Residence of fish in the vicinity of a decommissioned oil platform in the North Sea

Jorgensen, T., Lokkeborg, S., and Soldal, A. V. 2002. Residence of sh in the vicinityof a decommissioned oil platform in the North Sea. – ICES Journal of Marine Science,59: S288–S293.The suggested use of decommissioned oil platforms as articial reefs initiated a study ofthe abundance and residence of sh in the vicinity of the Albuskjell 2/4 Fox platform in theNorwegian sector of the North Sea. A study of sh residence was carried out by means ofcylindrical coded ultrasonic VEMCO transmitters surgically implanted into the abdominalcavity of sh caught by handline and pots near the platform. After the operation, the shwere kept in a tank of running seawater to ensure that only fully recovered sh werereleased. Twenty-nine cod and two haddock were tagged. Eight ultrasonic receiversanchored around the platform recorded the presence of tagged sh. An additional receiverwas placed at a neighbouring platform 8 km away. Data were collected from 25 May to13 August 1998 and showed that approximately 50% of the tagged sh remained at ornear the platform throughout this period. Four tagged cod were registered by the receiverat the neighbouring platform. Five tagged cod have been reported caught, one at thestudy platform, two at a nearby platform, and two at 9 and 150 km distance, respectively.When the platform was revisited in May 1999 four cod were detected.