Cool fact…
Mackerel icefish are one of the most common fish species found in the shallower waters of the Kerguelen Plateau and along with Patagonian toothfish, form the basis for a commercial fishery in the region. Icefish are remarkable because they lack haemoglobin or red blood cells, resulting in blood that is an opalescent white/gray in colour, and cream coloured gills, liver and heart.

Fish and invertebrates

Trawl net deployment
Trawl net deployment (Photo: T Lamb)
Jellyfish of the Periphylla genus

Many weird and wonderful fish and invertebrate species inhabit the waters surrounding Heard Island and McDonald Islands (HIMI).

Some of these species are important prey for the land-based marine predators in the region, so knowing where they occur and in what quantity is important for managing and conserving the integrity of the ecosystem.

A book to assist Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) observers in the identification of benthic invertebrate bycatch in the HIMI region has been developed: Field identification guide to Heard Island and McDonald Islands benthic invertebrates: a field guide for scientific observers aboard fishing vessels [PDF]

Research trawls

A trawling program was undertaken as a component of the marine science voyage conducted by the Australian Antarctic Division over summer 2003/04.

During the trawl program a midwater trawl net was used to catch fish and larger invertebrates, and a plankton net was used to catch the smaller zooplankton.

Trawls were conducted from the surface down to depths of 600 metres. The trawl data will be analysed in comparison with the acoustics, oceanographic and predator tracking data to see if large scale patterns in abundance and distribution of fish and invertebrates influence the predators’ choice of foraging areas.

One of the most interesting invertebrates commonly caught during the voyage was the very large jellyfish of the Periphylla genus. These jellyfish are known for their extremely large size – one reasonably intact specimen that was laid out on the ships trawl deck reached five metres or more! (see picture)

This page was last updated on 28 February 2005.