DEMERSAL FISHING DISTURBANCE INCREASES PREDATION RISK FOR WHELKS (BUCCINUM-UNDATUM L.)

Field observations by divers indicated that a high rate of predation o f whelks (Buccinum undatum) by starfish (Asterias rubens) occurred in an area disturbed by scallop dredging, although these whelks mostly ap peared to be alive and externally undamaged. The ability of whelks to escape from starfish was tested in the laboratory after they were drop ped or rolled to simulate direct physical contact with bottom fishing gear. Dropping whelks did not significantly affect their escape behavi our, but whelks which had been rolled took significantly longer to rig ht themselves and were significantly less likely to perform an escape response than whelks that had not experienced this treatment. This stu dy suggests that demersal fishing may indirectly increase whelk mortal ity by increasing their risk of predation. (C) 1998 Elsevier Science B .V. All rights reserved.