A comparison between the commercial and recreational fisheries of the surf clam, Donax deltoides

The catch of the pipi or surf clam, Donax deltoides, is shared in Australia by the commercial and recreational sectors, with recreational harvesters collecting them for bait and/or for food. Assessment of how catch acid effort are partitioned between these users is necessary for effective management of this resource, particularly because surf clam populations are prone to large temporal variations in distribution and abundance, and high recruitment variability, making stock assessment and hence management difficult. We quantified catch, effort and catch rates for this fishery at an important site for pipi harvesting. A logbook study of commercial fishers, and an on-site bus-route survey of recreational fishers gave an estimate for the total harvest from Stockton Beach, NSW, of 237.7 metric tonnes per year, of which over 80% (191.2 t) was taken by commercial harvesters, 18% (43.1 t) by recreational food harvesters, and less than 2% (3.4 t) by anglers for bait. Recreational harvesting by food gatherers accounted for approximately 85% (102,228 collector-hrs) of the combined effort for all sectors of 120,650 collector-hrs, with 4% (4794 collector-hrs) spent by bait gatherers and only 11% (13,628 collector-hrs) by commercial fishers. Both commercial fishers and recreational anglers were selective, targeting larger pipis (>45 mm in length), while recreational food collectors took what they could get, sometimes taking animals as small as 10 mm. Effort and catch were highest for the commercial fishery in winter, declining sharply in October, but were higher in summer for the recreational fishery. Catch rates explained much of this difference, with commercial catch rates declining from 36.7 kg/collector-hrs in autumn to 16.1 kg/collector-hrs in Summer, while recreational catch rates were always far lower. Such large differences were surprising in a hand-gathering fishery for which no gear is allowed, and we suggest that experience of collectors is an important factor in such large differences in catch rates. Pipis show large differences in spatial location on the shore and inexperienced collectors often cannot find them, leading to fluctuating catches. (C) 2000 Elsevier Science B.V. All rights reserved.