Thirty years down the line: Changes in the recreational fishery in the Blackwood estuary, south-western Australia

Beckley, L. and Prior, S. (2008) Thirty years down the line: Changes in the recreational fishery in the Blackwood estuary, south-western Australia. In: Australian Society for Fish Biology Conference and Worksho, 15-18 Sept 2008, Sydney, Australia.

Abstract

Although anecdotal evidence about changes in recreational fishing quality abounds, quantitative historical data on recreational fisheries in Western Australia is unusual. In this study, fishing effort, catch and catch rates by recreational anglers in the Blackwood Estuary in 2005‐06 were determined using a roving creel survey and contrasted with unique, published data collected in this system by the same method during 1974‐75. Patterns in seasonality of effort and catches recorded in the two surveys were similar with the summer and autumn months favoured by local and tourist anglers alike. Sillago schomburgkii and Arripis georgianus still dominated the catch but the highly targeted, endemic, estuarine‐resident species Acanthopagrus butcheri had declined considerably in the catch. Surprisingly, total effort in 2005‐06 was similar to that expended in 1974‐75 but there was a marked shift towards shore based angling concentrated at easily accessible locations in the lower reaches of the estuary. Overall, from the information on time spent fishing prior to each interview, duration of fishing trips appears to have reduced considerably over the 30 year period. Both boat‐based and shore‐based catch rates had also declined markedly with the overall catch rate only 0.835 fish per angler per hour compared to the earlier 4.170 fish/ angler/ h. Total estimated catch was only 20% of that estimated for 1974‐75. Although size distribution data were not collected in 1974‐75, the recent data indicate that, despite an apparent high release rate of small or undesirable fishes, compliance with minimum legal length regulations was poor for several species. The influence of the imposition of recent bag limits was explored by applying the 2005 limits to the recorded catches of each angling party in 1974‐75 and, although catches of A. berda would have been less, there was negligible effect on overall catch rates. High resolution temporal and spatial data on distribution of fishing effort in terms of numbers of anglers is presented and the total number of anglers fishing in the Blackwood Estuary in 2005‐06 was also calculated.

Item Type:	Conference Item
Murdoch Affiliation(s):	School of Environmental Science
URI:	http://researchrepository.murdoch.edu.au/id/eprint/13765

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