The Evidence Based Decision Making (EBDM) paradigm encourages managers to base their decisions on the strongest available evidence, but it has been criticized for placing too much emphasis on the choice of study design method without considering the types of questions that are being addressed as well as other relevant factors such as how well a study is implemented. Here we review the objectives of Australia’s Marine Park network, and identify the types of questions and data analysis that would address these objectives. Critically, we consider how the design of a monitoring program influences our ability to adequately answer these questions, using the strength of evidence hierarchy from the EBDM paradigm to assess the adequacy of different design strategies and other sources of information. It is important for conservation managers to recognize that the types of questions monitoring programs are able to answer depends on how they are designed and how the collected data are analyzed. The socio-political process that dictates where protected areas are placed typically excludes the strongest types of evidence, Random Controlled Trials (RCTs), for certain questions. Evidence bases that are stronger than ones commonly employed to date, however, could be used to provide a causal inference, including for those questions where RCTs are excluded, but only if appropriate designs such as cohort or case-control studies are used, and supported where relevant by appropriate sample frames. Randomized, spatially balanced sampling, together with careful selection of control sites, and more extensive use of propensity scores and structured elicitation of expert judgment, are also practical ways to improve the evidence base for answering the questions that underlie marine park objectives and motivate long-term monitoring programs.
The sustainable management of flats fishing requires establishing limits on the number of boats as its demand continues to grow. This study integrated different techniques to determine the carrying capacity in a recreational fishery: optimum boating density, visual fish census, geographic information system, fishing guides interviews and decision theory. The optimum boating density was based on the effective fishing area (EFA) and on the optimum density. The EFA represented 36% of the bay and was calculated from 53 fishing trips tracked with GPS data loggers. The data were analyzed in a geographic information system that incorporated the effect of the winds on the fish behavior. The maximum number of boats was calculated under four scenarios: northern winds, eastern winds, south-eastern winds and calm winds. The optimum density (average = 1.2 Km2, SD = 0.5) was obtained from anglers' statements. The decision theory results showed that the maximum number of boats under wind variability could be up to 89 boats in the fishery.
Game theory has been an effective tool to generate solutions for decision making in fisheries involving multiple countries and fleets. Here, we use a coupled bio-economic model based on a Baltic Sea dynamic multispecies food web model called BALMAR and, we compare non-cooperative (NC) and cooperative game (grand coalition: GC) solutions. Applications of game theory based on a food web model under climate change have not been studied before and the present study aims to fill this gap in the literature. The study focuses on the effects of climate variability on the biological, harvest and economic output of the game models by examining two different climate scenarios, a first scenario characterized by low temperature and high salinity and a second scenario by high temperature and low salinity. Our results showed that in the first scenario sprat spawning stock biomass (SSB) and harvest dropped dramatically both in the NC and the GC cases whereas, herring and cod SSBs and harvests were higher compared to a base scenario (BS) keeping temperature and salinity at mean historical levels. In the second scenario, the sprat SSB and the harvest was higher for both GC and NC cases while the cod and the herring SSBs and harvests were lower. The total GC payoffs clearly outperformed the NC payoffs across all scenarios. Likewise, the first and second scenario GC payoffs for countries were higher except for Poland. The findings suggested the climate vulnerability of Baltic Sea multi-species fisheries and these results would support future decision-making processes of Baltic Sea fisheries.
Ship strikes are one of the main human-induced threats to whale survival. A variety of measures have been used or proposed to reduce collisions and subsequent mortality of whales. These include operational measures, such as mandatory speed reduction, or technical ones, such as detection tools. There is, however, a lack of a systematic approach to assessing the various measures that can mitigate the risk of ship collisions with whales. In this paper, a holistic approach is proposed to evaluate mitigation measures based on a risk assessment framework that has been adopted by the International Maritime Organization (IMO), namely the Formal Safety Assessment (FSA). Formal Safety Assessment (FSA) is “a rational and systematic process for assessing the risk related to maritime safety and the protection of the marine environment and for evaluating the costs and benefits of IMO's options for reducing these risks”. The paper conceptualizes the use of a systematic risk assessment methodology, namely the FSA, to assess measures to reduce the risk of collisions between ships and whales.
A cocktail of land-based sources of pollution threatens coral reef ecosystems, and addressing these has become a key management and policy challenge in the State of Hawaiʻi, other US territories, and globally. In West Maui, Hawaiʻi, nearly one quarter of all living corals were lost between 1995 and 2008. Onsite disposal systems (OSDS) for sewage leak contaminants into drinking water sources and nearshore waters. In recognition of this risk, the Hawaiʻi State Department of Health (DOH) is prioritizing areas for cesspool upgrades. Independently, we applied a decision analysis process to identify priority areas to address sewage pollution from OSDS in West Maui, with the objective of reducing nearshore coral reef exposure to pollution. The decision science approach is relevant to a broader context of coastal areas both statewide and worldwide which are struggling with identifying pollution mitigation actions on limited budgets.
The accumulation of aquatic organisms on the wetted surfaces of vessels (i.e., vessel biofouling) negatively impacts world-wide shipping through reductions in vessel performance and fuel efficiency, and increases in emissions. Vessel biofouling is also a potent mechanism for the introduction and spread of marine non-indigenous species. Guidance and regulations from the International Maritime Organization, New Zealand, and California have recently been adopted to address biosecurity risks, primarily through preventive management. However, appropriate reactive management measures may be necessary for some vessels. Vessel in-water cleaning or treatment (VICT) has been identified as an important tool to improve operating efficiency and to reduce biosecurity risks. VICT can be applied proactively [i.e., to prevent the occurrence of, or to remove, microfouling (i.e., slime) or prevent the occurrence of macrofouling organisms – large, distinct multicellular organisms visible to the human eye], or reactively (i.e., to remove macrofouling organisms). However, unmanaged VICT includes its own set of biosecurity and water quality risks. Regulatory policies and technical advice from California and New Zealand have been developed to manage these risks, but there are still knowledge gaps related to the efficacy of available technologies. Research efforts are underway to address these gaps in order to inform the regulatory and non-regulatory application of VICT.
Climate-driven changes in ocean currents have facilitated the range extension of the long-spined sea urchin (Centrostephanus rodgersii) from Australia’s mainland to eastern Tasmania over recent decades. Since its arrival, destructive grazing by the urchin has led to widespread formation of sea urchin ‘barrens’. The loss of habitat, biodiversity and productivity for important commercial reef species in conjunction with the development of an urchin fishery has led to conflicting objectives among stakeholders, which poses complex challenges for regional management. Stakeholder representatives and managers were engaged via a participatory workshop and subsequent one-on-one surveys to trial a structured decision-making process to identify effective ecosystem-based management strategies. We directly and indirectly elicited each stakeholder’s preferences for nine alternative management strategies by presenting them with the 10-year consequences of each strategy estimated from an ecosystem model of Tasmanian reef communities. These preferences were included in cost-effectiveness scores that were averaged (across stakeholders) to enable strategy ranking from most to least cost-effective. Rankings revealed strategies that included sea urchin removal or translocation of predatory lobsters were the most cost-effective. However, assessment of stakeholders’ individual cost-effectiveness scores showed some disparity among stakeholders’ preferences in high ranking strategies. Additionally, evaluating inconsistencies within some stakeholders’ scores that included direct or indirect preferences revealed conflicting objectives and cognitive bias as the most plausible explanations for these inconsistencies. Our study illustrates how structured decision-making can effectively facilitate ecosystem-based management by engaging stakeholders step-by-step towards management strategy implementation, identifying psychological barriers to decision-making and promoting collective learning.
Marine policy and management has to cope with a plethora of human activities that cause pressures leading to changes to the natural and human systems. Accordingly, it requires many policy and management responses to address traditional, cultural, social, ecological, technical, and economic policy objectives. Because of this, we advocate that a fully-structured approach using the IEC/ISO 31010 Bow-tie analysis will allow all elements to be integrated for a cost-effective system.
This industry-standard system, described here with examples for the marine environment, will fulfil many of the demands by the users and uses of the marine system and the regulators of those users and uses. It allows for bridging several aspects: the management and environmental sciences, the management complexity and governance demands, the natural and social sciences and socio-economics and outcomes. Most importantly, the use of the Bow-tie approach bridges systems analysis and ecosystem complexity. At a time when scientific decisions in policy making and implementation are under question, we conclude that it provides a rigorous, transparent and defendable system of decision-making.
Prioritization of marsh-management strategies is a difficult task as it requires a manager to evaluate the relative benefits of each strategy given uncertainty in future sea-level rise and in dynamic marsh response. A modeling framework to evaluate the costs and benefits of management strategies while accounting for both of these uncertainties has been developed. The base data for the tool are high-resolution uncertainty-analysis results from the SLAMM (Sea-Level Affecting Marshes Model) under different adaptive-management strategies. These results are combined with an ecosystem-valuation assessment from stakeholders. The SLAMM results and stakeholder values are linked together using “utility functions” that characterize the relationship between stakeholder values and geometric metrics such as “marsh area,” marsh edge,” or “marsh width.” The expected-value of each site’s ecosystem benefits can then be calculated and compared using estimated costs for each strategy. Estimates of optimal marsh-management strategies may then be produced, maximizing the “ecosystem benefits per estimated costs” ratio.
The coral reef ecosystems of the U.S. Virgin Islands are some of the most intensively surveyed and threatened tropical ecosystems on earth. These coral reefs vary widely in terms of biophysical structure, seascape context, socio-economic value and exposure to threats presenting a complex challenge for resilience-based management. How and where should managers prioritize actions to maximize conservation outcomes? To meet multiple conservation objectives, a novel map-based decision-support tool was designed which synthesized large amounts of data to help managers identify and rank coral reefs according to multiple ecological qualities, ecosystem services and threats. The spatial framework integrates local expert knowledge from SCUBA divers, scientific field data and spatial models to characterize and rank priority coral reefs. With user-defined flexibility, the tool provides information to guide management processes such as risk assessments of coastal development, management of protected areas, site selection in science and monitoring design, broader marine spatial planning and community education and outreach.