Publication Abstract

Progress in a lobster stock enhancement experiment on the English east coast

R.C.A. Bannister

Scientists of the Ministry of Agriculture, Fisheries and Food have developed the use of techniques to rear lobsters in the laboratory to juvenile stage XII, and have pioneered their microtagging and release onto natural habitat in an important east coast lobster fishery. The habitat chosen reflects the knowledge that settling lobster larvae prefer rocky substrate with crevices, and that this preference determines the distribution and abundance of stocks. This approach is also being followed by other teams working in Wales, Scotland and France, and the total number of juveniles released by all groups is approximately 110 000. The work has now entered the second phase, to monitor abundance and survival of the hatchery stock. Initially monitoring was done by diver, but the main emphasis now involves a combination of target fishing and quayside monitoring of fishermen's landings.

In the MAFF experiments undersized lobsters caught at sea, and sized lobsters landed at the quayside, are passed through a tag detector. Animals giving a positive response are later verified as microtagged by X-ray and dissection at the laboratory, and assigned to a release batch by decoding the tag.

In 1988 MAFF scientists recovered 26 microtagged lobsters in the size range 43 to 84 mm carapace length. In 1989 a total of 110 microtagged lobsters were recovered, in the size range 54 to 96 mm. Recoveries came from batches released in 1983, 1984 and 1985. Capture positions obtained from scientific trapping suggest that recaptures have stayed very close to--the release sites. MAFF results are giving useful information on capture rate, position and growth rate and comparable results are being obtained by the other teams.

Reference:

R.C.A. Bannister, 1991. Progress in a lobster stock enhancement experiment on the English east coast. Progress in Underwater Science, 16: 1-16.