Project Title: Survey of benthic and other marine invertebrates of the Prydz Bay region, Antarctica. Investigators: Dr W. Zeidler and Mrs K.L. Gowlett-Holmes, South Australian Museum, Adelaide. Project Aims: To collect marine invertebrate specimens from the bycatch of pelagic and marine trawls conducted by ANARE personnel. Results: A variety of marine invertebrates were collected from pelagic and ... benthic trawls, and incidentally by other means as follows:-
1) IYGPT net - 88 samples from 39 sites. Fauna consisted mainly of amphipods (see link below), medusae, pteropod molluscs, copepods and euphasids, with ostracods, mysids and carid prawns being less common. 2) Benthic trawls - 22 samples from 21 sites. Fauna consisted mainly of glass sponges, medusae, corals, echinoderms, anenomes and ascidians. 3) RMT net - 5 samples from 5 sites. A few polychaetes and amphipods. 4) From fish (from 1 and 2) - several species of parasitic copepods and leaches. 5) Drift net - site 29. Several pelagic polychaetes, amphipods and chaetognaths. 6) Mud grab - site 32. Several bryozoans and ophiuroids. 7) CTD winch wire - site 28. Several sea pens and ophiuroids.
Most marine invertebrates were collected from the benthic trawls, often in large numbers. Frequently the best and greatest variety of specimens were caught in the wings of the net, and the co-operation of the crew in collecting these specimens is greatly appreciated. Several organisms, such as glass sponges, ascidians, sea pens, and echinoderms, were dominant in most trawls, with other groups present in varying quantities. Subtle changes in the fauna were noted in relation to the depth and geographic location of stations, but no pattern can be determined until the material collected is properly curated and identified. However, bottom trawls from shallower depths tended to be dominated by sponges, crinoids and ascidians.
Comments on the fauna collected are as follows:-
Sponges - about 3 or 4 glass sponges dominated most benthic trawls. Other species of sponges were less common. A large yellow species, which was common at Heard Island, was only collected on two occasions.
Medusae - sometimes numerous, but usually too damaged for identification.
Corals - one species of octocoral was very common in most trawls, as was a large species of sea pen. Soft corals and scleractinian corals were very rare.
Bryozoans - relatively rare, although they appear to be common on rocks that came up in the net.
Annelids - several polychaetes were found associated with sponges and octocorals. One large polynoid (scale worm), similar to the common Heard Island species, was present in small numbers in most benthic trawls. Two species of leach were found parasitic on icefish (mainly Chionodraco spp.), and a third species was found on skates (Bathyraja sp.).
Spinunculans and Echiurans - present in most bottom trawls, but never very numerous. A good collection was obtained, and will be of special interest to Dr Stan Edmonds, who is an honourary researcher at the South Australian Museum.
Echinoderms - starfish generally were common in most bottom trawls, as were holothurians. Crinoids were more common in bottom trawls from shallower depths. Echinoids were never numerous, but were present in most bottom trawls. One specimen, a stalked crinoid, is of special interest.
Pycnogonoids - relatively common in most bottom trawls. A good collection of several species was obtained, and will hopefully form the basis of a research project.
Molluscs (excluding cephalopods) - these were relatively rare, but several species of interest were obtained, mainly opisthobranchs, bivalves and chitons.
Crustaceans - relatively rare except for pelagic amphipods (IGYPT trawls).
Ascidians - common in most bottom trawls, dominated by 2-3 species.
Others - several other animal groups were represented in the trawls, but they were rarely numerous, and often only occurred in a few trawls, e.g. nemerteans, hydroids, brachiopods etc.
Concluding remarks: The aims of the project were achieved within the limits of the gear available, and no problems with gear, other than torn nets, were encountered. The variety of marine invertebrates collected was naturally limited by the gear used, and if future benthic surveys are envisaged then I would recommend the use of beam trawls and dredges to collect the smaller organisms. The benthic fauna of Prydz Bay is much more diverse and abundant than that found at Heard Island (Voyage 7.2 1990). The specimens collected will be curated and housed in the South Australian Museum, Adelaide, where they will be studied by resident curators and specialists interstate and overseas. A brief analysis of the specimens collected indicates that several may be of species new to science, and it is expected that several research papers will result once the specimens have been studied in detail. Ultimately, the material collected will form the basis of a reference collection for future research.
The fields in this dataset are: notes site suborder family species numbers