Systematic list of benthic invertebrates identified in the Heard Island and McDonald Islands region from 129 beam trawl or epibenthic sled samples.

This database provides the most comprehensive systematic list of mega-epibenthic assemblages in the Australian Economic Exclusive Zone (AEEZ) of Heard Island and McDonalds Islands (HIMI) at water depths between 168 and 970 m. Data were collected to better understand the types and distribution of benthic invertebrates, their vulnerability to bottom fishing, and the effectiveness of the HIMI Marine Protected Area (MPA) for representing and protecting the regions benthic biodiversity. A total 504 taxa from 14 phyla were collected from 129 stations throughout HIMI. Two methods, beam trawl (for non-complex flat terrains) and epibenthic sled (for more complex, rough terrains), were used to sample the megabenthos. Both the trawl and sled were fitted with a 1 cm-2 mesh cod-end with a net opening (height x width) of 2.7 x 1.2 m for the beam trawl and 1.2 x 0.6 m for the epibenthic sled. Samples were sorted into broad taxonomic groups onboard the sampling vessel then frozen for later analysis. In the laboratory, samples were sieved over a 1 cm mesh and all dead material removed. Megabenthos were identified to the lowest possible taxonomic level by using the available literature and assistance of taxonomic specialists. All non-colonial taxa were counted and then weighed. Colonial taxa that could not be counted as individuals, e.g. demosponges and bryozoans, were separated to the lowest taxonomic level and a whole weight recorded per sample. Taxonomic expertise was provided by Dick Williams (Osteichthyes and Chondrichthyes) of the Australian Antarctic Division; Daphne Fautin and Andrea Crowther (Actinaria) of the University of Kansas; Cardin Wallace (Actinaria) from Queensland Museum; Elizabeth Turner (Bivalvia and Gastropoda) and Genefor Walker-Smith (Invertebrates) from the Tasmanian Museum and Art Gallery; Phillip Bock (Bryozoa), Mark Norman (Cephalopoda), Gary Poore (Crustacea), Joanne Taylor (Decapoda), Mark O'Loughlin (Holothuriodea), Jan Watson (Hydrozoa), Tim O'Hara (Ophiuroidea and Asteroidae), Robin Wilson (Polychaeta) and David Staples (Pycnogonida) of Museum Victoria; Igor Smirnov (Ophuroidea) of the University of Russia; and Andrew Hosie (Cirripedia) of the Western Australian Museum. A reference collection of the taxa is lodged at the Tasmanian Museum and Art Gallery, Hobart, Tasmania. On 2022-11-02 a minor data update was made to add scanned copies of old worksheets.