PARENT SESSION
Poster Session #23: Fish, Lakes, Streams, and Wetlands.
Wednesday, August 8, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Evaluation of the YOY Baltic herring bioenergetic model and the implications for the Baltic Sea.

Van Tassell, Jason¹, Hansson, Sture¹, ¹

ABSTRACT- Baltic Sea herring (Clupea harengus) is an important species in the Baltic Sea system as a dominant zooplanktivore, prey of the dominant piscivore cod, and commercial fish of the fisheries industry. Young of year (YOY) herring is the largest component of consumption on zooplankton by the herring population of the Baltic Sea. Earlier work improved the herring bioenergetic model for the YOY age class, but the model in recent research indicated unrealistic growth patterns and therefore overestimation of consumption. To evaluate the quality of the model for YOY herring, we combined an in situ functional response, temperature data, feeding period, and feeding dependent activity with the bioenergetic model to determine if growth predicted by the model matched observed growth. The model underestimated growth of YOY herring. After analysis and modification of cost parameters, the model growth estimates agreed with actual YOY growth. Using the revised bioenergetic model, YOY herring consumption estimates were lower than previous estimates but still remained an important part of the herring population consumption and the total zooplanktivory in the Baltic Sea.

KEY WORDS: bioenergetic models, baltic sea, herring