Ecosystem-based Management Framework Research Articles

Evaluating bottom-up forcing of a rocky intertidal resource harvest on a high trophic-level consumer group

The importance of ecosystem-based management (EBM) frameworks for resource harvest has increased over the past several decades as ecosystems face numerous anthropogenic stressors. In these frameworks, resource managers must consider the suite of interactions that comprise food webs and how resource harvest drives responses in non-target organisms. In rocky intertidal zones along North Atlantic coastlines, rockweed (Ascophyllum nodosum)—a canopy-forming brown seaweed—has been commercially harvested for centuries, yet most research on the effects of harvest have focused on the responses of the target resource and the macroinvertebrate assemblage. In this study, we used a Before-After Control-Impact experiment to assess the bottom-up effects of commercial rockweed harvest on a high trophic-level consumer group (birds) in Maine (USA). Overall, there was no evidence for strong bottom-up forcing of rockweed harvest on birds' site visitation. There was a small (fewer than two birds) positive effect size of harvest during the one-year post-harvest recovery interval. Several of the trends observed for the full bird assemblage appear to be driven more strongly by the low tide than the high tide bird assemblage. Independent of treatment, site visitation by birds was low in our study (60% of surveys recorded no birds) and highlights questions about the use of rocky intertidal habitats relative to other habitat types in coastal birds' home ranges. To our knowledge, there are no comparable assemblage-level bird studies in this system that can provide context to our results. Further research on coastal birds’ habitat use within home ranges and food-web connections with rockweed-associated macroinvertebrates is needed to more confidently incorporate this high trophic-level consumer group into an EBM framework for a rocky intertidal resource harvest.

Evaluating red tide effects on the West Florida Shelf using a spatiotemporal ecosystem modeling framework

The West Florida Shelf (WFS), located in the eastern Gulf of Mexico, fosters high species richness and supports highly valuable fisheries. However, red tide events occur regularly that can impact fisheries resources as well as ecosystem state, functioning, and derived services. Therefore, it is important to evaluate and quantify the spatiotemporal impacts of red tides to improve population assessments, mitigate potential negative effects through management, and better understand disturbances to support an ecosystem-based management framework. To model red tide effects on the marine community, we used Ecospace, the spatiotemporal module of the ecosystem modeling framework Ecopath with Ecosim. The inclusion of both lethal and sublethal response functions to red tide and a comprehensive calibration procedure allowed to systematically evaluate red tide effects and increased the robustness of the model and management applicability. Our results suggest severe red tide impacts have occurred on the WFS at the ecosystem, community, and population levels in terms of biomass, catch, and productivity. Sublethal and indirect food-web effects of red tide triggered compensatory responses such as avoidance behavior and release from predation and/or competition.. This study represents a step forward to operationalize spatiotemporal ecosystem models for management purposes that may increase the ability of fisheries managers to respond more effectively and be more proactive to episodic mortality events, such as those caused by red tides.

Multiscale relationships between humpback whales and forage species hotspots within a large marine ecosystem.

Fluctuations in prey abundance, composition, and distribution can impact predators, and when predators and fisheries target the same species, predators become essential to ecosystem-based management. Because of the difficulty in collecting concomitant predator-prey data at appropriate scales in patchy environments, few studies have identified strong linkages between cetaceans and prey, especially across large geographic areas. During summer 2018, a line-transect survey for cetaceans and coastal pelagic species was conducted over the continental shelf and slope of British Columbia, Canada, and the US West Coast, allowing for a large-scale investigation of predator-prey spatial relationships. We report on a case study of humpback whales (Megaptera novaeangliae) and their primary prey-Pacific herring (Clupea pallasii), northern anchovy (Engraulis mordax), and krill-using generalized additive models to explore the relationships between whale abundance on 10-km transect segments and prey metrics. Prey metrics included direct measures of biomass densities on segments and an original hotspot metric. For each prey species, segments in the upper fifth percentile for biomass density (across all segments) were designated hotspots, and whale counts on a segment were evaluated for their relationship to number of hotspot segments (species-specific and multispecies) within 25, 50, or 100 km. Whale abundance was not strongly related to direct measures of biomass densities, whereas models using hotspot metrics were more effective at describing variation in whale abundance, underscoring that evaluating prey at relevant and measurable scales is critical in patchy, dynamic marine environments. Our analysis highlighted differences in the distribution and prey availability for three humpback whale distinct population segments (DPSs) as defined under the US Endangered Species Act, including threatened and endangered DPSs that forage within the California Current Large Marine Ecosystem. These linkages provide insights into which prey species whales may be targeting in different regions and across multiple scales and, consequently, how climatic variability and anthropogenic risks may differentially impact these distinct predator-prey assemblages. By identifying scale-appropriate prey hotspots that co-occur with humpback whale aggregations, and with targeted, consistent prey sampling and estimations of potential consumption rates by whales, these findings can help inform the conservation and management of humpback whales within an ecosystem-based management framework.

Enhancing data mobilisation through a centralised data repository for Atlantic salmon (Salmo salar L.): Providing the resources to promote an ecosystem-based management framework.

Data and knowledge mobilisation are significant challenges in ecology and resource management, with the journey from data collection through to management action often left incomplete due to difficulties sharing information across diverse and dispersed communities. This disconnect between science and management must be resolved if we are to successfully tackle the increasing impact of human activity on our ecosystems. Across their North Atlantic range, Atlantic salmon (Salmo salar L.) populations are in steep decline in many areas and urgent actions are required to curb this decline. Being commercially important this species has been subject to intense research, but management action often suffers from both a lack of access to this knowledge resource and support for its integration into effective management strategies. To respond to this challenge, the science and management communities must place higher priority on mobilising existing and emerging knowledge sources to inform current and future resource use and mitigation strategies. This approach requires a more complete picture of the current salmon ecology data and knowledge landscape, new mechanisms to enable data mobilisation and re-use, and new research to describe and parameterise the responses of wild populations to habitat changes. Here we present a unique interface for registering and linking data resources relevant to the Atlantic salmon life cycle that can address the data mobilisation aspect of these challenges. The Salmon Ecosystem Data Hub is a salmon-specific metadata catalogue, natively interoperable with many existing data portals, which creates a low resistance pathway to maximise visibility of data relevant to Atlantic salmon. This includes the capacity to annotate datasets with life-stage domains and variable classes, thereby permitting dispersed data to be formally contextualised and integrated to support hypotheses specific to scenario-based modelling and decision-making. The alignment and mobilisation of data within the Salmon Ecosystem Data Hub will help advance the development of appropriate environmentally driven forecast models and an ecosystem-based management approach for Atlantic salmon that optimises future management strategies.

Ecosystem service approach for community-based management towards sustainable blue economy

The present study was undertaken to examine the role of community-based fishers in blue economy taking ecosystem and livelihood development and sustainability of Gulf of Mannar, Tamil Nadu, India. A questionnaire was designed to capture context-specific community-based blue economy practices. The virtual factors and environmental determinants which affect the sustainability of ecosystem between resource benefitters were evaluated. A significant difference is noticed between male and female beneficiaries for preference to all the variables except enhanced waste management practices variable (insignificant difference- 0.183; Mann-Whitney U test). All the variables significantly advance the livelihood sustainability of ecosystem-dependent population and the ecosystem service evaluation process. The present survey also resulted that the better sustainability of blue economy involved the significant implementation of growth agendas by minimizing the effluent and sewage disposal, developmental activities in industrial areas, disaster outbreak and eliminating harmful fishing practices, overfishing and instead incentivizing approaches that promote growth, improve conservation, build sustainable fisheries, and terminate the IUU (illegal, unreported and unregulated) fishing. An ecosystem-based management framework, improved governance is required to grow and improve the sustainability of livelihood and ecosystem towards a blue economy. Innovative financing to direct investments into economic activities is also needed to enhance ocean health. A further step would be to assess how such human inputs or improved management practices could be included in the set of ecosystem service indicators.

Think Ecosystems: Healthy Ecosystems are the Foundation for Sustainable and Integrated Coastal Management

The coming decade will be extremely important in terms of steering the world onto a sustainable development path as we are facing multiple global challenges from climate change, biodiversity loss, pandemics, poverty, and inequality. The global community increasingly recognizes the urgency, for instance through its commitment towards fulfilling the Sustainable Development Goals (SDG) by 2030. This “deadline” coincides with a recent declaration by the United Nations (UN) to declare the decade 2021 to 2030 as the Decade of Ecosystem Restoration, recognizing the crucial role that nature and ecosystems play for sustainable development. Coastal areas are particularly vulnerable, exposed as they are to the impacts of climate change, and with large coastal populations dependent on, and often competing for, dwindling coastal resources. Sector-based coastal resource management is no longer an option as broader, ecosystem-based management frameworks are needed, that include all coastal sectors and acknowledge the values of ecosystems as foundations for sustainable resource utilization, and as solutions towards adapting to climate change. If more holistic approaches to coastal management have been adopted that build on the true values of nature and ecosystems, it will be possible to manage coastal resources and biodiversity in a sustainable manner that creates synergies and co-benefits rather than causing conflicts between stakeholders and sectors. For this to happen, some challenges need to be overcome. First, all the coastal stakeholders, including in particular the coastal communities, have to be brought together and be part of the decision-making process and management plans. Second, the existing institutional structures have to be transformed to ensure better collaboration and coordination across the current sector and institutional boundaries. This paper discusses some emerging trends in integrated coastal resources management, and outline needs for the world and its coasts to enable the move towards a sustainable future.

Seasonal flow dynamics exacerbate overlap between artisanal fisheries and imperiled Ganges River dolphins

Here we quantify the effects of artisanal fisheries on the ecology of a small cetacean, the Ganges River dolphin (Platanista gangetica gangetica, GRD), in a large river system of Nepal. We examine the size-classes of fisheries’ catches, behavioural changes in GRD in response to fishing activities, and diel overlap between GRD and fishing activity. We observed high human exploitation rates (> 60% of the total catch per effort) of GRD-preferred prey sizes, indicating risks of high resource competition and dietary overlap, especially during the low water season when resource availability is reduced. Competitive interactions in the feeding niches during the low water season, plus temporal overlap between the peak exploitation and critical life-history events (e.g., reproduction), likely have ecological consequences. Furthermore, we detected 48% (95% CI 43–52%) increase in the chance of behavioural changes among dolphins exposed to anthropopressure (fishing activity), risking social behaviour impairment in exposed dolphins. The higher diel overlap and increased diel coefficient as the surveys progressed towards the monsoon season suggest temporal shifts in GRD socio-behavioural states and seasonal effects on resource partitioning, respectively. This work identifies drivers of small cetaceans-fisheries interactions and their consequences, and can be used to help reduce biologically significant fishing impacts on small cetaceans. Mitigation strategies, together with river sanctuary and distanced-based approaches, should be urgently included in a framework of ecosystem-based management.

Developing the use of convolutional neural networking in benthic habitat classification and species distribution modelling

Abstract Management of the marine environment is increasingly being conducted in accordance with an ecosystem-based approach, which requires an integrated approach to monitoring. Simultaneous acquisition of the different data types needed is often difficult, largely due to specific gear requirements (grabs, trawls, and video and acoustic approaches) and mismatches in their spatial and temporal scales. We present an example to resolve this using a convolutional neural network (CNN), using ad hoc multibeam data collected during multi-disciplinary surveys to predict the distribution of seabed habitats across the western English Channel. We adopted a habitat classification system, based on seabed morphology and sediment dynamics, and trained a CNN to label images generated from the multibeam data. The probability of the correct classification by the CNN varied per habitat, with accuracy above 60% for 85% of habitats in a training dataset. Statistical testing revealed that the spatial distribution of 57 of the 100 demersal fish and shellfish species sampled across the region during the surveys possessed a non-random relationship with the multibeam-derived habitats using CNN. CNNs, therefore, offer the potential to aid habitat mapping and facilitate species distribution modelling at the large spatial scales required under an ecosystem-based management framework.

From ‘clean and green’ to ‘brown and down’: A synthesis of historical changes to biodiversity and marine ecosystems in the Marlborough Sounds, New Zealand

Ecosystem-based management (EBM) is a potential antidote to the alleviation of multiple stressors in highly-valued and contested marine environments. An understanding of the magnitude and drivers of past ecosystem changes can inform the development of realistic ecological and social outcomes for different places. These goals should aim to increase the ecological health and resilience of coastal ecosystems and their connected land- and sea-scapes by minimising anthropogenic disturbances. To address knowledge gaps, we present a marine historical synthesis of the Marlborough Sounds in New Zealand's South Island. These rias are strongly coupled to the surrounding land and inland river catchments. We took an integrated approach by examining effects of land use change on coastal ecosystems, along with case studies of the effects of exploitation on foundational marine species. We found that ecosystems have gone through a series of transformations since Māori settlement ca. 700 years ago, with localised extirpations of marine megafauna, overharvesting of exploited species, and disruption to ecological functioning through ongoing clearfelling of terrestrial and marine biogenic communities since European settlement in the 1800s. There has been a decline from great abundance of marine life to relative scarcity, which is currently evident to local people in increased effort and reduced allowable catches of fish and shellfish. Recovery of biodiversity in the short-term within the Marlborough Sounds is uncertain, given ongoing multiple and interacting stressors from unsustainable land-use and over-exploitation of marine life. Lifting baselines are possible but will require significant changes to land and marine management to restore ecological health and enhance resilience in the face of climate change. Increased marine protection, regeneration of biodiverse biogenic habitats, spatial fishing measures to increase predators of sea urchins, stricter regulation of plantation forestry and a replanting prohibition in critical erosion source areas, are all needed within an EBM framework. Large experimental areas are proposed to develop, test and integrate different management techniques, and to facilitate community understanding, participation, and support for the transition to EBM.

Biomolecular Composition and Revenue Explained by Interactions between Extrinsic Factors and Endogenous Rhythms of Saccharina latissima.

This review provides a systematic overview of the spatial and temporal variations in the content of biomolecular constituents of Saccharina latissima on the basis of 34 currently available scientific studies containing primary measurements. We demonstrate the potential revenue of seaweed production and biorefinery systems by compiling a product portfolio of high-value extract products. An investigation into the endogenous rhythms and extrinsic factors that impact the biomolecular composition of S. latissima is presented, and key performance factors for optimizing seaweed production are identified. Besides the provisioning ecosystem service, we highlight the contribution of green-engineered seaweed production systems to the mitigation of the ongoing and historical anthropogenic disturbances of the climate balance and nutrient flows. We conclude that there are risks of mismanagement, and we stress the importance and necessity of creating an adaptive ecosystem-based management framework within a triple-helix partnership for balancing the utilization of ecosystem services and long-term resilience of aquatic environment.

Food-Web and Ecosystem Structure of the Open-Ocean and Deep-Sea Environments of the Azores, NE Atlantic

The Marine Strategy Framework Directive intends to adopt ecosystem-based management for resources, biodiversity and habitats that puts emphasis on maintaining the health of the ecosystem alongside appropriate human use of the marine environment, for the benefit of current and future generations. Within the overall framework of ecosystem-based management, ecosystem models are tools to evaluate and gain insights in ecosystem properties. The low data availability and complexity of modelling deep-water ecosystems has limited the application of ecosystem models to few deep-water ecosystems. Here, we aim to develop an ecosystem model for the deep-sea and open ocean in the Azores exclusive economic zone with the overarching objective of characterising the food-web and ecosystem structure of the ecosystem. An ecosystem model with 45 functional groups, including a detritus group, two primary producer groups, eight invertebrate groups, 29 fish groups, three marine mammal groups, a turtle and a seabird group was built. Overall data quality measured by the pedigree index was estimated to be higher than the mean value of all published models. Therefore, the model was built with source data of an overall reasonable quality, especially considering the normally low data availability for deep-sea ecosystems. The total biomass (excluding detritus) of the modelled ecosystem for the whole area was calculated as 24.7 t km-². The mean trophic level for the total marine catch of the Azores was estimated to be 3.95, similar to the trophic level of the bathypelagic and medium-size pelagic fish. Trophic levels for the different functional groups were estimated to be similar to those obtained with stable isotopes and stomach contents analyses, with some exceptions on both ends of the trophic spectra. Omnivory indices were in general low, indicating prey speciation for the majority of the groups. Cephalopods, pelagic sharks and toothed whales were identified as groups with key ecological roles in the ecosystem. Due to concerns on the use of ecosystem models with low confidence in exploring management decisions and ecological theories, the current version of this model should only be use with caution until biomass estimates are validated with survey data or the model is fitted to time

Turning casualty into opportunity: fragmenting dislodged colonies is effective for restoring reefs of a Mediterranean endemic coral

Within the framework of ecosystem-based management, restoration appears as a sensible option to counteract the global decline of coral reefs. Several techniques involving sexual and asexual coral propagules have been used for the restoration of reefs. Culturing of fragments has proved fruitful since it takes advantage of the capability of corals to asexually reproduce, providing a number of novel colonies that can be replanted. This method however, when using fragments detached from a colony, might be stressful for the wild donor. Astroides calycularis is an endemic and endangered Mediterranean scleractinian coral forming massive colonies mostly at shallow depth. It is subject to anthropogenic impact, particularly from damage due to accidental contacts by SCUBA divers, and it is expected to suffer from sea storms of increasing power under the projected climate change scenarios. Corals of opportunity (i.e. dislodged colonies found alive on the seabed) may be a useful resource for the restoration of A. calycularis reefs, given that the fragment-based transplant technique is effective for this species as it is for other massive corals. A one-year transplant experiment was carried out along an exposed rocky shore in NW Sicily (Mediterranean Sea) to test the feasibility of using fragments of corals of opportunity for restoration purposes. The transplants revealed high survival rates and higher number of new polyps than in control colonies. The original size of transplanted fragments did not influence their capability to bud new polyps and was not related to their survival rate. The applied technique provides the opportunity to restore rocky reefs, even the very shallow ones, through direct transplant of coral fragments, thus making reef restoration a feasible option in ecosystem-based management plans for this species.

Testing fisher-developed alternatives to fishery management tools for community support and regulatory effectiveness

This research develops a methodology to evaluate public support for fishing regulations, comparing existing regulations designed without much public input, to possible alternative regulations based fishers' ecological knowledge (FEK) and preferences. First, a survey and open-ended interview was completed with 42 fishers in St. Croix, U.S. Virgin Islands (33% of the total number of currently registered commercial fishers on island) regarding general matters of fishery health and productivity, with heightened focus on the management of a mutton snapper (Lutjanus analis) spawning aggregation. The interview results suggest that fishers view management tools in terms of spatial and temporal parameters, and how much those regulations influence gear selection. Fishers respond primarily to socioeconomic pressures, but recognize and support ecological goals of regulations, particularly those that provide protections to important stocks throughout their spawning season. A Discrete Choice Model (DCM) was developed based on the results of the fisher surveys and was administered to 182 individuals, including 54 residents of St. Croix and all 42 fishers interviewed. Eight DCM options were presented to respondents who selected their regulatory preference in a pair-wise fashion. In seven of eight pairs, public respondents selected fisher-preferred, FEK-based regulatory frameworks. These results suggest FEK can be used to develop fishery regulations that will meet management goals, and be broadly supported by both members of the fishing community and the general public. In this manner, ecosystem-based management frameworks can be improved by incorporating fishers and their FEK, particularly for small-scale fisheries.

Confronting the implementation of marine ecosystem-based management within the Common Fisheries Policy reform

This paper confronts, by meta-synthesis of the literature, the definition of ecosystem-based management provided in the reform of the European Common Fisheries Policy (CFP) with the specific measures and the institutional framework foreseen in it.By analysing the reform of the CFP by means of the ecosystem-based management framework, we conclude that there is a lack of instruments to deal with the social sustainability objective while economic and ecological sustainability could be simultaneously achieved with the specific measures considered in the reform.Individually analysed, the specific measures could further benefit ecosystem-based management implementation, although not all the observed or analysed consequences of the implementation of these measures move in this direction. In that sense we conclude that the success of the ecosystem based management of EU fisheries depends much more on the specific implementation of the measures and on the accompanying incentives, which in the end, implies that the institutional and political settings will determine its success.

Fewer but Not Smaller Schools in Declining Fish and Krill Populations

Many pelagic species (species that live in the water column), including herring and krill, aggregate to form schools, shoals, or swarms (hereafter simply "schools," although the words are not synonyms). Schools provide benefits to individual members, including locomotory economy and protection from predators that prey on individuals, but paradoxically make schooling species energetically viable and commercially attractive targets for predators of groups and for fishers. Large schools are easier to find and yield greater prey/catch than small schools, and there is a requirement from fields as diverse as theoretical ecology and fisheries management to understand whether and how aggregation sizes change with changing population size. We collated data from vertical echosounder surveys of taxonomically diverse pelagic stocks from geographically diverse ecosystems. The data contain common significant positive linear stock-biomass to school-number relationships. They show that the numbers of schools in the stocks change with changing stock biomass and suggest that the distributions of school sizes do not change with stock biomass. New data that we collected using a multibeam sonar, which can image entire schools, contained the same stock-biomass to school-number relationship and confirm that the distribution of school sizes is not related to changing stock size: put simply, as stocks decline, individuals are distributed among fewer schools, not smaller schools. Since school characteristics affect catchability (the ease or difficulty with which fishers can capture target species) and availability of prey to predators, our findings have commercial and ecological implications, particularly within the aspirational framework of ecosystem-based management of marine systems.

Review and refinement of an existing qualitative risk assessment method for application within an ecosystem-based management framework

Abstract The adoption of risk-based methodologies is considered essential for the successful implementation of an ecosystem approach to fisheries and broader aquatic management. To assist with these initiatives, one of the qualitative risk assessment methods adapted for fisheries management over a decade ago has been reviewed. This method was updated to ensure compliance with the revised international standards for risk management (ISO 31000) and to enable consideration of ecological, economic, social, and governance risks. The review also addressed the difficulties that have been encountered in stakeholder understanding of the underlying concepts and to increase the discipline in its application. The updates include simplifying the number of consequence and likelihood levels, adopting graphical techniques to represent different consequence levels, and discussing how changes in uncertainty can affect risk scores. Adopting an explicit “weight of evidence” approach has also assisted with determining which consequence scenarios are considered plausible and, where relevant, their specific likelihoods. The revised methods therefore incorporate the conceptual elements from a number of qualitative and quantitative approaches increasing their reliability and enabling a more seamless transition along this spectrum as more lines of evidence are collected. It is expected that with continued application of these methods, further refinements will be identified.

Consequences of a government-controlled agricultural price increase on fishing and the coral reef ecosystem in the republic of kiribati.

BackgroundEconomic development policies may have important economic and ecological consequences beyond the sector they target. Understanding these consequences is important to improving these policies and finding opportunities to align economic development with natural resource conservation. These issues are of particular interest to governments and non-governmental organizations that have new mandates to pursue multiple benefits. In this case study, we examined the direct and indirect economic and ecological effects of an increase in the government-controlled price for the primary agricultural product in the Republic of Kiribati, Central Pacific.Methods/Principal FindingsWe conducted household surveys and underwater visual surveys of the coral reef to examine how the government increase in the price of copra directly affected copra labor and indirectly affected fishing and the coral reef ecosystem. The islands of Kiribati are coral reef atolls and the majority of households participate in copra agriculture and fishing on the coral reefs. Our household survey data suggest that the 30% increase in the price of copra resulted in a 32% increase in copra labor and a 38% increase in fishing labor. Households with the largest amount of land in coconut production increased copra labor the most and households with the smallest amount of land in coconut production increased fishing the most. Our ecological data suggests that increased fishing labor may result in a 20% decrease in fish stocks and 4% decrease in coral reef-builders.Conclusions/SignificanceWe provide empirical evidence to suggest that the government increase in the copra price in Kiribati had unexpected and indirect economic and ecological consequences. In this case, the economic development policy was not in alignment with conservation. These results emphasize the importance of accounting for differences in household capital and taking a systems approach to policy design and evaluation, as advocated by sustainable livelihood and ecosystem-based management frameworks.

Killifish habitat suitability as a measure of coastal restoration performance: Integrating field data, behavioral trials and simulation

One of the goals of the Comprehensive Everglades Restoration Plan (CERP) is to restore more natural salinity regimes to the coastal bays of South Florida (USA) with the aim of improving their degraded estuarine function (e.g., as productive feeding and nursery areas). Here, we examined the occurrence (presence–absence) and concentration (presence-only fish density) of goldspotted killifish (Floridichthys carpio) observed in an ongoing fish survey as potential indicators of restoration performance in Biscayne Bay, Florida. To determine F. carpio salinity affinity, we applied regression analyses to field data and performed behavioral choice trials in the laboratory, whereby individuals were exposed to a salinity gradient (10–50). Analysis of field data indicated a parabolic relationship between killifish occurrence and salinity, where occurrence is maximized at salinity ∼22. Killifish concentration was unrelated to salinity. Experimental salinity choice results tended to agree with field observations of occurrence and demonstrated a preference for intermediate salinity levels (10–30). Finally, we performed a simulation exercise to compare seasonal changes in habitat suitability within our study domain over the course of one year. Seasonal comparisons were performed as a proxy for assessing different freshwater management alternatives. We applied the relationship between killifish occurrence and salinity that resulted from analyses of field data to the output of a published hydrodynamic salinity transport model. This exercise provided areal estimates of suitable habitat gained or lost, as well as maps indicating the geographic distribution of habitat quality by season. We conclude that: (1) continued field monitoring of goldspotted killifish occurrence is warranted for its utility as a biological indicator of nearshore salinity conditions in an ecosystem-based management framework and (2) the regression relationships revealed by the present study may be useful in habitat suitability modeling exercises, especially those that compare impacts of different freshwater flow scenarios via simulation.

New approaches to simulating the complex interaction effects of multiple human impacts on the marine environment

Abstract The interplay of anthropogenic effects presents significant challenges to modelling and managing marine resources. The increasing awareness of the complexity of the interaction of human impacts has led to a demand for end-to-end (E2E) models that attempt to include all major processes in a single framework. These whole-of-system models are potentially very useful as numerical laboratories to explore the potential spectrum of responses from the interplay of anthropogenic effects. However, despite their limitations and early stage of development, the output of E2E models is under increasing social pressure to provide “simple” answers to highly complex problems. Here, we suggest some approaches that can be included in E2E models for considering the potential effects of complex interactions on community and ecosystem services. We show how assumptions and parameterizations made in existing E2E models can be altered to allow processes to shift with the dynamic response to both natural and human drivers. Alternative ways for interpreting complex model output, non-linearity, handling uncertainty, and how to include multispecies interaction effects within a framework of ecosystem-based management are suggested. We point out parts of the marine system that have been neglected in model development, but now should be included to understand interaction effects from multiple anthropogenic stressors. The E2E model framework also needs to be further expanded from an often-skewed focus on ecological systems to a more even-handed treatment of socio-ecological systems, including cultural aspects. Future progress in E2E models will require an interdisciplinary framework involving both qualitative and quantitative approaches, closer cooperation between empiricists and modellers, and the development of consistent terminology.

Eco-labeling seafood: Addressing impacts to vulnerable seafloor species, communities, habitats and ecosystems in data-poor regions

Certification and eco-labeling schemes for the ecological sustainability of seafood have increased in recent years due, in large part, to consumer demand. While most attention has been focused on the population status and trends of target and bycatch species, the conservation of vulnerable species, communities, habitats and ecosystems (VSCHEs) has not consistently been addressed in an adequate manner, especially in data-poor systems. Unfortunately knowledge of VSCHE distribution patterns is inadequate, and even the leading fishery certification agencies only broadly address impacts to VSCHEs. Little guidance has been given to third party certifiers for gathering and evaluating appropriate information for assessing VSCHEs, and there is no explicitly precautionary method of assessing their vulnerability in an information poor environment. These shortcomings led to significant differences in how the impacts of fisheries on VSCHEs have been evaluated from one assessment to another, potentially resulting in a certified fishery when existing information suggests there are significant impacts. This study develops an explicit approach for data mining and evaluation for the eco-labeling certification process; proposes a precautionary method for assessing vulnerability of VSCHEs based on exposure, sensitivity and resilience and provides an example of how these can be integrated into existing fishery certification frameworks. This overall approach is also amenable for use by governmental agencies to advance conservation of VSCHEs within ecosystem-based management frameworks. & 2012 Elsevier Ltd. All rights reserved.