Potential of Parasites for Use as Biological Indicators of Migration, Feeding, and Spawning Behavior of Northwestern Atlantic Herring (Clupea harengus)

Abstract

A parasite survey of Atlantic herring, Clupea harengus, collected from the Bay of Fundy, Nova Scotian Shelf, and Gulf of St. Lawrence, was conducted from May 1981 to November 1983. A total of 2380 herring were examined and 18 parasite species identified. These included the acanthocephalan Echinorhynchus gadi previously unreported from herring in the northwestern Atlantic and the monogenean Gyrodactyloides andriaschewski herein described from herring for the first time. The geographic distributions of the parasites, their seasonal dynamics, and relation to size of herring were recorded to determine whether they could be used as biological indicators, both to differentiate between individual herring populations and to determine their movements. Seven of the 18 species identified showed varying degrees of potential as biological indicators. Although no single parasite species was found which could clearly differentiate one population of herring from another, the differential prevalences and intensities of Anisakis simplex, Hysterothylacium aduncum, Derogenes varicus, Lecithaster gibbosus, Cryptocotyle lingua, Scolex pleuronectis, and Eimeria sardinae all provided valuable contributions to the knowledge already accumulated on herring migration, feeding, and spawning behavior. Parasite indicators, used in conjunction with other data and techniques, could eventually be used to distinguish between individual populations of herring.