Potential of a trap-fishery for the spiny lobster Palinurus delagoae off eastern South Africa : has the stock recovered?

• Main Author: Boucher, Monique
• Other Authors: Branch, George M
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2014
• Subjects: Applied Marine Science
• Online Access: http://hdl.handle.net/11427/7488

Includes bibliographical references (leaves 35-40) === An experimental trap fishery for the deep-water lobster spiny lobster Palinurus delagoae commenced in 2004, and was run until 2006. Data collected by on-board scientific observers were used to explore fishing effort, catches and catch per unit effort. The recent data were compared with those for a previous experiment conducted in 1994-1997, which apparently contributed to the collapse of the stock, to determine whether the stock had recovered and could sustain a trap fishery. There was a demonstrable recovery of the P. delagoae stock after the previous stock collapse, according to the catch rates and the size composition of catches between 2004-2006. However, catches of P. delagoae declined between 2004-2006. This was related to decreases in effort and in catch per unit effort over the three years. This, and a simultaneous decline in the by-catch of P. delagoae in the prawn trawl fishery off KwaZulu-Natal, suggests that the P. delagoae stock is extremely vulnerable to concomitant trawl and trap fishing. It is recommended that trap fishing should either be permitted at low levels of effort and catch only, or once more be suspended to allow the resource to recover.