Ecosystem-based management (EBM) of the ocean considers all impacts on and uses of marine and coastal systems. In recent years, there has been a heightened interest in EBM tools that allow testing of alternative management options and help identify tradeoffs among human uses. End-to-end ecosystem modeling frameworks that consider a wide range of management options are a means to provide integrated solutions to the complex ocean management problems encountered in EBM. Here, we leverage the global advances in ecosystem modeling to explore common opportunities and challenges for ecosystem-based management, including changes in ocean acidification, spatial management, and fishing pressure across eight Atlantis (atlantis.cmar.csiro.au) end-to-end ecosystem models. These models represent marine ecosystems from the tropics to the arctic, varying in size, ecology, and management regimes, using a three-dimensional, spatially-explicit structure parametrized for each system. Results suggest stronger impacts from ocean acidification and marine protected areas than from altering fishing pressure, both in terms of guild-level (i.e., aggregations of similar species or groups) biomass and in terms of indicators of ecological and fishery structure. Effects of ocean acidification were typically negative (reducing biomass), while marine protected areas led to both “winners” and “losers” at the level of particular species (or functional groups). Changing fishing pressure (doubling or halving) had smaller effects on the species guilds or ecosystem indicators than either ocean acidification or marine protected areas. Compensatory effects within guilds led to weaker average effects at the guild level than the species or group level. The impacts and tradeoffs implied by these future scenarios are highly relevant as ocean governance shifts focus from single-sector objectives (e.g., sustainable levels of individual fished stocks) to taking into account competing industrial sectors' objectives (e.g., simultaneous spatial management of energy, shipping, and fishing) while at the same time grappling with compounded impacts of global climate change (e.g., ocean acidification and warming).
Ecosystem-based Management (EBM)
Korea's acceptable biological catch (ABC) for total allowable catch (TAC) management has been estimated by a five-tier system that relies on population-based stock assessment models according to available ecological information for pelagic or demersal species. To overcome the limitations of the current ABC estimation system based on population dynamic models, this study attempted to integrate the ecosystem-based fisheries assessment (EBFA) approach into Korea's current ABC estimation system, and has developed an ABC estimation approach for ecosystem-based TAC management. To estimate an ecosystem-based ABC, ABC estimated by the current ABC estimation system was adjusted depending on the species risk index (SRI) that was derived from risk analysis of EBFA. During the process, the SRI-F relationship which generalizes the relationship between SRI and fishing mortality (F) was devised, and was used to estimate an ecosystem-based ABC. Also, the SRI projection as a function of the F scenario was conducted to estimate the regression coefficient of a relationship of SRI and F. We demonstrated an ecosystem-based ABC estimation by applying it to the chub mackerel, one of the TAC species in Korea's large purse seine fishery. As a result, the F at ABC (0.39/year) was adjusted as 0.365/year, while ABC (180,000 mt) was reduced to 170,393 mt. We found that this approach can be used to conservatively estimate the TAC in an ecosystem-based context for quota-managed fisheries.
Cumulative effects in the marine environment increase the risk of environmental, economic or social collapse because the combined effects of new and existing marine industries, climate change and other stressors are often not accounted for in the determination of environmental capacity. Ecosystem-based management and the development of tools that translate complex social-ecological processes into dynamic, adaptable management strategies are needed to avoid these pitfalls. Previous work has highlighted disconnects between how cumulative effects are interpreted and assessed by science agencies, funding agencies, and management agencies, but has largely missed how investors are interpreting them. These social-ecological boundary and threshold issues illuminate the pivotal challenge of institutional change and agency behaviors that are needed to address cumulative effects. Using scenario planning techniques, a team of researchers from the Sustainable Seas National Science Challenge in Aotearoa New Zealand engaged key decision makers and stakeholders in creative thinking and constructive conversation aimed at bridging some of these institutional and behavioral disconnects. A range of different strategies regarding how to address cumulative effects were proposed by the assembled participants, but the need for collaborative networks that enable collective thought and action across boundaries was emphasized throughout the day. This paper explores the themes that emerged and some of the barriers that must be addressed to facilitate bold action on the topic of cumulative effects.
Ecological indicators are widely used to characterise ecosystem health. In the marine environment, indicators have been developed to assess the ecosystem effects of fishing to support an ecosystem approach to fisheries. However, very little work on the performance and robustness of ecological indicators has been carried out. An important aspect of robustness is that indicators should respond specifically to changes in the pressures they are designed to detect (e.g. fishing) rather than changes in other drivers (e.g. environment). We adopted a multi-model approach to compare and test the specificity of commonly used ecological indicators to capture fishing effects in the presence of environmental change and under different fishing strategies. We tested specificity in the presence of two types of environmental change: “random”, representing interannual climate variability and “directional”, representing climate change. We used phytoplankton biomass as a proxy of the environmental conditions, as this driver was comparable across all ecosystem models, then applied a signal-to-noise ratio analysis to test the specificity of indicators with random environmental change. For directional change, we used mean gradients to apportion the quantity of change in the indicators due to fishing and the environment. We found that depending on the fishing strategy and environmental change, ecological indicators could range from high to low specificity to fishing. As expected, the specificity of indicators to fishing almost always decreased as environmental variability increased. In 55–76% of the scenarios run with directional change in phytoplankton biomass across fishing strategies and ecosystem models, indicators were significantly more responsive to changes in fishing than to changes in phytoplankton biomass. This important result makes the tested ecological indicators good candidates to support fisheries management in a changing environment. Among the indicators, the catch over biomass ratio was most often the most specific indicator to fishing, whereas mean length was most often the most sensitive to change in phytoplankton biomass. However, the responses of indicators were highly variable depending on the ecosystem and fishing strategy under consideration. We therefore recommend that indicators should be tested in the particular ecosystem before they are used for monitoring and management purposes.
The advancement and expansion of a scientific field depends on its ability to organize its findings and establish a basis in the professional literature. In late 2015, a review was undertaken to examine the body of literature regarding the Large Marine Ecosystems (LMEs) of the world. Trends in the literature were studied to explore this approach as a means for implementing ecosystem-based management of coastal and marine resources, with the objective of providing guidance for filling gaps in the scientific literature supporting this concept. Since 1995, there has been an increase in the number of peer-reviewed, scientific journal articles related to the LME approach, termed “LME articles.” Based on this review, we observed that between 1983 and early 2016, 392 LME journal articles were published. In the examined literature, there is a strong focus on fisheries and fisheries-related considerations and concerns, with 59% of the most relevant journal articles focused on fish or fisheries. Future publications should draw on the experience of past and current LME projects to inform and provide tools for future projects to address the socioeconomic aspects of implementing ecosystem-based management. This review also highlights a connection between investments in LME projects by the Global Environment Facility and the amount of corresponding publications regarding the supported LMEs.
During the past decade, global environmental policy discussions have encouraged countries to engage in an ecosystem approach to managing the oceans. An ecosystem approach involves the integrated management of species, other natural services, and the multiple uses of the coast. Improving ecosystem based management efforts requires a better understanding of how it is included within national level policies that influence marine resource management. Chile has committed to implement international recommendations to include ecosystem based management. This study operationalizes an approach to assess the extent to which ecosystem based management is being implemented at national scales through the synthesis of agenda setting documents and national level policy/regulatory responses. The study specifically searches for ecosystem based management principles, as defined by the Convention of Biological Diversity in State of the Nation presidential speeches, national sectorial policies, national decrees and national programs issued between 1990 and 2014 (n = 1335 documents). Results show that although national level policies in Chile increasingly share common grounds with ecosystem based management principles, the overall approach is poorly mainstreamed into agenda setting speeches and reports. Working with existing institutional settings and institutional capacity are key features to maintain trajectories for the implementation of ecosystem based management in national policies. The approach presented complements research on marine policy implementation by effectively informing how national level policies can be analyzed under the lens of ecosystem based management.
Published research is reviewed to provide examples of both positive and negative interactions of contaminants and: climate change; habitat change; invasive and introduced species; and, eutrophication including harmful algal blooms. None of these stressor interactions results solely in negative effects. Research must shift from examining contaminants or other stressors in isolation to considering potential positive and negative effects of interactions, with the ultimate goal of providing the necessary information for the effective management of ecosystem services.
In this study we investigate if eutrophication management has the potential to substantially affect which areas are going to be most suitable for commercial fishing in the future. We use a spatial ecosystem model, forced by a coupled physical-biogeochemical model, to simulate the spatial distribution of functional groups within a marine ecosystem, which depends on their respective tolerances to abiotic factors, trophic interactions, and fishing. We simulate the future long-term spatial developments of the community composition and their potential implications for fisheries under three different nutrient management scenarios and changing climate. The three nutrient management scenarios result in contrasting developments of bottom oxygen concentrations and phytoplankton abundance, with substantial effects on fish production. Nutrient load reduction increases the spatial extent of the areas suitable for the commercially most valuable demersal fish predator and all types of fisheries. This suggests that strategic planning of fishery management strategies could benefit from considering future changes in species distributions due to changes in eutrophication. We show that combining approaches from climate research, physical oceanography, biogeochemistry, biogeography, and trophic ecology with economical information provides a strong foundation to produce scientific knowledge that can support a multisectoral management of ecosystems.
Ecosystem-based fisheries management (EBFM) was developed to move beyond single species management by incorporating ecosystem considerations for the sustainable utilization of marine resources. Due to the wide range of fishery characteristics, including different goals of fisheries management across regions and species, theoretical best practices for EBFM vary greatly. Here we highlight the lack of consensus in the interpretation of EBFM amongst professionals in marine science and its implementation. Fisheries policy-makers and managers, stock assessment scientists, conservationists, and ecologists had very different opinions on the degree to which certain management strategies would be considered EBFM. We then assess the variability of the implementation of EBFM, where we created a checklist of characteristics typifying EBFM and scored fisheries across different regions, species, ecosystems, and fishery size and capacity. Our assessments show fisheries are unlikely to meet all the criteria on the EBFM checklist. Consequentially, it is unnecessary for management to practice all the traits of EBFM, as some may be disparate from the ecosystem attributes or fishery goals. Instead, incorporating some ecosystem-based considerations to fisheries management that are context-specific is a more realistic and useful way for EBFM to occur in practice.
The Marine Strategy Framework Directive (MSFD) requires an ecosystem-based approach to assess the state of Europe's seas. To date, assessment is carried out on an indicator by indicator basis. Integration of indicators is required to undertake a more holistic assessment of the state of the marine environment. Here, an integrated approach to assess benthic habitats is proposed. Within this conceptual method, four OSPAR benthic habitat indicators relating to biodiversity (D1) and sea-floor integrity (D6) descriptors are linked together. For the integration, benthos, environmental and anthropogenic pressure data are required. State indicators are assessed along a gradient of pressure to facilitate threshold values to be quantified and provide advice on management measures. The method also includes a feedback system whereby best available evidence on benthos, its sensitivity and disturbance assessments can be replaced with ground-truthed data. The proposed method can be expanded to include other related indicators under the different descriptors (e.g. commercial fish and shellfish (D3), food webs (D4) and eutrophication (D5)) where relevant. The concept is a first step towards integration of benthic indicators and could be applied to monitoring requirements under other Directives such as the Habitat or Water Framework Directive.