Sustainability in the provision of ecosystem services requires understanding of the vulnerability of social-ecological systems (SES) to tipping points (TPs). Assessing SES vulnerability to abrupt ecosystem state changes remains challenging, however, because frameworks do not operationally link ecological, socio-economic and cultural elements of the SES. We conducted a targeted literature review on empirical assessments of SES and TPs in the marine realm and their use in ecosystem-based management. Our results revealed a plurality of terminologies, definitions and concepts that hampers practical operationalisation of these concepts. Furthermore, we found a striking lack of socio-cultural aspects in SES vulnerability assessments, possibly because of a lack of involvement of stakeholders and interest groups. We propose guiding principles for assessing vulnerability to TPs that build on participative approaches and prioritise the connectivity between SES components by accounting for component linkages, cascading effects and feedback processes.
Found in the coastal waters of all continents, gillnets are the largest component of small-scale fisheries for many countries. Numerous studies show that these fisheries often have high bycatch rates of threatened marine species such as sea turtles, small cetaceans and seabirds, resulting in possible population declines of these non-target groups. However, few solutions to reduce gillnet bycatch have been developed. Recent bycatch reduction technologies (BRTs) use sensory cues to alert non-target species to the presence of fishing gear. In this study we deployed light emitting diodes (LEDs) - a visual cue - on the floatlines of paired gillnets (control vs illuminated net) during 864 fishing sets on small-scale vessels departing from three Peruvian ports between 2015 and 2018. Bycatch probability per set for sea turtles, cetaceans and seabirds as well as catch per unit effort (CPUE) of target species were analysed for illuminated and control nets using a generalised linear mixed-effects model (GLMM). For illuminated nets, bycatch probability per set was reduced by up to 74.4 % for sea turtles and 70.8 % for small cetaceans in comparison to non-illuminated, control nets. For seabirds, nominal BPUEs decreased by 84.0 % in the presence of LEDs. Target species CPUE was not negatively affected by the presence of LEDs. This study highlights the efficacy of net illumination as a multi-taxa BRT for small-scale gillnet fisheries in Peru. These results are promising given the global ubiquity of small-scale net fisheries, the relatively low cost of LEDs and the current lack of alternate solutions to bycatch.
The Mediterranean Sea is a biodiversity hotspot where intense fishing pressure is associated with high bycatch rates of protected species (sea turtles and cetaceans) and top predators (sharks). Since the conservation of these species has become a priority, fishery scientists are faced with the challenge of reducing incidental catch, which entails high rates of mortality. Among the species threatened by fishing activities, the loggerhead turtle (Caretta caretta) is a charismatic species considered as “vulnerable” at the global scale. In the Mediterranean Sea trawl nets are the gears with the highest probability of catching protected species incidentally. A new flexible Turtle Excluder Device (TED) was tested for the first time on commercial bottom trawlers to assess its effectiveness in reducing bycatch in the Mediterranean Sea. Analysis of the total catches of the hauls made with and without the TED showed that the difference in terms of weight was not significant. The catch of the main commercial species showed similar rates without a significant loss of size (i.e. total length) with the exception of the largest anglerfish (Lophius spp.). The bycatch of control nets included mostly rays and sharks, but never turtles, although the authors learned from the crews of other vessels operating in the same areas at the time of the trials that they had caught some loggerhead turtles. Our study demonstrates that TED scan be adopted without significantly affecting commercial catch. This informs fishers and managers for a practical and effective means that may reduce the bycatch of threatened species in coastal Mediterranean demersal multispecies fisheries. The measures involving gear modifications require significant investment but they are technically feasible and are capable of improving the conservation prospects of these endangered species. Besides ensuring normal earnings, the TED induced a significant reduction of debris and litter in the codend, thus reducing catch sorting time and improving catch quality.
There is recent evidence of widespread declines of shovelnose ray populations (Order Rhinopristiformes) in heavily fished regions. These declines, which are likely driven by high demand for their fins in Asian markets, raises concern about their risk of over-exploitation and extinction. Using life-history theory and incorporating uncertainty into a modified Euler-Lotka model, the maximum intrinsic rates of population increase (rmax) were estimated for nine species from four families of Rhinopristiformes, using four different natural mortality estimators. Estimates of mean rmax, across the different natural mortality methods, varied from 0.03 to 0.59 year-1 among the nine species, but generally increased with increasing maximum size. Comparing these estimates to rmax values for other species of chondrichthyans, the species Rhynchobatus australiae, Glaucostegus typus, and Glaucostegus cemiculus were relatively productive, while most species from Rhinobatidae and Trygonorrhinidae had relatively low rmax values. If the demand for their high-value products can be addressed then population recovery for some species is likely possible, but will vary depending on the species.
Many tropical and subtropical species are sensitive to sudden temperature changes, especially drops in temperature. During winters 2009–2010 and 2010–2011, unusually cold temperatures occurred in many parts of Florida, USA, resulting in increased mortality of Florida manatees, sea turtles, fish, corals, and other species. The Florida manatee, in particular, is highly susceptible to cold stress and death when water temperatures drop below 20°C. We sought to characterize the magnitude and timing of reports of cold-related manatee carcasses in relation to fluctuations in water and air temperatures in central-east and central-west Florida during the six winters from 2008 to 2014. We used a generalized linear model to predict counts of manatee carcasses with a cold-related cause of death reported over 7-day bins in relation to various short-term (two weeks or less) and cumulative (incrementally summed from the start of the winter) heating-degree-day effects (HDD; < 20°C) and a categorical winter variable. Using water temperature data, the top-ranked model in both regions included a short-term temperature effect (14-day HDD sum) that preceded increases in reports of cold-related manatee carcasses by 7 days. Cumulative exposure to cold weather over the winter amplified effects on mortality in the central-east region. Quantifying the relationship between cold events and manatee mortality helps us prepare for rescue and salvage operations when extremely cold weather is forecast. This is especially important because anticipated loss or degradation of warm-water refuges due to human activities and sea level rise could potentially impact the manatee population in the future. These methods could also be applied to other species susceptible to cold-related mortality.
- Despite a relatively long history of scientific interest fuelled by exploratory research cruises, the UK deep sea has only recently emerged as the subject of targeted and proactive conservation. Enabling legislation over the past 10 years has resulted in the designation of marine protected areas and the implementation of fisheries management areas as spatial conservation tools. This paper reflects on progress and lessons learned, recommending actions for the future.
- Increased investment has been made to improve the evidence base for deep‐sea conservation, including collaborative research surveys and use of emerging technologies. New open data portals and developments in marine habitat classification systems have been two notable steps to furthering understanding of deep‐sea biodiversity and ecosystem functioning in support of conservation action.
- There are still extensive gaps in fundamental knowledge of deep‐sea ecosystems and of cause and effect. Costs of new technologies and a limited ability to share data in a timely and efficient manner across sectors are barriers to furthering understanding. In addition, whilst the concepts of natural capital and ecosystem services are considered a useful tool to support the achievement of conservation goals, practical application is challenging.
- Continued collaborative research efforts and engagement with industry to share knowledge and resources could offer cost‐effective solutions to some of these barriers. Further elaboration of the concepts of natural capital and ecosystem services will aid understanding of the costs and benefits associated with human–environment interactions and support informed decision‐making in conserving the deep sea.
- Whilst multiple challenges arise for deep‐sea conservation, it is critical to continue ongoing conservation efforts, including exploration and collaboration, and to adopt new conservation strategies that are implemented in a systematic and holistic way and to ensure that these are adaptive to growing economic interest in this marine area.
In Paris in 2015, the global community agreed to limit global warming to well below 2 ∘∘C, aiming at even 1.5 ∘∘C. It is still uncertain whether these targets are sufficient to preserve marine ecosystems and prevent a severe alteration of marine biogeochemical cycles. Here, we show that stringent mitigation strategies consistent with the 1.5 ∘∘C scenario could, indeed, provoke a critical difference for the ocean’s carbon cycle and calcium carbonate saturation states. Favorable conditions for calcifying organisms like tropical corals and polar pteropods, both of major importance for large ecosystems, can only be maintained if CO22 emissions fall rapidly between 2025 and 2050, potentially requiring an early deployment of CO22 removal techniques in addition to drastic emissions reduction. Furthermore, this outcome can only be achieved if the terrestrial biosphere remains a carbon sink during the entire 21st century.
No-take marine protected areas (MPAs) are an important tool for conserving marine biodiversity and managing fisheries. However, with increasing environmental change driven by local and global stressors, it is critical to understand whether MPAs can continue to provide social, economic and conservation benefits in the long-term. Here, we compare coral reef benthic and fish assemblages across 17 paired MPA-fished control sites on three heavily populated, high elevation “mainland” islands, and four lowly populated, low elevation “offshore” islands that differed in their exposure to recent typhoons. Despite lower cover of macroalgae in MPAs compared to fished areas, especially on mainland islands, there were no consistent differences in benthic assemblages or total hard coral cover between paired MPA and fished reefs. Typhoons had severe negative effects on live hard coral cover, regardless of island type or MPA protection, and typhoon impacted reefs supported different fish assemblages and lower total biomass of fish, compared to non-impacted reefs. Although fish assemblage structure and total biomass differed between mainland and offshore islands, MPAs consistently supported a higher total biomass of fish than fished areas, with the magnitude of the MPA effect lower on typhoon impacted reefs. Our findings suggest that despite inherent differences in environmental conditions between mainland and offshore island coral reefs, MPAs can provide benefits to fish biomass, even when reefs are affected by typhoons. The development of management strategies that incorporate sound coastal land-use practices, while positioning MPAs in areas less prone to typhoon impact, will provide MPAs the best chance of success if climatic extremes increase.
This study investigates the bottlenose dolphin (Tursiops truncatus, Montagu 1821) habitat use in the Portofino marine protected area (NW Italy) and adjacent waters, a core area for the dolphins and a highly touristic area in the Mediterranean Sea. A permanent automated real-time passive acoustic monitoring system, able to detect and track dolphins continuously, was tested in the area within the activities of the Life+ Nature project ARION. The habits of bottlenose dolphins was investigated considering the resident rate inside the area, which quantifies the amount of time dolphins spent in these waters, by means of random forest regression. The dependency of dolphin resident rate was analyzed in relation to four explanatory variables: sea surface temperature, season, time of day, and proximity to the coast. Dolphins spent more time in the area during spring and when sea surface temperature ranged between 15–16°C. Summer resulted the season with lower dolphin residency with significant difference between working day and weekend, in the last the lowest residency was recorded. Main findings provide important information to properly manage the area in order to protect bottlenose dolphins.
Marine spatial planning aims to create a framework for the oceans and seas that minimise conflicts between economic activities within the marine environment while maintaining good environmental status. Although reports by international – and national – organisations suggest there are economic benefits to marine spatial planning this analysis has, to date, been aspatial. Employing an explorative Q methodology approach with ten participants, this paper seeks to address this spatial and distributive gap by exploring stakeholders (marine renewable energy, fishing industry, aquaculture and marine tourism) perceptions of the economic impacts of marine spatial planning across varying (local to national) geographical scales in the U.K. The paper develops a typology of three different perspectives on the economic impacts of marine spatial planning: the optimistic ‘place-makers’; the sceptical ‘place-holders’; and the utilitarian ‘place-less’. Findings highlight that participants loading onto a specific ‘type’ cannot simply be explained by stakeholder categorisation. This research contributes to the coastal management literature by identifying differing perceptions on the ‘spatial economic impact’ of marine spatial planning by economic actors utilising marine and coastal areas in the U.K.
The success of Marine Spatial Planning (MSP) depends on the effective participation of small-scale fishers (SSFs), and the extent to which marine governance in general can address the problems they face. As Poland's MSP in areas that are key to small-scale fisheries are yet to begin, this paper explores tensions in the country's looming coastal MSP processes through clarifying both the risks faced by SSFs and their perspectives on MSP. Using semi-structured interviews with SSFs and analytical literature reviews on small-scale fisheries, it is found that Poland's MSP is cast against a contentious history of marine resource management that shapes negative perceptions of and attitudes towards both the European Union-mediated MSP and marine scientists. Notably, SSFs believe that (1) authorities often undervalue and underutilize their experiential knowledge, (2) MSP is intended primarily to facilitate the siting of offshore wind farms and, (3) scientific knowledge is either not effectively communicated or is at the service of investors. A discussion follows that proposes measures through which planners can ensure procedural fairness. The paper concludes by offering TURF-Reserves as a novel and integrated co-management system within MSP which has potentials for empowering SSFs and revitalizing Poland's small-scale fisheries, while ensuring effective marine protection.
Natural protected areas are often required to concurrently support conservation and tourism development. Estimating the ecosystem's carrying capacity and setting up visitor access limitations is a common approach in maximising resource use to avoid environmental degradation. Our research used a case study strategy and a political ecology approach to analyse the conflict surrounding a carrying capacity-based management plan implemented in a Mediterranean marine protected area under severe pressure from scuba diving. A mixed documental and discourse analysis method based on fieldwork, grey literature and 16 semi-structured interviews with representatives of seven groups of stakeholders was used. Results indicate that although the carrying capacity approach was instrumentally supported by all groups, conventional scientific ecological knowledge played only a specious role in decision-making. Factors related to path dependency, neoliberal governance frameworks, uneven distribution of power among stakeholders and regulatory weaknesses were found to be the most influential in facilitating increased visitor pressure in the reserve. We conclude that, in order to be effective and mitigate social conflict, natural resource management strategies based on the carrying capacity concept must be complemented with a precursory assessment of the biopolitical context to align the goals of planning with the possibilities of the socially constructed environment.
Multi-purpose marine protected areas (MPAs) are prevalent world-wide as institutional mechanisms deployed in the marine environment to manage multiple uses, conserve resources and protect ecosystems. Yet some people may experience disadvantage following the implementation of new MPAs. One understudied aspect of MPAs is the distribution of advantages and disadvantages and how best to address the “justice” concerns that they raise. This article identifies a framework of principles, methods and tools to address these concerns. It devises a “MPA justice model” and demonstrates its applicability to a Taiwanese case study. In 2014, Taiwan proclaimed its first multiple-purpose MPA, the South Penghu Marine National Park and the case study shows ways that the MPA’s socio-economic sustainability could have been better accomplished. The article focuses on future MPA establishment that incorporates distributional fairness and procedural legitimacy into MPA site designation and zoning design - but might also be adapted to use retrospectively in MPA review processes.
Ocean ecosystems are in decline, yet we also have more ocean data, and more data portals, than ever before. To make effective decisions regarding ocean management, especially in the face of global environmental change, we need to make the best use possible of these data. Yet many data are not shared, are hard to find, and cannot be effectively accessed. We identify three classes of challenges to data sharing and use: uploading, aggregating, and navigating. While tremendous advances have occurred to improve ocean data operability and transparency, the effect has been largely incremental. We propose a suite of both technical and cultural solutions to overcome these challenges including the use of natural language processing, automatic data translation, ledger-based data identifiers, digital community currencies, data impact factors, and social networks as ways of breaking through these barriers. One way to harness these solutions could be a combinatorial machine that embodies both technological and social networking solutions to aggregate ocean data and to allow researchers to discover, navigate, and download data as well as to connect researchers and data users while providing an open-sourced backend for new data tools.
Boundary spanning – the practice of facilitating knowledge exchange to address complex sustainability challenges – has the potential to align research and policymaking and increase the uptake of research in decision making. But the goals, methods, and outcomes of boundary-spanning activities in the environment sector can be difficult to describe, missing an opportunity to share lessons learned and improve as a community of practice. This paper describes boundary-spanning activities to integrate research about environmental sustainability with federal ocean policy dialogues in the U.S. We describe the process of organizing, facilitating, and learning from a series of meetings in which five interdisciplinary researchers engaged with federal ocean policy audiences. While the longer-term impacts of the activities associated with these meetings are subtle and remain difficult to detect, more immediate outcomes are observable. These include new professional relationships among researchers and policy staff, reported relevance of the research to general policy discourse, and a narrative that frames the opportunity for policymakers to learn from past industrialization on land as they manage an emerging industrial revolution in the ocean. By presenting the process and outcomes of our boundary-spanning activities, we aim to stimulate timely debate within ocean policy, management, and research communities about the importance of multiple benefits provided by healthy and intact ocean ecosystems and how to protect them in the face of the expanding industrialization of the ocean.
Kelp farming is increasing along the temperate coastlines of the Americas and Europe. The economic, ecological, and social frameworks surrounding kelp farming in these new areas are in contrast with the conditions of progenitor kelp farming regions in China, Japan, and Korea.
Thus, identifying and addressing the environmental and social impacts of kelp farming in these regions is vital to ensuring the industry’s long-term sustainability. Here, a conceptual model of the human and natural systems supporting this nascent kelp aquaculture sector was developed using Maine, USA as a focal region. Potential negative impacts of kelp aquaculture were identified to be habitat degradation, overfishing of wild seeds, predation and competition with wild fish and genes, and transmission of diseases. Increased food security, improved restoration efforts, greater fisheries productivity, and alternative livelihoods development were determined to be potential positive impacts of kelp aquaculture. Changes in biodiversity and productivity resulting from either negative or positive impacts of kelp aquaculture were confirmed to have downstream effects on local fisheries and coastal communities. Recommendations to improve or protect the ecosystem services tangential to kelp farming include: define ecosystem and management boundaries, assess ecosystem services and environmental carrying capacity, pursue ecologically and socially considerate engineering, and protect the health and genetic diversity of wild kelp beds. Recommendations to ensure that kelp farming improves the well-being of all stakeholders include: increase horizontal expansion, expand and teach Best Management Practices, and develop climate change resiliency. Additionally, an integrated management strategy should be developed for wild and farmed kelp to ensure that kelp aquaculture is developed in the context of other sectors and goals.
Many of the world's shark populations are in decline, indicating the need for improved conservation and management. Well managed and appropriately located marine parks and marine protected areas (MPAs) have potential to enhance shark conservation by restricting fisheries and protecting suitable habitat for threatened shark populations. Here, we used shark occurrence records collected by commercial fisheries to determine suitable habitat for pelagic sharks within the Australian continental Exclusive Economic Zone (EEZ), and to quantify the amount of suitable habitat contained within existing MPAs. We developed generalised linear models using proportional occurrences of pelagic sharks for three families: Alopiidae (thresher), Carcharhinidae (requiem), and Lamnidae (mackerel) sharks. We also considered aggregated species from the Lamnidae and Carcharhinidae families (‘combined sharks’ in the models). Using a set of environmental predictors known to affect shark occurrence, including chlorophyll-a concentration, salinity, sea surface temperature, and turbidity, as well as geomorphological, geophysical, and sedimentary parameters, we found that models including sea surface temperature and turbidity were ranked highest in their ability to predict shark distributions. We used these results to predict geographic regions where habitat was most suitable for pelagic sharks within the Australian EEZ, and our results revealed that suitable habitat was limited in no-take zones within MPAs. For all shark groupings, suitable habitats were found mostly at locations exposed to fishing pressure, potentially increasing the vulnerability of the pelagic shark species considered. Our predictive models provide a foundation for future spatial planning and shark management, suggesting that strong fisheries management in addition to MPAs is necessary for pelagic shark conservation.
The current arrangements for the management of the marine resources of Bangladesh are not adequate for sustainable management. Marine Spatial Planning (MSP) may be a tool to achieve sustainable management of marine resources. The Government of Bangladesh is planning for the development of MSP for sustainable management of the marine resources in the Bay of Bengal. However, a clear understanding of the current and required legal and institutional arrangements for the development of MSP in Bangladesh is essential for sustainable management of the marine resources. This article analyzes the current legal and institutional arrangements concerning the management of marine resources and explores potential inadequacies for the development of MSP for sustainable management. The article refers to the legal and institutional arrangements of other coastal states which have already developed MSP to find out the required arrangements for the development of MSP in Bangladesh.
The expansion of marine protected areas in pelagic areas has been crucial to achieve sufficient protection of the oceans. However, there is still some controversy about whether these protected areas actually cover the vital areas for some species. We investigate the summer distribution of the critically endangered Balearic Shearwater and its overlap with the Special Protection Area for seabirds (SPA), using the Gulf of Cadiz as a case study. This area holds the SPA named Marine Area of Gulf of Cádiz, covering 2314.2 km2. A dataset of nine years of vessel-based surveys between 2006 and 2017 was analysed, using Kernel Density Estimation to generate the core area polygons for each year. The area located off the Bay of Cádiz, southeast of the mouth of the Guadalquivir, has revealed as a very consistent key area for this species during summer. This area, covering 1082 Km2, regularly hosted populations that exceeded the threshold for area of international importance (IBA criteria) for the species. The current SPA covers less than 40% of this new key area. The limitation in the number of years of monitoring and seasonal differences in the dataset used to establish the boundaries of the current protected area may be at the base of these discrepancies. This study emphasizes the importance of synthesizing and collecting long-term information to define marine protected areas and to assess their efficiency over the time. Furthermore, our study highlights the urgent need to expand this marine protected area to protect effectively this critically threatened species.
Bigi Pan Multiple Use Management Area (MUMA, IUCN category VI) is a coastal protected area situated in the Northwest Suriname between the Atlantic Ocean and the Nickerie River. The area is characterized by wetlands with mangrove forests, contains high biodiversity, and is of socio-economic, ecological and ornithological importance. However, the MUMA is overexploited and subject to competition between various income generating activities, including uncontrolled fisheries and unregulated tourism combined. Insufficient capacity of government agencies for enforcement and policy implementation and lack of communication between relevant government agencies has further contributed to unsustainable practices that diverge from ‘wise use’ and conservation. This article analyses the case of Bigi Pan MUMA from the perspective of collaborative governance. It explores how local communities address the conflicts, user pressure, and implementation gaps that lead to unsustainable practices in Bigi Pan MUMA. In addition, it explores the potential of stakeholder engagement with the local community and key user groups to provide meaningful and regular opportunities to actively participate in decision-making structures and to deliberate on management actions. The conclusion finally presents arguments on how collaborative governance can become more effective by including local communities and by strengthening local decision-making and management.