Does Ocean Productivity Contribute to Dune Ecosystem Function? Connecting Wrack Subsidies to Oregon Dune Coastal Protection and Conservation Services (2016-18)

Sally Hacker
Department of Integrative Biology
Oregon State University
3029 Cordley Hall
Corvallis, OR 97331
Phone: 541-737-3707
Email

Co-PIs: Peter Ruggiero, OSU; Francis Chan, OSU

In the wake of recent coastal “super storms” and large tsunamis, there is growing recognition that coastal communities are increasingly vulnerable to damages caused by flooding and erosion. This vulnerability is accentuated by the fact that our coasts support large populations of people over relatively small areas, and that these communities are at the frontlines of sea level rise and extreme storms. Recently, more attention is being paid to the importance of natural barriers, especially sandy beaches and dunes that provide critical ecosystem services (i.e., benefits people obtain from nature), such as coastal protection, habitat conservation, and recreation. Climate change-induced alterations in vegetation, accelerated sea level rise, and potentially intensifying storms, along with human activities such as development, shoreline hardening, and conservation management, all influence the way dunes function, significantly affecting ecosystem services.

It is well known that sandy beaches are exposed to marine subsidies in the form of macrophyte wrack (macroalgae and seagrasses) delivered from nearshore rocky reefs and estuaries, however little is known about the connectivity and potential dependence of dunes on these subsidies. The limited wrack subsidy patterns surveyed on Pacific Northwest beaches provide intriguing preliminary evidence that marine wrack may play a larger role in sandy beach and dune ecosystem food web and nutrient dynamics than previously thought. Could marine subsidies to beaches play a role in dune vegetation productivity, and thus, the geomorphology and coastal protection services of dunes more generally?

Dr. Sally Hacker and her research team’s project will be the first of its kind to explore the potential dynamic relationship between ocean productivity, dune ecosystem function, and coastal protection and conservation services. To grasp how these dune ecosystem functions are linked requires research and analytical approaches that integrate ecology, oceanography, biogeochemistry, geomorphology, and ecosystem service science. While climate change may have negative impacts for coastal protection by increasing the probability of erosion and overwash, wrack subsidies may partially mitigate these effects. Dr. Hacker’s research team hopes to continue to engage with coastal community organizations to utilize the research results in important conservation and management issues relevant to beach grass invasion, coastal protection, and the endangered population of the Western snowy plover.

Strategic Plan Focus Areas: Healthy Coastal Ecosystems, Resilient Communities and Economies

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