The effect of pingers on harbour porpoise, Phocoena phocoena bycatch and fishing effort in the turbot gill Net fishery in the Turkish Black Sea coast

This is the preliminary and the first study for understanding the effect of acoustic deterrent devices (pingers) on catch rates of fish (target turbot fish, Schophthalmus maeoticus and non target thornback ray, Raja clavata) and harbour porpoise (Phocoena phocoena) bycatch directly in the turbot gill net fishery in the Black Sea conditions. Sea trials carried out using Dukane NetMark™ 1000 pingers in an active (with pinger) and in a control (without pingers) turbot gill net between March 5 and April 2, 2006 off the Sinop Peninsula. The results showed that Dukane NetMark™1000 pingers have been significantly shown to be effective in reducing P. phocoena bycatch in turbot gill net fisheries without significantly affecting target and non-target fish size and catch. The "habituation" problem of the species should also be further investigated in the future