African Journal of Marine Science 2006, 28(3&4): x–x Printed in South Africa — All rights reserved Copyright © NISC Pty Ltd AFRICAN JOURNAL OF MARINE SCIENCE ISSN 1874–232X Short Communication White shark and other chondrichthyan interactions with the beach-seine (treknet) fishery in False Bay, South Africa SJ Lamberth Marine and Coastal Management, Department of Environmental Affairs and Tourism, Private Bag X2, Rogge Bay 8012, South Africa e-mail: lamberth@deat.gov.za Introduction Shark, fishery and human interactions are an obvious and inevitable result of marine fisheries and aquatic recreation, as is the case with the beach-seine fishery in False Bay on the south coast of South Africa. Beach-seine nets were introduced into the Cape Province during the mid-1600s, but under strict control of the settlement commander (Thom 1952). Sector conflict between the beach-seine and other fisheries has existed since the 1700s, whereas concerns over the ecosystem effects of this fishery surfaced in the late 1800s (Gilchrist and Williams 1910, Lamberth 1994). Shark catches became an issue in the 1970s with the growing public perception that large catches of this collec- tive group of ‘keystone’ predators were causing ecological imbalances in False Bay (Lamberth et al . 1994). In a subsequent study, these and other concerns surrounding the fishery were found to be mostly groundless (Lamberth 1994). Since 1998, beach-seine and shark interactions, specifi- cally white shark Carcharodon carcharias, have again become a public issue because human fatalities and injuries accredited to this species have increased in waters around the Cape (Cliff 2006). Among others, public percep- tion is that beach-seine operations and/or the blood and stress response of catches are attracting C. carcharias into nearshore waters, bringing them into contact with bathers, surfers and other water users. This study tests the validity of these claims by reviewing beach-seine catch and effort in False Bay in relation to C. carcharias activity, over a 35- year period. Material and Methods Available catch data comprise records of around 11 400 beach-seine hauls in False Bay from 1974 to 2005 (Figure 1). These data vary in accuracy from the low-confidence commercial catch returns (Marine and Coastal Management, Netfish System — 8 500 hauls) to medium- confidence diarised hauls (J Petty, beach-seine right-holder — 2 001 hauls, C Fallows, Apex Images — 600 hauls) to high-confidence monitored catches (Lamberth et al. 1994 — 311 hauls). Incident records of C. carcharias over the same time period are from Cliff (2006). Public perception has been that an apparent increase in the nearshore occurrence of white sharks Carcharodon carcharias in False Bay, on the south coast of South Africa, can at least be partly attributed to beach-seine (treknet) operations attracting sharks into this coastal area. To assess the merit of these concerns, all available beach-seine catch-and-effort data from the False Bay fishery over a 32-year period were analysed. A total of 27 cartilaginous species from 15 families was recorded in around 11 400 hauls from 1974 to 2006. Most (98%) of these comprised small benthic invertebrate feeders such as smooth houndshark Mustelus mustelus and lesser guitarfish Rhinobatos annulatus. Large sharks such as C. carcharias and ragged-tooth shark Carcharias taurus were rare, occurring in <0.2% of hauls. The only medium to large sharks that occurred frequently (15% of hauls) in any appreciable numbers (0.3 per haul) were bronze whalers Carcharhinus brachyurus. The relatively high numbers of C. brachyu- rus compared with Carcharodon carcharias , their overlapping size distributions and the difficulty of identi- fying sharks from a distance, suggests that many of the sharks observed following beach-seine nets are the bronze whalers. Overall, the frequency of occurrence of C. carcharias in the nets is much lower than would be predicted from the high number of observations in the nearshore region. Furthermore, beach-seine fishing rights in False Bay have been reduced from around 170 in the 1970s to five at present. There has been no corresponding decrease in shark incidents. On the contrary, shark incidents have increased from two in the 1970s to six during the period 2000–2005. Overall, there appears to be no strong link between beach-seine activity and human incidents with white sharks in False Bay. Keywords: