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Using landing statistics and fishers’ traditional ecological knowledge to assess conservation threats to Pacific goliath grouper in Colombia
Abstract
Groupers are vulnerable to fishing pressure largely because of their life‐history traits. The Pacific goliath grouper (PGG; Epinephelus quinquefasciatus ), the largest reef fish inhabiting the tropical Eastern Pacific region, is suspected to be subject to high levels of exploitation, but scarce information exists on their population status and the species remains classed as Data Deficient according to the International Union for Conservation of Nature (IUCN) Red List.
This study documents for the first time the threats to the PGG along the Colombian Pacific coast, where one of the few active fisheries for this species persists. Reconstructed landings of groupers and traditional ecological knowledge, gathered throughout several coastal villages, were used to obtain a historical and contemporary overview of the PGG status in Colombia.
Over the past 20 years grouper landings in the Colombian Pacific have been around 200 tons per year. Landings of PGG have averaged ~35 tons per year and are now close to matching those of the historically most landed grouper on this coast, the rooster hind ( Hyporthodus acanthistius ). The current small‐scale fishery for PGG focuses on immature small individuals, with most taken from the extensive southern mangroves. Until recently fishers have captured PGG exclusively with handlines, but new fishing practices (spearfishing) and markets commanding higher prices for small individuals are increasing the extinction risk for the PGG.
The exploitation of PGG in the Colombian Pacific may not be as severe as in other countries where severe population declines are suspected (e.g. Mexico). Low coastal human population density and the presence of relatively intact mangroves, essential habitat for juvenile fishes, contribute to the persistence of PGG populations throughout the Colombian Pacific.
National and regional conservation and management measures should identify and protect mangrove nurseries and offshore spawning aggregation sites. Well‐enforced protected nurseries and spawning aggregation sites will then protect juvenile and adult PGG, improving the sustainability of this fishery.
... Species in this category commonly lack the necessary information to determine their actual conservation status and could potentially fall into any of the other categories of the Red List of Species (Luiz et al. 2016). Similar to its vulnerable and widely protected Atlantic counterpart, Epinephelus itajara, the PGG is likely experiencing population declines because of fishing pressure (Castellanos-Galindo et al. 2018). ...
... This could lead to a fishing selectivity towards smaller individuals. Similar fishing selectivity and market dynamics for PGG have been identified in Colombia (Castellanos-Galindo et al. 2018) as well as for other species, including red snapper (Lutjanus peru) in the Gulf of California (Erisman et al. 2010). This market demand towards smaller individuals might be driving this apparent decline in PGG, rather than indicating an actual population decline. ...
... Consequently, implementing incentives in environmental education and monitoring programs led by community members can enhance environmental stewardship and promote sustainable resource use (Gasalla and de Castro 2016). For example, nongovernmental organizations' initiatives in northern Pacific Colombia have led to a decrease in fishing pressure on PGG based on claims that the species is at risk of extinction [likely by applying the IUCN risk status (CR and more recently VU) for AGG to PGG] (Castellanos-Galindo et al. 2018). ...
The Pacific goliath grouper, Epinephelus quinquefasciatus , is the largest reef fish of the tropical Eastern Pacific. The IUCN categorizes it as Data Deficient because of the lack of population data and the risk posed by fishing. Using fishers' local ecological knowledge, we assessed Pacific goliath grouper historical catch trends along Panama's Pacific coast. Handline and speargun catches showed significant declines in the average weight of Pacific goliath grouper landed from 1958 to 2018. Market demand and environmental degradation were identified as primary drivers of the Pacific goliath grouper perceived decline. Local ecological knowledge demonstrated that valuable fisheries information can be derived and used to inform species' population trends.
... Despite signs of severe overfishing, the IUCN Red List categorizes the PGG as "Data Deficient" due to minimal species-specific data on fishing intensity and a complete lack of fishery-independent biological and ecological data (Sadovy de Mitcheson et al., 2013). An active fishery for the species has been documented in Pacific Colombia (Castellanos-Galindo et al., 2018). In Buenaventura (main fish market in Pacific Colombia), the fishery is characterized by the targeting of "mero especial" ("special grouper, ") which are groupers between 2.5 and 25 kg. ...
... In Buenaventura (main fish market in Pacific Colombia), the fishery is characterized by the targeting of "mero especial" ("special grouper, ") which are groupers between 2.5 and 25 kg. These small fish often fetch higher commercial values (US$ 3.7 per kilo) than groupers >25 kg (US$1.8 per kilo) (Baos et al., 2015;Castellanos-Galindo et al., 2018). In most northern areas (north of Cabo Corrientes), the prices per kilo of PGG (US$ 2 per kilo) are the same regardless of the size (Castellanos-Galindo et al., 2018). ...
... These small fish often fetch higher commercial values (US$ 3.7 per kilo) than groupers >25 kg (US$1.8 per kilo) (Baos et al., 2015;Castellanos-Galindo et al., 2018). In most northern areas (north of Cabo Corrientes), the prices per kilo of PGG (US$ 2 per kilo) are the same regardless of the size (Castellanos-Galindo et al., 2018). Although fishing pressure for PGG in Pacific Colombia has been speculated to be less severe than in other countries (Sala et al., 2004;Castellanos-Galindo et al., 2018), there is scant information on the overall health of the population, including whether or not overfishing is occurring. ...
The effects of fishing on the demography and population ecology of sex-changing fishes are largely unknown, despite the fact that their fisheries provide important economic and nutritional resources in coastal communities throughout the tropics, especially in Latin America. Species with female-first sex change often have naturally skewed sex ratios in the adult population, and fishing pressure can alter this natural bias, limiting egg production and fertilization success. How fishing alters demography and population vital rates depends on which sizes and sexes are selected. We consider two types of fishery selectivity “asymptotic (selecting the largest fish) and plate-sized (selecting fish between in a narrow, but small, size range)” that to represent fisheries for two important fish species of the Tropical Eastern Pacific, the Pacific goliath grouper (Epinephelus quinquefasciatus) and the endemic sailfin grouper (Mycteroperca olfax) of the Galapagos Islands, known locally as bacalao. Each of these large, long-lived species support small scale fisheries of significant value, but there is limited information on fishing effort, selectivity, or population trends. Using a population model, we estimate how the biology of these species contributes to their risk of overexploitation under different possible scenarios of fishing and reproductive biology. Specifically, we consider how variation in growth rates and fertilization rates interact with selectivity to affect age structure and sex ratios. We compare two metrics of population status: the spawning potential ratio (SPR), and the relative standing biomass after fishing (BF/B0). In our modeled populations, when fertilization rates were reduced, fishing rapidly decreased the spawning potential of both species, but did not affect biomass at moderate levels of fishing mortality. However, we predict low fertilization success, fast somatic growth, and asymptotic selectivity of fisheries for sex-changing species decreases both spawning potential and biomass, even at low levels of exploitation, suggesting these factors can cause rapid depletion of sex-changing species. Our findings highlight key gaps in our knowledge of spawning behavior and fertilization success of sex-changing fishes that must be filled if we are to sustainably manage these culturally and economically significant fisheries.
... Groupers and other reef fish species in the Epinephelidae family are usually highly prized by fishers, who target these larger fishes of higher commercial value and economic importance Castellanos-Galindo et al., 2018;Hamilton et al., 2011Hamilton et al., , 2012Sáenz-Arroyo et al., 2005;Stallings, 2009). These reef fishes also have ecological importance and perform environmental services, such as biocontrol of invasive species (Mumby et al., 2011), influences on prey populations and in the maintenance of coral reefs (Coleman et al., 2010;Graham et al., 2003;Stewart and Jones, 2001) and cleaning interactions . ...
... Among these are the groupers from the Epinephelidae family, some which have high commercial value and are commonly found in fishing landings in the southeast and northeast Brazilian coasts (Gerhardinger et al., 2006b;Begossi et al., 2012;Silvano et al., 2017;Condini et al., 2018;Previero and Gasalla, 2018;Begossi et al., 2019;Zapelini et al., 2019). The growing research on fishers' LEK has provided useful information on reproduction, ecology and fisheries of groupers, by bringing new data and contributing to fill gaps in scientific knowledge in Brazil Ferreira et al., 2014;Gerhardinger et al, 2006bGerhardinger et al, , 2009Neto et al., 2002;Zapelini et al., 2017) and elsewhere (Castellanos-Galindo et al., 2018;Gaspare et al., 2015;Maia et al., 2018;Mavruk et al., 2018;Sáenz-Arroyo et al., 2005). However, most of these studies have addressed only one or two threatened grouper species, whereas fewer studies have investigated and compared fishers' LEK among several grouper species (Gaspare et al., 2015;Mavruk et al., 2018). ...
... These data from fishers' knowledge suggested that this grouper species may not be severely overfished in the studied region, although fishers mention this species as overexploited in the region around the Abrolhos bank (Bender et al., 2013;Zapelini et al., 2019), which is also located in the northeastern Brazilian coast, south to our study region. Therefore, considering that LEK is the unique source of information for E. morio in the studied region, it would be desirable to conduct complementary studies of fisheries or underwater surveys to better define the population status of this vulnerable species, as has been done for other grouper species (Bender et al., 2014;Castellanos-Galindo et al., 2018;Silvano et al., 2017;Condini et al., 2018;Begossi et al., 2019). Overall, fishers' LEK indicated that the two smaller and less known species of groupers (C. ...
Studies on local ecological knowledge (LEK) of small-scale fishers can provide new information on fishing dynamics, biology, ecology and conservation status of exploited fish. The groupers (Epinephelidae family) include reef fish of high commercial value, which have been threatened by overfishing, due to their large body size and slow growth. This study aimed to record and to analyze fishers' LEK on the biology, ecology, perceptions on management rules and temporal changes on abundance and size of five grouper species (Mycteroperca bonaci, Epinephelus adscensionis, E. itajara, E. morio and Cephalopholis fulva) in the northeastern Brazilian coast. Another goal was to compare LEK with available scientific data on these grouper species. A total of 64 fishers were interviewed in three fishing communities, about biology and conservation status (size and abundance trends) of the studied groupers. Overall, there was a high agreement between LEK and scientific data on fish diet and migration of the studied fishes, but low agreement and less knowledge by fishers about fish reproduction. According to fishers' LEK, all the studied species showed a decline on abundance, besides declines in size (length or biomass), when comparing fisheries nowadays and when each fisher started fishing (past situation). The threatened fish E. itajara showed the largest decreases in size over time, according to fishers' LEK. Fishers mentioned that they know and agree with management rules that prohibit fishing of certain aquatic species, especially E. itajara. The information from fishers’ LEK provided useful and new data for some of the studied reef fishes in the highly diverse, but relatively poorly known northeastern Brazilian coast. These results from LEK can thus contribute to fill current knowledge gaps in the scientific literature, to suggest new hypotheses to be investigated and to improve conservation and management of this commercially important and threatened group of reef fishes.
... In data-poor regions, stakeholder input and consultation not only fill data gaps but offer opportunities for communities to acquire ownership of resource management and resource-related decision-making (Yang and Pomeroy, 2017;Zolkafli et al., 2017;Castellanos-Galindo et al., 2018). Community ownership over conservation measures can be supported by researchers and local non-profits by collaborating with local fishers and community members to aid in documenting data, facilitating projects, and synthesizing community needs Szostek et al., 2017;Chung et al., 2019;Brandt et al., 2020). ...
... This process of collaboration with community members, transferring their experiences and understanding of their environments via mapping exercises is called Participatory GIS (PGIS) (Dunn, 2007). PGIS is a low-cost method that has been used in many studies to guide ecosystem management (Croll et al., 2005;Levine and Feinholz, 2015;Strickland-Munro et al., 2016), estimate fishing effort (Thiault et al., 2017), provide location data for rare or endangered species distributions (Rajamani, 2013;Mason et al., 2019), assess anthropogenic threats to coastal environments Castellanos-Galindo et al., 2018), and estimate the distribution and magnitude of bycatch (Moore et al., 2010;Pilcher et al., 2017). The various obstacles and challenges associated with identifying the risk of bycatch in SSF can benefit from incorporating different pieces of the puzzle by using PGIS (Lewison et al., 2018). ...
Uncertainties about the magnitude of bycatch in poorly assessed fisheries impede effective conservation management. In northern Peru, small-scale fisheries (SSF) bycatch negatively impacts marine megafauna populations and the livelihoods of fishers which is further elevated by the under-reporting of incidents. Within the last decade, accounts of entangled humpback whales (HBW) (Megaptera novaeangliae) off the northern coast of Peru have increased, while Eastern Pacific leatherback turtles (LBT) (Dermochelys coriacea) have seen over a 90% decline in nesting populations related in large part to bycatch mortality. By leveraging the experience and knowledge of local fishers, our research objectives were to use a low-cost public participation mapping approach to provide a spatio-temporal assessment of bycatch risk for HBW and LBT off two Peruvian fishing ports. We used an open-source, geographic information systems (GIS) model, the Bycatch Risk Assessment (ByRA), as our platform. Broadly, ByRA identifies high bycatch risk areas by estimating the intersection of fishing areas (i.e., stressors) with species habitat and evaluating the exposure and consequence of possible interaction between the two. ByRA outputs provided risk maps and gear risk percentages categorized as high, medium, and low for the study area and seven subzones for HBW in the austral winter and LBT in the austral summer. Overall, the highest bycatch risk for both species was identified within gillnet fisheries near the coast. Bycatch risk for most gear types decreased with distance from the coast. When we separated the ByRA model by port, our map outputs indicate that bycatch management should be port specific, following seasonal and spatial variations for HBW, and specific fishing gear impacts for HBW and LBT. Combined with direct bycatch mitigation techniques, ByRA can be a supportive and informative tool for addressing specific bycatch threats and marine megafauna conservation goals. ByRA supports a participatory framework offering rapid visual information via risk maps and replicable methods for areas with limited resources and data on fisheries and species habitat.
... Artisanal and small-scale fisheries hold the main supply of hydrobiological resources on the Pacific coast and are currently responsible for a significant proportion of the seafood consumed in the country, with gross revenues in the range of US $10-20 million per year. In 2017, landings from artisanal and small-scale fisheries in the Pacific region were valued at US $10.8 million, of which Buenaventura (56.9%) and Tumaco (21.2%) accounted for the majority of the landings since these two ports are the largest of the region (Castellanos-Galindo et al., 2018). In addition, it is estimated that approximately 400,000 people-mainly in coastal communities-depend exclusively on fishing activity as an economic activity for their livelihood (Esquivel et al., 2014). ...
Small-scale fisheries (SSF) contribute to nearly half of global landings and provide multiple socioeconomic benefits to coastal communities. The pacific coast SSF represents 37% of the total fisheries landings in Colombia. Scientific literature continually shows that tropical marine habitats are most vulnerable to oceanic changes associated with climate change. This study prioritized three pelagic species (Euthynnus lineatus, Scomberomorus sierra, and Cynoscion albus) based on their landing statistics to develop potential current and future species distributions using five ensembled machine learning models including Artificial Neural Network (ANN), Maximum Entropy (MaxEnt), Boosted Regression Tree (BRT), Random Forest (RF), and Classification Tree (CT). Future distributions of these species in the medium-term (2050s) and long-term (2080s) were modeled using the Representative Concentration Pathways (RCP) 2.6 and 8.5 emission scenarios for four ensembled Global Circulation Models (GCMs) obtained from the Coupled Model Intercomparison Project Phase 5 (CMIP5). In addition, change detections were calculated to identify contraction and expansion of areas, and the distributional core shift was determined to estimate the spatial movements. Results indicate that E. lineatus and S. sierra will potentially move to deeper waters away from the coastline. Alternatively, C. albus could be a species to potentially gain more importance for the fishing sector due to potential variations in climate. These results constitute a critical scientific basis for evaluating the climate change vulnerability of the fishing sector and the decision-making process in the future of small-scale fishery management in the southern Colombian Pacific Ocean.
Coastal small-scale fisheries remain largely unassessed and unregulated worldwide, which leads to a high risk of overfishing. Availability and quality of data are major barriers to performing model-based assessments, particularly in low and middle-income countries. In that context, alternative assessment methods are key to defining priorities, as well as prompting and guiding management actions. In this study, we assessed the vulnerability to overfishing of 10 extremely data-poor species of coastal groundfish in Peru, by applying an adapted Productivity Susceptibility Analysis (PSA). We classified fisheries-related Susceptibility attributes and streamlined a process to assess and integrate multiple fisheries and gears into a single score for each attribute. The data quality scores regarding productivity and susceptibility were between "limited" and "no data", across all stocks. Therefore, expert knowledge was key for completing the assessment. Stocks of four species presented extremely high Vulnerability to overfishing: broomtail grouper (V=2.57), grape-eye seabass (V=2.50), pacific goliath grouper (V=2.28) and galapagos sheephead wrasse (V=2.24). Three showed high Vulnerability to overfishing: black snook (V=2.13), harlequin wrasse (V=2.05) and chino (V=2.01). Two showed medium Vulnerability to overf-ishing: mulata (V=1.89) and pacific beakfish (V=1.89). Only the stock of bumphead parrotfish showed low Vulnerability to overfishing (V=1.73). We contrasted the resulting Vulnerability scores with the limited available information on the statuses of these stocks, to evaluate the accurateness of the overfishing probability thresholds proposed in PSA literature. We found that Vulnerability scores were mostly consistent with contrasted information and that the thresholds remain useful to inform fisheries management in extremely data-poor contexts. Our results shed light on the need for the implementation of fishing regulations and the generation of biological and fishery-related data on coastal groundfish in Peru.
The giant grouper ( Epinephelus lanceolatus ) is the largest reef fish in the Indo‐Pacific (~2.5 m TL, >400 kg), and it is highly susceptible to overfishing. Despite regional protections and documented population declines, the species is listed by IUCN as Data Deficient due to minimal long‐term population data and a paucity of life history information. This study used historical fishing records derived from newspaper articles, fishing magazines, grey literature and naturalists' descriptions to collate life history information and reconstruct giant grouper population trends from 1854 to 1958 in Queensland, Australia. Historical recreational catch trends of four biologically distinct grouper size classes demonstrated that over 92 years, fishing disproportionately affected two size classes: immature (fish below reproductive size) and mature individuals. Changes in the probability of capturing a grouper within a recreational fishery were examined as a proxy of relative abundance. The probability of catching a giant grouper within a popular recreational fishery significantly declined from 81% in 1860 to 2% in 1958. Further analysis based on a non‐probabilistic method of giant grouper sighting records showed fluctuations in the giant grouper population trajectory, from a steady decline during the early 20th century to an increase during WWII (1939–1945) followed by a reduction in the last half of the 20th century. This study highlights the importance of archival sources to uncover population trends of rare species by combining quantitative assessments and biological inferences to determine the timing and occurrence of population declines and recoveries and inform how vulnerable fish species respond to the cumulative effects of fishing over time.
While few have contemplated the potential impacts of climate change on small-scale fisheries and fishermen in the Colombian Pacific, understanding these effects is crucial for devising effective adaptation strategies. This study presents the outcomes of a vulnerability assessment related to climate change for fishermen in the Colombian South Pacific. The assessment employed a multivariable model that considered the sensitivity of marine and coastal ecosystems that support fishing resources alongside fishermen’s adaptability to changes in the biophysical environment. Socioeconomic factors were also scrutinized. The study revealed that 80% of the surveyed fishermen are at a medium to high level of vulnerability due to changes in the distribution of key commercial species, which influences the productivity of their traditional fishing sites. Their vulnerability is primarily attributed to low usage of fishing technologies, the boat engine’s limited propulsion capacity, and a lack of diversity and sustainability in fishing gear. These elements increase their reliance on fishing sites close to the coast (approximately 3 km to 5 km from the shoreline), resulting in a low adaptive capacity for the fishermen. The dominant factor driving the sensitivity component was the economic significance of the fishing gear and the fact that the gear could be more diverse and durable. These findings provide a critical scientific basis for assessing the fishing sector’s vulnerability to climate change and informing future collaborative decision-making in managing small-scale fisheries in the Colombian South Pacific Ocean.
Recreational spearfishing is a fishing method that occurs globally, yet receives considerably less attention in the scientific literature relative to other recreational fishing methods, such as angling. Lack of scientific information on spearfishing may negatively affect the development and management of marine recreational fisheries. We conducted a systematic review of 102 peer-reviewed papers published between 1967 and 2022 pertaining to marine recreational spearfishing. Based on this literature review, we provide an overview of key insights across social, economic, and ecological dimensions of marine recreational spearfishing. While spearfish-ers represent less than 5% of marine recreational fish-ers, the participants are younger and may differ from recreational anglers in their motivations, with suggestions of increased well-being generated from a close connection with the sea during underwater fishing. Recreational spearfishers mostly target species of moderate to high levels of vulnerability that are mid to high trophic level carnivores. Though spearfishers Supplementary Information The online version contains supplementary material available at https:// doi.
The Atlantic Goliath Grouper (AGG), Epinephelus itajara, the largest Epinephelidae in the Atlantic Ocean, it is classified as critically endangered in Brazil. In the Brazilian northeast, studies focusing on the species are still incipient. Here we study the occurrence, habitat use, and spatial distribution of AGG in Alagoas (Brazil) by combining participatory methods, such as Citizen Science and Local Ecological Knowledge. Living individuals represented 64% (n = 85) of the records, while dead individuals were 36% (n = 47), with 14 records from illegal captures. Juveniles are common in estuaries and shallow natural coastal reefs, while adults are distributed in deeper areas on natural and artificial reefs. The occurrence was significantly higher on Alagoas’ southern coast. The São Francisco River (SFR) estuary stood out with 52 occurrences. We mapped 37 occurrence sites for AGG distributed along the coast, emphasising an artificial reef near SFR that received 12 reports about aggregations. The influence area of the SFR was indicated as a priority for species conservation due to the identification of a nursery and possible aggregations close to its mouth. We highlight the urgency of implementing short and long-term management actions along Alagoas’ coast.
The Pacific region is considered a biodiversity hotspot and presents high species endemic levels. The Colombian Pacific basin occupies an area of approx. eight million hectares, located in the country's west. The literature about the economic valuation of ecosystem services (ES) and the spatial information on natural resources in the Colombian Pacific basin was revised through various information sources to document the earliest approximation to the state, spatial distribution, and economic value of the natural capital at the scale of biomes, specific ecosystems, and political-administrative units. Our assessment estimated a natural capital loss of 40 billion Int.2020/year (51% of Colombia's GDP in 2020) for 15 ecosystem services. This research establishes that a potential expansion in livestock production systems will generate an additional loss of natural capital between six and eight billion Int.2020/year. Lastly, the policy challenges and gaps in research and management concerning this remaining natural capital in the Colombian Pacific basin are pointed out.
The subsistence strategies that coastal fishing communities have developed over time are closely related to their interaction with the sea. Fishing is generally the principal economic activity of the members of these communities; however, the use of botanical resources has also contributed to their subsistence through time. This is the case of the Huanchaco fishing community that live on the north coast of Peru. They use reeds to construct sea vessels for fishing and other plants growing locally for diverse economic and cultural activities. To study their traditional relationships with useful plants, an ethnobotanical survey was conducted with 40 members of the fishing community. The objective of this research was to determine the use of local plants for daily activities and the intracultural variation of that knowledge as it relates to age and gender. Results showed that people use plants for food, medicinal, and industrial purposes, and that women and elderly people are more knowledgeable about medicinal and industrial plants than their male and younger counterparts. Although processes of modernization have influenced many aspects of the fishing community’s lifestyle, the existing TEK suggests that plants still play an important role in their daily subsistence strategies.
Small-scale fisheries (SSF) remain a largely under-assessed and overlooked sector by governments and researchers, despite contributing approximately 50% to global fish landings and providing food and income for millions of people. The multi-species, multi-gear and data-poor nature of SSF makes implementation of traditional single-species management approaches – like catch-quotas or size limits – particularly challenging and insufficient. A more holistic approach is thus required, which demands assessment of ecological impacts. Here we carried out an estimation of selected ecological indicators of the impact of fisheries (mean length, maximum body size, mean trophic level, trophic and spatial guilds, threatened species and landed by-catch) based on the nominal catch of different gears in three representative SSF along the Colombian Pacific using landings data collected in multiple years (2011–2017). Results showed that taxonomic, size-based, functional and conservation features of the nominal catch vary greatly with geographical location and gear type used. Overall, handlines and longlines tend to select larger sizes and higher trophic levels than nets, but they also catch a higher proportion of intrinsically vulnerable species and species of conservation concern. This challenges the idea that more selective gears have overall lower ecological impacts. In contrast, nets target a wider size range – although focusing on small or medium sized fish – and include a higher diversity of trophic and spatial guilds, which could arguably be considered a more “balanced harvest” type of fishing that retains ecosystem structure and functionality. Bottom trawls, though, exhibited a relatively high percentage of landed by-catch, an undesirable feature for any fisheries in terms of sustainability. We propose that the assessment of a suite of ecological indicators, like those implemented here, should be included as part of periodic evaluations of multi-gear and multi-species SSF in tropical coastal areas, as a practical step toward ecosystem-based fisheries management.
Effective management of fisheries depends on the selectivity of different fishing methods, control of fishing effort and the life history and mating system of the target species. For sex-changing species, it is unclear how the truncation of age-structure or selection of specific size or age classes (by fishing for specific markets) affects population dynamics. We specifically address the consequences of plate-sized selectivity, whereby submature, “plate-sized” fish are preferred in the live reef food fish trade. We use an age-structured model to investigate the decline and recovery of populations fished with three different selectivity scenarios (asymptotic, dome-shaped and plate-sized) applied to two sexual systems (female-first hermaphroditism and gonochorism). We parameterized our model with life-history data from Brown-marbled grouper (Epinephelus fuscoguttatus) and Napoleon fish (Cheilinus undulatus). “Plate-sized” selectivity had the greatest negative effect on population trajectories, assuming accumulated fishing effort across ages was equal, while the relative effect of fishing on biomass was greatest with low natural mortality. Fishing such sex-changing species before maturation decreased egg production (and the spawning potential ratio) in two ways: average individual size decreased and, assuming plasticity, females became males at a smaller size. Somatic growth rate affected biomass if selectivity was based on size at age because in slow growers, a smaller proportion of total biomass was vulnerable to fishing. We recommend fisheries avoid taking individuals near their maturation age, regardless of mating system, unless catch is tightly controlled. We also discuss the implications of fishing post-settlement individuals on population dynamics and offer practical management recommendations.
Fishers' knowledge research is an approach to fisheries research that has a relatively long history, yet has generally failed to become integrated into the fisheries science mainstream alongside approaches that rely primarily on the knowledge of professional scientists. Its continued position on the margins of fisheries science has not however stopped fishers' knowledge researchers from publishing an expanding literature, which they often use to advocate for the greater consideration of fishers' knowledge by fisheries scientists and managers. They believe that the unique and often highly qualitative knowledge of fishers could inform better decision-making, resulting in improved socio-ecological outcomes for fisheries. This review first outlines the scope of the fishers' knowledge literature, before outlining five waves of fishers' knowledge research that have developed over the last century. For each wave, the nature of the fishers' knowledge documented during it is noted, as is the research and dissemination approach taken by its practitioners. The impact of that wave on mainstream fisheries science is then assessed. Overall, it is found that only one wave of fishers' knowledge research is beginning to have consistent success integrating with mainstream fisheries science, a wave that omits the research of many of the unique elements of fishers' knowledge. Other waves have died out, or are in danger of dying out, either because they have failed to be noticed by mainstream fisheries scientists or because mainstream fisheries scientists have not welcomed their outputs. It is summarized that fishers' knowledge research will only continue as a productive activity if mainstream fisheries scientists begin to open their discipline to other knowledge cultures and if fishers' knowledge researchers facilitate this action by disseminating their research so that it is more accessible to these scientists.
The value of big old fat fecund female fish (BOFFFFs) in fostering stock productivity and stability has long been underappreciated
by conventional fisheries science and management, although Hjort (1914) indirectly alluded to the importance of maternal effects. Compared with smaller mature females, BOFFFFs in a broad variety
of marine and freshwater teleosts produce far more and often larger eggs that may develop into larvae that grow faster and
withstand starvation better. As (if not more) importantly, BOFFFFs in batch-spawning species tend to have earlier and longer
spawning seasons and may spawn in different locations than smaller females. Such features indicate that BOFFFFs are major
agents of bet-hedging strategies that help to ensure individual reproductive success in environments that vary tremendously
in time and space. Even if all else were equal, BOFFFFs can outlive periods that are unfavourable for successful reproduction
and be ready to spawn profusely and enhance recruitment when favourable conditions return (the storage effect). Fishing differentially
removes BOFFFFs, typically resulting in severe truncation of the size and age structure of the population. In the worst cases,
fishing mortality acts as a powerful selective agent that inhibits reversal of size and age truncation, even if fishing intensity
is later reduced. Age truncation is now known to destabilize fished populations, increasing their susceptibility to collapse.
Although some fisheries models are beginning to incorporate maternal and other old-growth effects, most continue to treat
all spawning-stock biomass as identical: many small young females are assumed to contribute the same to stock productivity
as an equivalent mass of BOFFFFs. A growing body of knowledge dictates that fisheries productivity and stability would be
enhanced if management conserved old-growth age structure in fished stocks, be it by limiting exploitation rates, by implementing
slot limits, or by establishing marine reserves, which are now known to seed surrounding fished areas via larval dispersal.
Networks of marine reserves are likely to be the most effective means of ensuring that pockets of old-growth age structure
survive throughout the geographic range of demersal species.
Mangrove forests are recognized for the important role they play for human societies in a changing world (Lee et al. 2014). Yet alarming levels of destruction and degradation occur in tropical regions, where these ecosystems flourish. A vivid example of degradation in the Neotropics is witnessed in Ecuador where 28-40 % of mangroves were lost to shrimp farming between 1970 and 2006 (Hamilton 2013).In the mid-twentieth century, the late geographer Robert West (Louisiana State University), inspired by images of Rhizophora mangrove trees more than 40 m high, referred to Colombia’s Pacific ultra-humid tidal forest as “the most luxuriant mangroves in the World” (West 1956). Sixty years later, these forests and the whole social-ecological system face increasing threats that are not prioritized in national and international conservation and management fora. This letter focuses on the history of exploitation of Colombia’s Pacific mangroves, and raises an urgent call to halt the threats facing ...
The goliath grouper Epinephelus itajara, a threatened fish has been protected from fishingin Brazil since 2002. However, poaching records have raised questions about the extent ofcompliance to the fishing moratorium. We compiled data of commercial landings figuringin official reports as well as episodes of apprehensions of illegal catches by environmentalpolice. According to reports, national catches declined seventy percent after the moratorium establishment, with an average of 393 tons per year of poaching between 2003 and2011. Although poachers are occasionally caught during environmental police raids alongBrazilian coast, in Pará State catches are reported to continue and poachers have targetedaggregations. Data from those episodes do not reflect the real number of poaching, whichis believed to be much higher, once fisher process fishes before landings to confuse thesupervision and weak enforcement efforts. As management strategies, we recommend thecontinuity of the fishing moratorium, besides increase in surveillance and enforcement. Thechoice of priority areas for concentration of goliath grouper conservation efforts may be aneffective approach.
Marine conservation activities around the globe are largely undertaken in the absence of comprehensive species-specific information. To address this gap, complete regional species assemblages of major marine taxa are being progressively assessed against the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The present study is the first analysis of entire major components of the biota of a large marine biogeographic region conducted in the Tropical Eastern Pacific (TEP). It is based on recently completed IUCN Red List assessments for all known species of bony and cartilaginous shorefishes, corals, mangroves, and seagrasses in the TEP. Twelve percent of the >1600 species assessed are in threatened categories, indicative of elevated extinction risk. Spatial analysis of all assessed taxonomic groups, including previous IUCN Red List assessments for seabirds, marine mammals, and marine turtles, highlights specific geographical areas of elevated threatened-species richness. The distribution of threatened species in the TEP is primarily linked to areas with high rates of overfishing, habitat loss, and increasing El Nino-Southern Oscillation (ENSO) event impacts, as well as oceanic islands with high stochastic risk factors for endemic species. Species assigned to the highest threat categories have life history traits that likely decrease their resilience to various regional and site-specific threats. Comprehensive information in the form of IUCN Red List assessments combined with spatial analysis will greatly help to refine both site- and species-specific marine conservation priorities in the TEP.
Groupers are a valuable fishery resource of reef ecosystems and are among those
species most vulnerable to fishing pressure because of life history characteristics
including longevity, late sexual maturation and aggregation spawning. Despite their
economic importance, few grouper fisheries are regularly monitored or managed at
the species level, and many are reported to be undergoing declines. To identify major
threats to groupers, the International Union for Conservation of Nature (IUCN) Red
List criteria were applied to all 163 species. Red List assessments show that 20 species
(12%) risk extinction if current trends continue, and an additional 22 species (13%)
are considered to be Near Threatened. The Caribbean Sea, coastal Brazil and
Southeast Asia contain a disproportionate number of Threatened species, while
numerous poorly documented and Near Threatened species occur in many regions.
In all, 30% of all species are considered to be Data Deficient. Given that the major
threat is overfishing, accompanied by a general absence and/or poor application of
fishery management, the prognosis for restoration and successful conservation of
Threatened species is poor. We believe that few refuges remain for recovery and that
key biological processes (e.g. spawning aggregations) continue to be compromised by
uncontrolled fishing. Mariculture, through hatchery-rearing, increases production of
a few species and contributes to satisfying high market demand, but many such
operations depend heavily on wild-caught juveniles with resultant growth and
recruitment overfishing. Better management of fishing and other conservation efforts
are urgently needed, and we provide examples of possible actions and constraints.
Understanding natural causes of density dependence is essential for identifying possible sources of population regulation.
Field experiments on a model system of coral reef fishes showed that small juveniles of Chromis cyanea suffer heavy mortality that is spatially density-dependent only in the presence of two suites of predators: transient piscivores
attacking from above, and reef-resident piscivores attacking from below. In the absence of either kind of predator, early
mortality of Chromis is virtually density-independent. Because piscivores may have regulatory roles in this and similar marine systems, overfishing
these predators may have ramifications for the remainder of the exploited community.
We evaluated goliath grouper's [Epinephelus itajara (Lichtenstein, 1822)] use of mangroves as essential nursery habitat by estimating absolute abundance, density, survival, age structure, home range, mangrove habitat association, habitat quality, and recruitment to the adult population. Densities (numbers km−1 mangrove shoreline) were calculated using Jolly-Seber mark-recapture methods for mangrove-lined rivers and mangrove islands of the Ten Thousand Islands (TTI) and Everglades National Park, which includes Florida Bay, Florida, USA. Juveniles had smaller home ranges around islands (170 m) than in rivers (586 m), as determined from observations on telemetered fish. Goliath grouper remained in mangrove habitats for 5-6 yrs (validated ages from dorsal spine sections), then emigrated from mangroves at about 1.0 m total length. In the TTI, juvenile densities around mangrove islands were higher (mean = 25 km−1, SE = 6.2, CV = 0.5) and less variable than those in rivers (mean = 11 km−1, SE = 4.2, CV = 1.2). Density was negatively correlated with the frequency of dissolved oxygen and salinity minima. Mean growth rate of recaptured fish around mangrove islands (0.358 mm d−1, 95% CL = 0.317-0.398) was significantly higher than that in rivers (0.289 mm d−1, 95% CL = 0.269-0.308). The annual survival rate, as estimated by the Kaplan-Meier method on telemetered fish, was 0.947 (95% CL = 0.834-1.0). Very low densities in Florida Bay were probably related to other water-quality variables in this human-altered system. The offshore abundance of adults was largely explained by abundance of mangrove, but not seagrass habitat. Mangrove habitat with suitable water conditions, which appears essential to the recovery and sustainability of goliath-grouper populations, should be protected and/or restored.
The goliath grouper Epinephelus itajara (Lichtenstein, 1822) is an integral part of tradi- tional coastal fisheries in Belize; however, recent anecdotal reports suggest declining catches, mean size and abundance, particularly of large adults. Quantifying goliath grouper abundance in the waters of Belize is an important first step in developing management plans that can protect stocks of the species as well as local fishing communities. To characterize the status of the goliath grouper in southern Belize, we used a 2 yr market survey, fishery-dependent collections and passive tagging. Market surveys revealed that the vast majority (98% or 1412) of 1441 goliath groupers examined at a fish market comprised juveniles. Eight of the 64 interviewed fishers were responsible for most of the catches (67.2%). Size distributions of goliath grouper collected from coastal to outer reef areas using setlines, longlines and drumlines confirmed the overall paucity of adults in local populations. Specif- ically, a 90-fold difference in catch rates was observed between adults (n = 1425) and juveniles (n = 16). Of 209, 45 (21.5%) tagged individuals were recaptured during assessments, observed in mar- keted catch or reported, with 39.3% taken from the Port Honduras Marine Reserve. Fishing mortal- ity was estimated at 0.27, while the specific growth rate was 0.29% d -1 . These results, together with documented loss of known spawning aggregations, suggest that goliath grouper in southern Belize are overfished. To allow population recovery, strict management and enforcement measures are required. Such a plan would have minimal impact on fishing communities, since no fishers are solely reliant on the species.
Few studies have examined predator-prey relationships in diverse communities such as those found on coral reefs. Here we
examined patterns of spatial and temporal association between the local abundance of predator and prey fishes at Lizard Island
on the Great Barrier Reef, Australia. We predicted that the nature of this association would have implications for patterns
of prey-fish mortality. Strong positive relationships between prey and piscivore abundance were found throughout the study.
Greater densities of predators and of prey were found on patch-reef habitats, compared with contiguous reef-slope habitats.
Declines in prey-fish abundance on patch reefs were density-dependent and correlated with the densities of predators. The
relative roles of recruitment and piscivore movement in determining patterns of predator and prey abundance were assessed
from surveys of recruit densities and an intensive programme of tagging two species of rock-cod, Cephalopholis cyanostigma and C. boenak (Serranidae), over 2 years. Patterns of recruitment explained little of the variation in the abundance and distribution of
piscivorous fish. If movement explains large-scale patterns of distribution, this was not evident from the tagging study.
The two rock-cod species were highly sedentary, with individuals on patch reefs seldom moving among reefs. Individuals on
reef slopes were also highly site-attached, although they moved greater distances than those on patch reefs. Although the
mechanisms responsible remain to be determined, this study demonstrated strong associations between the abundance of piscivorous
fish and their prey on coral reefs. This relationship appeared to be an important factor in producing density-dependent declines
in the abundance of prey.
New information on the presence and relative abundances of 41 reef-building (zooxanthellate) coral species at 11 eastern Pacific and 3 central Pacific localities is examined in a biogeographic analysis and review of the eastern Pacific coral reef region. The composition and origin of the coral fauna and other reef-associated taxa are assessed in the context of dispersal and vicariance hypotheses. A minimum variance cluster analysis using coral species presence–absence classification data at the 14 localities revealed three eastern Pacific reef-coral provinces: (1) equatorial– mainland Ecuador to Costa Rica, including the Galápagos and Cocos Islands; (2) northern– mainland México and the Revillagigedo Islands; (3) island group– eastern Pacific Malpelo Island and Clipperton Atoll, and central Pacific Hawaiian, Johnston and Fanning Islands. Coral species richness is relatively high in the equatorial (17–26 species per locality) and northern (18–24 species) provinces, and low at two small offshore island localities (7–10 species). A high proportion (36.6%, 15 species) of eastern Pacific coral species occurs at only one or two localities; of these, three disappeared following the 1982–83 ENSO event, three occur as death assemblages at several localities, and five are endangered with known populations of ten or fewer colonies. Principal component analysis using ordinal relative density data for the 41 species at the 14 localities indicated three main species groupings, i.e., those with high, mid, and narrow spatial distributions. These groupings correlated with species population-dynamic characteristics. These results were compared with data for riverine discharges, ocean circulation patterns, shoreline habitat characteristics, and regional sea surface temperature data to help clarify the analyses as these measures of environmental variability affect coral community composition. Local richness was highest at localities with the highest environmental variability. Recent information regarding the strong affinity between eastern and central Pacific coral faunas, abundance of teleplanic larvae in oceanic currents, high genetic similarity of numerous reef-associated species, and appearances of numerous Indo-west Pacific species in the east Pacific following ENSO activity, suggest the bridging of the east Pacific filter bridge (formerly east Pacific
barrier).
The goliath grouper Epinephelus itajara is a large sized (> 400 kg) and critically endangered marine fish, which is protected in many countries, including Brazil. Through the application of semi-structured interviews, we investigated the local ecological knowledge of seven fishermen specialist on catching E. itajara from the Babitonga bay, Santa Catarina, Brazil. Local long-line fisheries for E. itajara seemed to be a disappearing tradition in the studied site, with a detailed inherent local ecological knowledge
system, which is also being lost. Our study also showed that fishermen engaged in recent fisheries, such as spear-fishing, can also possess a detailed local ecological knowledge system. Through the analysis of fishermen local ecological knowledge, several aspects of E. itajara life history were registered. This species is found in the inner and outer Babitonga bay, from saline waters to areas with a large input of freshwater, and inhabits submerged wooden substrates and artificial reefs such as shipwrecks, mooring
pillars and cargo containers. It is known to spawn in December and subsequent summer months in the studied area. Spawning aggregations are usually seen in December (during full moon), being also eventually observed in January and February by our informants. While lobsters, spadefishes and octopuses seem to constitute the most important food items of inner bay E. itajara,
outer bay individuals may feed on catfishes, crustaceans and other fish species. The goliath grouper is regarded as pacific and curious fish, but frequently display agonistic behavior in the presence of divers. Based on the perception of well experienced spear fishermen, we hypothesize that E. itajara undertakes seasonal migrations from the inner to the outer bay during summer,
and that the studied population is suffering from growth over-fishing. Our data provides a practical evidence of how joining scientific and local ecological knowledge will likely benefit E. itajara local conservation and management practices by adding important new biological data into the decision-making process.
The department of Chocó, on the Colombian Pacific coast
experiences 8,000 to 13,000 mm of average annual precipitation.
Lloró (5°30‧N, 76°32‧W, 120m) has received
above 12,700 mm (1952-1960). Using the NCEP/NCAR Reanalysis data,
we show that the ocean-land-atmosphere interaction over the easternmost
fringe of the tropical Pacific, enhanced by the dynamics of a low-level
westerly jet (“CHOCO”), contributes to explain the existence
of such record-breaking hydrological region. Deep convection develops
from low-level moisture convergence by the CHOCO jet, combined with
high-level easterly trade winds, orographic lifting on the western
Andes, low surface pressures and warm air. Precipitation is organized in
mesoscale convective complexes, in turn dynamically linked to the jet.
The strength of the CHOCO jet (centered at 5°N) is associated with
the gradient of surface air temperatures between western Colombia and
the Niño 1+2 region, thereby exhibiting strong annual and
interannual variability, which contributes to explaining Colombia's
hydro-climatology and its anomalies during ENSO.
Full Article Access here:
http://www.int-res.com/articles/esr2006/2/n002p001.pdf
The goliath grouper Epinephelus itajara (Epinephelidae) is an exceptionally large marine fish that inhabits sub-tropical and tropical waters of the Americas and western Africa. Due to a lack of readily observable morphological variation in specimens across its range, the goliath grouper has been regarded as a single species. We tested the hypothesis that Pacific and West Atlantic populations constitute a single species by analyzing nuclear and mitochondrial DNA sequence data. We found numerous fixed genetic differences for mitochondrial loci between Pacific and West Atlantic goliath grouper (genetic distance D ≈ 3.5% at 16S and D ≈ 6% at cytochrome b; st = 0.98 [p < 0.001] for 16S and st = 0.98 [p < 0.001] for cytochrome b). The nuclear S7 intron showed 3 fixed nucleotide differences between Pacific and West Atlantic populations. Within the West Atlantic, we found few absolute genetic differences (D < 0.01 at 16S and D < 0.02 at cytochrome b), but statistically significant population structure based on haplotype frequency data (st = 0.04 [p = 0.05] at 16S; st = 0.14 [p < 0.001] at cytochrome b). These data indicate that (1) goliath grouper in the West Atlantic are subdivided into discrete populations, (2) goliath grouper populations in the Pacific and western Atlantic represent 2 (or more) distinct species, and (3) these distinct populations/species require separate management and conservation strategies. We resurrect the species Epinephelus quinquefasciatus (Bocourt 1868) for Pacific goliath grouper.
The Goliath grouper, Epinephelus itajara, a large-bodied (approximately 2.5 m TL, > 400 kg) and critically endangered fish (Epinephelidae), is highly vulnerable to overfishing. Although protected from fishing in many countries, its exploitation in Mexico is unregulated; a situation that puts its populations at risk. Fishery records of E. itajara are scarce, which prevents determination of its fishery status. This work aimed to elucidate the E. itajara fishery in the northern Yucatan Peninsula by 1) analyzing available catch records and 2) interviewing veteran fishermen (local ecological knowledge) from two traditional landing sites: Dzilam de Bravo and Puerto Progreso. Historic fishery records from two fishing cooperatives were analyzed in order to elucidate the current situation and offer viable alternatives for conservation and management. Catches have decreased severely. Local knowledge obtained from fishermen represented a very important source of information for reconstructing the fisheries history of this species. Conservation measures that incorporate regional and international regulations on critically endangered fish species are suggested.
Shifting environmental baselines are inter-generational changes in perception of the state of the environment. As one generation replaces another, people's perceptions of what is natural change even to the extent that they no longer believe historical anecdotes of past abundance or size of species. Although widely accepted, this phenomenon has yet to be quantitatively tested. Here we survey three generations of fishers from Mexico's Gulf of California (N=108), where fish populations have declined steeply over the last 60 years, to investigate how far and fast their environmental baselines are shifting. Compared to young fishers, old fishers named five times as many species and four times as many fishing sites as once being abundant/productive but now depleted (Kruskal-Wallis tests, both p<0.001) with no evidence of a slowdown in rates of loss experienced by younger compared to older generations (Kruskal-Wallis test, n.s. in both cases). Old fishers caught up to 25 times as many Gulf grouper Mycteroperca jordani as young fishers on their best ever fishing day (regression r(2)=0.62, p<0.001). Despite times of plentiful large fish still being within living memory, few young fishers appreciated that large species had ever been common or nearshore sites productive. Such rapid shifts in perception of what is natural help explain why society is tolerant of the creeping loss of biodiversity. They imply a large educational hurdle in efforts to reset expectations and targets for conservation.
En los últimos años prestigiosos investigadores económicos han señalado la importancia de la geografía para entender el desarrollo económico en el largo plazo, así como las diferencias en los niveles de renta que se observan entre países y entre las regiones de un mismo país. Esta literatura empírica se aparta del análisis de los determinantes próximos de las desigualdades en los niveles de productividad, básicamente capital humano e infraestructura, para ir un poco más a fondo tratando de encontrar las raíces de las diferencias en el ingreso. En esa literatura predominan dos variantes principales: los que encuentran un efecto directo de la geografía sobre el nivel del ingreso per capita, vía su efecto sobre la productividad agrícola, la salud y el acceso a los mercados, y los que argumentan que ese efecto se produce vía la influencia que la geografía tuvo en el pasado sobre la creación de instituciones que han tenido una gran continuidad en el tiempo. Pero en ambas corrientes es evidente que la geografía es uno de los aspectos más importantes para tener en cuenta y entender el desempeño económico de largo plazo de un país o región. Por esa razón, en este trabajo hemos querido estudiar en detalle los aspectos principales de la geografía física de la Costa Caribe, una región rezagada en su desarrollo económico en relación al resto del país. En la primera sección se describen las principales características de la geografía física de la Costa Caribe: orografía, ubicación de los principales cuerpos de agua, altitud sobre el nivel del mar, régimen de lluvias y características agro ecológicas de los suelos, así como sus usos actuales y potenciales. Luego se analiza la distribución espacial de la población en el territorio Caribe, con énfasis en la densidad población entre las diferentes subregiones.
Researchers have long recognized the importance of ecological differences at the species level in structuring natural communities yet until recently have often overlooked the influence of intraspecific trait variation, which can profoundly alter community dynamics [1]. Human extraction of living resources can reduce intraspecific trait variation by, for example, causing truncation of age and size structure of populations, where numbers of older individuals decline far more with exploitation than younger individuals. Age truncation can negatively affect population and community stability, increasing variability in population and community biomass [2-6], reducing productivity [7-10] and life-history diversity in traits such as the spatial and temporal pattern of reproduction and migration [4, 11-16]. Here, we quantified the extent of age truncation in 63 fished populations across five ocean regions, as measured by how much the proportions of fish in the oldest age groups declined over time. The proportion of individuals in the oldest age classes decreased significantly in 79% to 97% of populations (compared to historical or unfished values, respectively), and the magnitude of decline was greater than 90% in 32% to 41% of populations. The pervasiveness and intensity of age truncation indicates that fishing is likely reducing the stability of many marine communities. Our findings suggest that more emphasis should be given to management measures that reduce the impact of fishing on age truncation, including no-take areas, slot limits that prohibit fishing on all except a narrow range of fish sizes, and rotational harvesting.
Traditional ecological knowledge (TEK) is increasingly advocated as a complementary source of information that can potentially be integrated into mainstream science, particularly to help improve fisheries management. However, less attention has been paid to identifying specific areas where the TEK of fishers may confirm or contradict conventional scientific knowledge (CSK); or where TEK may provide new insights for fisheries systems characterized by multi-species and multi-gear usage. We conducted a qualitative exploration of TEK of grouper fishing patterns and compared the findings with an analysis of catch data in order to elucidate the extent of fishing pressure on groupers. We further compared TEK of the ecology and biology of groupers with published CSK to understand the complementarity between the two domains. Data collection methods included structured open-ended questionnaire, semi-structured interviews with key informants, focus group discussions, personal observations and a literature review. Results indicate that TEK complements CSK in terms of catch assessment and the ecology of groupers. TEK provides additional information on fishing gear, specific grouper species caught, habitat use and feeding habits; however, TEK contradicts CSK regarding spawning aggregation behavior. TEK offers new knowledge on environmental threats facing groupers, but fishers lack knowledge on reproductive modes and life history traits (i.e. hermaphroditism and spawning season) of groupers. We conclude that, in a conducive democratic setting based upon mutual respect and trust, TEK can complement conventional science and help to make more informed management decisions for sustainable fishing.
In efforts to protect the world's oceans, the Convention on Biological Diversity has moved the goal of establishing marine protected areas (MPAs) to cover 10% of the ocean from 2012 to 2020. This adjustment suggests that the rush to establish MPAs without proper resources does not resolve conservation problems. In fact, such actions may create a false sense of protection that camouflages degradation of marine ecosystems on regional scales. To exemplify this phenomenon, we reviewed MPA efficacy in the Gulf of California, Mexico, where some 23,300 km2 have been decreed as MPAs. With the exception of Cabo Pulmo National Park, MPAs have not met conservation or sustainability goals. We examined MPA budgets and foundations’ investment in the region and found that funding for management is not the limiting factor in MPA efficacy, although funding for enforcement may be deficient. We conclude that MPAs have failed because of insufficient no-take zones, lack of enforcement, poor governance, and minimal community involvement. We need a new philosophy to implement MPAs to take advantage of the scientific knowledge and monetary investment that have been generated worldwide and ensure that they complement effective fisheries management outside their borders.
Many of the world's most vulnerable and rapidly changing ecosystems are also among the most data-poor, leading to an increased interest in use of local ecological knowledge (LEK) to document long-term environmental change. The integration of multiple knowledge sources for assessing species abundance and distribution has gained traction over the past decade as a growing number of case studies show concordance between LEK and scientific data. This study advances the use of quantitative approaches for synthesizing LEK by presenting a novel application of bootstrapping and statistical modeling to evaluate variance in ecological observations of fisheries practitioners. We developed an historical record of abundance for 22 marine species in Puget Sound, Washington (USA), using LEK, and we quantified variation in perceptions of abundance trends among fishers, divers, and researchers. These individuals differed in aspects of their information environments, which are characterized by how, when, and where an individual has acquired ecological information. Abundance trends derived from interviews suggest that populations of long-lived rockfishes (Sebastes spp.) have been in decline since at least the 1960s and that three rockfishes protected under the Endangered Species Act were perceived as relatively less abundant than other species. Differences in perception of rockfish abundance trends among age groups were consistent with our hypothesis that the reported magnitude of decline in abundance would increase with age, with younger respondents more likely to report high abundance than older individuals across all periods. Temporal patterns in the mean and variance of reported rockfish abundance indices were qualitatively similar between fishers and researchers; however, fishers reported higher indices of abundance than researchers for all but one rockfish species. The two respondent groups reported similar changes in rockfish abundance from the 1940s to 2000s, except for two recreationally valuable species that fishers perceived as having undergone greater declines than perceived by researchers. When aggregated at appropriate spatial-temporal scales and in a culturally appropriate manner, observations of resource users are a valuable source of ecological information. Continued development of creative analytical tools for synthesizing multiple knowledge sources will be essential for advancing the formal use of LEK in assessments of marine species.
A single annual minimum in mean marginal increment ratios during May-August supported the hypothesis that jewfish up to at least age 10 can be aged by counting the opaque marks observed on otolith sections. Male jewfish ranged 3-26 yr old; females, 0-37 yr. Growth was similar for males and females, averaging >100 mm/yr through age 6, then slowing to about 30 mm/yr by age 15, and finally declining to <10 mm/yr after age 25. Observed total length and age data were described well by the following von Bertalanffy growth model: total length (mm) = 2006 (1 - e (-0.126(age(yrs)+0.49))). Jewfish spawned from June through December, with peak activity from July through September. Male jewfish matured when 4-6 yr old; females matured when 6 or 7 yr old. Their relatively slow growth, longevity, and behavioral characteristics, such as the tendency to form spawning aggregations, make jewfish populations highly susceptible to overfishing. -from Authors
Colombia has coasts on both the Atlantic and Pacific Oceans, but its marine fisheries are limited by the relatively small size of commercially important stocks. However, diverse fishery resources have traditionally been exploited by coastal communities, and industrial fisheries have grown in recent years with the intensification of tuna fishing in both oceans. The management of Colombia's fisheries has been hampered by frequent administrative changes, which has notably led to the disappearance of a part of the official landings data. We estimated total fisheries removals (reported plus discards and unreported catches) in the Colombian Atlantic and Pacific Oceans for the period 1950-2006. We used secondary sources of information to estimate missing data, and we estimated subsistence fishing and the unreported by-catches of the shrimp and tuna fisheries. We used available information on seafood prices to estimate the relative economic impact (gross revenues) of the small-scale and industrial sectors for the period 2000-2006. Our results suggest that for the period 1950-2006, the Colombian marine fisheries catches may have been almost twice the landings reported by FAO on behalf of the country (2.8 times higher in the Atlantic; 1.3 times higher in the Pacific). Although the total gross revenues of industrial fisheries were higher than those of the small-scale sector, the latter commanded higher gross revenues in the Atlantic in 2006.
This study reports the distribution, abundance and habitat use of juvenile goliath grouper Epinephelus itajaraalong fringing red mangrove Rhizophora mangleshorelines of the Florida Keys, USA. The species has been protected from fishing in US waters since 1992, after reaching commercial extinction, yet juvenile habitat use remains poorly studied. The aim of this study was
to evaluate the importance of underwater mangrove habitat structure and complexity in determining distribution of juvenile goliath grouper in the Florida Keys. Visual underwater surveys were used to record juvenile presence, abundanceand size. Habitat characteristics as continuous variables (depth,
canopy, overhang and prop root width) and nominal variables (bottom type, sun exposure, shoreline shape and shoreline type) were also recorded. Juveniles aggregated in sites with high structural complexity, soft sediment and eroded shorelines. Well-developed fringing red mangrove shorelines
were the preferred juvenile goliath grouper habitat.
Managing most marine finfisheries to achieve optimum yields is an unattainable dream. Protecting these resources from serious depletion through precautionary management seems the only practical option. But even this is of limited application if we demand scientific data for each managed fishery. There are too few researchers to do the work and, in any event, such research would usually not be cost-effective. Thus, we need not merely precautionary management; we need data-less management.
Generalidades sobre la pesquería y biología de las chernas y meros (Pisces: Serranidae) en el Pacífico colombiano
- Gómez A. E.
Gómez, A. E., & Zapata, L. A. (1999). Generalidades sobre la pesquería y
biología de las chernas y meros (Pisces: Serranidae) en el Pacífico
colombiano. Boletín Científico INPA, 6(1), 227-246.
Groupers of the World: A Field and Market Guide
- M T Craig
- Y J Sadovy De Mitcheson
- P C Heemstra
Craig, M. T., Sadovy de Mitcheson, Y. J., & Heemstra, P. C. (2011). Groupers
of the World: A Field and Market Guide. Grahamstown, South Africa:
NISC (Pty) Ltd.
Epinephelus quinquefasciatus
- B Erisman
Erisman, B. (2011). Epinephelus quinquefasciatus. In IUCN Red List of
Threatened Species v2011.2. Available at http://www.iucnredlist.org.
Accessed on 29 May 2017.
La Voz de los Pescadores de la Costa Atlántica de Guatemala
- W D Heyman
- R T Graham
Heyman, W. D., & Graham, R. T. (2000b). La Voz de los Pescadores de la
Costa Atlántica de Honduras. Tela, Honduras: Prolansate.
The Voice of the Fishermen of Southern Belize
- W D Heyman
- R T Graham
Heyman, W. D., & Graham, R. T. (2000a). The Voice of the Fishermen of
Southern Belize. Punta Gorda, Belize: Toledo Institute for Development
and Environment (TIDE) & Trinational Alliance for the Gulf of Honduras
(TRIGOH).
Libro rojo de peces marinos de Colombia
- G A Castellanos-Galindo
- R Baos
- L A Zapata
Castellanos-Galindo, G. A., Baos, R., & Zapata, L. A. (2017). Epinephelus
quinquefasciatus. In L. V. Chasqui, F. A. Polanco, P. A. Acero, P. A.
Mejía-Falla, A. Navia, L. A. Zapata, & J. P. Caldas (Eds.), Libro rojo de
peces marinos de Colombia (pp. 432-436). Santa Marta, Colombia:
Instituto de Investigaciones Marinas y Costeras INVEMAR, Ministerio
de Ambiente y Desarrollo Sostenible.
Groupers of the World
- P. C. Heemstra
- J. E. Randall
Libro rojo de peces marinos de Colombia. La serie Libros Rojos de Especies Amenazadas de Colombia
- L Mejía
- A Acero
Mejía, L., & Acero, A. (2002). Libro rojo de peces marinos de Colombia. La serie
Libros Rojos de Especies Amenazadas de Colombia. Bogotá, Colombia:
INVEMAR, Instituto de Ciencias Naturales -Universidad Nacional de
Colombia, and Ministerio del Medio Ambiente.
Colombia, Pacífico, Tomo II. Proyecto Biopacífico
- F. Pereira-Velásquez
Escalafón de la competitividad de los departamentos de Colombia
- J J C Ramírez
- P , J M De Aguas
Ramírez, J. J. C., & de Aguas, P.,. J. M. (2015). Escalafón de la competitividad
de los departamentos de Colombia 2015. Santiago de Chile, Chile: CEPAL
Naciones Unidas.
- Y Sadovy
- A Eklund
Sadovy, Y., & Eklund, A. (1999). Synopsis of Biological Data on the Nassau
Grouper, Ephinephelus striatus, and the Jewfish, E. itajara. NOAA
Technical Report. Seattle, Washington, USA: University of California
Libraries.
Complementarity of fishers' traditional ecological knowledge and conventional science: Contributions to the management of groupers (Epinephelinae) fisheries around Mafia Island
- L Gaspari
- I Bryceson
- K Kulindwa
Gaspari, L., Bryceson, I., & Kulindwa, K. (2015). Complementarity of fishers'
traditional ecological knowledge and conventional science:
Contributions to the management of groupers (Epinephelinae)
fisheries around Mafia Island, Tanzania. Ocean & Coastal Management,
114, 88-101.
- P C Heemstra
- J E Randall
Heemstra, P. C., & Randall, J. E. (1993). Groupers of the World (Vol. 16).
La pesca en el Pacífico
- F Pereira-Velásquez
- Colombia
- Pacífico
- I I Tomo
- Proyecto
- Biopacífico
Pereira-Velásquez, F. (1993). La pesca en el Pacífico. In P. Leyva (Ed.),
Colombia, Pacífico, Tomo II. Proyecto Biopacífico. Santa Fe de Bogotá,
Colombia: Fondo para la Protección del Medio Ambiente, FEN.