Fisheries Research 67 (2004) 39–53 Stock structure of Australian herring (Arripis georgiana) in southwestern Australia Suzanne G. Ayvazian a,∗ , Trevor P. Bastow a,b , John S. Edmonds a,c , Jason How d , Gabrielle B. Nowara a a Western Australian Marine Research Laboratories, PO Box 20, North Beach, Western Australia 6020, Australia b Australian Petroleum CRC/Petroleum and Environmental Organic Geochemistry, Curtin University of Technology, PO Box U1987, Perth, Western Australia 6845, Australia c Endocrine Disrupter Research Laboratory, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0052, Japan d Center for Ecosystem Management, Edith Cowan University, Joondalup, Western Australia 6027, Australia Received 13 March 2002; received in revised form 25 July 2003; accepted 6 August 2003 Abstract Arripis georgiana is a commercially and recreationally important nearshore pelagic fish distributed along southern Australia. Presently, the fisheries in each state are managed independently and stand to benefit from improved understanding of the biological stock structure of this species. Three stock delineation techniques were used to examine the stock structure, mark/recapture, allozyme electrophoresis and stable isotope analysis of otolith carbonate. Tag recaptures revealed that adult fish tagged on the western south coast of Western Australia in autumn, predominantly migrate to the west while fish tagged along the lower west coast of Western Australia were all recaptured locally. Electrophoretic results indicated negligible genetic differentiation between populations covering over 4800 km of coastline (overall F st =-0.0007). Oxygen isotope ratios of the otolith carbonate revealed that, in general, the fish had not spent their entire life in the waters where they were captured. These results support the single stock hypothesis and provide evidence that Australian herring is a migratory species, with a westward migration along southern Australia to the lower west coast of Western Australia prior to spawning. Management of this species should be considered in a cooperative interstate framework. © 2003 Elsevier B.V. All rights reserved. Keywords: Australian herring; Arripis georgiana; Stock structure; Allozyme electrophoresis; Stable isotopes 1. Introduction Australian herring (Arripis georgiana Valenci- ennes, 1831) is an abundant pelagic fish occurring in coastal and estuarine habitats along the west and south coasts of Australia from Shark Bay, West- ern Australia to Port Phillip Bay, Victoria (Hutchins and Swainston, 1986). Their life history involves an ∗ Corresponding author. Tel.: +61-8-9246-8442; fax: +61-8-9447-3062. E-mail address: sayvazian@fish.wa.gov.au (S.G. Ayvazian). annual summer westward migration along the south- ern coast followed by an summer–autumn spawning in Western Australia, principally between Perth on the west coast and Bremer Bay on the south coast (WFRC, 1973; 1 Fairclough et al., 2000a). Larvae and 1 This is based on information contained in a restricted publi- cation ‘Documents Relating to a Scientific Workshop on Salmon and Herring at Waterman on 14 and 15 December 1972’ which was prepared to meet the need of the West Australian Research Committee, Department of Fisheries and Fauna, Western Australia, and issued in Perth 1973. 0165-7836/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.fishres.2003.08.003