ACCURACY OF BENTHIC INVERTEBRATE BY-­CATCH IDENTIFICATION BY OBSERVERS OPERATING IN THE HEARD ISLAND AND MCDONALD ISLANDS PATAGONIAN TOOTHFISH LONGLINE FISHERY

As a means of testing the accuracy of observer identifications and to provide additional data on benthic invertebrate by-catch; observers operating aboard the longline fishing vessel Antarctic Chieftain were asked to identify and retain all benthic invertebrate by-catch from a recent voyage to Heard Island and McDonald Islands (HIMI) for onshore verification by taxonomists at the Australian Antarctic Division (AAD). Observers displayed a high level of accuracy (89%) in the identification of longline invertebrate by-catch. Common taxonomic errors included the misclassification of stylasterids, bryozoans and alyconarians; an issue prevalent in similar fisheries. This suggests the need for further training in the classification of cnidarians (stony corals, soft corals and stylasterids) and coral-like organisms (bryozoans), particularly as these groups are of high conservation value and are potentially vulnerable to the cumulative impacts of bottom fishing