PNWTOX-The Columbia River plume and HABs in the Pacific Northwest: bioreactor, barrier or conduit?

University Of Washington, Seattle WA

Investigators

Abstract

The overall objective of this project is to improve predictability of harmful algal bloom (HAB) events in Pacific Northwest (PNW) coastal waters by advancing our understanding of HAB development, dissipation, transport and mixing processes using existing data in parallel with state of the art physical and bio-physical models that include, for the first time, both the Columbia River (CR) plume and potential HAB source regions off both Oregon and Washington. Intellectual Merit: This project will make use of results and data from two recently completed, temporally overlapping 5-year, multi-institutional, interdisciplinary studies jointly funded by NSF and NOAA (1. The Ecology and Oceanography of Harmful Algal Blooms in the PNW, and 2. River Influences on Shelf Ecosystems), to improve predictability of arrival of HABs, in particular, toxigenic Pseudo-nitzschia (PN), at PNW shores. The overriding conclusion from both studies is that lack of understanding of the effect of the CR plume on cross-shelf and alongshelf transport and mixing is the greatest impediment to understanding how phytoplankton, in particular, HABs, arrive on coastal beaches. In this project, Drs. Hickey, Lessard and collaborators at NOAA, UC Santa Cruz, Canada's Institute of Ocean Sciences will build on the wealth of complementary information and enhanced knowledge generated in the two earlier research programs to study the transport and mitigation of HABs to the Washington coast from both northern and southern sources and extend our analyses to species other than PN. Hypotheses to be tested include: 1. The Columbia River plume is a bioreactor for growth but not toxin production. 2. During downwelling winds, the Columbia River plume inhibits shoreward transport of toxic blooms. 3. During upwelling winds the Columbia River plume enhances shoreward transport of toxic blooms below the surface layer. 4. The Columbia River plume enhances northward transport of toxic blooms along the coast. Broader Impacts: A large group of Government and Tribal bodies (e.g., Washington State Dept. of Fish and Wildlife, the Dept. of Health, the Quileute tribe) with interests in coastal shellfish resources will benefit from both the improved understanding of the likely occurrence of toxic Pseudo-nitzschia as well as a forecasting ability so that harvest closures for razor clams and Dungeness crabs can be minimized. New information on Alexandrium may allow managers to shorten the typical annual Paralytic Shellfish Poisoning beach closures. This project will provide interdisciplinary training for one graduate student and one Postdoctoral fellow. The questions addressed will provide an excellent opportunity for newly graduated Ph.D.s to broaden their training in interdisciplinary coastal oceanography.