Presentation Title

Alexandrium ecology in Puget Sound: bloom transport and climate pathways

Session Title

Session S-09A: Harmful Algal Blooms, Climate, Shellfish, and Public Health - Emerging Issues in a Changing World

Conference Track

Harmful Algal Blooms and Shellfish

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Start Date

2-5-2014 10:30 AM

End Date

2-5-2014 12:00 PM

Abstract

The Puget Sound Alexandrium Harmful Algal Bloom (PS-AHAB: www.tiny.cc/psahab) program seeks to understand environmental controls on the benthic (cyst) and planktonic life stages of the toxic dinoflagellate Alexandrium catenella, and disentangle the effects of climate pathways on the timing and location of blooms. Spatially detailed mapping of winter cyst distributions in 2011, 2012, and 2013 found the highest cyst concentrations in Bellingham Bay in the north and Quartermaster Harbor in central Puget Sound (see presentation by C. L. Greengrove at this conference). The potential for blooms to initiate from these locations was determined by a series of controlled germination experiments in the laboratory using cysts isolated from benthic sediments. Transport of blooms was evaluated using a high-resolution hydrodynamic simulation of Puget Sound and adjacent coastal waters (MoSSea: http://faculty.washington.edu/pmacc/MoSSea/). Within this model domain, passive particles were released from the seed beds and tracked for 20 days. In two weeks, particles released from Bellingham Bay made it out of the Strait of Juan de Fuca to the outer Washington coast whereas particles released from Quartermaster Harbor mostly stayed in the main basin of Puget Sound. No particles entered Hood Canal, suggesting that physical transport mechanisms may prevent toxic cells from contacting shellfish in this basin of Puget Sound. Laboratory experiments showed that maximal growth rates (~0.3-0.5 μ d-1) occur over a broad range of temperatures (~14-24°C) at salinities (20-35 psu) typical for Puget Sound (see presentation by B. D. Bill at this conference). These ranges were used to define favorable habitat for A. catenella using model output from the MoSSea simulation. A 40-year global climate projection was regionally downscaled and coupled to MoSSea to determine temporal and spatial changes to favorable habitat under the A1B greenhouse gas emissions scenario. A comparison between present-day and circa-2050 conditions allows us disentangle the effects of three climate pathways on favorable habitat for A. catenella in Puget Sound: 1) changing ocean inputs (associated with upwelling winds), 2) changing streamflow magnitude and timing, and 3) increased direct insolation.

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Language

English

Format

application/pdf

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May 2nd, 10:30 AM May 2nd, 12:00 PM

Alexandrium ecology in Puget Sound: bloom transport and climate pathways

Room 615-616-617

The Puget Sound Alexandrium Harmful Algal Bloom (PS-AHAB: www.tiny.cc/psahab) program seeks to understand environmental controls on the benthic (cyst) and planktonic life stages of the toxic dinoflagellate Alexandrium catenella, and disentangle the effects of climate pathways on the timing and location of blooms. Spatially detailed mapping of winter cyst distributions in 2011, 2012, and 2013 found the highest cyst concentrations in Bellingham Bay in the north and Quartermaster Harbor in central Puget Sound (see presentation by C. L. Greengrove at this conference). The potential for blooms to initiate from these locations was determined by a series of controlled germination experiments in the laboratory using cysts isolated from benthic sediments. Transport of blooms was evaluated using a high-resolution hydrodynamic simulation of Puget Sound and adjacent coastal waters (MoSSea: http://faculty.washington.edu/pmacc/MoSSea/). Within this model domain, passive particles were released from the seed beds and tracked for 20 days. In two weeks, particles released from Bellingham Bay made it out of the Strait of Juan de Fuca to the outer Washington coast whereas particles released from Quartermaster Harbor mostly stayed in the main basin of Puget Sound. No particles entered Hood Canal, suggesting that physical transport mechanisms may prevent toxic cells from contacting shellfish in this basin of Puget Sound. Laboratory experiments showed that maximal growth rates (~0.3-0.5 μ d-1) occur over a broad range of temperatures (~14-24°C) at salinities (20-35 psu) typical for Puget Sound (see presentation by B. D. Bill at this conference). These ranges were used to define favorable habitat for A. catenella using model output from the MoSSea simulation. A 40-year global climate projection was regionally downscaled and coupled to MoSSea to determine temporal and spatial changes to favorable habitat under the A1B greenhouse gas emissions scenario. A comparison between present-day and circa-2050 conditions allows us disentangle the effects of three climate pathways on favorable habitat for A. catenella in Puget Sound: 1) changing ocean inputs (associated with upwelling winds), 2) changing streamflow magnitude and timing, and 3) increased direct insolation.