Community studies .2. Estimation of abundance of abyssal demersal fishes; A comparison of data from trawls and baited cameras

The abundance of the macrourid Coryphaenoides (Nematonurus) armatus was investigated using a single warp trawl and baited camera al soundings from 2500 to 5000 m in the north-east Atlantic Ocean. There was no significant relationship between abundance (n km(-2)) as determined from swept area of the trawl and numbers of fish photographed at standard baits. However, riming of the first arrival (t(arr) s) of the first fish at bail correlated well with the trawl data through the relationship:

n = 6 x 10(8)/t(arr)(2)

It is concluded that by measurement of arrival times, the baited camera provides a cost-effective complement to trawl sampling for estimating abundance of deep-water fish including Synaphobranchus kaupi, Antimora rostrata and C. (N). armatus. However, some abundant species such as the roundnose grenadier Coryphaenoides rupestris is were not attracted to baited long-lines or bailed cameras and therefore could be sampled only by trawl. (C) 1996 The Fisheries Society of the British Isles