Moore, S. K., University of Washington, Scho, Seattle, WA, USA, mooresk@u.washington.edu
Feifel, K. M., University of Washington, School of Oceanography, Seattle, WA, USA,
Mantua, N. J., University of Washington, Aquatic and Fishery Sciences, Seattle, WA, USA,
Trainer, V. L., NOAA Fisheries, Marine Biotoxins Program, NWFSC, Seattle, WA, USA,
Hickey, B. M., University of Washington, School of Oceanography, Seattle, WA, USA,
Cox, A. M., University of Rhode Island, Graduate School of Oceanography, Narragansett, RI, USA,

LARGE-SCALE CLIMATE VARIABILITY AND PARALYTIC SHELLFISH TOXINS IN PUGET SOUND SHELLFISH ON INTERANNUAL TO INTERDECADAL TIMESCALES

Observations of paralytic shellfish toxins (PSTs) in Puget Sound shellfish from 1957 are used as a proxy to describe Alexandrium catenella bloom dynamics and examine the influence of large-scale patterns of climate variability on interannual to interdecadal timescales. Contrary to previous findings, ENSO variations were not correlated with PST concentrations in shellfish. This is due to a mismatch in the timing of ENSO teleconnections with the Northwest and the typical seasonality of toxicity in Puget Sound. Shellfish toxicity appears to co-vary with phases of the Pacific Decadal Oscillation (PDO) and the sea temperature window of optimal growth conditions for A. catenella. However, the 50 to 70 year periodicity of PDO is longer than the historical record of shellfish toxicity which limits the statistical analysis of this relationship. Profiles of benthic cysts of A. catenella in sediments from a 40 cm long core from Sequim Bay co-vary with local shellfish toxicity from 1977. Preliminary results from an analysis of a 198 cm long core, also from Sequim Bay, suggest that the relationship of cyst occurrence with PDO can be examined over a much longer window of time. By extrapolating mechanisms leading to shellfish toxicity on smaller and more localized scales, we predict that rising water temperatures associated with anthropogenic global warming may promote earlier and longer lasting toxic events in Puget Sound.

Oral presentation

Presentation is given by student: No
Session #:120
Date: 03-03-2008
Time: 13:30