1School of Biological, Earth & Environmental Sciences, University of New South Wales, 2052. t.mullaney@student.unsw.edu.au
2 Wollongong City Council, Locked Bag 8821, South Coast Mail Centre, Wollongong NSW 2500 Australia
The East Australian Current (EAC) and the Tasman Front dominates the oceanography off the east coast of New South Wales (NSW), Australia. This study aimed to identify the larval fish assemblages transported within the EAC and which taxa were entrained into the Tasman Front region and therefore advected away from the coast. These two locations are likely areas of enhanced biological productivity that may influence the larval fish communities. The study surveyed larval fish communities in these regions and compared EAC versus coastal sites (northern NSW) and EAC versus Tasman Sea sites (Tasman Front region). The northern NSW zone contained 93 taxa with the most common being Sardinops sagax (21.1%), carangids (18.7%), Scomber australasicus (14.8%) and myctophids (5.8%). The communities of the EAC, dominated by myctophids, carangids and S. australasicus differed from the coastal sites dominated by S. sagax. Unlike the northern NSW zone, the two communities in the Tasman Front zone were differentiated more by abundance rather than composition. Sixty two families occurred in the Tasman Front zone, with S. australasicus (27.2%), S. sagax (19.9%), bothids (14.4%) and myctophids (9.0%) dominating. More taxa and greater abundance occurred closer to the coast and more taxa and greater abundance was found in the EAC than the Tasman Sea. Coastal and shelf species (S. sagax, S. australasicus, Engraulis australis, bothids, serranids and carangids) drove the trend of greater abundance closer to the coast. Myctophids were the only family to show a relatively uniform distribution with distance from the coast and between the two water bodies (EAC and Tasman Sea). Higher numbers of taxa and abundance in the EAC compared with the Tasman Sea was not expected as the EAC is relatively oligotrophic. This trend, however, diminished with distance from the coast and may only be associated with the initial stages of the Tasman Front. The presence of coastal species from the northern NSW zone at EAC sites in the Tasman Front zone suggests coastal assemblages are being entrained into the EAC as it begins its meander towards New Zealand.
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