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Cumulative Impacts in Marine & Coastal Systems

Harmonizing the law, science and practice of cumulative impact assessment to better manage human activities that impact coasts and oceans.

Project Goals

The number and intensity of impacts in our ocean are continually increasing and management of these impacts has failed to keep pace. This is especially true for management of cumulative impacts because it is difficult to account for the cumulative effect of multiple impacts co-occurring in space and time and interacting synergistically. For example, marine mammals are sensitive to particular pollutants that enter the coastal environment as a result of human activities. Pollutants that compromise marine mammal immune systems make them increasingly susceptible to the impacts of limited food supply from overfishing.

Without accounting for these cumulative effects, human activities will not be managed according to their proportional impact on the coastal environment. For a quarter of a century, scientific studies have shown that our efforts to accurately assess and minimize the cumulative effects of human activities on the ocean have failed, resulting in continued ecosystem degradation.

Even though environmental regulations, laws and policies commonly require project proposals to account for and mitigate cumulative environmental impacts, there were no streamlined or universally agreed upon legal, policy or management approaches to do so. Cumulative impact assessment practitioners, such as resource managers or coastal development applicants, therefore requested a set of standards and guidance on comprehensive and effective impact analysis to improve ocean ecosystem health for the long-term.

Our Strategy

During previous project work conducted by COS, resource managers and non-governmental partners identified improving understanding of the law, science and practice of cumulative impacts as a key need. To respond to this need, we deployed a three-pronged research strategy:

State of the Law: Through an analysis of California state policy guidance, case law, statutory and regulatory law and agency environmental review decision documents, Early Career Fellows—Erin Prahler, Sarah Reiter, Meredith Bennett, Ashley Erickson and Molly Melius— working with Meg Caldwell, synthesized the legal boundaries of cumulative impact assessments and identified areas that provided flexibility for new approaches to cumulative impact management.

State of the Science: Early Career Fellow Megan Mach, working with Rebecca Martone and in collaboration with WWF-Canada, reviewed and distilled the scientific literature around cumulative effects into an overview of the state of the science. The report details “best practices” scientists should use to accurately characterize ecosystem health and assess the level and intensity of ecosystem impacts using regional rather than project-level analyses.

State of the Practice: Alongside legal and scientific research, Research Analyst Lindley Mease and Visiting Fellow Melissa Foley evaluated how practitioners interpret legal requirements and approach cumulative impact assessments using social-science-based survey techniques. The survey was distributed to practitioners in California, British Columbia, New Zealand and Queensland, Australia, to understand the trends in, challenges to, and opportunities for improving assessments across multiple geographies.

Sharing our Findings

Ecological Society of America Annual Meeting

In August 2014 at the Ecological Society of America Annual Meeting in Sacramento, California, Meg Caldwell opened the conference by presenting results of our review during her plenary keynote address, Living in a world where 1+1=4: aligning the law, science, and practice of multiple stressors in marine ecosystems.

International Marine Conservation Congress

In August 2014, at the International Marine Conservation Congress (IMCC) in Glasgow, Scotland, Early Career Fellows Sarah Reiter and Megan Mach, Visiting Fellow Melissa Foley and Program Lead Rebecca Martone presented results from these reviews with the international scientific and management community through a tailored symposium and a scenario-based focus group.

Related Projects

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