Abstract

The populations of Astacus astacus L., the only endemic species of crayfish in Finland, have undergone a strong decline during this century. This has mainly resulted from the crayfish plague. Aphanomyces astaci Schikora, but can also be ascribed to the increasing eutrophication and pollution of inland waters and to the engineering works performed on them. The economical consequences have been severe for the crayfish fisheries. Owing to the large amount of in land waters, about 3 million ha, Finland has an exceptionally great potential for crayfish production. The utilization of these natural resources demand considerable research on crayfish ecology, physiology, pathology, and fisheries. An extensive research program was started in the Bureau of Fisheries Investigation (from 1971 the Finnish Game and Fisheries Research Institute, Fisheries Division) in 1967 to investigate the possibility of increasing crayfish production in Finland. Particular attention has been paid to the distribution of Astacus in Finland, the environmental requirements, population structure, density, and food of Astacus in different biotopes and waters and the spreading of the crayfish plague in Finland. Studies have also been made on the ecology, physiology, and cultivation of the plague-resistant American crayfish, Pacifastacus leniusculus Dana, which has recently been introduced into Finland. In addition, during the past few years investigations on the physiology of Astacus and Pacifastacus including the acetylcholineactivity of the nervous system, have also been undertaken at the Zoophysiological Laboratory, University of Turku. In 1973 a research program on the ecology and stress-physiology of Astacus, especially on the adaptations to stresses caused by pollution and long exposures to low temperatures, was initiated in the Institute of Ecology, University of Kuopio. Investigations on the effects of different toxins entering the aquatic environment, especially phenols and chlorinated phenols, on the nervous function of crayfish have recently been started in the Institute of Zoophysiology, University of Helsinki.

Supplemental Documents

• There are no supplementary documents for this article

Cited By

Citations: