Marine environments are subject to a range of human disturbances. Identifying effective conservation strategies, in order to manage or mitigate the negative impacts of human activities, requires a way to first identify and evaluate the impact of activities on ecosystem components. Multicriteria decision analysis (MCDA) techniques such as the Analytic Hierarchy Process (AHP) offer a way to systematically evaluate and integrate stakeholder opinion in order to set priorities and make decisions. With a goal to synthesize current knowledge of the potential impacts of human activity on breeding and non-breeding seabirds in the western North Atlantic Ocean, we present a case study involving the use of AHP to assess sensitivity of species to such hazards as: fisheries bycatch, oiling, light pollution, vessel traffic, marine debris, and offshore wind turbines. Based on responses from ten North Atlantic seabird experts, fisheries bycatch (particularly when involving suspended gill nets) was identified as the greatest risk across a wide range of species, with an overall relative value of 0.47 ± SE 0.026. Oiling risk was the second most highly ranked (0.26 ± 0.026, of which 0.214 corresponded with surface oil, 0.044 with oil and gas platform interactions), and was considered to have the greatest potential impact on alcids (Common and Thick-billed Murre, Atlantic Puffin, Razorbill, Dovekie). Offshore wind turbines (0.097 ± 0.022), marine debris (0.08 ± 0.016), light pollution (0.058 ± 0.0077), and traffic (0.042 ± 0.0053) were considered to be less serious risks for seabirds than fisheries bycatch and oiling. In addition to demonstrating how relative risk can be quantified using a multicriteria decision analysis technique such as AHP, we summarize the sensitivities of fourteen seabirds and suggest ways in which multicriteria decision analysis can enhance conservation planning.
Fishery managers worldwide are evaluating methods for incorporating climate, habitat, ecological, social, and economic factors into current operations in order to implement Ecosystem Approaches to Fishery Management (EAFM). While this can seem overwhelming, it is possible to take practical steps toward EAFM implementation that make use of existing information and provide managers with valuable strategic advice. Here, we describe the process used by the U.S. Mid-Atlantic Fishery Management Council (Council) to develop an ecosystem-level risk assessment, the initial step proposed in their recently adopted EAFM guidance document. The Council first defined five types of Risk Elements (ecological, economic, social, food production, management) and identified which management objectives aligned with each element. Based on an existing ecosystem status report for the region and other existing sources (including expert opinion), potential ecological, social, economic, and management indicators were identified for each risk element. Finally, low, low-moderate, moderate-high, and high risk criteria were defined for each indicator, and the indicator data were used to score each risk element using the criteria. The ultimate outcome is a ranked risk assessment in order to focus on the highest risk issues for further evaluation and mitigation. The risk assessment highlights certain species and certain management issues as posing higher cumulative risks to meeting Council management objectives when considering a broad range of ecological, social, and economic factors. Tabular color coded summaries of risk assessment results will be used by the Council to prioritize further EAFM analyses as well as research plans over the coming 5 years. As ecosystem reporting and operational EAFM continue to evolve in future years, the Council foresees integrating these efforts so that ecosystem indicators are refined to meet the needs of fishery managers in identifying and managing risks to achieving ecological, social, and economic fishery objectives. Overall, ecosystem indicator-based risk assessment is a method that can be adapted to a wide range of resource management systems and available information, and therefore represents a promising way forward in the implementation of EAFM.
The coastal and marine environment is often managed according to the principles of sustainable development, which include environmental, economic, and social dimensions. While each are equally important, social sustainability receives a lower priority in both policy and research. Methodologies for assessing social sustainability are less developed than for environmental and economic sustainability, and there is a lack of data on the social aspects of sustainable development (such as social equity), which constitutes a barrier to understanding social considerations and integrating them into natural resource management. This paper explores a threat and risk assessment to the marine estate in New South Wales, Australia, which identified and categorised both the benefits that communities gain from the marine estate and the threats to those benefits. A broad range of benefits were identified including participation (e.g., socialising and sense of community), enjoyment (e.g., enjoying the biodiversity and beauty), cultural heritage and use, intrinsic and bequest values, the viability of businesses, and direct economic values. Threats to community benefits were categorised as resource use conflict, environmental, governance, public safety, critical knowledge gaps and lack of access. An integrated threat and risk assessment approach found that the priority threats to community benefits were environmental threats (e.g., water pollution), critical knowledge gaps (e.g., inadequate social and economic information), governance (e.g., lack of compliance), resource-use conflict (e.g., anti-social behaviour), and lack of access (e.g., loss of fishing access). Threat and risk assessment is an evidence-based tool that is useful for marine planning because it provides a structured approach to incorporating multiple types of knowledge and enables limited resources to be targeted to the threats identified as being most important to address.
This study provides an integrated perspective to ecosystem based management (EBM) by considering a diverse array of societal goals, i.e. sustainable food supply, clean energy and a healthy marine ecosystem, and a selection of management measures to achieve them. The primary aim of this exercise is to provide guidance for (more) integrated EBM in the North Sea based on an evaluation of the effectiveness of those management measures in contributing to the conservation of marine biodiversity. A secondary aim is to identify the requirements of the knowledge base to guide such future EBM initiatives.
Starting from the societal goals we performed a scoping exercise to identify a “focal social-ecological system” which is a subset of the full social-ecological system but considered adequate to guide EBM towards the achievement of those societal goals. A semi-quantitative risk assessment including all the relevant human activities, their pressures and the impacted ecosystem components was then applied to identify the main threats to the North Sea biodiversity and evaluate the effectiveness of the management measures to mitigate those threats.
This exercise revealed the need for such risk-based approaches in providing a more integrated perspective but also the trade-off between being comprehensive but qualitative versus quantitative but limited in terms of the “focal” part of the SES that can be covered. The findings in this paper provide direction to the (further) development of EBM and its knowledge base that should ultimately allow an integrated perspective while maintaining its capacity to deliver the accuracy and detail needed for decision-making.
Management of and planning for the Canadian marine environment can be disrupted by conflict, but conflict is inevitable given the plurality of actors, interests, values, and uses of marine space. Unresolved conflict may impede governance objectives and threaten the sustainability of social-ecological systems. Innovative institutional arrangements such as adaptive comanagement theoretically reduce conflict and support sustainable management. The southwest New Brunswick Bay of Fundy Marine Advisory Committee (MAC) was assembled in 2004 to address conflict between marine users and to further marine planning. As an innovative planning institution influenced by comanagement theory, the MAC experience served as a case study to develop governance measures for the Canadian Fisheries Research Network Comprehensive Fisheries Sustainability Framework, which includes a consideration of ecological, social, economic, and governance dimensions of sustainability. One of the most important but neglected aspects of sustainability measurements involves the assessment of governance and planning effectiveness. An assessment of the MAC experience through a comprehensive sustainability evaluation framework offers significant lessons for advancing the theoretical and empirical literature on adaptive comanagement through deeper consideration of challenges in creating institutions of “good governance.” In doing so, the case study also contributes to the Comprehensive Fisheries Sustainability Framework by testing some measures of governance effectiveness, including co-operation, resources, transparency, accountability, and inclusivity.
Based on a validated underwater oil spill model and the hydrodynamic background provided by an unstructured grid, finite-volume, coastal ocean model (FVCOM), a series of numerical experiments are conducted to study the impact of error in ocean dynamical background currents on the 3D transport of underwater spilled oil, in terms of three metrics including oil centroid position, sweeping area, and sweeping volume. Numerical result shows that a larger error in ocean dynamical background currents results in a larger model error expectation and uncertainty for all three metrics. As model time increases, the model error mainly increases and the error growth rate varies unevenly. The sensitivity of the oil spill model to background current error can be interpreted as an integrated result of the temporal and spatial variations of the background current and the movement of oil droplets of different sizes.
Hazards resulting from asteroid ocean impacts were modelled using hydrocode simulations to examine the near-field effects including the initial formation and subsequent long range propagation of tsunami waves that can transport potentially damaging energy far from the impact site.
Three-dimensional simulations of oblique impacts into deep water, with trajectory angles ranging from 27° to 60° above the horizontal, were performed with the Los Alamos Rage hydrocode. The simulations include atmospheric effects such as ablation and airbursts. These oblique impact simulations are performed in order to help determine whether there are additional dangers due to the obliquity of impact not covered by previous studies. The energy transferred to both the air blast wave and the water are calculated as well as the amount of sea water lofted into the upper atmosphere. Water crater sizes and subsequent surface elevation profiles, surface pressures, and depth-averaged mass fluxes within the water are prepared for use in far-field propagation studies. Like previous three-dimensional simulations, these simulations show that except at exceedingly shallow entry angles below those simulated here the resulting waves are roughly circular and that the initial waves and central jet oscillation are highly turbulent and dissipate a lot of the energy.
Two-dimensional axisymmetric simulations of long range propagation of impact tsunami were performed using the Lawrence Livermore ALE3D hydrocode on the NASA Pleiades supercomputer. These simulations showed that impacts under 1 gigaton TNT equivalent into the deep ocean basins will create deep-water waves that undergo dispersion, whereas impacts onto continental shelves will create shallow-water waves that do not suffer dispersion. The simulations also showed that on the order of 1% of the kinetic energy of the impact is converted into the tsunami wave. This is an order of magnitude less than previous semi-empirical estimates of ∼15% based on explosion test data and laboratory scale impacts.
Oil spill response (OSR) in the Arctic marine environment conducted as part of operational planning and preparedness supporting exploration and development is most successful when knowledge of the ecosystem is readily available and applicable in an oil spill risk assessment framework. OSR strategies supporting decision-making during the critical period after a spill event should be explicit about the environmental resources potentially at risk and the efficacy of OSR countermeasures that best protect sensitive and valued resources. At present, there are 6 prominent methods for spill impact mitigation assessment (SIMA) in the Arctic aimed at supporting OSR and operational planning and preparedness; each method examines spill scenarios and identifies response strategies best suited to overcome the unique challenges posed by polar ecosystems and to minimize potential long-term environmental consequences. The different methods are grounded in classical environmental risk assessment and the net environmental benefit analysis (NEBA) approach that emerged in the 1990s after the Exxon Valdez oil spill. The different approaches share 5 primary assessment elements (oil physical and chemical properties, fate and transport, exposure, effects and consequence analysis). This paper highlights how the different Arctic methods reflect this common risk assessment framework and share a common need for oil spill science relevant to Arctic ecosystems. An online literature navigation portal, developed as part of the 5-year Arctic Oil Spill Response Technologies Joint Industry Programme, complements the different approaches currently used in the Arctic by capturing the rapidly expanding body of scientific knowledge useful to evaluating exposure, vulnerability and recovery of the Arctic ecosystem after an oil spill.
Vessel traffic has been increasing rapidly in the Arctic, and within the Canadian Arctic, tourist vessels are the fastest growing maritime sector. Vessel traffic can cause a variety of impacts on whales, including ship strikes and acoustic disturbance. Here, the overlap between tourist vessels (e.g., pleasure craft/yachts and passenger vessels/cruise ships) and whale concentration areas is assessed within the Inuvialuit Settlement Region of the western Canadian Arctic. Different management measures which could be used to reduce impacts on whales are also assessed. Passenger vessels have had a relatively constant overlap with whale concentration areas through time, whereas pleasure craft have had a recent and rapid increase. Passenger vessels may have a greater impact on whales, compared to pleasure craft, since they are larger and travel faster. Excluding vessels from the two marine protected areas in the region would have no impact on whales within concentration areas, since vessels would likely just be displaced to adjacent areas with similar whale concentrations. Restricting vessels to the Canadian government's proposed low-impact corridor may reduce impact slightly, but creating a corridor completely outside of the known whale area could more significantly reduce the potential impact of vessels on whales in those areas. Restricting vessel speed within whale areas would also reduce the impact of passenger vessels, but would not likely reduce the impact of pleasure craft. Overall, a combination of management measures may be the best way to reduce impacts on whales in concentration areas.
Assessing risks to marine ecosystems is critical due to their biological and economic importance, and because many have recently undergone regime shifts due to overfishing and environmental change. Yet defining collapsed ecosystem states, selecting informative indicators and reconstructing long-term marine ecosystem changes remains challenging. The IUCN Red List of Ecosystems constitutes the global standard for quantifying risks to ecosystems and we conducted the first Red List assessment of an offshore marine ecosystem, focusing on the southern Benguela in South Africa. We used an analogous but collapsed ecosystem – the northern Benguela – to help define collapse in the southern Benguela and derived collapse thresholds with structured expert elicitation (i.e. repeatable estimation by expert judgment). To capture complex ecosystem dynamics and reconstruct historical ecosystem states, we used environmental indicators as well as survey-, catch- and model-based indicators. We listed the ecosystem in 1960 and 2015 as Endangered, with assessment outcomes robust to alternative model parametrizations. While many indicators improved between 1960 and 2015, seabird populations have suffered large declines since 1900 and remain at risk, pointing towards ongoing management priorities. Catch-based indicators often over-estimated risks compared to survey- and model-based indicators, warning against listing ecosystems as threatened solely based on indicators of pressure. We show that risk assessments provide a framework for interpreting data from indicators, ecosystem models and experts to inform the management of marine ecosystems. This work highlights the feasibility of conducting Red List of Ecosystems assessments for marine ecosystems.