Fishing activity in waters beyond national jurisdiction generates multiple management issues, such as data poor fisheries, management of straddling fish stocks and lack of impact assessments on deep-sea Vulnerable Marine Ecosystems (VMEs). Fishing strategy is the key to understanding and managing high seas fisheries, targeting highly migratory resources that are widely distributed. An international fleet, including Spanish flag bottom trawlers, operates along the Patagonian shelf in Southwest Atlantic waters, which includes an unregulated strip of continental shelf beyond national jurisdiction. The Spanish fleet's fishing strategy was analyzed, and based on on-board observer data collected from 1989 to 2015, three main fishing seasons were identified: a first season mainly targeting Argentinean squid (Illex argentinus) from January to March, a second season targeting hake (Merluccius hubbsi) from April to August, and a third season from September to December showing an opportunistic and heterogeneous behavior. Findings were framed within current knowledge on resource distribution. A preliminary observation of the inter-annual CPUE rates of target species during their respective fishing seasons highlights the possible existence of species linkages and bioclimatic cycles which may affect species distribution and abundance in the area and might require future research. Even if current fishing activity from the Spanish fleet does not overlap deep-water VMEs, any slight change in the fishing strategy to deeper waters (i.e. the fleet targeting high density I. argentinus areas below 300 m, or a change in the target species) would be critical for the conservation of VMEs in these waters.
Ocean acidification may pose a major threat to commercial fisheries, especially those for calcifying shellfish species. This study was undertaken to estimate the potential economic costs resulting from ocean acidification on UK wild capture and aquaculture shellfish production. Applying the net present value (NPV) and partial equilibrium (PE) models, we estimate both direct and economy-wide economic losses of shellfish production by 2100. Estimates using the NPV method show that the direct potential losses due to reduced shellfish production range from 14% to 28% of fishery NPV. This equates to annual economic losses of between ö3 and ö6 billion of the UK’s GDP in 2013, for medium and high emission scenarios. Results using the PE model showed the total loss to the UK economy from shellfish production and consumption ranging from ö23–ö88 million. The results from both the direct valuation and predicted estimate for the economic losses on shellfish harvest indicate that there are regional variations due to different patterns of shellfish wild-capture and aquaculture, and the exploitation of species with differing sensitivities to ocean acidification. These results suggest that the potential economic losses vary depending on the chosen valuation method. This analysis is also partial as it did not include a wider group of species in early-life-stages or predator-prey effects. Nevertheless, findings show that the economic losses to the UK and its devolved administrations due to ocean acidification could be substantial. We conclude that addressing ocean acidification with the aim of preserving commercially valuable shellfish resources will require regional, national or international solutions using a combined approach to reduce atmospheric CO2 emissions and shift in focus to exploit species that are less vulnerable to ocean acidification.
Aquatic ecosystems are of global importance for maintaining high levels of biodiversity and ecosystem services, and for the number of livelihoods dependent on them. In Bangladesh, coastal and delta communities rely on these systems for a livelihood, and the sustainability of the productivity is seriously threatened by both climate change and unsustainable management. These multiple drivers of change shape the livelihood dependence and adaptation responses, where a better understanding is needed to achieve sustainable management in these systems, while maintaining and improving dependent livelihoods. This need has been addressed in this study in the region of Satkhira, in the southwest coast of Bangladesh, where livelihoods are highly dependent on aquatic systems for food supply and income. Traditional wild fish harvest in the rivers and aquaculture systems, including ghers, ponds, and crab points have been changing in terms of the uses and intensity of management, and suffering from climate change impacts as well. By means of six focus groups with 50 participants total, and validated by expert consultations, we conduct an analysis to understand the main perceived impacts from climate and human activities; and the adaptation responses from the aquatic system livelihoods. We find that biodiversity has decreased drastically, while farmed species have increased and shrimp gher farming turned more intensive becoming the main source of income. All these changes have important implications for food supply in the region and environmental sustainability. Dramatic responses taken in the communities include exit the fisheries and migration, and more adaptive responses include species diversification, crab fattening and working more on the pond and gherinfrastructure. This study evidences the results of the combination of multiple stressors in productive systems and the barriers to adaptation in aquatic ecosystem dependent communities.
Increasing maritime traffic in the Arctic has heightened the oil spill-related risks in this highly sensitive environment. To quantitatively assess these risks, we need knowledge about both the vulnerability and sensitivity of the key Arctic functional groups that may be affected by spilled oil. However, in the Arctic these data are typically scarce or lacking altogether. To compensate for this limited data availability, we propose the use of a probabilistic expert elicitation methodology, which we apply to seals, anatids, and seabirds. Our results suggest that the impacts of oil vary between functional groups, seasons, and oil types. Overall, the impacts are least for seals and greatest for anatids. Offspring seem to be more sensitive than adults, the impact is greatest in spring, and medium and heavy oils are the most harmful oil types. The elicitation process worked well, yet finding enough skilled and motivated experts proved to be difficult.
Both Venice and Miami are highly vulnerable to sea level rise and climate change. We examine the two cities´ biophysical environments, their socioeconomic bases, the legal and administrative structures, and their vulnerabilities and responses to sea level rise and flooding. Based on this information we critically compare the different adaptive responses of Venice and Miami and suggest what each city may learn from the other, as well as offer lessons for other vulnerable coastal cities.
Remote coastal communities often lack direct exposure to tourism activities, resulting in low levels of awareness of tourism. Low levels of awareness and limited understanding of tourism may nullify meaningful participation in widely advocated tourism planning and development strategies, such as community-based tourism (CBT). This paper presents data from a research project that sought to explore the viability of tourism as a development strategy for remote fishing communities in the Philippines. Interviews revealed that awareness of tourism within two remote coastal communities in the Philippines was minimal. These results indicate the limited potential for effective and meaningful participation by locals in tourism development planning as called for by the CBT strategy. Thus, the discussion focuses on theoretical and alternative approaches to tourism development when tourism awareness levels are lacking. As a consequence, a new approach, the Social Entrepreneurship Tourism Model, is proposed, to address the shortcomings of CBT for remote fishing communities with low tourism awareness levels as defined by this study.
Persistent plastics, with an estimated lifetime for degradation of hundreds of years in marine conditions, can break up into micro- and nanoplastics over shorter timescales, thus facilitating their uptake by marine biota throughout the food chain. These polymers may contain chemical additives and contaminants, including some known endocrine disruptors that may be harmful at extremely low concentrations for marine biota, thus posing potential risks to marine ecosystems, biodiversity and food availability. Although there is still need to carry out focused scientific research to fill the knowledge gaps about the impacts of plastic litter in the marine environment (Wagner et al. in Environ Sci Eur 26:9, 2014), the food chain and human health, existing scientific evidence and concerns are already sufficient to support actions by the scientific, industry, policy and civil society communities to curb the ongoing flow of plastics and the toxic chemicals they contain into the marine environment. Without immediate strong preventive measures, the environmental impacts and the economic costs are set only to become worse, even in the short term. Continued increases in plastic production and consumption, combined with wasteful uses, inefficient waste collection infrastructures and insufficient waste management facilities, especially in developing countries, mean that even achieving already established objectives for reductions in marine litter remains a huge challenge, and one unlikely to be met without a fundamental rethink of the ways in which we consume plastics. This document was prepared by a working group of Regional Centres of the Stockholm and Basel Conventions and related colleagues intended to be a background document for discussion in the 2017 Conference of the Parties (COP) of the Basel Convention on hazardous wastes and the Stockholm Convention on persistent organic pollutants (POPs). The COP finally approved that the issue of plastic waste could be dealt by its Regional Centres and consistently report their activities on the matter to next COP’s meetings.
Utilization of marine and terrestrial protected areas is fundamentally important for their acceptance and success. Yet even appropriate uses can negatively impact resources requiring managers to make decisions as to when the impacts become unacceptably large. These decisions can be difficult because the level at which impacts occur may be far below the level at which resource persistence is threatened. In Glacier Bay National Park, Alaska, managers must make a recurring decision regarding the number of cruise ships that are allowed to enter the park each year. Cruise ships bring >95% of all visitors to the park but have been involved in several lethal collisions (ship strikes) with humpback whales. Using an individual-based simulation model, we demonstrate that increasing the annual ship volume from current to maximum allowable levels would have negligible impacts on population growth of whales. Over the next 30 years the median number of collisions would likely increase from 3 (95% CI: 0–7) to 4 (1–8) or, worst case scenario, from 5 (0–7) to 8 (3−13), while median annual growth rates would, at most, shift from 4.4% (3.7%–5.2%) to 4.2% (3.5%–4.9%), depending upon assumptions. By comparison, a median of 67 (50–82) ship strikes would need to occur over the next 30 years to threaten the persistence of whales. Confronted with an impact level that is far below what would threaten the conservation of whales, managers are tasked with the decision of placing values on 2 million additional visitors for every additional dead whale. We argue that decision-making related to use-impact trade-offs for protected areas could be more consistent and effective if site-values are defined explicitly, clearly communicated among stakeholders, and linked to biological metrics. Protected areas managers can then utilize monitoring programs to evaluate management effectiveness when the objective is conserving both resources and values.
The competition for marine space is a recognized challenge, and the implementation of new activities, such as those emerging from Blue Growth initiatives, may amplify this competition. The marine spatial planning (MSP) framework requires decision makers to analyse spatially explicit environmental and socio-economic data to determine where user conflicts are or might emerge and consider several potential management scenarios. In the present research, a spatially explicit Bayesian belief network (BBN) was applied for this purpose. The BBN was developed to analyse the potential reallocation of artisanal fishing effort to alternative sites due to the introduction of a new, non-take area: an offshore aquaculture site along the Basque continental shelf. The constructed model combined discrete, operational fisheries data, continuous environmental data, and expert judgment to produce fishing activity suitability maps for three different métiers (longlines, nets and traps). The BBN was run with various effort reallocation scenarios for each metier, and the best alternative fishing locations were identified based on environmental suitability, past revenue, and past fishing presence. The closure had a lesser effect on net and longline activity, displacing 10% and 7% of local fishing effort respectively. Comparatively, 50% of all local effort by traps took place within the closed grounds, and few alternative sites were identified. Nets were found to have the greatest number of alternative fishing grounds surrounding the aquaculture site. The present research demonstrates how BBNs can support spatially explicit scenario building and user-user conflict analysis for sustainable and successful ecosystem-based marine spatial planning.
Stakeholder involvement plays a crucial role within Integrated Coastal Management (ICM) and is considered beneficial for gaining trust and knowledge and reducing conflicts. Nevertheless, disagreement and opposition among stakeholders and lack of manager experiences in participatory approaches have caused delays in ICM processes. A major challenge is to systematically guide target oriented discussions of heterogenic groups in order to reach consensus decisions based on sustainability objectives. Hence, this research aims to provide a stakeholder preference and planning tool that can be used to support participatory processes. For this, the DeCyDe-4-Sustainability methodology was tested and built upon. Seventeen applications with coastal experts, graduate students and stakeholders of ICM initiatives were carried out, which showed how the methodology can be adjusted and used for guiding stakeholder discussions systematically and generating a common understanding, for raising awareness about sustainability and evaluating concrete measures using success criteria. With a sound preparation, adaptation to local needs and combination with an indicator-based evaluation, the methodology can be applied to guide stakeholder involvement processes within ICM. The System Approach Framework (SAF) with its stepwise approach from the issue identification to the implementation of a solution and evaluation of success was found to serve as a suitable frame. Hereby, the modified stakeholder preference and planning tool can guide discussions from generating a general view of an area and problems therein, down to the selection and evaluation of concrete measures to tackle the problem and its effects on a larger level and contribution to a sustainable coastal development.
While there are several areas containing shallow coral habitats in the Gulf of Mexico (GOM), the availability of suitable reef habitat at mesophotic depths (~30–150 m) along the continental shelf margin suggests the potential for ecologically connected coral populations across hundreds of kilometers in the northwest (NW) GOM. The NW GOM includes a relatively high proportion of mesophotic habitats, including salt diapirs in Flower Garden Banks National Marine Sanctuary (FGBNMS), Bright Bank, and McGrail Bank, the latter two being Habitat Areas of Particular Concern (HAPCs). In response to a proposed expansion plan for the sanctuary boundaries to include additional mesophotic banks in the NW GOM, we investigated the genetic connectivity of the depth-generalist coral Montastraea cavernosa, a ubiquitous member of scleractinian communities throughout the Tropical Western Atlantic. Montastraea cavernosa populations in the NW GOM demonstrated strong connectivity with relatively high levels of gene flow and no significant genetic differentiation occurring over banks up to 120 km apart. Historical migration models based on genetic data predicted panmixia of M. cavernosa across the NW GOM. The comparisons between genetic and biophysical models (see Garavelli et al., 2018) highlight not only the importance of incorporating multiple assessments of connectivity into management schemes, but also the potentially stochastic nature of oceanographic patterns in the NW GOM and their effect on migration estimates among coral habitats. These trends indicate that M. cavernosa populations have remained well-connected in the NW GOM and that coral populations on each bank have likely been receiving larval recruitment through time. Thus, M. cavernosapopulations should be managed as a combined unit within the NW GOM, which supports the proposal to expand the NMS boundaries to include mesophotic habitats beyond West and East FGB.
Recent shifts in the geographic distribution of marine species have been linked to shifts in preferred thermal habitats. These shifts in distribution have already posed challenges for living marine resource management, and there is a strong need for projections of how species might be impacted by future changes in ocean temperatures during the 21st century. We modeled thermal habitat for 686 marine species in the Atlantic and Pacific oceans using long-term ecological survey data from the North American continental shelves. These habitat models were coupled to output from sixteen general circulation models that were run under high (RCP 8.5) and low (RCP 2.6) future greenhouse gas emission scenarios over the 21st century to produce 32 possible future outcomes for each species. The models generally agreed on the magnitude and direction of future shifts for some species (448 or 429 under RCP 8.5 and RCP 2.6, respectively), but strongly disagreed for other species (116 or 120 respectively). This allowed us to identify species with more or less robust predictions. Future shifts in species distributions were generally poleward and followed the coastline, but also varied among regions and species. Species from the U.S. and Canadian west coast including the Gulf of Alaska had the highest projected magnitude shifts in distribution, and many species shifted more than 1000 km under the high greenhouse gas emissions scenario. Following a strong mitigation scenario consistent with the Paris Agreement would likely produce substantially smaller shifts and less disruption to marine management efforts. Our projections offer an important tool for identifying species, fisheries, and management efforts that are particularly vulnerable to climate change impacts.
Marine protected areas (MPAs) conserve marine biodiversity and ecosystems by limiting or prohibiting resource use in specific areas. Reduced access to a marine resource will invariably impact local communities which reside nearby and utilise those resources. Social dimensions are recognised as crucial to the success of MPAs in meeting environmental goals, however, these dimensions are poorly understood. While much research is focused on developing countries, the majority of recent growth in MPA coverage is occurring in more economically developed settings. This research aims to address this gap by exploring the diversity of social impacts associated with an established MPA on the mid-coast of Western Australia. A range of extractive and non-extractive stakeholders were interviewed to identify the type of impacts experienced and how these are associated with attitudes towards the MPA. The results demonstrate there is a strong association between the nature of the impacts experienced by stakeholders and their attitudes. The social impacts are not distributed uniformly among stakeholders, with some groups of extractive users suffering the majority of the negative impacts and holding highly critical attitudes. The most common adverse impacts affect individual users’ well-being including feelings of fear, stress, uncertainty and inequity, while impacts on fishing activities are limited. Those who reported broader scale community or environmental benefits held largely positive assessments of the MPA. Together these results illustrate the importance of identifying and mitigating the full spectrum of social impacts experienced, as opposed to a narrow focus on the disruption of fishing activities or socio-economic impacts alone.
The deep sea has become an area of increasing interest due to the potential for mining the seafloor for valuable minerals. However, a critical knowledge gap in terms of understanding the economic value that the deep sea provides to societies makes it extremely difficult to estimate the long term economic impacts of mining activities. This article conducts a systematic review and meta-analysis of previous literature on the economic value of the deep sea, with the objective of integrating the findings of previous literature and identifying areas for future research. 25 studies were included in the systematic review, of which 15 were included in the meta-analysis. Although the systematic review reveals a lack of sufficient data to accurately estimate the economic value of the deep sea, the meta-analysis indicates that the functioning of the deep sea as an ecosystem significantly influences the economic value that it provides to society. The limited number of studies identified, along with the broad variety in their methods, scope, valuation perspective and purpose, emphasizes the need for future research into economic value-aspects of the deep sea. More importantly, this study reveals an urgent need for further scientific research into the deep sea's ecosystem in order to ensure the resource is managed sustainably in the long-term.
The interaction between fishing gears and the marine environment define ‘fisheries,’ and the effect of gears on marine ecosystems and fish stocks has been the source of much debate. Here, we present the first summary of globally reconstructed fisheries catches by major gear categories for 1950–2014. We used the Sea Around Us reconstructed global catch database that accounts for reported and unreported fisheries catches, and associated all catches to a fishing gear category. We assigned all industrial (i.e., large-scale) fisheries catches to industrial gear categories by fishing country, taxon, year and the area of fishing. Additionally, we derived catches by individual small-scale gear types for the most-important small-scale fishing countries in each of nine regions around the world, and applied their gear use to similar countries in each of the regions, to serve as a preliminary small-scale catch-by-gear assignment that can be improved upon over time. The combination of these account for gear use for all marine fisheries globally. We found that two industrial gear types, bottom trawling and purse seining, jointly account for over 53% of all catches, while bottom trawling alone dominated discarded catches. In the small-scale sector, over 60% of catches were caught by gillnets, various line gear, and encircling nets. Small-scale fisheries contributed most to the value of landed catches, while industrial bottom trawlers were responsible for discarding large amounts of potentially valuable catches. Catches by purse seines fluctuated over time, mainly due to variability of the underlying species, e.g., anchovies and sardines. The distribution and scale of use of different fishing gears, combined with knowledge of their divergent environmental impacts should allow a new wave of research into the global impacts of fisheries.
On some measures, the global governance of plastic is improving. Curbside recycling and community cleanups are increasing. Companies like Toyota, Walmart, and Procter & Gamble are reducing waste to landfill. And all around the world, as research consolidates and activism intensifies, towns, cities, and legislatures are banning some uses of plastic, such as for grocery bags and as microbeads in consumer products. Yet the amount of plastic flowing into the oceans is on track to double from 2010 to 2025. Why? Partly, the dispersal, durability, and mobility of microplastics make governance extremely hard. At the same time, the difficulty of governing plastic has been rising as production accelerates, consumption globalizes, pollution sources diversify, and international trade obscures responsibility. As pressures and complexities mount, the global governance of plastic – characterized by fragmented authority, weak international institutions, uneven regulations, uncoordinated policies, and business-oriented solutions – is failing to rein in marine plastic pollution. In large part, as this article demonstrates, this governance landscape reflects industry efforts to resist government regulation, deflect accountability, and thwart critics, coupled with industry advocacy of corporate self-regulation and consumer responsibility as principles of governance. These findings confirm the need for more hard-hitting domestic regulation of industry as well as an international plastics treaty to scale up local reforms.
A holistic basis for achieving ecosystem‐based management is needed to counter the continuing degradation of coral reefs. The high variation in recovery rates of fish, corresponding to fisheries yields, and the ecological complexity of coral reefs have challenged efforts to estimate fisheries sustainability. Yet, estimating stable yields can be determined when biomass, recovery, changes in per area yields and ecological change are evaluated together. Long‐term rates of change in yields and fishable biomass‐yield ratios have been the key missing variables for most coral reef assessments. Calibrating a fishery yield model using independently collected fishable biomass and recovery data produced large confidence intervals driven by high variability in biomass recovery rates that precluded accurate or universal yields for coral reefs. To test the model's predictions, I present changes in Kenyan reef fisheries for >20 years. Here, exceeding yields above 6 tonnes km−2 year−1 when fishable biomass was ~20 tonnes/km2 (~20% of unfished biomass) resulted in a >2.4% annual decline. Therefore, rates of decline fit the mean settings well and model predictions may therefore be used as a benchmark in reefs with mean recovery rates (i.e. r = 0.20–0.25). The mean model settings indicate a maximum sustained yield (MSY) of ~6 tonnes km−2 year−1 when fishable biomass was ~50 tonnes/km2. Variable reported recovery rates indicate that high sustainable yields will depend greatly on maintaining these rates, which can be reduced if productivity declines and management of stocks and functional diversity are ineffective. A number of ecological state‐yield trade‐off occurs as abrupt ecological changes prior to biomass levels that produce MSY.
Many climate change adaptation scholars recognise the complexities in the governance of adaptation. Most have used the concept of ‘barriers to adaptation’ in an attempt to describe why governance of adaptation is challenging. However, these studies have recently been critiqued for over simplifying complex governance processes by referring to the static concept of barriers, thereby ignoring dynamic complexity as a root explanatory cause. This paper builds the argument that how barriers are currently used in the literature is insufficient to explain why the governance of adaptation often proves difficult. We adopt a so-called mechanism-based approach to investigate how and why the governance of ecosystem-based adaptation (EbA) reaches impasses in five cases in Thailand and the Netherlands. Our findings show six causal mechanisms that explain impasses in the five case studies: (1) frame polarisation, (2) timing synchronisation, (3) risk innovation, (4) rules of the game, (5) veto players and (6) lost in translation. Several of these causal mechanisms are recurring and emerge under specific contextual conditions or are activated by other mechanisms. Our findings provide valuable insights into the impasses in the governance of EbA and allow for critical reflections on the analytical value of the mechanism-based approach in explaining why the governance of adaptation proves difficult and how this can be overcome.
Managing diverse ecosystems is challenging because structuring drivers are often processes having diffuse impacts that attenuate from the people who were “managed” to the expected ecosystem-wide outcome. Coral reef fishes targeted for management only indirectly link to the ecosystem’s foundation (reef corals). Three successively weakening interaction tiers separate management of fishing from coral abundance. We studied 12 islands along the 700-km eastern Caribbean archipelago, comparing fished and unfished coral reefs. Fishing reduced biomass of carnivorous (snappers and groupers) and herbivorous (parrotfish and surgeonfish) fishes. We document attenuating but important effects of managing fishing, which explained 37% of variance in parrotfish abundance, 20% of variance in harmful algal abundance, and 17% of variance in juvenile coral abundance. The explained variance increased when we quantified herbivory using area-specific bite rates. Local fisheries management resulted in a 62% increase in the archipelago’s juvenile coral density, improving the ecosystem’s recovery potential from major disturbances.
Mexico registers about 60% of the total of marine mammals worldwide. However, species listed under a risk category show that, globally, Mexico faces big marine mammal conservation challenges. Thus, it becomes essential to successfully apply the existing knowledge into interdisciplinary conservation programs. We generated a presence/absence species richness map containing all 47 marine mammal species recorded in Mexico's Exclusive Economic Zone. After selecting nine oceanographic variables influencing marine mammal species richness, the top three factors influencing such richness were sea surface temperature and dissolved oxygen grouped in component #1, and salinity composed component #2. We also identified the species that are protected within a Marine Protected Area (MPA) category and its representation in management programs of these areas. Currently, 98% of marine mammal species distributed in Mexican waters are protected within an MPA; nevertheless, around 12% of them are not listed in management programs. Three priority sites in the Pacific Ocean and one for the Gulf of Mexico were identified to promote their conservation. Considering the sentinel and umbrella attributes of marine mammals, the information presented here will not only benefit their populations, but will also contribute to address marine species and ecosystems threats and improve the effectiveness of conservation plans.