Trends in annual CPUE and evidence of sex and size segregation of Sphyrna lewini: management implications in coastal waters of northeastern Australia

Published source details Noriega R., Werry J.M., Sumpton W., Mayer D. & Lee S.Y. (2011) Trends in annual CPUE and evidence of sex and size segregation of Sphyrna lewini: management implications in coastal waters of northeastern Australia. Fisheries Research, 110, 472-477.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Use an alternative commercial fishing method Action Link

Use an alternative commercial fishing method

A replicated study in 1996–2006 in 10 shallow coastal areas in the Coral Sea off the northeast coast of Australia (Noriega et al. 2011) found that drumlines caught larger individuals of scalloped hammerhead shark Sphyrna lewini, compared to surface mesh nets. Average shark length was greater in drumlines (2.1 m) than mesh nets (1.9 m). Size at maturity for the region was reported to be from 2.0 m total length for females and from 1.8 m total length for males. A total of 128 sharks were caught in drumlines and 350 in mesh nets. Data were collected from 344 drumline and 35 mesh net deployments operated by the Queensland Shark Control Program at 10 locations along the east coast of Queensland between 1996 and 2006. Individual drumlines consisted of a single baited hook suspended by chain, two metres below a float anchored to the seabed. Bait was 1–2 kg of mullet Mugil cephalus or shark flesh (species not given). Mesh nets were 186 m long and 6 m deep (mesh 0.5 m). Gears were deployed in 8–10 m depth, 300–1,000 m from, and parallel to, the beach. Both gears were checked by trained fishing contractors and drumlines rebaited, on 15–20 days each month. Full gear specifications are given in the paper.

(Summarised by: Chris Barrett)