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Improving Tools for Monitoring Multiple HAB Toxins at the Land-Sea Interface in Coastal California

This project began in September 2015 and was completed in August 2019

The impacts of cyanobacteria (blue-green algae) toxins are an emerging public health and environmental issue in brackish and marine ecosystems, yet coastal harmful algal bloom (HAB) monitoring programs to date have focused solely on marine HAB toxins. We are studying the risks associated with the coastal cyanobacteria threat and developing monitoring protocols that will aid in better managing California ecosystems at the land-sea interface.

Why We Care
HAB monitoring has generally been water body–dependent, focusing either on marine or freshwater toxins, but not both. Cyanobacterial toxins have previously been considered a public health issue only for freshwater, with concerns about impacts to drinking and recreational waters and ecosystem impacts. However, a number of recent studies focused in California coastal waters have shown these toxins can have effects far downstream, creating cause for concern in brackish and marine habitats.

One example that exemplifies the threat these toxins pose was the deaths of over 30 endangered sea otters in Monterey Bay in 2010 from microcystins in contaminated shellfish they had consumed. Microcystin contamination has also been documented in marine waters of the Klamath and San Francisco estuaries and Rodeo Lagoon from river inputs to Monterey Bay, coastal lagoons, and estuaries in San Diego, and many California streams. Other cyanotoxins (saxitoxin, cylindrospermopsin, anatoxin-a) have been detected in California freshwater systems that connect to the coastal ocean, but are not routinely screened in marine outflows.

What We Are Doing
We are assessing the extent and predominance of toxic marine alga, cyanobacteria, and their toxins at the land-sea interface and determining the influence of freshwater inflow and marine inputs on the algal community and toxins along the California coast. We are using field samples and lab cultures to improve the passive toxin sampling device known as Solid Phase Toxin Tracking (SPATT), enabling detection of multiple toxins (including cylindrospermopsin, anatoxin-a, microcystins, domoic acids, okadaic acids, and saxitoxin).

We are identifying toxins and toxigenic species for targeting by routine monitoring and providing “best practice” approaches for using SPATT to anticipate toxic events and expand temporal coverage of monitoring programs. Our results will be transferred to stakeholders, including: Regional Ocean Observing systems, the Yurok Tribe, the Southern California Coastal Water Research Project, San Diego Regional Water Quality Control Board, the State Water Quality Control Board (water quality managers), the U.S. Geological Survey, and the U.S. Environmental Protection Agency.

The project leader is Dr. Meredith Howard, Southern California Coastal Water Research Project. The project team includes researchers from the University of Southern California, University of California Santa Cruz, and the U.S. Geological Survey Kansas Water Science Center. This project is part of the NCCOS Monitoring and Event Response for Harmful Algal Blooms (MERHAB) program.

Benefits of Our Work
Expanding use of the proven HAB SPATT sampler and developing monitoring strategies will enhance existing HAB monitoring (e.g., California’s HABMAP and Cyanobacteria HAB network) in these systems and add a HAB component to existing state water quality monitoring programs (e.g., surface water ambient monitoring program) by providing technology to identify algal toxins in areas previously not thought to be threatened. The project will also directly influence California strategies to manage nutrients and develop water quality criteria for estuarine habitats

A finalized SPATT standard operating protocol has been published on protocols.io, an open access repository for scientific methods.

A partnership was established with the California State Water Resources Control Board (SWRCB) to integrate some of the findings and monitoring strategies for land-sea interface regions used in this study into the development of the California Freshwater HABs Monitoring Framework.

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