Our oceans are heavily utilized by a wide variety of human activities that exert pressures which negatively impact marine ecosystems, occasionally leading to unsustainable rates of exploitation. A linkage framework approach can be used to make independent associations between sectors, activities, and the pressures they introduce. However, in reality, many different sectors and their associated activities overlap in time and space, potentially changing the severity of their impact as pressures combine, and undermine the efforts of environmental managers to mitigate the harmful effects of those activities. Here, we present a spatially resolved approach to assess the potential for combined effects using a linkage framework assessment. Using illustrative examples from the Northeast Atlantic, we show the likelihood of changes in pressure severity as a result of multiple overlapping activities. Management options to limit pressure introduction are explored and their benefit—measured as a reduction in the area of seabed impacted—assessed. In its simplest form, the approach can be used to develop potential precautionary management options in areas where data availability is poor and more comprehensive management measures where data are more widely available.
Rotational harvesting is one of the oldest management strategies applied to terrestrial and marine natural resources, with crop rotations dating back to the time of the Roman Empire. The efficacy of this strategy for sessile marine species is of considerable interest given that these resources are vital to underpin food security and maintain the social and economic wellbeing of small-scale and commercial fishers globally. We modeled the rotational zone strategy applied to the multispecies sea cucumber fishery in Australia’s Great Barrier Reef Marine Park and show a substantial reduction in the risk of localized depletion, higher long-term yields, and improved economic performance. We evaluated the performance of rotation cycles of different length and show an improvement in biological and economic performance with increasing time between harvests up to 6 y. As sea cucumber fisheries throughout the world succumb to overexploitation driven by rising demand, there has been an increasing demand for robust assessments of fishery sustainability and a need to address local depletion concerns. Our results provide motivation for increased use of relatively low-information, low-cost, comanagement rotational harvest approaches in coastal and reef systems globally.
The science-based management of natural resources requires knowledge exchange between scientists and environmental decision-makers, however, this exchange remains a significant challenge. Rather, evidence suggests that decision-makers rely on individual experience or other secondary sources of knowledge in isolation from scientific evidence when formulating decisions, potentially compromising the effectiveness of their decisions. As a result a new field of research broadly characterised as ‘knowledge exchange’ has emerged, focused largely on identifying and overcoming the barriers to knowledge exchange among scientists and decision-makers. More recently knowledge exchange research has also begun to explore the relationship between science and decision-making specifically in relation to marine ecosystems and resources. The aim of this paper is to review the literature in relation to knowledge exchange for natural resource management, with a focus on recent evidence in relation to the management of marine resources. This review identifies critical barriers inhibiting knowledge exchange among marine scientists and decisions-makers, such as the inaccessibility of science to decision-makers as well as institutional barriers that limit the extent to which scientists and decision-makers can prioritise knowledge exchange activities. Options for overcoming these barriers, such as novel approaches to knowledge exchange (e.g. – knowledge co-production, knowledge brokers and boundary organisations) and the enabling environments and institutional reforms needed to complement efforts to improve knowledge exchange, are also identified. This review concludes by articulating the gaps in our understanding of knowledge exchange, to help guide future research in this field and improve the sustainable management of marine resources.
Under the 2013 Reform of the European Union's Common Fisheries Policy (CFP), fisheries management aims to ensure that, within a reasonable time frame, the exploitation of marine biological resources restores and maintains populations of harvested stocks above levels that can produce the maximum sustainable yield (MSY). The CFP also calls for the implementation of an ecosystem-based approach to fisheries management (EBFM). In this paper, we present the concept of maximum sustainable dead biomass (MSDB) and its associated management reference points for fishing mortality and spawning-stock biomass as alternatives to those associated with MSY. The concept of MSDB is illustrated by a dynamic pool production model of a virtual fish stock which takes into account variations in natural mortality (M), fishing mortality (F), and exploitation pattern. Our approach implies a compensatory mechanism whereby survivors may benefit from compensatory density dependence and is implemented through progressive substitution of M with F for varying rates of total mortality (Z). We demonstrate that the reference points for fishing mortality and spawning-stock biomass associated with MSDB are less sensitive to increasing compensation of M with F than those associated with MSY and more sensitive to changes in selection pattern. MSDB-based reference points, which are consistent with maximum stock productivity, are also associated with lower fishing mortality rates and higher stock biomasses than their MSY-based counterparts. Given that selection pattern can be influenced through fishery input measures (e.g. technical gear measures, decisions on areas, and/or times of fishing), whereas variations of M in response to F are not controllable (indeed poorly understood), that the results of many fish stock assessments are imprecise, that maximum stock productivity corresponds to MSDB and that MSY-based reference points may best be considered as limits, we propose that MSDB-based reference points provide a more appropriate basis for management under an EBFM.
La Gomera (Canary Islands, Spain) is home to an extraordinarily high cetacean species diversity. However, the protection status of cetaceans in the Canary Islands is limited and mainly determined through the SAC provision of the European Union Habitats Directive, which refers to two species in relation to practical conservation. All other cetaceans are included in the Canary Islands Catalogue of Protected Species, but it remains unclear what that protection entails. At the same time, anthropogenic threats ranging from, habitat degradation, ship strikes and disturbance through whale watching tourism are increasing steadily. In 2008, more than 600,000 tourists went to see cetaceans in the Canaries, while most of this tourism branch is centred on the island of Tenerife where a "Marine Park for Cetaceans" has been established. But again it remains unclear to what extent such a park contributes to marine conservation in the area. Here, a Marine Protected Area is proposed and laid out for La Gomera, Tenerife's neighbouring island, where cetacean tourism is still at a low level. This MPA is especially designed for the long-term development of whale watching tourism and other uses in a sustainable way. Such a new MPA at La Gomera could provide a useful comparative model that might inform management practices in Tenerife and other high volume areas. "Sustainable" thereby means to achieve a long standing equilibrium between the development of whale watching tourism and the maintenance of healthy cetacean populations and their marine environment. The proposed management measures are based upon the experience of many years of best practice established through the close collaboration between an NGO and local whale watching operators. Although specially designed for the waters off La Gomera, this model can serve as a blueprint for other areas as well.
The Surfrider Foundation, in partnership with Point 97 and the state of Washington, recently completed the Washington Coastal and Ocean Recreation Study and today released the final report. The study collected economic and spatial data on “non-consumptive” recreational uses such as beach going, kayaking, wildlife viewing, hiking and biking, and surfing. These recreational uses are widely practiced along the extent of Washington’s coast (Pacific Coast & Strait of Juan de Fuca). Information from the study will be used as part of the state’s marine spatial planning process, which is a collaborative endeavor to analyze and allocate the spatial and temporal distribution of human activities in marine environments to achieve ecological, economic, and social objectives.
Implementation of adaptation actions to protect biodiversity is limited by uncertainty about the future. One reason for this is the fear of making the wrong decisions caused by the myriad future scenarios presented to decision-makers. We propose an adaptive management (AM) method for optimally managing a population under uncertain and changing habitat conditions. Our approach incorporates multiple future scenarios and continually learns the best management strategy from observations, even as conditions change. We demonstrate the performance of our AM approach by applying it to the spatial management of migratory shorebird habitats on the East Asian–Australasian flyway, predicted to be severely impacted by future sea-level rise. By accounting for non-stationary dynamics, our solution protects 25 000 more birds per year than the current best stationary approach. Our approach can be applied to many ecological systems that require efficient adaptation strategies for an uncertain future.
The abundance of a species' population in an ecosystem is rarely stationary, often exhibiting large fluctuations over time. Using historical data on marine species, we show that the year-to-year fluctuations of population growth rate obey a well-defined double-exponential (Laplace) distribution. This striking regularity allows us to devise a stochastic model despite seemingly irregular variations in population abundances. The model identifies the effect of reduced growth at low population density as a key factor missed in current approaches of population variability analysis and without which extinction risks are severely underestimated. The model also allows us to separate the effect of demographic stochasticity and show that single-species growth rates are dominantly determined by stochasticity common to all species. This dominance—and the implications it has for interspecies correlations, including co-extinctions—emphasizes the need for ecosystem-level management approaches to reduce the extinction risk of the individual species themselves.
Ocean acidification, the progressive change in ocean chemistry caused by uptake of atmospheric CO2, is likely to affect some marine resources negatively, including shellfish. The Atlantic sea scallop (Placopecten magellanicus) supports one of the most economically important single-species commercial fisheries in the United States. Careful management appears to be the most powerful short-term factor affecting scallop populations, but in the coming decades scallops will be increasingly influenced by global environmental changes such as ocean warming and ocean acidification. In this paper, we describe an integrated assessment model (IAM) that numerically simulates oceanographic, population dynamic, and socioeconomic relationships for the U.S. commercial sea scallop fishery. Our primary goal is to enrich resource management deliberations by offering both short- and long-term insight into the system and generating detailed policy-relevant information about the relative effects of ocean acidification, temperature rise, fishing pressure, and socioeconomic factors on the fishery using a simplified model system. Starting with relationships and data used now for sea scallop fishery management, the model adds socioeconomic decision making based on static economic theory and includes ocean biogeochemical change resulting from CO2 emissions. The model skillfully reproduces scallop population dynamics, market dynamics, and seawater carbonate chemistry since 2000. It indicates sea scallop harvests could decline substantially by 2050 under RCP 8.5 CO2 emissions and current harvest rules, assuming that ocean acidification affects P. magellanicus by decreasing recruitment and slowing growth, and that ocean warming increases growth. Future work will explore different economic and management scenarios and test how potential impacts of ocean acidification on other scallop biological parameters may influence the social-ecological system. Future empirical work on the effect of ocean acidification on sea scallops is also needed.
Pursuit of the triple bottom line of economic, community and ecological sustainability has increased the complexity of fishery management; fisheries assessments require new types of data and analysis to guide science-based policy in addition to traditional biological information and modeling. We introduce the Fishery Performance Indicators (FPIs), a broadly applicable and flexible tool for assessing performance in individual fisheries, and for establishing cross-sectional links between enabling conditions, management strategies and triple bottom line outcomes. Conceptually separating measures of performance, the FPIs use 68 individual outcome metrics—coded on a 1 to 5 scale based on expert assessment to facilitate application to data poor fisheries and sectors—that can be partitioned into sector-based or triple-bottom-line sustainability-based interpretative indicators. Variation among outcomes is explained with 54 similarly structured metrics of inputs, management approaches and enabling conditions. Using 61 initial fishery case studies drawn from industrial and developing countries around the world, we demonstrate the inferential importance of tracking economic and community outcomes, in addition to resource status.