Level Of Scientific Uncertainty Research Articles

Implementing the precautionary approach into fisheries management: Biomass reference points and uncertainty buffers

AbstractThe precautionary approach to fisheries management advocates for risk‐averse management strategies that include biological reference points and account for scientific uncertainty (i.e. process, model and observation uncertainty). In this regard, two approaches have been recommended: (a) biomass reference points to safeguard against low stock biomass, and (b) uncertainty buffers that reduce the catch limit as a function of the scientific uncertainty. This study compares the effectiveness of these two precautionary approaches in recovering over‐exploited fish stocks. We evaluate the performance of more than 80 harvest control rules (HCRs) within a stochastic management strategy evaluation (MSE) framework for three stocks with contrasting life‐history parameters and under various levels of scientific uncertainty. The results show that both approaches reduce the risk of overfishing at the expense of expected yield. This risk‐yield trade‐off strongly depends on the HCRs, life‐history parameters of the species, as well as the level of the scientific uncertainty. Nevertheless, some combinations of biomass threshold and limit reference points as well as uncertainty buffers lead to a more favourable risk‐yield trade‐off than other rules. This study elucidates the multiple factors affecting the effectiveness of management strategies and highlights key features of HCRs for precautionary fisheries management.

Management strategy evaluation using the individual-based, multispecies modeling approach OSMOSE

End-to-end ecosystem modeling platforms, including OSMOSE, are key tools for informing ecosystem-based fisheries management (EBFM). End-to-end models ideally implement two-way interactions between model components, yet two-way interactions between high trophic level (HTL) functional groups and humans (fisheries managers and fishers) are currently missing in OSMOSE. We developed a management strategy evaluation (MSE) framework for OSMOSE, which allows for feedback between HTL functional groups and fisheries managers. This framework couples OSMOSE to a management procedure integrating decision rules and accounting for scientific uncertainty and the acceptable risk of overfishing. We applied the MSE framework to the OSMOSE model of the West Florida Shelf, so as to conduct an evaluation of total allowable catch (TAC) strategies for red grouper (Epinephelus morio) in a context of episodic events of natural mortality. Our simulations indicate that TAC strategies that assume higher scientific uncertainty and/or lower acceptable risk of overfishing result in higher biomass-related metrics for red grouper. However, the levels of scientific uncertainty and acceptable risk of overfishing impose a trade-off between biomass-related and catch-related metrics for red grouper. Our simulations also indicate that updating red grouper TAC more frequently in a context of episodic events of natural mortality does not have a large impact on biomass-related and catch-related metrics for red grouper and other functional groups. The MSE we conducted for red grouper is strategic, and its outcomes, which were obtained under a specific set of assumptions, must be considered preliminary. We discuss how future research could help enhance understanding of the possible impacts of TAC strategies for red grouper. The MSE framework designed for OSMOSE links the dynamics of HTL functional groups to that of fisheries managers, thereby allowing OSMOSE to be better suited for informing EBFM. This framework is an invaluable asset in assessing the performance of fisheries management strategies, but could also be used for other purposes, such as the evaluation of research monitoring programs.

Models of science–policy interaction: Exploring approaches to Bisphenol A management in the EU

This study investigated science–policy interaction models and their limitations under conditions of uncertainty. In detail, it looked at the management of the suspected endocrine-disrupting chemical Bisphenol A (BPA). Despite growing evidence that BPA is hazardous to human and environmental health, the level of scientific uncertainty is still high and, as a result, there is significant disagreement on the actual extent and type of risk. Analysis of decision-making processes at different regulatory levels (EU, Sweden, and the Swedish municipality of Gothenburg) exposed chemicals risk management and associated science–policy interaction under uncertainty.The results of the study show that chemicals management and associated science–policy interaction follow the modern model of science–policy interaction, where science is assumed to ‘speak truth to policy’ and highlights existing limitations of this model under conditions of uncertainty. The study not only explores alternative models (precautionary, consensus, science–policy demarcation. and extended participation) but also shows their limitations. The study concludes that all models come with their particular underlying assumptions, strengths, and limitations. At the same time, by exposing serious limitations of the modern model, the study calls for a rethinking of the relationship between science, policy, and management.

In search of integrative logics

On 24 July 2010, the Democrats in the US Congress declared that US climate change legislation was 'dead on arrival'. After the House of Representatives passed the Waxman-Markey bill by a vote of 219 to 212 one year earlier, the task of saving the patient (the environment) by passing simi lar legislation fell to US senators, who instead allowed the bill to die on the operating table. Along with failing to ratify the 1997 Kyoto Protocol limiting greenhouse gas (GHG) emissions, this was the second major disappointment regarding the role of the US in mitigating climate change. GHGs are deemed responsible for human-induced, potentially catastrophic warming of the Earth's atmo sphere, increasing global air and ocean temperatures which may result in elevated sea levels, desertification and security threats from population relocation (IPCC 4th Assessment Report, 2007: 30). While many countries have initiated steps to reduce their nations' GHGs, including China's plans to introduce a carbon trading scheme in the next five years (The China Daily, 2010), the US, as the second largest C02, emitter remains idle. To understand US hesitance to enact climate policy, it is necessary to recognize the climate change debate as a transnational issue involving actors with competing institutional logics pitted against one another (Ansari et al., 2011). We know from previous work that strategists and organi zations interpret the world in terms of institutional logics/frames there is a long history of evi dence on this point (e.g. Friedland and Alford, 1991; Lewicki et al., 2003; Thornton and Ocasio, 2008) and that their responses are thus at least in part a function of prevailing logics. Therefore, we need to think about the critical issue of climate change which is perhaps THE challenge today for organizations in terms of how logics are shaping the debate and how those logics might be adjusted or reframed to reach agreement about action going forward. For example, many in the US maintain a logic of skepticism about climate change (Hoffman, 2011). Contrarians and advocates disagree about the level of scientific uncertainty and the costs of mitigating climate change. These competing institutional logics are advanced at local, national and transnational levels as corpora tions and their stakeholders battle over the necessity of mitigation. Thus, understanding the failure of the US to enact climate policy relates to the 'difficulty of solving global problems that ignore the local dimension' (Carrus et al., 2005: 238). At the local level, community and regional institutions influence institutional logics by shaping how social issues are defined and negotiated (Gray and Stites, 2010; Greenwood et al., 2010; Marquis and Battilana, 2009; Thornton and Ocasio, 2008). Citizens draw on 'cultural narratives

The Melting Himalayas: Cascading Effects of Climate Change on Water, Biodiversity, and Livelihoods

The Greater Himalayas hold the largest mass of ice outside polar regions and are the source of the 10 largest rivers in Asia. Rapid reduction in the volume of Himalayan glaciers due to climate change is occurring. The cascading effects of rising temperatures and loss of ice and snow in the region are affecting, for example, water availability (amounts, seasonality), biodiversity (endemic species, predator-prey relations), ecosystem boundary shifts (tree-line movements, high-elevation ecosystem changes), and global feedbacks (monsoonal shifts, loss of soil carbon). Climate change will also have environmental and social impacts that will likely increase uncertainty in water supplies and agricultural production for human populations across Asia. A common understanding of climate change needs to be developed through regional and local-scale research so that mitigation and adaptation strategies can be identified and implemented. The challenges brought about by climate change in the Greater Himalayas can only be addressed through increased regional collaboration in scientific research and policy making.

Assessing Invasion Impact: Survey Design Considerations and Implications for Management of An Invasive Marine Plant

We use a three-year study of sheltered low shore assemblages colonised by the non-indigenous Asian kelp Undariapinnatifida to explore survey design issues for assessing the ecological impacts of invasive species. The weight of evidence overall suggested little impact from Undaria on low shore assemblages, with control–impact contrasts that could plausibly be interpreted as impacts probably reflecting natural causes. We demonstrate that the potential for reaching incorrect conclusions regarding the impacts of invasive species using control–impact designs is greater than when such designs are used to assess traditional forms of anthropogenic impact. We suggest that a before–after control–impact framework is essential, but recognise that such an approach has a number of limitations. In particular, there is no assurance that the before–after impact site will be invaded at all, or to the extent that provides worst-case impact information for coastal managers. We discuss possible ways of assessing invasive species impacts, but suggest that the uncertainty inherent in extrapolating impact information to other places and times means that the precautionary principle should be applied, and ‘worst-case’ impacts assumed, until the level of scientific uncertainty is reduced. Such an approach should only be applied, however, after an evaluation of the feasibility, costs and benefits of managing a particular pest in relation to other priorities for invasive species.