Identification of phytoplankton species found in digestive tracts of northern anchovies

Abstract

In 1991, the neurotoxin, domoic acid, contaminated northern anchovies (.Engraulis mordax Girard) in Monterey Bay, California. Over 100 brown pelicans and Brandt’s cormorants died after consuming the contaminated anchovies. The diatom species, Pseudonitzschia australis Frenguelli, has been implicated as the domoic acid-producer in this incident. Other Pseudonitzschia species have also been shown to produce domoic acid. The stomach contents of anchovies caught in Monterey Bay during the following summer were analyzed to identify the Pseudonitzschia species present and the abundance of each species. The Pseudonitzschia species present in water samples taken in Monterey Bay at the same time were also obtained. These findings illustrate the risk of possible contamination inherent in the composition of the anchovies’ diet and its relation to the plankton composition of the surrounding water. This report also provides a basis for further study on the accumulation of domoic acid by anchovies.