A METHOD FOR DEPLOYMENT OF EXTERNALLY ATTACHED SONIC FISH TAGS FROM AMANNED SUBMERSIBLE AND THEIR EFFECTS ON COELACANTHS

A method for attaching acoustic transmitters externally to deep-water fishes in situ is described. Tags, each comprising a transmitter conne cted to a dart, were fired at fish from a pneumatic gun held by the ma nipulator arm of a submersible. The method was applied successfully fo r tagging coelacanths and may have application for use with other spec ies of fishes living at depths to about 1000 m. The usefulness of dire ct observation for monitoring the effects of tags on fish is evaluated in relation to the effects of the tagging method on coelacanths. An a lternative method is to attach transmitters externally to the fish in situ. While this has been achieved by darting or spearing some species of fishes and whales at the water surface (Nelson 1990; Goodyear 1993 ), the method has not been applied successfully to tag fish at depth. Here we describe a method for deploying acoustic tags from a submersib le. The method was used to tag coelacanths, Latimeria chalumnae, epibe nthic fish which live in water depths below 160 m and never come close to the water surface. Effects of the tagging method on the fish are d escribed.