Coasts are key sources of primary production with highly dependant trophic linkages between plants and animals, as nursery and breeding sites of benthic and arboreal life, as well as physical shelter and protection from severe storms, river flows and large tsunami waves. Within tropical latitudes, mangrove coasts nestle mostly between two other iconic ecosystems of coral reefs and tropical rainforests. All three are intimately inter-connected, providing mutual protection and sustenance. Each of these ecosystems also create biota-structured environments, where the organisms themselves provide and build the physical structure amongst which associated life is nurtured and sheltered. Without this living structure, these habitats and the many organisms dependant on them, simply would not exist. This essentially identifies how such a large group of plants and animals are so vulnerable. For example, bordering Mangrove Coasts, colonial coral reefs often flourish in the shallow warm seas created and protected from land runoff by mangrove vegetation (Duke & Wolanski 2001). Mangroves absorb unwanted nutrients and sediments of turbid waters to stabilize eroding and depositional shorelines. In modern human times, this buffering role also includes the capture of harmful chemicals in runoff waters from agricultural lands. The specialised plant assemblages of Mangrove Coasts provide a broad range of essential, and often under-valued, ecosystem services along with their more acknowledged roles as habitats of high productivity, and as fishery nursery sites (Robertson & Duke 1990). In such ways, the consequences of disturbing Mangrove Coast habitats are expected to have far-reaching implications and impacts on neighbouring ecosystems and dependant biota. See: http://www.springerreference.com/index/chapterdbid/350631
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The coastal area of the Niger Delta is the home to oil explorations and exploitations in Nigeria. Oil spill incidents are common along the Nigeria. The main sources of oil spill on the Niger Delta are: vandalisation of the oil pipelines by the local inhabitants; ageing of the pipelines; oil blow outs from the flow stations; cleaning of oil tankers on the high sea and disposal of used oil into the drains by the road side mechanics. By far the most serious source of oil spill is through the vandalisation of pipelines either as a result of civil disaffection with the political process or as a criminal activity. To reduce the rate of oil incidents along the Nigerian Coast particularly as a result of vandalisation, the Federal Government through an act of the National Assembly created the Niger Delta Development Commission (NDDC). Part of the responsibilities of the commission is to develop a master plan for the development of the Niger Delta, provide infrastructure and create an enabling environment for industrialisation and employment. There are also several other laws dealing with issues related to oil pollution in the environment. Also, standards for the development of the environmental sensitivity index maps for the coast of Nigeria have been developed by the Environmental Systems Research institute (ESRI). These standards are to be used by all the oil companies to prepare ESI maps for their areas of operations in Nigeria. Furthermore, apart from the mechanical and chemical oil spill cleaning methods that have been used in managing oil spill problems, oil spill models have on several occasions being used to manage oil spills on the Nigerian Coast. A number of Federal and state agencies deal with the problems of oil spill in Nigeria. The agencies include: the Department of Petroleum Resources (DPR), the Federal Ministry of Environment, the State Ministries of Environment and the National Maritime Authority. There is also the “Clean Nigeria Associates” which is an umbrella through which the Oil companies tackle major oil spills. There is a need to create serious awareness among the populace on the implications of oil spill incidents on the environment. Governments must assist the rural communities in claiming their rights on oil spills and ensure that digital ESI maps are readily available for managing oil spill maps. Government should have strict rules for local oil tankers that would ply our coastal and inland waters as a result of the new cabotage law that is just being passed into law in the country.
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A multidisciplinary long-term field experiment was conducted to evaluate the use of chemical dispersants to reduce the adverse environmental effects of oil spills in nearshore, tropical waters. Three study sites, whose intertidal and subtidal components consisted of mangroves, seagrass beds, and coral reefs, were studied in detail before, during, and after exposure to untreated crude oil or chemically dispersed oil. This study simulated an unusually high (“worst case”) exposure level of dispersed oil and a moderate exposure level of untreated oil. The third site served as an untreated reference site. Assessments were made of the distribution and extent of contamination by hydrocarbons over time, and the short- and long-term effects on survival, abundance, and growth of the dominant flora and fauna of each habitat. The whole, untreated oil had severe, long-term effects on survival of mangroves and associated fauna, and relatively minor effects on seagrasses, corals, and associated organisms. Chemically dispersed oil caused declines in the abundance of corals, sea urchins, and other reef organisms, reduced coral growth rate in one species, and had minor or no effects on seagrasses and mangroves. Conclusions were drawn from these results on decision making for actual spills based on trade-offs between dispersing or not dispersing the oil. This report deals only with the major results of the study. A large number of parameters were monitored, but in the interest of brevity only the most important aspects of the study are reported here. A detailed description of the methods used and a complete presentation and discussion of results is given in Ballou et al.²
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A jet fuel spill in Ensenada Honda, Naval Station Roosevelt Roads, Puerto Rico, was investigated to determine impacts on mangrove communities and to develop a mitigation plan to reverse the damage. The spill caused rapid, widespread damage to mangroves, killing almost six hectares of forest. Residual contamination of water and sediments was very low. Mitigation recommendations were developed for this incident and other mangrove forests affected by oil spills. The recommendations place primary emphasis on natural recovery, with additional actions to increase colonization and/or survival of propagules as needed.
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On August 11, 2006 more than 2 million liters of Bunker C oil spilled in southern Guimaras Island, central Philippines. Over 200 kilometers of coastline have been affected including the traditional livelihood in the island. The immediate effects involved death of marine fauna and massive mortality of mangroves which accounted to almost one hectare and two years after the incident some albino propagules of Rhizophora stylosa were observed. Additionally, some species of mangroves found in heavily impacted sites exhibited significant reduction of leaf sizes. Monitoring of the deforested mangrove areas three years after the incident showed a varying recruitment-to-mortality ratio. Recruitment and settlement of seedlings was impaired in areas where dead trees are extracted mainly for firewood purposes. The harvesting of dead trees created a forest gap, exposed the area to surging waves and thus increased the hydrodynamics. On the other hand, faster recovery dynamics was observed in area where the dead trees are not harvested. The presence of logs trapped the available propagules and facilitated the colonization of new cohorts. Quantification of polyaromatic hydrocarbons (PAHs) in mangrove sediments showed higher rate of decomposition. Three years after the oil spill, the level of PAHs in sampled sites were within the safe level based on the National Oceanic and Atmospheric Administration (NOAA) standards. However, sub-lethal, long term monitoring should be carried out further to focus on the species-specific long term responses.
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The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic) and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique) to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique) and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.
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In a review of the literature on impacts of spilled oil on marshes, 32 oil spills and field experiments were identified with sufficient data to generate recovery curves and identify influencing factors controlling the rate of recovery. For many spills, recovery occurred within 1-2 growing seasons, even in the absence of any treatment. Recovery was longest for spills with the following conditions: Cold climate; sheltered settings; thick oil on the marsh surface; light refined products with heavy loading; oils that formed persistent thick residues; and intensive treatment. Recovery was shortest for spills with the following conditions: Warm climate; light to heavy oiling of the vegetation only; medium crude oils; and less-intensive treatment. Recommendations are made for treatment based on the following oiling conditions: Free-floating oil on the water in the marsh; thicker oil (>0.5cm) on marsh surface; thinner oil (<0.5cm) on marsh surface; heavy oil loading on vegetation; and light to moderate oil loading on vegetation.
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This article examines the role of a particular area of the law of contract in a specific commercial context involving the relationship of a general building contractor and a sub-contractor. The focus is upon the formation of agreement through the submission of bids to carry out work put out to tender. An empirical examination of the attitudes of these builders to the tendering procedure has been carried out and is related to proposals to change the law on "firm offers". To what extent do those in business rely on legal sanction as a method of guaranteeing the expectations to which a promise may give rise? The aim of this article is to provide a case study for Weber's discussion of the extent that the law of contract is required to support the development of commercial relations in a market economy. This article forms part of a limited literature empirically examining the use and non-use of law by the business community. It also reflects upon the legitimising force of the general principles of classical contract law.
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Duke, N.C. 2013. ‘World Mangrove iD: expert information at your fingertips’ App Store Version 1.0 for iPhone and iPad, Dec 2013. MangroveWatch Publication, Australia – e-book. https://itunes.apple.com/us/app/mangrove-id/id761487621?mt=8 The World Mangrove iD app is an e-book, and a living expert guide to all mangrove plants worldwide. Do you have an interest in the fascinating world of mangroves? Do you have questions like; What mangrove is that?; or What mangroves grow in my country? Maybe also, Why are mangroves important? You will find all your answers, and more, in the World Mangrove iD e-book app. It is just like having your very own mangrove expert on call. This nearly complete botanical guide has descriptions and images at your fingertips of all known mangrove plants. It has been compiled and written by Dr Norman C Duke, long time mangrove ecologist and marine science specialist, for MangroveWatch Ltd, the charitable, not-for-profit environmental monitoring NGO for tidal wetlands. The guide provides more than 500 exquisite images, world distribution records and authoritative botanical descriptions of all 85 mangrove plant species, hybrids and varieties occurring worldwide; plus a selection of 15 common Associate plants you are likely to come across. The information and data presented provides the very latest up-to-date botanical information from Dr Duke's Mangrove Flora Project conducted over the last three decades. The purpose of the guide is two-fold: one, to show off the diversity and distribution of these plants; and two, to improve our knowledge of them. For this, you are invited to contribute by helping fill remaining gaps revealed in the guide. It could be a new image, or just a better one, or, it could be more information on peak flowering and fruiting periods, or even a new species! Such observations are essential information for understanding what is happening in the world around us! And, things are changing more and more rapidly. Scientists and environmental managers everywhere need your help. The knowledge you have of local occurrences and events is essential and much needed! Check out the list for any selected country, and let Dr Duke know if that country species list needs correction or updating. In so doing, please use the Capture facility to send a message and photograph showing diagnostic parts of the specimen to verify your observations; along with the location where it was growing. Your contribution maybe more important than you might imagine; you will be acknowledged, especially when any of your information is used in future upgrades of the guide. So, come and find out more about these absolutely fascinating plants. You will not be disappointed!
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The British Petroleum Deepwater Horizon Oil Spill in the Gulf of Mexico was the biggest oil spill in US history. To assess the impact of the oil spill on the saltmarsh plant community, we examined Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data flown over Barataria Bay, Louisiana in September 2010 and August 2011. Oil contamination was mapped using oil absorption features in pixel spectra and used to examine impact of oil along the oiled shorelines. Results showed that vegetation stress was restricted to the tidal zone extending 14 m inland from the shoreline in September 2010. Four indexes of plant stress and three indexes of canopy water content all consistently showed that stress was highest in pixels next to the shoreline and decreased with increasing distance from the shoreline. Index values along the oiled shoreline were significantly lower than those along the oil-free shoreline. Regression of index values with respect to distance from oil showed that in 2011, index values were no longer correlated with proximity to oil suggesting that the marsh was on its way to recovery. Change detection between the two dates showed that areas denuded of vegetation after the oil impact experienced varying degrees of re-vegetation in the following year. This recovery was poorest in the first three pixels adjacent to the shoreline. This study illustrates the usefulness of high spatial resolution airborne imaging spectroscopy to map actual locations where oil from the spill reached the shore and then to assess its impacts on the plant community. We demonstrate that post-oiling trends in terms of plant health and mortality could be detected and monitored, including recovery of these saltmarsh meadows one year after the oil spill.
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The increased prominence of the petroleum industry in Nigeria since the 1960s has given rise to a concomitant upsurge of real and imagined ecological disturbances, especially in the oil-producing areas of the country. An overview of the growth and development of the oil and petrochemical industry in Nigeria is presented. Notable cases of polluting disturbances during the 25 years of its existence are also cite dto highlight the causes and effects on the social, economic, agricultural and ecological characteristics of human and other biotic occupants of the oil regions. The imminent expansion schemes could expose the environment to disturbances from exploration and drilling activities, gas flares, refinery effluents and refractory products and massive spillages due to handling operations. The existing regulating governing the control of environmental pollution are viewed as inadequate and needing revision and overhauing. Recommendations are given as guides for the activities of the Nigerian National Petroleum Corporation in the prevention, control, and treatment of oil and petrochemical pollution.
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Observations on the effects of oil pollution on tropical marine habitats are reported. The pollution was caused by the wreckage of a tanker off the Atlantic entrance to the Panama Canal. Infralittoral communities such as coral reefs remained unaffected because no detergents have been used in eliminating the oil. Repopulation of intertidal rocks covered by dried tar took place 2 months after the incident. Greatest damage occurred on microfauna and intertidal organisms in sandy beaches and mangroves.
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This short review article summarizes the results from long term assessment of an oil spill into a coastal fringe mangrove ecosystem in Panama. The study combined chemical and biological assessment methods to demonstrate that a time period of up to 20 years or longer is required for deep mud coastal habitats to recover from the toxic impact of catastrophic oil spills. This is due to the long term persistence of oil trapped in anoxic sediments and subsequent release into the water column.
Chapter
This chapter provides an overview of mangrove management, assessment, and monitoring. It addresses the need for integrated planning and management, based on sound legal principles. The central part of the chapter covers mangrove conservation and planting. Conserving existing mangrove forest is often more effective than planting new forests. When a decision for planting has been made, one has to differentiate between planting on degraded and non-degraded sites and distinguish between replanting, rehabilitation, restoration, and afforestation. Emphasis is put on the need for careful selection of appropriate sites and species and on an ecosystem-based approach to mangrove planting and management which uses and supports natural regeneration and other natural processes. Since the primary intention with any rehabilitation intervention works is for improved protection of existing seedlings and forests from degradation or destruction, then planting should be undertaken only if absolutely necessary. Involving local communities in mangrove management is an effective way of maintaining and enhancing the protection function of the mangrove forest while providing livelihood for local people and contributing to better assessment and governance of natural resources. Assessment of the status of mangrove forests is essential for better conservation planning and management. This includes research and economic assessment and valuation. The last section highlights the importance of applied/participatory as well as academic and long-term monitoring (see also chapter “Mangroves: Unusual Forests at the Seas’ Edge”).
Chapter
Mangroves form distinct sea-edge forested habitat of dense, undulating canopies in both wet and arid tropic regions of the world. These highly adapted, forest wetland ecosystems have many remarkable features, making them a constant source of wonder and inquiry. This chapter introduces mangrove forests, the factors that influence them, and some of their key benefits and functions. This knowledge is considered essential for those who propose to manage them sustainably. We describe key and currently recommended strategies in an accompanying article on mangrove forest management (Schmitt and Duke 2015).
Chapter
The damage to mangrove communities and fisheries were studied following extensive oil pollution of the coastal areas of northern Ecuador and southern Colombia in 1976. During the acute phase of the oil spill oil covered 2–3 m vertically on the mangrove trees along the sea front, and had penetrated 20–70 m horizontally. Acute effects on the mangrove communities included defoliation of trees, mortality of sessile organisms, and migration of semi-sessile and mobile crustaceans and molluscs. Dead fishes, sea snakes and sea birds were also found. The relatively large tidal range caused considerable washing off of the deposited oil from roots and trunks, and four months later the major part of the oil on the mangrove trees had disappeared. Previously defoliated mangroves had, with some exceptions, recovered, and mobile organisms had re-entered the affected area. In some areas where mangrove had died there was erosion of the substrate. The oil spill affected the local fishery in a number of ways; for example, the absence of tuna in the region during that year suggested oil avoidance reactions in this group.
Article
The mangrove forests of Southeast Asia are highly biodiverse and provide multiple ecosystem services upon which millions of people depend. Mangroves enhance fisheries and coastal protection, and store among the highest densities of carbon of any ecosystem globally. Mangrove forests have experienced extensive deforestation owing to global demand for commodities, and previous studies have identified the expansion of aquaculture as largely responsible. The proportional conversion of mangroves to different land use types has not been systematically quantified across Southeast Asia, however, particularly in recent years. In this study we apply a combined geographic information system and remote sensing method to quantify the key proximate drivers (i.e., replacement land uses) of mangrove deforestation in Southeast Asia between 2000 and 2012. Mangrove forests were lost at an average rate of 0.18% per year, which is lower than previously published estimates. In total, more than 100,000 ha of mangroves were removed during the study period, with aquaculture accounting for 30% of this total forest change. The rapid expansion of rice agriculture in Myanmar, and the sustained conversion of mangroves to oil palm plantations in Malaysia and Indonesia, are identified as additional increasing and under-recognized threats to mangrove ecosystems. Our study highlights frontiers of mangrove deforestation in the border states of Myanmar, on Borneo, and in Indonesian Papua. To implement policies that conserve mangrove forests across Southeast Asia, it is essential to consider the national and subnational variation in the land uses that follow deforestation.
Article
Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world's mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070.
Article
As part of an ongoing study of the long-term effects of the Zoe Colocotroni oil spill of March 1973, in Bahia Sucia, Puerto Rico, the effects of the remaining oil on the red mangrove trees in the impact area were investigated. Measurements of sodium and potassium were made on leaf samples taken from trees from oil-affected areas and reference areas. Sediment core samples were taken from the root zone of the trees sampled at each site and analyzed for hydrocarbons by gravimetric and gas chromatographic methods. The results show a relationship between sediment hydrocarbon concentration and the ratio of sodium to potassium for mangrove leaves sampled on each site. The values of this ratio for the leaves had the largest values, relecting an oil-induced impairment of the salt (Na) exclusion mechanism.
Article
During a three-week period in 1970 an estimated 65,000 barrels of 34° API gravity crude oil were discharged from the Chevron Main Pass Block 41C Platform, 11 miles east of the Mississippi River Delta. Two thousand barrels of chemical dispersants were sprayed on the platform and surrounding water surface. It is estimated that between 25–30% of the oil evaporated during the first 24 hours, 10–20% was recovered from the water surface, less than 1% dissolved, and less than 1% of the oil was identified in sediments within a 5-mile radius of the platform. The remaining oil emulsified and dispersed to undetectable levels, biodegraded, or photooxidized. The highest measured concentrations in water at the platform and at 1 mile were: oil-in-water emulsion, 70 to 1 ppm; dissolved hydrocarbons, 0.2 to 0.001 ppm; dispersant 1–3 to unmeasurable (<0.2ppm). Total extractable organic matter was highest in sediments near the Mississippi River Delta and in the inland bays. Spilled oil, identified in bottom sediments by gas chromatography, showed rapid weathering after 1 week to 1 month and at the end of 1 year was reduced to a few percent of the amount after the spill. Spilled oil was not found in the sediment below 1.5 inches. Over 550 species of benthic organisms were identified in 233 benthic samples. The number of species and number of individuals of benthic organisms showed low values in some samples near the platform. However, seasonal variations, bottom sediment type, and possibly other environmental parameters made it impossible to determine whether these locations had been affected by the spilled oil. There was no correlation of number of species, number of individuals, or other biological parameters with the hydrocarbon content of the sediments for samples from within a 10-mile radius of the platform. This lack of correlation suggests lack of significant effect of oil on benthic organisms. Extensive trawl samples showed no alteration in the annual life cycle of commercially important shrimp. Blue crabs were observed throughout the area, and the number of species of fish collected were comparable to a prior survey.
Article
During 1978 and 1979, sediment samples were collected in the mangrove areas on the west side of Bahia Sucia, Puerto Rico, to examine the effects of oil discharged from the tanker Zoe Colocotroni (March 18, 1973) on the infaunal community. Samples for benthic community analysis a