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PROJECT TITLE: Forecasts and Projections of Environmental and Anthropogenic
Impacts on Harmful Algal Blooms in Coastal Ecosystems

Dates: July 2010-June 2013
Source: California Ocean Protection Council and California Sea Grant

Raphael Kudela - lead; UC Santa Cruz
Clarissa Anderson - UC Santa Cruz
Dave Caron - University of Southern California
Yi Chao - UCLA & JPL
Meredith Howard - SCCWRP
Burt Jones - University of Southern California
Heather Kerkering - CeNCOOS
Gregg Langlois - California Department of Public Health

Summary: Our proposed project seeks to further the development and implementation of ecological forecast models with application to aquatic vectors of human and wildlife illness. Key environmental predictors of harmful algal blooms include temperature, salinity, and nutrient concentrations, all of which will be altered by projected climate responses to global warming and land-use change. While it can be argued that these variables predict pretty much all phytoplankton dynamics, and have shown low success in past HAB modeling efforts, California and the US west coast are somewhat unique from a modeling perspective. Unlike many other ecosystems impacted by harmful algae, the physical, chemical, and ecological makeup of the coastal waters of California are largely dominated by upwelling. The boundary along the coast between the upwelled water and the warmer adjacent ocean surface water is usually a front with an associated equatorward jet. The seasonal succession of microplankton in upwelling systems follows the general pattern of coastal temperate seas, with diatom dominance in spring, a progressive contribution of heterotrophic organisms during summer and a major contribution of dinoflagellates in late summer and early fall. However, this seasonal pattern shows considerable temporal and spatial heterogeneity, related to episodic wind-forcing cycles and different hydrographic structures.

A tremendous advantage in modeling and predicting HAB events in California is that the successional patterns can be “reset” as a function of short-term environmental conditions (e.g. upwelling/downwelling), providing short-term (days to weeks) predictability in addition to the underlying seasonal and interannual variability that can be used to identify HAB-favorable conditions. Despite the inherent predictability (compared to other coastal regions with HAB problems) of the California Current, relatively little effort has been applied towards development of predictive forecasts. Researchers have urged long-term monitoring approaches for Pseudo-nitzschia, which causes Amnesiac Shellfish Poisoning, recognizing the prevalence of short-term and inconsistent research efforts within the field and the consequential difficulty in developing robust predictive models.

The California Harmful Algal Bloom Monitoring and Alert Program (Cal-HABMAP) was established to address these issues by coordinating researchers, managers, and end users working on HAB issues specific to California; this group is working towards the creation of a coordinated, statewide HAB monitoring and alert program that will yield multiple social, economic, and ecological benefits. One specific goal is to build on existing monitoring and modeling efforts, expanding to the entire State of California. A predictive modeling system for the potential presence of toxigenic phytoplankton blooms in the specified target regions will not only aid managers in the protection of human health but will provide a key resource for examining past and future effects of climate change on the coastal processes that control outbreaks of shellfish toxins at varying levels of anthropogenic stress.

Our primary objectives are to implement existing HAB models from Santa Barbara and Monterey Bay previously developed as research exercises, to test and expand these existing models in other regions, to begin developing a similar modeling effort for paralytic shellfish poisoning, and to provide consistent field monitoring and validation data to adequately assess the model results. A metric of our success will be the development and transfer to our partners (HABMAP, CeNCOOS, SCCOOS, NOAA National Centers for Coastal Ocean Science) of a web-based tool for forecasting probability of HAB events, tracking known blooms, and accessing the underlying data (environmental conditions, HAB monitoring data, satellite and model results) that are readily accessible by researchers, resource managers, and interested members of the public.