ABSTRACT
Juvenile White Sharks (JWS), Carcharodon carcharias, have been recorded in shark control programs (SCPs) since their inception in the late 1930s in New South Wales (NSW) and early 1960s in Queensland (Qld). Recent satellite tracking of JWS (1.75-2.6 m total length) indicates that they are seasonally resident, with extended periods in the nearshore surf zone, at a small number of interconnected areas along the east coast of Australia. The JWS also showed directed and consistent periods of travel, with infrequent coastal visits, when transiting between these areas. These differences in behavior may have important rami¢cations for interpreting long-term trends in catch-perunit-effort (CPUE) from SCPs. We used generalized linear models to examine CPUE and size of JWS from 1993 to 2009 from both shark control programs. We further examined the movements of 20 satellite-tracked sharks in relation to SCP beach areas. Analyses indicated a concordance
between beaches of higher CPUE and residency areas of tracked sharks, suggesting that data from these areas are more conducive to long-term monitoring. Signi¢cantly larger JWS were caught in Qld SCP gears. Seasonal peaks in SCP CPUE corresponded with movement of satellite-tracked JWS past SCP areas. Satellite tracking has previously indicated two nursery areas on the east coast: one in the Port Stephens region near Newcastle, NSW, and the other at Corner Inlet-Ninety Mile Beach region of eastern Victoria. A third region along the eastern side of Fraser Island, Qld, has also been suggested by satellite tracking, but data were comparatively few. CPUE data from the Qld SCP indicate that this area, and Bundaberg on the north of Fraser Island, may be an additional seasonally important area on the east Australian coast. Proximity to the 60-120-m contour, orientation of a beach relative to the directed migrations of JWS, and beach length may play a role in the frequency of encounter between SCP gear and JWS. Moon phase may also in·uence the onshore movement of JWS both at residency areas and over areas of transit, because the lowest SCP CPUE were recorded around the full moon.
