The presence of plastic marine debris in our oceans has emerged rapidly in the last few years as an environmental impact urgently in need of attention, and plastic will be a pollutant of concern for the foreseeable future. Concerns have been raised about possible adverse health impacts as a result of microplastic ingestion by marine wildlife as well as human seafood consumers, yet there is very little data to inform appropriate management actions and consumer advice. Now is the time to consider the best strategic choices for the research, management and outreach needed to address priority issues around microplastics. It is essential to treat marine plastic pollution not only as an area in need of comprehensive research and waste management solutions, but also as a permanent pollutant in order to formulate management responses similar to those for other pollutants. First, it is essential to consider developing monitoring protocols to gather important baseline information about microplastics to inform management responses. Second, targeted research is needed to identify differences in microplastic accumulation among selected species and fisheries. Third, research is needed to explore potential threshold levels of microplastics in seafood that could trigger management actions or consumer advisories. Finally, a range of model management practices to address microplastics should be considered, such as regulating inputs from wastewater, assessing what consumer advisories are needed, and taking into account localized inputs from gear used in seafood harvesting and cultivation.
Fishery improvement projects (FIPs) are emerging as a popular market‐based means to improve fisheries sustainability and have been employed in scores of fisheries around the world; however, project ability to realize improvements has been highly variable, and little is known about how fishery and project conditions affect improvement efforts. In order to evaluate the effectiveness of the FIP model as a tool for improving diverse fisheries around the world, we compile a unique dataset of social, ecological and economic characteristics for over 60 FIPs globally, which we use to identify key attributes correlated with improvements in fishing practices, management and/or on‐the‐water outcomes. Using a random forest classifier, we identify three important attributes related to FIP effectiveness in demonstrating improvements. Specifically, FIPs are more likely to have achieved improvements with increased cumulative project time, when regional‐level management arrangements are present and when the target species has a moderate inherent vulnerability to fishing. Interestingly, improvements were not correlated with a number of expected features, including a fishery's socio‐economic setting or baseline performance against the desired sustainability standard (e.g. the Marine Stewardship Council fisheries standard). This study improves our understanding of factors related to FIP effectiveness in improving fisheries practices and management and provides key insights for practitioners into important attributes to consider when implementing the FIP model to promote fisheries sustainability.
Indicators are effective tools for summarizing and communicating key aspects of ecosystem state and have a long record of use in marine pollution and fisheries management. The application of biodiversity indicators to assess the status of species, habitats, and functional diversity in marine conservation and policy, however, is still developing and multiple indicator roles and features are emerging. For example, some operational biodiversity indicators trigger management action when a threshold is reached, while others play an interpretive, or surveillance, role in informing management. Links between biodiversity indicators and the pressures affecting them are frequently unclear as links can be obscured by environmental change, data limitations, food web dynamics, or the cumulative effects of multiple pressures. In practice, the application of biodiversity indicators to meet marine conservation policy and management demands is developing rapidly in the management realm, with a lag before academic publication detailing indicator development. Making best use of biodiversity indicators depends on sharing and synthesizing cutting-edge knowledge and experience. Using lessons learned from the application of biodiversity indicators in policy and management from around the globe, we define the concept of ‘biodiversity indicators,’ explore barriers to their use and potential solutions, and outline strategies for their effective communication to decision-makers.
We revisit the challenges and prospects for ocean circulation models following Griffies et al. (2010). Over the past decade, ocean circulation models evolved through improved understanding, numerics, spatial discretization, grid configurations, parameterizations, data assimilation, environmental monitoring, and process-level observations and modeling. Important large scale applications over the last decade are simulations of the Southern Ocean, the Meridional Overturning Circulation and its variability, and regional sea level change. Submesoscale variability is now routinely resolved in process models and permitted in a few global models, and submesoscale effects are parameterized in most global models. The scales where nonhydrostatic effects become important are beginning to be resolved in regional and process models. Coupling to sea ice, ice shelves, and high-resolution atmospheric models has stimulated new ideas and driven improvements in numerics. Observations have provided insight into turbulence and mixing around the globe and its consequences are assessed through perturbed physics models. Relatedly, parameterizations of the mixing and overturning processes in boundary layers and the ocean interior have improved. New diagnostics being used for evaluating models alongside present and novel observations are briefly referenced. The overall goal is summarizing new developments in ocean modeling, including: how new and existing observations can be used, what modeling challenges remain, and how simulations can be used to support observations.
There is a growing impetus to increase marine protected areas coverage globally from 6% to 30% in 2030. Successfully establishing and maintaining marine protected areas require incorporating public preferences into their establishment and management. We investigate the role of alternate management regimes (top-down and bottom-up) on preferences for marine protected areas and the marginal rate of substitution between natural and man-made capital using a case study in the Asia-Pacific region of Okinawa, Japan. We implemented a choice experiment survey to infer which attributes of marine protected areas are most important for the respondents. We use our survey results to calculate respondents’ willingness to support marine protected areas in Okinawa. This study contributes to the policy debate on management of marine protected areas with empirical data that characterizes the perception of Okinawan residents with respect to the role of local coastal communities (bottom-up) compared to central government based agencies (top-down) management. We extend the analysis and estimate the trade-offs to residents in Okinawa between natural capital (i.e. coral coverage and marine biodiversity attribute) and man-made capital (i.e. restrictions on coastal development). We find that the underlying management regime affects the local residents’ valuation of the marine protected area with residents showing a higher willingness to support bottom-up management regimes. There is also substantial differences in the willingness to support different characteristics of marine protected areas by management type. Finally, we find that the marginal rate of substitution between natural capital and man-made capital varies by management type such that residents would need to be compensated relatively less in terms of man-made capital in the presence of a policy scenario that proposes an increase in natural capital under a bottom-up management regime.
Scotland's National Marine Plan (NMP) consists of various objectives and policies which aim to support sustainable development within the marine environment while upholding the integrity of the ecosystem through the adoption of an ‘ecosystem approach to planning’. While this approach is not new, momentum has been gaining in research for accounting for the relationships between physical, chemical, and biological elements, functions, and processes of an ecosystem in marine spatial planning. Given that the NMP is under statutory review in 2017–2018 following three years since its publication, the outputs of this paper aim to inform the review by exploring how national and sectoral objectives and policies address ecosystem service sections and phases by using the UK National Ecosystem Assessment classification system as a reference. The analysis demonstrates that cultural benefits are the most accounted for, while the cultural final services which underpin such benefits are the least accounted for. Furthermore, there are no national objectives or policies which account for provisioning final services. The paper provides 12 distinct policy recommendations to enhance the uniformity of ecosystem services in the NMP.
Ecosystem service (ES) trade-offs have been broadly recognized and studied over the past decade. However, how to coordinate the relationships among ES trade-offs to achieve win–win outcomes remains a considerable challenge for decision makers. Here, we summarize the current approaches applied to minimize ES trade-offs for win–wins and analyze the trade-offs among different ESs and their drivers. Based on a systematic review of the literature from 2005 to 2018, we identified 170 potentially relevant articles, 47 of which were selected for the review, recording 70 actual or potential trade-offs. Analysis of these case studies showed that trade-off pairs between provisioning services and regulating services/biodiversity accounted for 80% of total pairs. Furthermore, more than half of the ES trade-offs were driven by land use/land cover changes. Harvest and resource demand, natural resource management, and policy instruments were also among the main drivers. Four approaches to coordinate ES trade-offs were identified, including ecosystem, landscape-scale, multi-objective optimization, and policy intervention (and other) approaches. Based on the above, we recommend a rigorous understanding of the roles of different stakeholders, spatial scales of management, trade-off dynamics, and integrated implementation of diverse approaches to coordinate ES trade-offs in order to better achieve win–win outcomes.
In Southwest Florida, a variety of human impacts had caused widespread losses of seagrass coverage from historical conditions. St. Joseph Sound and Clearwater Harbor lost approximately 24 and 51%, respectively, of their seagrass coverage between 1950 and 1999, while Tampa Bay and Sarasota Bay had lost 46% and 15%, respectively, of their seagrass coverage between 1950 and the 1980s. However, over the period of 1999 to 2016, the largest of the six estuaries, Tampa Bay, added 408 ha of seagrass per year, while the remaining five estuaries examined in this paper added approximately 269 ha per year. In total, seagrass coverage in these six estuaries increased 12,171 ha between the 1980s and 2016. Focused resource management plans have held the line on nitrogen loads from non-point sources, allowing seagrass resources to expand in response to reductions in point source loads that have been implemented over the past few decades.
The global ocean has warmed substantially over the past century, with far-reaching implications for marine ecosystems1. Concurrent with long-term persistent warming, discrete periods of extreme regional ocean warming (marine heatwaves, MHWs) have increased in frequency2. Here we quantify trends and attributes of MHWs across all ocean basins and examine their biological impacts from species to ecosystems. Multiple regions in the Pacific, Atlantic and Indian Oceans are particularly vulnerable to MHW intensification, due to the co-existence of high levels of biodiversity, a prevalence of species found at their warm range edges or concurrent non-climatic human impacts. The physical attributes of prominent MHWs varied considerably, but all had deleterious impacts across a range of biological processes and taxa, including critical foundation species (corals, seagrasses and kelps). MHWs, which will probably intensify with anthropogenic climate change3, are rapidly emerging as forceful agents of disturbance with the capacity to restructure entire ecosystems and disrupt the provision of ecological goods and services in coming decades.
Understanding how no-take zones (NTZs) shape the population dynamics of key herbivores is crucial for the conservation and management of temperate benthic communities. Here, we examine the recovery patterns of sea urchin populations following a high-intensity storm under contrasting protection regimes in the NW Mediterranean Sea. We found significant differences in the recovery trends of Paracentrotus lividus abundance and biomass in the five years following the storm. The P. lividus populations outside the NTZ recovered faster than the populations inside the NTZ, revealing that predation was the main factor controlling the sea urchin populations inside the NTZ during the study period. Arbacia lixula reached the highest abundance and biomass values ever observed outside the NTZ in 2016. Our findings reveal that predation can control the establishment of new sea urchin populations and emphasize top-down control in NTZs, confirming the important role of fully protected areas in the structure of benthic communities.
Shallow coral reefs provide food, income, well-being and coastal protection to countries around the Indian Ocean and Asia. These reefs are under threat due to many anthropogenic stressors including pollution, sedimentation, overfishing, sea surface warming and habitat destruction. Ocean acidification interacts with these factors to exacerbate stress on coral reefs. Effective solutions in tackling the impact of ocean acidification require a thorough understanding of the current adaptive capacity of each nation to deal with the consequences. Here, we aim to help the decision-making process for policy makers in dealing with these future challenges at the regional and national levels. We recommend that a series of evaluations be made to understand the current status of each nation in this region in dealing with ocean acidification impacts by assessing the climate policy, education, policy coherence, related research activities, adaptive capacity of reef-dependent economic sectors and local management. Indonesia and Thailand, are selected as case studies. We also highlight general recommendations on mitigation and adaptation to ocean acidification impacts on coral reefs and propose well-designed research program would be necessary for developing a more targeted policy agenda in this region.
Getting an overall view of primary data available from existing Earth Observation Systems and networks databases for the Mediterranean Sea, the main objective of this paper is to identify temporal and geographic data gaps and to elaborate a new method for providing a prioritisation of missing data useful for end-users that have to pinpoint strategies and models to fill these gaps. Existing data sources have been identified from the analysis of the main projects and information systems available. A new method to perform the data gap analysis has been developed and applied to the whole Mediterranean basin as case study area, identifying and prioritise geographical and temporal data gaps considering and integrating the biological, geological, chemical and physical branches of the total environment. The obtained results highlighted both the main geographical data gaps subdividing the whole Mediterranean Sea into 23 sub-basins and the temporal data gaps considering data gathered since 1990. Particular attention has been directed to the suitability of data in terms of completeness, accessibility and aggregation, since data and information are often aggregated and could not be used for research needs. The elaborated inventory of existing data source includes a database of 477 data rows originated from 122 data platforms analysed, able to specify for each dataset the related data typologies and its accessibility. The obtained results indicate that 76% of the data comes from ongoing platforms, while the remaining 25% are related to platforms with non-operational monitoring systems. Since the large amount of analysed records includes data gathered in inhomogeneous ways, the prioritisation values obtained for each identified data gap simplify the data comparison and analysis. Lastly, the data gaps inventory contains geographic and temporal information for any missing parameter at the whole basin scale, as well as the spatial resolution of each available data.
Climate change is poised to exacerbate coastal erosion. Recent research has presented a novel strategy to tackle this issue: dual wave farms, i.e., arrays of wave energy converters with the dual function of carbon-free energy generation and coastal erosion mitigation. However, the implications of sea level rise – another consequence of climate change – for the effectiveness of wave farms as coastal defence elements against shoreline erosion have not been studied so far. The objective of this work is to investigate how the coastal defence performance of a dual wave farm is affected by sea level rise through a case study (Playa Granada, southern Iberian Peninsula). To this end, a spectral wave propagation model, a longshore sediment transport formulation and a one-line model are combined to obtain the final subaerial beach areas for three sea level rise scenarios: the present situation, an optimistic and a pessimistic projection. These scenarios were modelled with and without the wave farm to assess its effects. We find that the dual wave farm reduces erosion and promotes accretion regardless of the sea level rise scenario considered. In the case of westerly storms, the dual wave farm is particularly effective: erosion is transformed into accretion. In general, and importantly, sea level rise strengthens the effectiveness of the dual wave farm as a coastal protection mechanism. This fact enhances the competitiveness of wave farms as coastal defence elements.
Marine protected areas (MPAs) have become one of the most widely employed marine management tools worldwide for conserving species and habitats, maintaining ecosystem functioning, and ensuring sustainable use of marine resources. In this study, we adopted a science-based, stakeholder-driven and ecosystem based approach to identify coastal and marine habitats for potential MPA declaration towards achieving Aichi target 11. In addition, we also proposed an integrated management approach for MPA management in Bangladesh. Primary data were collected through stakeholder consultations from the three coastal zones of Bangladesh and secondary data were collected from an extensive literature review. We developed a priority index to select the most important habitats for MPA declaration. Our analysis suggests five potential habitats within the maritime boundary of Bangladesh for MPA declaration. These habitats cover an area of 8838 km2 which is about 7.5% of the total maritime area of Bangladesh. Declaration of the MPAs will contribute to conserve the nursing and breeding habitats of fishes, crabs and seabirds, and thus will protect the marine biodiversity. To achieve this goal, local community involvement is required. This study will serve as a baseline for declaring MPAs in a solid scientific way through community engagement.
Marine aquaculture is a rapidly growing industry that presents both opportunities and risks for the environment and society. Whether aquatic farming (bivalves and finfish) in the ocean can mitigate food security concerns and be done without significant ecological impact depends in large part on the governance infrastructure of the sector. This study assesses the relationships at the nation-state level between existing aquaculture policy determined by survey and literature review, indicators of the quality of governance, and assessments of the ecological potential for highly productive aquaculture. The possible socio-ecological implications of Blue Growth for nations around the world are then discussed. There are numerous unexploited opportunities for countries, like those in the Pacific and Caribbean, with good governance and growth potential to pursue marine aquaculture, particularly to potentially alleviate local food security concerns. In comparison, countries already producing marine aquaculture do not have the most biologically suitable waters (e.g., China), but are more closely aligned with private capital – showing production is clearly possible, but may be less sustainable or optimal. Notably, many countries active in the marine aquaculture space appear to have some level of associated regulation and environmental oversight, but appear to lack clear frameworks for emerging growth in the sector, particularly offshore production. This study provides one of the first global evaluations of sustainable aquaculture potential under current governance, policy, and capital patterns.
Stock enhancements are commonly advocated as a solution to declining fish populations. They consist of releasing hatchery individuals in the wild, to increase stock abundance and provide socio-economic benefits. Some argue that stock enhancement science focusses too narrowly on technical and economic aspects, with insufficient investigations of the social impacts (positive and negative) on local communities. The present study investigated the potential impacts the planned Marava (Siganus argenteus) stock enhancement could have on local fishers from Taiarapu (French Polynesia). Ninety-six local fishers were interviewed, using semi-structured questionnaires, to gather information on the data-poor coastal fishery, the importance of Marava as a target species, and the fishers’ perceptions of stock enhancement and of the fisheries management regime. Fishers reported overall finfish abundance to have declined and attributed this mainly to overfishing caused by the growing number of fishers, undersized fish being caught, and pollution. Results suggested that wild Marava was insignificant within this coastal fishery, as it was rarely caught. Although 90.6% of the interviewees approved of enhancing Marava stocks, this intervention was thought unlikely to enhance fishers’ livelihoods through mitigating overharvesting (particularly due to certain fishing practices including night spearfishing and harvesting juveniles). Our results also showed that coastal fishers were more concerned with inequalities between different stakeholders of the fishery, especially offshore fishers, under the current management regime than the state of the fishery and suggest that the local fisheries agency should attempt to address these existing inequalities before engaging in stock enhancement.
Marine plastic debris, including microplastics (<5 mm in size), comprises a suite of chemical ingredients and sorbed chemical contaminants. Thus, microplastics are a potential, and debated, source of anthropogenic chemicals for bioaccumulation and biomagnification. Several studies have investigated the role of microplastics as a vector of contaminants to marine organisms via modeling exercises, laboratory experiments, and field studies. Here, we examined relationships among chemical contaminants and microplastics in lanternfish (family Myctophidae), an important link in marine food webs, from the North Pacific Ocean as a case study from the field. We compared the body burden of several chemical groups (bisphenol A [BPA], nonylphenol [4-NP], octylphenol [4n-OP], alkylphenol ethoxylates [APEs], pesticides, polychlorinated biphenyls [PCBs], and polybrominated diphenyl ethers [PBDEs]) in fish caught within and outside the North Pacific Subtropical Gyre where plastic is known to accumulate. We also tested whether there was a relationship between chemical concentrations in fish and plastic density at each sampling location. Mean concentrations of common plastic constituents (BPA, 4-NP, 4n-OP, APEs, and total PBDEs) were comparable between myctophids collected within and outside the North Pacific Gyre. Pesticides were higher in lanternfish caught outside the gyre and were associated with lower plastic density. Total PCBs were also higher in fish outside the gyre. In contrast, lower chlorinated PCB congeners were higher in fish residing in the accumulation zone and were correlated with higher plastic density. This finding is consistent with other studies demonstrating an association between lower chlorinated PCBs and plastics in biota and suggests that microplastic may be a transport mechanism for some chemicals in nature.
This article explores the prospects for adaptive governance in a proposed marine transboundary conservation initiative in East Africa. Adaptive governance that involves interdependent state and non-state actors learning and taking action on joint environmental problems is suggested for effective transboundary resource governance. Using the concept of adaptive co-management, the current multi-stakeholder marine governance systems in southern Kenya and northern Tanzania are compared to illuminate opportunities and constraints for adaptive marine transboundary conservation governance between Kenya and Tanzania. The concept of networks and the formal method of social network analysis (SNA) are applied as the main methodological device. Using questionnaire and semi-structured interviews, social network data of 70 organizations (local resources users, government agencies and NGOs) was generated from Kenya (n = 33) and Tanzania (n = 37). Results show the existence of strong collaboration networks for marine resource governance in both Kenya and Tanzania. Social proximity is the common driver of network formation. Collaboration networks in Kenya and Tanzania have contributed to enhanced learning among marine resource managers. Conclusions point to the need to focus on common challenges relating to low levels of rule-compliance, limited access to information on the state of resources and poor integration of science into marine management decisions. Finally, differences in views regarding the state of marine ecosystems need to be addressed to improve prospects for joint problem-solving in marine transboundary conservation.
Microplastics are emergent contaminants in the marine environment. They enter the ocean in a variety of sizes and shapes, with plastic microfiber being the prevalent form in seawater and in the guts of biota. Most of the laboratory experiments on microplastics has been performed with spheres, so knowledge on the interactions of microfibers and marine organisms is limited. In this study we examined the ingestion of microfibers by the sea anemone Aiptasia pallida using three different types of polymers: nylon, polyester and polypropylene. The polymers were offered to both symbiotic (with algal symbionts) and bleached (without algal symbionts) anemones. The polymers were introduced either alone or mixed with brine shrimp homogenate. We observed a higher percentage of nylon ingestion compared to the other polymers when plastic was offered in the absence of shrimp. In contrast, we observed over 80% of the anemones taking up all types of polymers when the plastics were offered in the presence of shrimp. Retention time differed significantly between symbiotic and bleached anemones with faster egestion in symbiotic anemones. Our results suggest that ingestion of microfibers by sea anemones is dependent both on the type of polymers and on the presence of chemical cues of prey in seawater. The decreased ability of bleached anemones to reject plastic microfiber indicates that the susceptibility of anthozoans to plastic pollution is exacerbated by previous exposure to other stressors. This is particularly concerning given that coral reef ecosystems are facing increases in the frequency and intensity of bleaching events due to global change stressors such as ocean warming and acidification.
Human-induced climate change such as ocean warming and acidification, threatens marine ecosystems and associated fisheries. In the Western Baltic cod stock socio-ecological links are particularly important, with many relying on cod for their livelihoods. A series of recent experiments revealed that cod populations are negatively affected by climate change, but an ecological-economic assessment of the combined effects, and advice on optimal adaptive management are still missing. For Western Baltic cod, the increase in larval mortality due to ocean acidification has experimentally been quantified. Time-series analysis allows calculating the temperature effect on recruitment. Here, we include both processes in a stock-recruitment relationship, which is part of an ecological-economic optimization model. The goal was to quantify the effects of climate change on the triple bottom line (ecological, economic, social) of the Western Baltic cod fishery. Ocean warming has an overall negative effect on cod recruitment in the Baltic. Optimal management would react by lowering fishing mortality with increasing temperature, to create a buffer against climate change impacts. The negative effects cannot be fully compensated, but even at 3 °C warming above the 2014 level, a reduced but viable fishery would be possible. However, when accounting for combined effects of ocean warming and acidification, even optimal fisheries management cannot adapt to changes beyond a warming of +1.5° above the current level. Our results highlight the need for multi-factorial climate change research, in order to provide the best available, most realistic, and precautionary advice for conservation of exploited species as well as their connected socio-economic systems.