An Early Warning System for Harmful Algal Blooms on Pacific Northwest Beaches

The neurotoxin domoic acid (DA), produced in Pacific Northwest (PNW) coastal waters by blooms of the diatom Pseudo-nitzschia (PN), bioaccumulates in razor clams, Dungeness crab, and other shellfish, causing amnesic shellfish poisoning when consumed. These shellfish support hundreds of millions of dollars annually in coastal tourism, and are essential to coastal tribes for subsistence and commercial income. Current beachside monitoring allows managers to detect when a toxic bloom has already arrived at a given beach but do not provide any advance warning, leading to preemptively conservative beach closures and large, potentially avoidable economic impacts. Longer lead time and improved spatial precision would let managers optimize their deployment of limited monitoring resources, and let them provide the public with longer advance warning as well. Here we describe a new NOAA Monitoring and Event Response to harmful algal blooms (MERHAB) program will institute a new, low-cost monitoring program for offshore HAB hotspots, and develop citizen-science partnerships with coastal communities that can make sustain this monitoring in the future. It will also build a state-of-the-art forecasting system for HAB transport to beaches, based on an existing, well-tested circulation model, which will be continuously re-validated against data from new NOAA and NSF observing system assets (glider lines and moorings). Results will be disseminated through an improved Pacific Northwest HAB Bulletin for time periods of razor clam digs. Multi-year data for forecast skill assessment will come from resumed monitoring of HABs on three Oregon beaches with Washington sites monitored by the ongoing Olympic Region HAB (ORHAB) program, and a newly deployed Environmental Sample Processor (ESP). A series of discussions with coastal resource managers, coastal boating/fishing communities, and operational forecasting groups within NOAA will be used to develop a roadmap for long-term sustainability of this Bulletin.

ity of this Bulletin.