USE OF MINIATURE RADIO-TRANSMITTERS TO TRACK THE MOVEMENTS OF DACE, LEUCISCUS-LEUCISCUS (L.) IN THE RIVER FROME, DORSET

Advances in radio-tag design have resulted in the production of tags s uitable for use with relatively small fish. A method of release intend ed to minimise stress and increase validity of early tracks was design ed. A technique of accurately locating radio-tags was developed and te sted. Preliminary tracking results show that dace are highly mobile, a nd are capable of extensive, and often rapid migrations, both up and d ownstream. Most of the dace studied exhibited similar behaviour patter ns, remaining at selected sites for extended periods of time, before r apidly relocating within the river.