FISH-LIFT: a device for sampling live fish with trawls

A device for collection of viable samples of salmonids and other fish by tr awl has been developed. The FISH-LIFT is in principle a closed aquarium con nected to the trawl cod-end, designed to produce the lowest possible turbul ence inside. The low turbulence allows the fish to swim unharmed in the aqu arium once caught. A grid may be mounted at the front of the aquarium to re tain certain size groups and to prevent unwanted items like jellyfish from entering. The aquarium may be either hoisted or hauled onboard the vessel t hrough the trawl slip. Three models have been tested so far during full-sca le surveys with a total of approximate to 280 hauls. The device has pr-oven successful and viable samples of up to 300 Atlantic salmon post-smelts wit h negligible: scale losses have been caught. Successful laboratory experime nts have been carried out with these fish. The FISH-LIFT is commended as a suitable tool for investigations requiring trawl caught live fish, as for t he study of external parasites, for loosely scaled fish, for deep water fis hes, for tagging experiments and fur the collection of filth for other expe riments and aquariums. (C) 2000 Elsevier Science B.V. All rights reserved.