The State of Climate Adaptation in U.S. Marine Fisheries Management

This report presents the results of EcoAdapt’s efforts to survey adaptation action in marine fisheries management by examining the major climate impacts on marine and coastal fisheries in the United States, assessing related challenges to fisheries management, and presenting examples of actions taken to decrease vulnerability and/or increase resilience. First, we provide a summary of climate change impacts and secondary effects on fisheries, focusing on changes in air and water temperatures, precipitation patterns, storms, ocean circulation, sea level rise, and water chemistry. We then examine non-climatic factors that affect fisheries management, such as overfishing, bycatch, pollution, habitat degradation and modification, invasive and non-native species, and conflicting uses of marine and coastal ecosystems. Next, we examine how the aforementioned issues combine to influence abundance and productivity, distribution and recruitment, and essential fish habitat. Then we present the results of a survey sent to federal, tribal, state, and other practitioners to identify challenges, needs, and opportunities for climate-informed fisheries management and conservation. Summaries of and trends in commonly used adaptation approaches and examples from our survey and other resources are presented in four broad categories (Gregg et al. 2011; Gregg et al. 2012):

  1. Capacity Building: Strategies include conducting research and assessments, investing in training and outreach efforts, developing new tools and resources, and monitoring climate change impacts and adaptation effectiveness.
  2. Policy: Strategies include developing adaptation plans, creating new or enhancing existing policies, and developing adaptive management strategies.
  3. Natural Resource Management and Conservation: Strategies include incorporating climate change into restoration efforts, enhancing connectivity, reducing local change, and reducing non-climate stressors that may exacerbate the effects of climate change.
  4. Infrastructure, Planning, and Development: Strategies include protecting critical coastal infrastructure used by the fishing industry, and creating or modifying coastal development measures (e.g., removing shoreline hardening, encouraging low-impact development) to increase habitat resilience.

The majority of adaptation efforts in fisheries management to date have been focused on capacity building, including conducting research and assessments, creating resources and tools, and monitoring how climatic changes are affecting species, habitats, and fishing communities. Finally, we discuss several more options to advance adaptation in the fisheries sector that are either not yet represented or are only partially addressed by the examples from our survey. 

A Window of Opportunity for Climate-Change Adaptation: Easing Tree Mortality by Reducing Forest Basal Area

Increasing aridity as a result of climate change is expected to exacerbate tree mortality. Reducing forest basal area – the cross-sectional area of tree stems within a given ground area – can decrease tree competition, which may reduce drought-induced tree mortality. However, neither the magnitude of expected mortality increases, nor the potential effectiveness of basal area reduction, has been quantified in dryland forests such as those of the drought-prone Southwest US. We used thousands of repeatedly measured forest plots to show that unusually warm and dry conditions are related to high tree mortality rates and that mortality is positively related to basal area. Those relationships suggest that while increasing high temperature extremes forecasted by climate models may lead to elevated tree mortality during the 21st century, future tree mortality might be partly ameliorated by reducing stand basal area. This adaptive forest management strategy may provide a window of opportunity for forest managers and policy makers to guide forest transitions to species and/or genotypes more suited to future climates.