Ecosystem-based Management Approach Research Articles

Examining the discrepancy and synergy between marine protected areas and fisheries management in the Bohai Sea, China

Marine protected areas (MPAs) and other area-based conservation measures used in conjunction with climate-smart fisheries management approaches are important for safeguarding ecosystem and fish population health. However, spatial management approaches are often implemented separately from non-spatial management interventions due to their distinct legislative processes, management priorities, and administrating agencies. As global ocean governance becomes increasingly spatial in compliance with the Kunming-Montreal Global Biodiversity Framework, it is imperative to examine the utility of MPAs as a wider ecosystem approach to complement traditional, single species fisheries management. In this study, we examine current policy and management transformations happening in the Bohai Sea in China and demonstrate the discrepancies and synergies between MPA governance and fisheries management. By evaluating their interactions in objective setting, area selection, and management regulations, we reveal the gaps in coordination and consultancy between the government agencies implementing fisheries and spatial conservation measures. In particular, there is ambiguity or lack of consideration of fisheries management objectives in the framing of conservation area objectives and regulations, and vice versa. In addition, the mismatch between stated objectives of MPAs and their geographic coverage of species distribution ranges suggests insufficient incorporation of fishery expertise in conservation planning. To strengthen the cooperation between fisheries and conservation authorities, we identify opportunities and actions for synergizing management goals and ecosystem-based approaches, improving the design of spatial restrictions, and better integrating spatial management interventions as a critical fisheries and ecosystem-based management approach. These proposed changes will necessitate the creation of processes for engaging the full spectrum of expertise and actors, enhancing collaborations at multiple scales and between different sectors. These findings offer practical insights into bridging the gap between fisheries management and MPAs and could inform further decisions on integrated management in the Bohai Sea and elsewhere.

Drivers of trophodynamics of the open-ocean and deep-sea environments of the Azores, NE Atlantic

Marine ecosystems associated with mid-oceanic elevations harbour unique pelagic and benthic biodiversity and sustain food webs critical for Nature’s contributions to people (NCP). The United Nations Sustainable Development Goals and the Convention on the Law of the Sea recognize the need to implement ecosystem-based management approaches to conserve the structure and functioning of oceanic and deep-sea ecosystems within sustainable reference points. However, uncertainties regarding the interactions between multiple drivers of change, and their impacts on the state of these ecosystems and the NCP, present significant challenges to effective management. Trophic models offer a holistic approach to identify the main drivers affecting the dynamics of marine ecosystems. Here, we used a food web model of the open-ocean and deep-sea environments of the Azores for identifying the drivers that best explain historical biomass trends of demersal fish of high commercial value. Our hindcast simulations suggested that historical trends can be explained by the combined effects of deep-sea fisheries exploitation and variability in environmental conditions, likely dominated by primary productivity anomalies. In particular, deficits in primary production and high levels of fishing exploitation might have contributed to the pronounced decline in biomass observed between 2008 and 2012. These findings reinforce that failure to consider environmental factors in ecosystem-based management may result in shortfalls at achieving biodiversity conservation and sustainability objectives, particularly in the context of climate change.

Management of jellyfish outbreaks to achieve good environmental status

Jellyfish and gelatinous zooplankton (GZ) in general, fulfill important ecological roles with significant impacts, although they are often oversimplified or misunderstood. This paper reviews the impacts, pressures, monitoring methods and current management strategies for various GZ groups. It also introduces potentially applicable indicators for their assessment in ecosystem-based management approaches, such as the European Marine Strategy Framework Directive (MSFD). This multi-faceted review is primarily envisioned to serve as a state-of-the-art document for scientists and policymakers to foster a holistic assessment and management of GZ across European regional seas. The systematic review on global impacts of GZ shows a notable increase in the number of studies since the early 2000s. Stings were the main cause of human health impacts. Mechanisms that impact biodiversity included direct predation, modification of trophic flows or competition for resources. Several GZ taxa may be beneficial to biodiversity acting as biological regulators and provide societal ecosystem services such as food provision or medical applications. The systematic review on monitoring techniques outlined a variety of methods, such as nets (the most common technique), continuous plankton recorder (CPR), polyp and jelly-fall monitoring, acoustic methods, remote aerial and underwater imaging, molecular methods, and citizen science. Furthermore, several currently employed management strategies were enumerated, including the use of anti-jelly nets, bubble curtains, chemical compounds, or the introduction of GZ predators. This study highlights the pressing need for enhanced GZ-dedicated monitoring, assessment, and anticipatory management of GZ populations to address future GZ crises more effectively and cost-efficiently. Moreover, exploring GZ ecosystem services unveils opportunities to harness marine resources while mitigating adverse effects, thereby supporting sustainable blue economies.

Consumption of Antarctic krill Euphausia superba by mackerel icefish, Champsocephalus gunnari off the South Orkney Islands: filling an information gap in the current ecosystem-based management approach

Consumption of Antarctic krill Euphausia superba by mackerel icefish, Champsocephalus gunnari off the South Orkney Islands: filling an information gap in the current ecosystem-based management approach

Top predator status and trends: ecological implications, monitoring and mitigation strategies to promote ecosystem-based management

The conservation and management of marine ecosystems hinge on a comprehensive understanding of the status and trends of top predators. This review delves into the ecological significance of marine top predators, examining their roles in maintaining ecosystem stability and functioning through an integrated analysis of current scientific literature. We first assess the efficacy of various monitoring methods, ranging from traditional field observations to cutting-edge technologies like satellite tracking and environmental DNA (eDNA) analysis and evaluating their strengths and limitations in terms of accuracy, spatial coverage, and cost-effectiveness, providing resource managers with essential insights for informed decision-making. Then, by synthesizing data from diverse marine ecosystems, this study offers a comprehensive overview of the trends affecting top predator populations worldwide. We explore the multifaceted impacts of human activities, climate change, and habitat degradation on the abundance and distribution of these key species. In doing so, we shed light on the broader implications of declining top predator populations, such as trophic cascades and altered community structures. Following a thorough assessment of successful strategies for reversing the decline of top predators, a compilation of recommendations is presented, encompassing effective governance interventions. A crucial aspect of effective ecosystem-based management is the implementation of robust monitoring strategies. Mitigation measures are imperative to reverse the adverse impacts on marine top predators. We present a comprehensive array of mitigation options based on successful case studies. These include the establishment of marine protected areas, the enforcement of fisheries regulations, and the promotion of sustainable fishing practices. We deepen the synergies between these strategies and their potential to mitigate human-induced stressors on top predator populations to safeguard their pivotal role in maintaining marine ecosystem structure and function. By examining marine top predators’ ecological significance, analyzing population trends, discussing monitoring techniques, and outlining effective mitigation strategies, we provide a comprehensive resource for researchers, policymakers, and stakeholders engaged in fostering ecosystem-based management approaches. We conclude that integrating these insights into current management frameworks will be essential to safeguard both top predators and the broader marine environment for future generations.

Ecosystem-based management approaches for watershed conservation and geosustainability

When contributors' goals and legislative and political structures vary, as they often do in the case of worldwide fish populations, it becomes more challenging to implement ethical fishing tactics. Canada, the United States, and Mexico all fish from Pacific regions anchovies in the California Modern. Climate-driven numbers and geographic dynamics may pollute the waters of collaborative aquaculture and lead to overloading. This research expands upon prior works using a game theoretic model of Tran's boundary sardine fisheries in different climatic conditions to account for ecological links. More significant economic advantages accrue from cooperation fishing tactics that consider the mackerel's role as feed for other species in the natural system, as opposed to plans that merely take note of the worth of mackerel harvests to a particular fishing nation. The maximum environmental benefit is obtained at a fishery rate for sardines barely less than the sardine Fishery Management Safe Yield. Ecological-based control of fisheries can increase sustainability and profits, but only if investors and policy makers consider the ecology in business-applicable models. Understanding and adapting to the fast alterations in habitat distributions due to climate change and designing ways to achieve viable and lucrative fishery amidst altering environments will necessitate an increased emphasis on ecosystem-based governance.

Stronger Hurricanes and Climate Change in the Caribbean Sea: Threats to the Sustainability of Endangered Coral Species

An increasing sea surface temperature as a result of climate change has led to a higher frequency and strengthening of hurricanes across the northeastern Caribbean in recent decades, with increasing risks of impacts to endangered corals and to the sustainability of coral reefs. Category five Hurricanes Irma and María during 2017 caused unprecedented damage to coral reef ecosystems across northeastern Puerto Rico, including mechanical destruction, localized sediment bedload (horizontal sediment transport and abrasion), and burial by hurricane-generated rubble fields. Hurricanes inflicted significant site-, depth-, and life history trait-specific impacts to endangered corals, with substantial and widespread mechanical damage to branching species, moderate mechanical damage to foliose species, and moderate to high localized damage to small-sized encrusting and massive morphotypes due to sediment bedload and burial by rubble. There was a mean 35% decline in Acropora palmata live cover, 79% in A. cervicornis, 12% in Orbicella annularis, 7% in O. faveolata, 12% in O. franksi, and 96% in Dendrogyra cylindrus. Hurricane disturbances resulted in a major regime shift favoring dominance by macroalgae, algal turf, and cyanobacteria. Recovery from coral recruitment or fragment reattachment in A. palmata was significantly higher on more distant coral reefs, but there was none for massive endangered species. Stronger hurricanes under projected climate change may represent a major threat to the conservation of endangered coral species and reef sustainability which will require enhancing coral propagation and restoration strategies, and the integration of adaptive, ecosystem-based management approaches. Recommendations are discussed to enhance redundancy, rapid restoration responses, and conservation-oriented strategies.

New tools and recommendations for a better management of harmful algal blooms under the European Marine Strategy Framework Directive

Marine harmful algal blooms (HABs), caused by various aquatic microalgae, pose significant risks to ecosystems, some socio-economic activities and human health. Traditionally managed as a public health issue through reactive control measures such as beach closures, seafood trade bans or closure of mollusc production areas, the multifaceted linkages of HABs with environmental and socio-economic factors require more comprehensive ecosystem-based management approach tools to support policies. This study promotes a coordinated understanding and implementation of HAB assessment and management under the Marine Strategy Framework Directive (MSFD), targeting the achievement of Good Environmental Status (GES) in European marine waters. We introduce two novel tools: GES4HABs (GES for HABs) decision tree, and MAMBO (environMental mAtrix for the Management of BlOoms), a decision support matrix. These tools aim to streamline HABs reporting and prioritize resource allocation and management interventions. The GES4HABs decision tree defines a sequence of decision steps to identify HAB management strategies according to their state (evaluated against predefined baselines) and causes (anthropic or natural). MAMBO is proposed to address different HABs and their interaction with human and environmental pressures. The matrix utilizes two axes: natural trophic status and level of human influence, capturing major aspects such as nutrient supply. While acknowledging the limitations of this simplified framework, MAMBO categorizes marine regions into quadrants of varying management viability. Regions with high human influence and eutrophic conditions are identified as most suitable for effective management intervention, whereas regions with minimal or mixed human influence are deemed less amenable to active management. In addition, we explore and describe various indicators, monitoring methods and initiatives that may be relevant to support assessments of HAB status and associated pressures and impacts in the MSFD reporting. Finally, we provide some recommendations to promote the consideration of HABs in ecosystem-based management strategies, intensify efforts for harmonizing and defining best practices of analysis, monitoring and assessment methodologies, and foster international and cross-sectoral coordination to optimize resources, efforts and roles.

A new Meso-Scale coarse-filter indicator for the Canadian boreal forest

Forest management planning and management agencies in Canada have been moving towards an ecosystem-based management (EBM) approach that honours whole ecosystem dynamics over all time and space scales. As part of this evolution, provincial, national, and international agencies have added coarse filter indicators to represent pre-industrial, or ‘natural’ range of variation (NRV) ecosystem conditions as ecologically defendable baselines. The intent was to balance the more traditional species specific (i.e., fine filter) approach to sustainability with a more holistic (i.e., coarse scale) model of ecosystem dynamics. The development and acceptance of coarse filter indicators has been neither linear nor straightforward. One of the more important assumptions inherent in an NRV strategy is that it captures relevant, meaningful patterns at the most appropriate scales in a practical way. To test this assumption, I used a spatially explicit simulation model to compare landscapes created under pre-industrial conditions with those created using four different thresholds of disturbance size commonly used today in boreal Canada. The results suggest that even a 10,000 ha upper size limit create significantly higher levels of homogeneity and fragmentation at intermediate spatial scales relative to pre-industrial landscape patterns. Towards developing a new, more robust coarse filter indicator, the net area burned at four grid sizes over 10 and 20 years was calculated for natural wildfire data from northern Saskatchewan. The results suggest that wildfire tends to cluster at all scales due largely to the influence of large infrequent wildfires. In contrast, data from two forest management areas in Alberta summarized at the same scales confirm that harvesting activity tends to spread out evenly across the landscape. Based on these findings, the NRV data was then refined to capture; 1) the percentage of grid cells where high disturbance levels occur (WHEREs – or WHERE you are) and the proportion where no disturbance occurs (WYNs – or Where You are Not). The WHERE-WYN indicator is unique in that it specifically integrates time as a dimension of landscape dynamics. It is also easily understood and calculated, corresponds directly to management activities, has NRV equivalents, and applicable to most of boreal Canada. Augmenting the current suite of coarse filter indicator with the WHERE-WYN combination addresses a critical gap in our NRV toolkit and will ultimately help create more sustainable landscapes.

Temporal distribution of plankton and fish species at Mithamoin Haor: Abundance, composition, biomass and ecosystem based management approach

Wetlands are the major climatically vulnerable habitat globally. In Bangladesh, Haors are the representative of wetland habitat that plays a significant role in ecology, economy, and social structure. In the present study, physicochemical and biological properties and their interaction at Mithamoin haor of Kishoreganj district of Bangladesh were depicted based on the samples collected from July 2020 to June 202. In total, 46 genera representing 4 different groups of phytoplankton were identified comprising the highest percentages of Chlorophyceae (44.52 %). Zooplankton was represented with 13 genera which was dominated by rotifer. During the study, 56 fish species of 7 orders were documented and the dominance was showed by Cypriniformes (46.84 %). Fish biomass was highest during January and the lowest during May. Planktivores were represented the predominant (55.32 %) group in the haor. Water temperature, transparency, pH and water depth were considered as the major environmental factors influencing the phytoplankton, zooplankton and fish biomass of the haor. Although some fish and plankton species have declined over time, the overall diversity of fish and plankton in the Mithamoin haor was relatively stable. Multiple strategies, including an ecologically oriented framework, might be useful for conserving the prevailing fishery resources of this wetland in future.

Structural Characterization of Island Rainforests and Secondary Groves in Southern Nigeria

This study characterized the structural attributes of island rainforests and secondary groves within Orogun region in southern Nigeria. The quasi-experimental design was used, and the vegetation structural characteristics were determined in both secondary groves (experimental sites) and island rainforests (control sites). The randomized systematic sampling was employed in dividing the study area into 6 zones which were selected upon the presence of mature rainforest islands and secondary groves respectively. Six plots were sampled in each ecosystem. Tree heights, tree girths, and plot sizes were the data collected. Both secondary groves and island rainforest plots were measured to first determine uniformity in the area covered by the trees, after which, size of 200 ft X 100 ft was chosen as the uniform area of plot from which data were gathered. Tree girths at breast height were determined using measuring tape; while tree heights were determined by the use of Abney level and measuring tape. The 15.0 version of the Statistical Package for the Social Sciences (SPSS) was used in the statistical tests of the stated hypotheses. Statistical results showed that t-value = 7.05, P(0.001) > 0.05 for tree heights; and t-value = 3.122, P(0.026) > 0.05 for the tree girths. The mean differences in the structural characteristics between the secondary and mature island rainforest were significant at 0.05 alpha level. This implies that trees within island rainforests are significantly taller and bigger. The higher structural attributes of the island rainforest revealed that over time, conservation of rainforest trees could positively impact on its structural attributes. Therefore, ecosystem-based management approach was recommended for the management and conservation of the rainforest trees and covers

Perceptions and attitudes of residents toward small-scale longline tuna fishing in the Galapagos Marine Reserve: conservation and management implications

Longlining represents a cost-effective fishing modality for catching tuna, but its use is contentious due to the unintended catch of endangered, threatened, and protected (ETP) species. In 2000, longlining was banned in the Galapagos Marine Reserve, Ecuador. Since then, local small-scale fishers have contested this decision. In contrast, longlining ban supporters argue that this regulation is fundamental for conserving ETP species, despite scientific and anecdotal evidence indicating that its effective implementation is unfeasible. We conducted an online survey to investigate Galapagos residents’ perceptions concerning longlining, its ecological impact, and diverse potential management strategies. Our findings revealed misconceptions about longline fishing, which highlight the need for improved public awareness and education regarding longline fishing practices, their impact on ETP species, and possible solutions to this complex social-ecological problem. Our study also highlights Galapagos residents’ openness to find a solution that addresses both fishers’ livelihoods and the conservation of ETP species. Galapagos residents are receptive to implementing evidence-based solutions, including testing new bycatch mitigation methods and more selective fishing gears, enhancing monitoring and enforcement, and creating market-based incentives that encourage progressive and adaptive improvements in fishing practices. To solve the Galapagos longline controversy, we recommend a holistic, adaptive, and evidence-based approach that encourages stakeholders to engage in open dialogue, fosters cross-sector collaboration, and promotes research, communication, and educational initiatives. By raising awareness through comprehensive, rigorous, and unbiased scientific information, this ecosystem-based management approach aims to ensure the sustainable development of the small-scale tuna fishery, while conserving the Galapagos’ invaluable and unique marine biodiversity.

Expanding ocean protection and peace: a window for science diplomacy in the Gulf.

The ecological state of the Persian or Arabian Gulf (hereafter 'Gulf') is in sharp decline. Calls for comprehensive ecosystem-based management approaches and transboundary conservation have gone largely unanswered, despite mounting marine threats made worse by climate change. The region's long-standing political tensions add additional complexity, especially now as some Gulf countries will soon adopt ambitious goals to protect their marine environments as part of new global environmental commitments. The recent interest in global commitments comes at a time when diplomatic relations among all Gulf countries are improving. There is a window of opportunity for Gulf countries to meet global marine biodiversity conservation commitments, but only if scientists engage in peer-to-peer diplomacy to build trust, share knowledge and strategize marine conservation options across boundaries. The Gulf region needs more ocean diplomacy and coordination; just as critically, it needs actors at its science-policy interface to find better ways of adapting cooperative models to fit its unique marine environment, political context and culture. We propose a practical agenda for scientist-led diplomacy in the short term and lines of research from which to draw (e.g. co-production, knowledge exchange) to better design future science diplomacy practices and processes suited to the Gulf's setting.

Systematic evaluation of a spatially explicit ecosystem model to inform area-based management in the deep-sea

The long-term provision of ecosystem goods and services depends on the operationalisation of ecosystem-based management approaches that ensure effective conservation and sustainable use of marine resources. This management challenge is addressed internationally through two United Nations instruments: Sustainable Development Goal (SDG) 14 - Life Below Water, and the Convention on the Law of the Sea (UNCLOS) for the Conservation and Sustainable Use of Marine Biological Diversity in Areas Beyond National Jurisdiction (BBNJ Agreement). To achieve sustainability and conservation goals as described in SDG 14 and the BBNJ Agreement, a combination of management tools, including area-based management tools (ABMTs), is necessary. Spatially explicit ecosystem models can inform policy frameworks by enabling ecosystem-wide assessments of ABMTs with indicators that track their management performance. However, the operational use of these complex models depends on the confidence and uncertainty of their predictions. Here, we present a framework to systematically evaluate the performance of a spatially explicit ecosystem model for deep-sea and open-ocean environments, using the ecosystem model for the EEZ of the Azores (NE Atlantic, Portugal) as a case study. The systematic approach aimed to determine the model's suitability as a tool to inform area-based management in the deep-sea. The framework was applied to Ecospace, the spatial-temporal module of the ecological modelling suite Ecopath with Ecosim. It consisted of a stepwise approach for model development and assessment through key parameterisation steps. The steps served for calibration of model parameter values and formal evaluation of temporal and spatial results against the best available reference data. Overall, this approach proved useful in identifying key model sensitivities and sources of uncertainty that arise when considering spatial variability in trophodynamics in the ecosystem model. Moreover, we concluded the model i) effectively predicted the observed inter-annual variability of benthic fish stocks in response to fisheries, trophic interactions, and environmental factors and ii) showed good and moderate spatial goodness-of-fit in replicating reference spatial distribution patterns of stocks and fishing activities. Despite its strengths, the spatial model has limitations related to uncertainties in model parameterisation and the spatial variability of trophodynamics. The systematic assessments presented in this study provide a framework for future model applications to predict the ecosystem-wide impacts of alternative spatial management measures in the deep-sea.

Multiple stakeholders’ perspectives of marine social ecological systems, a case study on the Barents Sea

The Barents Sea ecosystem components and services are under pressure from climate change and other anthropogenic impacts. Following an Ecosystem-based management approach, multiple simultaneous pressures are addressed by using integrative strategies, but regular prioritization of key issues is needed. Identification of such priorities is typically done in a ‘scoping’ phase, where the characterization of the social-ecological system is defined and discussed. We performed a scoping exercise using an open and flexible multi-stakeholder approach to build conceptual models of the Barents Sea social-ecological system. After standardizing vocabulary, a complex hierarchical model structure containing 155 elements was condensed to a simpler model structure containing a maximum of 36 elements. To capture a common understanding across stakeholder groups, inputs from the individual group models were compiled into a collective model. Stakeholders' representation of the Barents Sea social-ecological system is complex and often group specific, emphasizing the need to include social scientific methods to ensure the identification and inclusion of key stakeholders in the process. Any summary or simplification of the stakeholders' representation neglects important information. Some commonalities are highlighted in the collective model, and additional information from the hierarchical model is provided by multicriteria analysis. The collective conceptual stakeholder model provides input to an integrated overview and strengthens prioritization in Ecosystem-based management by supporting the development of qualitative network models. Such models allow for exploration of perturbations and can inform cross-sectoral management trade-offs and priorities.

A conceptual model for enabling sustainable management of soil-sediment-water ecosystems in support of European policy

Abstract The health of soil-sediment-water ecosystems is under pressure from economic activities and a changing climate. This decreases health and hampers the service provision capacity of these ecosystems and thus impacts human well-being. Protecting and where feasible restoring of ecosystem health has currently become the key European environmental policy objective and for this it is needed to take an entire system approach and engage stakeholders. ‘Entire’ means that soil, sediment and water are regarded as closely interlinked environmental matrices that need to be managed by taking a ‘river (or mountain) to sea’ perspective, crossing spatial, discipline, political and cultural boundaries. This paper presents a conceptual model to support that purpose. Essentially, the conceptual model presents an approach for ecosystem-based management aimed to achieve healthy ecosystems, i.e. soil-sediment-water ecosystems that have the continued capacity to support ecosystem services to the benefit of their users. The model proposes a cyclic (iterative, learning-by-doing) approach and integrates soil-sediment-water, ecosystems, ecosystem services, users (stakeholders), pressures, information, management strategy and program of measures as building blocks. To successfully apply the model, it is above all needed to take an entrepreneurial approach, i.e. leave comfort zones, take an adventurous road, learn together to manage together, be adaptive and consider other than only command-and-control solutions. Furthermore, authorities should become facilitative leaders to engage users in co-creation of an ecosystem-based management strategy. Real live and place-based experimenting with multiple stakeholders, such as in the Living Labs and Lighthouses that are proposed in the EU soil mission, may provide an ideal instrument for such application, i.e. where the conceptual model can be used and support the achievement of European environmental policy objectives.

Bed-scale impact and recovery of a commercially important intertidal seaweed

As the value of ecosystem-based management (EBM) approaches is increasingly recognized in marine ecosystems, it is critical that the impacts of resource harvest are assessed at various spatial scales. This is particularly true for habitat-forming resources, such as wild seaweeds, that act as foundation species by physically structuring ecosystems. The impacts of spatially heterogeneous harvest may change with scale, and have different management implications based on the ecosystem process or organism under consideration. Ascophyllum nodosum (hereafter rockweed) is a canopy-forming fucoid seaweed endemic to rocky coastlines in the North Atlantic Ocean that has been harvested for centuries. We conducted a Before-After Control-Impact study of commercial rockweed harvest at 38 sites across the coast of Maine (USA) from 2018 to 2020 in an effort to understand impact and one-year recovery of two rockweed bed structural characteristics, height and biomass, at a scale similar to a single harvest event. Our results indicate that rockweed harvest is spatially heterogeneous at the scale of the rockweed bed, and as a result, the effect sizes of harvest at this scale are smaller than those reported in previous studies that assessed smaller spatial scales. Mean rockweed biomass recovered to pre-harvest values after one year of recovery, but mean rockweed height remained lower at impacted sites. While post-harvest recovery was generally high in our study, sites that experienced higher intensities of harvest were less likely to fully recover height or biomass one year post-harvest. Our findings provide resource managers with a bed-scale perspective that can inform EBM approaches, particularly for population-level management of harvested resources and impacts of harvest on highly mobile organisms—such as birds and fish—that interact with these ecosystems at larger spatial scales.

Managing reservoir fisheries: a critical look at reservoir physical environment

This short note follows a discussion on a study that assessed reservoir fisheries and ecosystem-based management approaches in Ghana. The main objectives of the study were to develop an understanding of how differences in reservoir morphometry and physicochemical characteristics influence ecosystem structures and fisheries productivity. This involved reviewing and updating empirical models for reservoir harvest estimations, relating morphometric characteristics of the reservoirs to fish production, assessing the exploitation levels and stock status of the reservoirs’ target species and providing a holistic description of the reservoirs’ biological interactions through a food web modelling approach. To manage reservoirs and associated riverine environments for the benefit of fish and fisheries, reservoirs' status and contribution to capture fisheries production have to be evaluated and addressed. Furthermore, the technical criteria and measures germane to assessment frameworks must be improved. Protecting and enhancing the physical environment of reservoirs for fish production requires considerations of ecosystem perspectives, optimal morphometric characteristics, duration of reservoir filling and development and prevention of critical nutrient enrichment. For enhancing Ghana's fish production, development strategies should focus on fisheries and aquaculture production in rivers, floodplains, lakes, reservoirs, and brackish water systems. Research, policy, and capacity-building issues related to developing these production systems must be addressed adequately. Moreover, to fully exploit their potential, the management requirements of the individual reservoir systems need to be assessed and appropriate regimes implemented with stakeholders.

Adherence to Best Practices for Stated Preference Valuation within the U.S. Marine Ecosystem Services Literature

Non-market economic values derived from stated preference (SP) methods are often of interest for policy analysis and evaluation, program design, green accounting, and damage assessments and are increasingly in demand with adoption of ecosystem-based management approaches that emphasize accounting for ecosystem services and their values. A recent guidance prescribes a set of twenty-three best practices guidelines (BPGs) to follow when conducting a SP study to ensure the validity of the results and maximize its ability to provide reliable economic value information. In this article, we evaluate adherence to these guidelines within the U.S. SP marine ecosystem service valuation literature. Our results suggest adherence by the literature to the guidelines is heterogeneous with none of the studies examined adhering to all guidelines and some guidelines being adhered to better than others. Evidence points to adherence differences between older and more recent studies, between studies using different SP valuation methods, and between studies valuing recreation ecosystem services and ones valuing other ecosystem services. Furthermore, a citation analysis suggests studies addressing elements embodied in the BPGs tend to have more citations all else being equal. We discuss several challenges to valuing marine ecosystem services and areas for improvement and inquiry.

The complexity of evaluating, categorising and quantifying marine cultural heritage

Despite the growing recognition that ecosystem-based management approaches to ocean governance need to recognise and integrate cultural dimensions to remain relevant, efficient, inclusive and equitable, the difficulty of meaningfully integrating these in ecosystem-based ocean management remains a challenge. This is particularly due to i) the difficulty of quantifying marine cultural heritage and cultural connections, ii) the complexity of identifying, evaluating and categorising ‘cultural ecosystem services’, particularly when it comes to intangible cultural heritage, and iii) the difficulty of spatially defining cultural heritage, connections and ecosystem services. There are several problems with current understandings and evaluations of marine cultural heritage, connections and cultural ecosystem services that first need to be addressed before attempting to quantify the social and cultural dimensions implicit in ecosystem-based ocean management. Challenges include the exclusion of some cultural 'services' that cannot be attributed an economic value because they are intangible, and the larger issue of Western-dominated conceptualisations, e.g., 'services’, 'ecosystems’, 'nature’, 'culture’. In this short communication we argue that the quantifying and simplification of marine cultural heritage and connections should be avoided altogether, as this can result in ecosystem collapse instead of ecosystem flourishing. The piece concludes by arguing that we need to qualify instead of quantify cultural dimensions of ecosystem-based ocean management, and develop contextual participatory research methodologies to better understand marine cultural heritage and cultural connections to marine social-ecological systems.