Storms, W. E. Scripps Institution of Oceanography, wenright@ucsd.edu
Garrison, D. L. National Science Foundation; Division of Ocean Sciences, dgarriso@nsf.gov
Franks, P. J.S. Scripps Institution of Oceanography, pfranks@ucsd.edu

 
PRODUCTION OF DOMOIC ACID IN TWO SPECIES OF THE DIATOM GENUS; PSEUDO-NITZSCHIA
 
Toxic and harmful blooms are becoming an increasingly wide-spread phenomenon (Anderson 1994). In 1987, the potent neurotoxin, domoic acid (DA), was associated with diatoms belonging to the genus Pseudo-nizschia (Subba Rao et al. 1989). Diatoms of the genus Pseudo-nitzschia are widely-distributed and often abundant in coastal and offshore waters. In 1991 P. australis bloomed in Northern California resulting in the deaths of pelagic seabirds including Brown Pelicans and Brandt's Cormorants (Work et al. 1993). In 1998 there was another extensive bloom and both sea lions and brown pelicans were stricken (Scholin pers. comm.). Laboratory studies of P. multiseries, a closely related species, have shown that DA is produced when silicate or phosphate is limiting but not when nitrate is absent. Preliminary studies with P. australis under silicate limitation suggest a similar response. A more thorough investigation into the conditions under which P. australis produces DA compared with P. multiseries was initiated using macronutrient-limited chemostats in light replete and light limited conditions. Potential differences between the species exist in the timing of DA initiation which could have significant impacts on the manner in which these species are monitored.
 
Day: Thursday, Feb. 4
Time:
Location: Sweeney Center
 
Code: SS42TH0579S