Article

The Design, Production and Validation of the Biological and Structural Performance of an Ecologically Engineered Concrete Block Mattress – A Nature Inclusive Design for Shoreline and Offshore construction

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  • ECOncrete
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Abstract

Over the past decade, the scientific community has studied, experimented, and published a notable body of literature on ecological enhancement of coastal and marine infrastructure (CMI). The Nature‐Inclusive Design (NID) approach refers to methods and technologies that can be integrated into the design and construction of CMI to create suitable habitat for native species (or communities) whose natural habitat has been degraded or reduced. To examine the compliance of new environmentally sensitive technologies with structural requirements and fiscal restraints, while providing ecosystem and habitat value, this paper presents the findings of a structural‐economical‐biological analysis of ecologically engineered Articulated Concrete Block Mattresses (ACBM). To evaluate the structural and biological performance of the ECO ACBM's, a pilot project was deployed in April 2017 at Port Everglades, FL, USA and evaluated against controls of adjacent artificial structures and smooth‐surface concrete blocks and monitored over a period of 2 years. The elements of ecological enhancement implemented in the fabrication and design of the ecologically enhanced ACBM’s were comprised of bio‐enhancing concrete additives and science‐based designs. Based on the results of this study, these design alterations have increased the richness and diversity of sessile assemblages compared to control blocks and adjacent artificial structures, and supported a higher abundance of mobile species. This ecological improvement was achieved within the operational limitations of conventional manufacturing and installation technologies, while complying with strict structural requirements for standard concrete marine construction. The results supported the working hypothesis, and demonstrated that modifications of concrete composition, surface texture, and macro‐design, have the potential to elevate the ecological value of concrete‐based CMI and promote a more sustainable and adaptive approach to coastal and marine development in an era of climate resilience building. This article is protected by copyright. All rights reserved.

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... Eco-engineering research -which seeks to integrate ecological and engineering principals for the benefit of humans and the environment -has received considerable attention in the last decade. Innovative construction materials (Margheritini et al., 2021;Sella et al., 2022) and design options have been investigated for a range of marine infrastructure, including artificial reefs, wind and wave power foundations and coastal defence structures (e.g. breakwater walls) (Firth et al., 2016a;Dafforn et al., 2015;Airoldi et al., 2020;Mitsch, 2012;Sutton-Grier et al., 2015;Langhamer and Wilhelmsson, 2009), with coastal defence structures attracting most of the eco-engineering efforts (Chapman and Underwood, 2011;Temmerman et al., 2013;Morris et al., 2018). ...
... A growing body of literature has focused on methods for modifying concrete-based marine infrastructure to support ecological targets (Sella et al., 2022;Firth et al., 2016a;Perkol-Finkel and Sella, 2014;Sella et al., 2018;Margheritini et al., 2021). Recent studies have targeted modifications of the composition of the concrete material (e.g. ...
... bio-enhanced concrete [for example, Econcrete Pty Ltd], marine concrete), development and enhancement of Low-Voltage Mineral Deposition technology (e.g. Biorock), High-Voltage Mineral Deposition technology and the design of concrete-based marine infrastructures, in order to enhance natural biological assemblages developing on the structures (Sella et al., 2022;Perkol-Finkel and Sella, 2014;Margheritini et al., 2021). Despite extended efforts, data gaps still exist, with no consensus reached on the most suitable artificial material to construct marine infrastructure. ...
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Man-made submerged structures, including shipwrecks, offering substrata for fouling organisms and fish, have been classified secondarily as artificial reefs (ARs). The current approach in AR design is that of low-profile structures placed on the seabed and attempting to mimic natural reef (NR) communities with the aim of mitigating degraded marine ecosystems. To examine the validity of this concept, a long-term comparison of the developing AR fouling communities to those of nearby NRs is required. A survey of the fouling reefal organisms was conducted on seven shipwrecks (Red Sea, Egypt), comprising three young (ca 20 years old) and four old (>100 years old) unplanned ARs, in comparison to nearby NR communities. The hypothesis tested was that the age of the ARs shapes the structure of their fouling coral communities. The results demonstrated distinct differences between ARs and NRs and between young and old ARs. While the species composition on ARs may resemble that of NRs after approximately 20 years, obtaining a similar extent of coral cover may require a full century. Moreover, differences in structural features between ARs and NRs may lead to differences in species composition that persist even after 100 years.
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Urban and periurban ocean developments impact 1.5% of the global exclusive economic zones, and the demand for ocean space and resources is increasing. As we strive for a more sustainable future, it is imperative that we better design, manage, and conserve urban ocean spaces for both humans and nature. We identify three key objectives for more sustainable urban oceans: reduction of urban pressures, protection and restoration of ocean ecosystems, and support of critical ecosystem services. We describe an array of emerging evidence-based approaches, including greening gray infrastructure, restoring habitats, and developing biotechnologies. We then explore new economic instruments and incentives for supporting these new approaches and evaluate their feasibility in delivering these objectives. Several of these tools have the potential to help bring nature back to the urban ocean while also addressing some of the critical needs of urban societies, such as climate adaptation, seafood production, clean water, and recreation, providing both human and environmental benefits in some of our most impacted ocean spaces. Expected final online publication date for the Annual Review of Marine Science, Volume 13 is January 3, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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There is worldwide concern about the environmental costs of conventional intensification of agriculture. Growing evidence suggests that ecological intensification of mainstream farming can safeguard food production, with accompanying environmental benefits; however, the approach is rarely adopted by farmers. Our review of the evidence for replacing external inputs with ecosystem services shows that scientists tend to focus on processes (e.g., pollination) rather than outcomes (e.g., profits), and express benefits at spatio-temporal scales that are not always relevant to farmers. This results in mismatches in perceived benefits of ecological intensification between scientists and farmers, which hinders its uptake. We provide recommendations for overcoming these mismatches and highlight important additional factors driving uptake of nature-based management practices, such as social acceptability of farming.
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Artificial structures are proliferating in the marine environment, resulting in 'ocean sprawl'. In light of the potential environmental impacts of this, such as habitat loss and alteration, it is becoming increasingly important to incorporate ecologically-sensitive design into artificial marine structures. The principles of eco-engineering and green infrastructure are embedded in urban planning practice for terrestrial and freshwater development projects. In marine planning, however, eco-engineering of blue-green infrastructure remains an emerging concept. This note provides a UK perspective on the progress towards uptake of eco-engineering approaches for enhancing biodiversity on artificial marine structures. We emphasise that, despite a clear 'policy pull' to incorporate biodiversity enhancements in marine structures, a range of proof-of-concept evidence that it is possible to achieve, and strong cross-sectoral stakeholder support, there are still few examples of truly and purposefully-designed blue-green artificial structures in the UK. We discuss the barriers that remain and propose a strategy towards effective implementation. Our strategy outlines a step-wise approach to: (1) strengthening the evidence base for what enhancements can be achieved in different scenarios; (2) improving clarity on the predicted benefits and associated costs of enhancements; (3) packaging the evidence in a useful form to support planning and decision-making; and (4) encouraging implementation as routine practice. Given that ocean sprawl is a growing problem globally, the perspective presented here provides valuable insight and lessons for other nations at their various states of progress towards this same goal.
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Artificial structures will be increasingly utilized to protect coastal infrastructure from sea-level rise and storms associated with climate change. Although it is well documented that the materials comprising artificial structures influence the composition of organisms that use them as habitat, little is known about how these materials may chemically react with changing seawater conditions, and what effects this will have on associated biota. We investigated the effects of ocean warming, acidification, and type of coastal infrastructure material on algal turfs. Seawater acidification resulted in greater covers of turf, though this effect was counteracted by elevated temperatures. Concrete supported a greater cover of turf than granite or high-density polyethylene (HDPE) under all temperature and pH treatments, with the greatest covers occurring under simulated ocean acidification. Furthermore, photosynthetic efficiency under acidification was greater on concrete substratum compared to all other materials and treatment combinations. These results demonstrate the capacity to maximise ecological benefits whilst still meeting local management objectives when engineering coastal defense structures by selecting materials that are appropriate in an ocean change context. Therefore, mitigation efforts to offset impacts from sea-level rise and storms can also be engineered to alter, or even reduce, the effects of climatic change on biological assemblages.
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The effects of climate change and an expanding human population are driving the need for the expansion of coastal and marine infrastructure (CMI), the development of which is introducing hard substrate into the marine environment on a previously unseen scale. Whilst the majority of previous research has focussed on how physical features affect intertidal macrobiotic communities, this study considered the effects of differences in the chemical composition of concrete on subtidal biofilm and macrobiotic communities. Two commonly used cement replacements, pulverised fly ash (PFA) and ground granulated blast-furnace slag (GGBS), were used in a combination of proportions to assess how concrete tiles with differing surface chemistries affect development of early successional stages of marine biofouling communities. Controlled leaching experiments showed that although total metal leaching varied considerably between tile type, tiles containing GGBS resulted in statistically lower amounts of metal released compared with tiles containing PFA. Concrete treatment had no effect on the percentage cover or richness of diatoms, but there were significant increases in both over the duration of the experiment. Concrete treatments containing GGBS had a lower richness of native macro-fouling species compared to the control, but there was no significant difference in non-native species richness among treatments. Results suggest that different components can be used to alter the surface chemistry of concrete to further enhance the ecological value of CMI more than physical features can achieve alone.
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Sedentary and mobile organisms grow profusely on hard substrates within the coastal zone and contribute to the deterioration of coastal engineering structures and the geomorphic evolution of rocky shores by both enhancing and retarding weathering and erosion. There is a lack of quantitative evidence for the direction and magnitude of these effects. This study assesses the influence of globally-abundant intertidal organisms, barnacles, by measuring the response of limestone, granite and marine-grade concrete colonised with varying percentage covers of Chthamalus spp. under simulated, temperate intertidal conditions. Temperature regimes at 5 and 10 mm below the surface of each material demonstrated a consistent and statistically significant negative relationship between barnacle abundance and indicators of thermal breakdown. With a 95% cover of barnacles, subsurface peak temperatures were reduced by 1.59 °C for limestone, 5.54 °C for concrete and 5.97 °C for granite in comparison to no barnacle cover. The amplitudes of short-term (15–30 min) thermal fluctuations conducive to breakdown via 'fatigue' effects were also buffered by 0.70 °C in limestone, 1.50 °C in concrete and 1.63 °C in granite. Furthermore, concentrations of potentially damaging salt ions were consistently lower under barnacles in limestone and concrete. These results indicate that barnacles do not enhance, but likely reduce rates of mechanical breakdown on rock and concrete by buffering near-surface thermal cycling and reducing salt ion ingress. In these ways, we highlight the potential role of barnacles as agents of bioprotection. These findings support growing international efforts to enhance the ecological value of hard coastal structures by facilitating their colonisation (where appropriate) through design interventions.
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Aquatic ecosystems are degraded by a variety of pressures as a result of the growing human population. Global-scale impacts include homogenization of biological communities, removal of top predators and ecosystem engineers, chemical pollution by excess nutrients and contaminants as well as deteriorating structural diversity, connectivity and process dynamics. There is a pressing societal need to reverse the decline in biodiversity and replace lost ecosystem functioning and services in aquatic ecosystems by enabling natural recovery or by active restoration. Common concepts and approaches for conservation, recovery and restoration in freshwater and marine ecosystems, aided by recent advances in ecological theory, include decision criteria on priorities for conservation, harnessing natural recovery by cessation of impacts, restoring connectivity and meso-habitat diversity as well as the geomorphological structural template including hydrodynamic processes. Re-oligotrophication at catchment or regional sea-scale benefits from integrating freshwater and marine restoration. Species or assemblages that convey biogenic structure or act as ecosystem engineers and keystone species should be given priority. Top-down control can be reinstated in closed systems. Differences between freshwater and marine ecosystems include the greater spatial restriction of many species in fresh water, the importance of rooted vegetation and insects in freshwater, and the much greater dispersal and connectivity in marine systems. These differences dictate different approaches, with more scope for active restoration work in fresh water and harnessing natural recovery in marine systems. Restoration schemes need clearly defined target states. They should generally take a process-oriented and stepwise adaptive management approach judging success against reference or control sites. Societal and political expectations need to be managed and restoration schemes should not promise too much. Even minor rehabilitation of degraded ecosystems can put back some biodiversity and key services. Sometimes ´Ersatz´-ecosystems are better than nothing and the best that can be achieved, especially in urban settings. Copyright
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Owing to a combination of increase in coastal population and processes related to global climate change, intense coastal development is inevitable. Shallow-water habitats are prone to be replaced by structures such as seawalls and breakwaters. While adding ample hard substrate to the seascape, these structures are not surrogates to natural habitats, and are often associated with nuisance and invasive species. These differences are attributed to design features including high inclination, low complexity and high homogeneity - all atypical of natural habitats. To date, coastal infrastructure has been designed with limited consideration to marine life developing on it. Consequently, its ability to provide ecosystem services similar to those offered by natural habitats has been severely compromised. This paper presents two case studies implementing ecological enhancement at the Brooklyn Bride Park waterfront. Both strategies are examples for restoring viable ecosystem services while also serving structural and societal goals. The first is an example of structural repairs of aging pier piles, by applying innovative technology of ecological concrete encasement which creates valuable habitat. The second is an example of boosting the ecological performance of a constructed riprap waterfront, by integrating precast tide-pools that add water-retaining habitat features lacking from standard coastal infrastructure.
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The effect of manmade activities is primarily local but can extend far away from the location of intervention. This underlines the importance of establishing coastal zone management plans covering large stretches of coastlines. In recent years, interest in Low Crested Structures (coastal defence structures with a low-crest) has been growing together with awareness of the sensitivity to environmental impacts produced by coastal defences. The relation between wave climate, beach erosion, beach defence means, habitat changes and beach value, which clearly exists based on EC research results, suggests the necessity of an integrated approach when designing coastal protection schemes. In accordance with this need, the present design guidelines cover structure stability and construction problems, hydro and morphodynamic effects, environmental effects (colonisation of the structure and water quality), societal and economic impacts (recreational benefits, swimming safety, beach quality). Environmental Design Guidelines for Low Crested Structuresis specifically dedicated to Low Crested Structures, and provides methodological tools both for the engineering design of structures and for the prediction of performance and environmental impacts of such structures. A briefing of current best practice for local and national planning authorities, statutory agencies and other stakeholders in the coastal zone is also covered. Presented in a generic way, this book is appropriate throughout the European Union, taking into account current European Commission policy and directives for the promotion of sustainable development and integrated coastal zone management. * Shows the reader how to perform an integrated design of coastal defence schemes * Presents latest insights on hydro-morphodynamics induced by structures * Provides directly applicable tools for the design of low crested structures * Highlights socio-economic perspectives in coastal defence design.
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Complexity is well accepted as one of the primary drivers of biodiversity, however, empirical support for such positive associations is often confounded with surface area and undermined by other potential explanatory factors, especially the type of structural component (e.g., pits, crevices, overhangs, etc.). In the present study, sample units (artificial substrates) of equal surface area (±0.2%) were used to simultaneously examine the independent effects of complexity and different structural component types on species richness (S), abundance (N), and community composition. We created simple and complex concrete substrates of four different geometric designs using novel software. The substrates (n = 8) were mounted onto granite seawalls (at two tidal heights) on two islands south of Singapore Island. After 13 months of colonization, all 384 tiles were collected and their assemblages compared. A total of 53 744 individuals of 70 species/morphospecies were collected and identified. Our results show that greater complexity can support greater species richness and different communities that are independent of surface area. Furthermore, the type of structure (e.g., "pits," "grooves," "towers") can have an effect on richness and community composition that is independent of complexity.
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Concrete based coastal and marine infrastructure (CMI) such as ports, piers, industrial facilities and coastal defense elements dominate coastal zones world-wide. Coastal hardening replaces natural habitats with urban/industrial waterfronts that cannot provide ecosystem services similar to those offered by undisturbed coastlines. As a result, CMI are often considered as sacrificed zones with no environmental value. Studies show that marine flora and fauna on CMI, is typically less diverse than natural assemblages, and is commonly dominated by nuisance and invasive species. Here we summarize the results of a 24 month monitoring study of a breakwater section (Haifa, Israel) composed of armor unites cast from a proprietary concrete mix with an ecological design (ECOncrete® Antifers – EA). The study compared benthic community structure (fish, invertebrates and algae), species richness, live cover, diversity and the ratio of invasive to local species, on EA to that of an adjacent breakwater section made of standard Antifers (SA) composed of Portland based concrete. The abundance, richness and diversity of invertebrates and fish were higher on and around the EA compared to SA, while the ratio of invasive to local species was considerably lower. Moreover, engineering species such as oysters, serpulid worms, bryozoans and coralline algae were more dominant on the EA than on the SA. These ecosystem engineers increase the complexity of the structure, by means of biogenic buildup, which increase the availability of food and shelter in the area, while potentially contributing to the structures stability and longevity via bioprotection. The study indicates the ability of design substrate alterations to facilitate competition for space between local and invasive species on CMI, and demonstrates the feasibility of applying environmentally sensitive technologies for enhancing the biological and ecological performance of structures like breakwaters, piers, and seawalls. Ecological enhancement of concrete based CMI increases the ecosystem services provided by the structure, without hampering its structural performance, and thus should be integrated into future coastal development projects, preferably and most efficiently from early planning stages.
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Interactions between organisms are a major determinant of the distribution and abundance of species. Ecology textbooks (e.g., Ricklefs 1984, Krebs 1985, Begon et al. 1990) summarise these important interactions as intra- and interspecific competition for abiotic and biotic resources, predation, parasitism and mutualism. Conspicuously lacking from the list of key processes in most text books is the role that many organisms play in the creation, modification and maintenance of habitats. These activities do not involve direct trophic interactions between species, but they are nevertheless important and common. The ecological literature is rich in examples of habitat modification by organisms, some of which have been extensively studied (e.g. Thayer 1979, Naiman et al. 1988).
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Reinforced concrete (RC) structures in marine environments are generally affected by harsh marine environmental actions, resulting in early performance degradation mainly due to chloride-induced deterioration. In such conditions, corrosion of rebar progresses rapidly, and also the cross-sectional area of rebar is reduced and consequently structural performance of RC structures will be degraded. In contrast, the surface of concrete structures is often covered with many marine sessile organisms under marine tidal and submerged conditions. These marine sessile organisms have been empirically known to enhance the durability of concrete though the effectiveness is not appropriately evaluated. This paper describes the long-term resistance of concrete with marine sessile organisms to chloride ion penetration in concrete. The effect and its sustainability of marine sessile organisms on chloride ion penetration in concrete were investigated through field exposure tests and laboratory tests. From the test results, the basal membrane, which is a matrix of marine sessile organisms, adheres to concrete strongly on a long-term basis though some gaps between concrete and the basal membrane can be observed. In addition, experimental results and simplified simulation clarified that the attachment of marine sessile organisms can enhance the long-term resistance of concrete to chloride ion penetration.
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Underwater cities have long been the subject of science fiction novels and movies, but the "urban sprawl" of artificial structures being developed in marine environments has widespread ecological consequences. The practice of combining ecological principles with the planning, design, and operation of marine artificial structures is gaining in popularity, and examples of successful engineering applications are accumulating. Here we use case studies to explore marine ecological engineering in practice, and introduce a conceptual framework for designing artificial structures with multiple functions. The rate of marine urbanization will almost certainly escalate as "aquatourism" drives the development of underwater accommodations. We show that current and future marine developments could be designed to reduce negative ecological impacts while promoting ecosystem services.
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Acting on the perception that they perform better for longer, most property owners in the United States choose hard engineered structures, such as bulkheads or riprap revetments, to protect estuarine shorelines from erosion. Less intrusive alternatives, specifically marsh plantings with and without sills, have the potential to better sustain marsh habitat and support its ecosystem services, yet their shoreline protection capabilities during storms have not been evaluated. In this study, the performances of alternative shoreline protection approaches during Hurricane Irene (Category 1 storm) were compared by 1) classifying resultant damage to shorelines with different types of shoreline protection in three NC coastal regions after Irene; and 2) quantifying shoreline erosion at marshes with and without sills in one NC region by using repeated measurements of marsh surface elevation and marsh vegetation stem density before and after Irene. In the central Outer Banks, NC, where the strongest sustained winds blew across the longest fetch; Irene damaged 76% of bulkheads surveyed, while no damage to other shoreline protection options was detected. Across marsh sites within 25 km of its landfall, Hurricane Irene had no effect on marsh surface elevations behind sills or along marsh shorelines without sills. Although Irene temporarily reduced marsh vegetation density at sites with and without sills, vegetation recovered to pre-hurricane levels within a year. Storm responses suggest that marshes with and without sills are more durable and may protect shorelines from erosion better than the bulkheads in a Category 1 storm. This study is the first to provide data on the shoreline protection capabilities of marshes with and without sills relative to bulkheads during a substantial storm event, and to articulate a research framework to assist in the development of comprehensive policies for climate change adaptation and sustainable management of estuarine shorelines and resources in U.S. and globally.
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Studies on carbon stock in salt marsh sediments have increased since the review by Chmura et al. (2003). However, uncertainties exist in estimating global carbon stor-age in these vulnerable coastal habitats, thus hindering the as-sessment of their importance. Combining direct data and in-direct estimation, this study compiled studies involving 143 sites across the Southern and Northern hemispheres, and pro-vides an updated estimate of the global average carbon ac-cumulation rate (CAR) at 244.7 g C m −2 yr −1 in salt marsh sediments. Based on region-specific CAR and estimates of salt marsh area in various geographic regions between 40 • S to 69.7 • N, total CAR in global salt marsh sediments is esti-mated at ∼10.2 Tg C yr −1 . Latitude, tidal range and elevation appear to be important drivers for CAR of salt marsh sedi-ments, with considerable variation among different biogeo-graphic regions. The data indicate that while the capacity for carbon sequestration by salt marsh sediments ranked the first amongst coastal wetland and forested terrestrial ecosystems, their carbon budget was the smallest due to their limited and declining global areal extent. However, some uncertainties remain for our global estimate owing to limited data avail-ability.
Article
As well as their destructive roles, plants, animals and microorganisms contribute to geomorphology and ecology via direct and indirect bioprotection, which can reduce weathering and erosion. For example, indirect bioprotection can operate via biotic influences on microclimate whereby physical decay processes associated with fluctuations in temperature and moisture (salt crystallization, thermal fatigue and wetting-drying), are limited. In the intertidal zone, the spatial and temporal distribution of macroalgae (seaweeds) is patchy, related to physical and ecological conditions for colonization and growth, and the nature and frequency of natural and anthropogenic disturbance. We examined the influence of seaweed canopies (Fucus spp.) on near-surface microclimate and, by implication, on conditions for mechanical rock decay and under-canopy ecology. Monitoring on hard artificial coastal structures in South West England, UK, built from limestone and concrete showed that both the range and maxima of daily summertime temperatures were significantly lower, by an average of 56% and 25%, respectively, in areas colonized by seaweed compared to experimentally cleared areas. Short-term microclimatic variability (minutes-hours) was also significantly reduced, by an average of 78% for temperature and 71% for humidity, under algal canopies during low-tide events. Using seaweed as an example, we develop a conceptual model of the relationship between biological cover and microclimate in the intertidal zone. Disturbance events that remove or drastically reduce seaweed cover mediate shifts between relatively stable and unstable states with respect to mechanical decay and ecological stress associated with heat and desiccation. In urban coastal environments where disturbance may be frequent, facilitating the establishment and recovery of canopy-forming species on rocks and engineered structures could enhance the durability of construction materials as well as support conservation, planning and policy targets for biodiversity enhancement.
Article
Urbanisation is recognised as a major pressure on coastal biodiversity. Increasing risks of flooding and erosion associated with future climate change indicate that new hard infrastructure will have to continue to be built – and existing structures upgraded – in areas of high social and economic value. Ecological enhancement involves undertaking management interventions at the design stage to improve the ecological potential of these structures, or to improve the ecological value of existing structures. Whilst scientific research into ecological enhancement methods and designs is growing, there has been limited discussion of the non-science drivers and mechanisms by which ecological enhancements can be successfully implemented in coastal infrastructure projects.We explore the science–policy–practice interfaces of the ecological enhancement of hard coastal structures from three perspectives. First, we outline the growing number of European and UK policies and legislative instruments that are increasing the need to consider ecological enhancement in coastal developments. These serve as a facilitative tool for making enhancement projects happen, constituting a significant ‘policy push’ for research and application in this area. Second, we examine the role of people in influencing the uptake of ecological enhancements. The critical role of ‘knowledge brokers’ and the need for effective and sustained collaboration between a range of groups and individuals to get research approved operational trials off the ground is discussed. Third, we examine where in the typical planning, design and build process current enhancement projects have been embedded, serving to illustrate how the science can be used in practice.
Article
Ecological engineering, defined as the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both, has developed over the last 30 years, and rapidly over the last 10 years. Its goals include the restoration of ecosystems that have been substantially disturbed by human activities and the development of new sustainable ecosystems that have both human and ecological values. It is especially needed as conventional energy sources diminish and amplification of nature's ecosystem services is needed even more. There are now several universities developing academic programs or departments called ecological engineering, ecological restoration, or similar terms, the number of manuscripts submitted to the journal Ecological Engineering continue to increase at an rapid rate, and the U.S. National Science Foundation now has a specific research focus area called ecological engineering. There are many private firms now developing and even prospering that are now specializing in the restoration of streams, rivers, lakes, forests, grasslands, and wetlands, the rehabilitation of minelands and urban brownfields, and the creation of treatment wetlands and phytoremediation sites. It appears that the perfect synchronization of academy, publishing, research resources, and practice is beginning to develop. Yet the field still does not have a formal accreditation in engineering and receives guarded acceptance in the university system and workplace alike.
Article
Shedding light on the ability of benthic artificial reef (AR) communities to resemble those of a natural reef (NR) is of great importance if we are to harness ARs as tools for rehabilitation and restoration of degraded marine habitats. Studying recruitment processes to experimental settlement plates attached to ARs and NRs reveal the factors that shape community structure at the two reef types, and determine the ability of an AR to support communities similar to those found in adjacent natural habitats. In this study, conducted in Eilat (Red Sea), we used settlement plates to test the hypothesis that differences in benthic communities between ARs and NRs are derived from differential recruitment processes. A monitoring period of 18 months revealed great differences in the recruitment of corals and other benthic communities between the studied ARs and adjacent NRs. The ARs were either made of PVC or metal and 10–17 years old when the study commenced. The recruitment of soft corals reflected the species assemblage found in the area, consisting mainly of the family Nephtheidae and Xeniidae, species, while that of stony corals was mostly determined by the life history traits of the recruited taxa, e.g., the opportunistic nature of the family Pocilloporidae. Benthic organisms, mainly filter feeders like bryozoans, bivalves, sponges and tunicates, were more abundant at the ARs than at the NRs, mainly on the underside of the plates. We suggest that this differential recruitment resulted from a synergistic effect of abiotic and biotic factors, including current regime, sedimentation load and larval settlement preferences, which subsequently differentiated the composition of the benthic communities at the ARs and NRs. Thus, in order to construct an AR for restoration purposes, it must offer similar structural features to those found in the natural surrounding, leading to recruitment of local taxa. However, if the AR and NR will differ structurally, the composition of recruits will also differ and eventually the communities at the two reef types will become distinct, hereby increasing the species diversity in the area.