New Zealand Journal of Marine and Freshwater Research abstracts
Observer effect on fisher bycatch reports in the New Zealand ling (Genypterus blacodes) bottom longlining fishery
Richard J. Burns
Ministry of Fisheries
P.O. Box 8324
Christchurch, New Zealand
email: burnsr@fish.govt.nz
Geoffrey N. Kerr
Environment, Society and Design
Lincoln University
P.O. Box 84
Canterbury, New Zealand
Abstract Reports by commercial fishers in New Zealand’s ling (Genypterus blacodes) bottom longline fishery were analysed to identify the influence of official fishery observers on reported weights of bycatch. Observer data show that on every day ling were taken by bottom longline, both individual transferable quota (ITQ) and non-quota (non-ITQ) bycatch were reported. However, commercial fishers reported ITQ bycatch on 82% of days fished, and non-ITQ bycatch on only 50% of days fished. Frequencies of reported bycatch were compared for fishers’ data with and without an observer aboard for the Chatham Rise, Campbell Plateau, and Bounty Plateau areas. Significant under-reporting of bycatch was indicated for some bycatch fish species in several areas in the absence of an observer. A sample selection model of reported spiny dogfish(Squalus acanthias) bycatch was used to model the effects of observers on whether spiny dogfish bycatch was reported at all, and the effects of observer presence and other independent variables on the quantity of spiny dogfish bycatch reported. The evidence reported here illustrates that misreporting of bycatch is common and can introduce significant errors into total catch estimation that can have serious implications for fishery sustainability.
Keywords spiny dogfish; Chatham Rise; Campbell Plateau; Bounty Plateau
New Zealand Journal of Marine and Freshwater Research, 2008, Vol. 42: 23–32
0028–8330/08/4201–0023 © The Royal Society of New Zealand 2008
M07004; Online publication date 1 February 2008
Received 15 January 2007; accepted 18 November 2007
PDF file of entire paper: Print-quality
(K) | screen-quality (K)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
