Mackerel icefish mainly goes to Asian and European markets. Its flesh is white, firm and oily.
This fish species is ideal for grilling, baking or steaming.
Scientific name: Champsocephalus gunnari
Other names: Icefish
Description: Mackerel icefish have long spindle-shaped bodies with large heads and elongate snouts. The mouth is large with small teeth. The body is a bluish-silver with whitish gills.
Size (length and weight): Up to 66 cm in length and 2 kg. Commonly found at about 35 cm in length.
Life span: Up to 15 years.
Habitat: Mackerel icefish are a schooling species usually found at depths of 30-250 metres. They have been found down to depths of 700 metres. They migrate up and down the water column in a daily cycle. Individuals become increasingly sedentary with age and tend to stay in deeper waters.
Prey: Small shrimp-like crustaceans such as krill and mysids.
Predators: Other fish, occasionally penguins and seals.
Reproduction: Mackerel icefish reach reproductive maturity at 3‑4 years of age. Sexually mature males have a significantly higher first dorsal fin than females. Adults move inshore for spawning. Spawning occurs over 2-3 months in autumn and winter. Females produce 10 000‑20 000 eggs. The eggs are relatively large and remain near the sea bed for about 3 months before hatching.
Other notes: The blood of mackerel icefish is nearly colourless due to a lack of haemoglobin. The blood also lacks myoglobin and carries compounds that prevent it freezing.
|Fishery found in||Gear used||Catch of this species is targeted or incidental|
|Heard Island and McDonald Islands Fishery||Bottom trawl||Targeted|
Management of catch
The Commonwealth catch of mackerel icefish is managed by quota. This means that the catch of this fish by commercial fishers is restricted by weight. AFMA also restricts the type of gear that can be used to fish for mackerel icefish.
Commercial fishers are required to fill in records of their catches, during each fishing trip and when they land their catch in a port. This helps us monitor how much is being caught.
AFMA decides on the amount that can be caught each year from expert advice and recommendations from fisheries managers, industry members and scientists. As mackerel icefish is an international species, advice and recommendations are also provided by the Commission for the Conservation of Antarctic Marine Living Resources.
AFMA also sets requirements for having scientific observers, supplying fishing data, satellite tracking of fishing vessels and fishing gear requirements to minimise impacts on wildlife.
Mackerel icefish are caught in the sub-Antarctic fishery around Heard Island and McDonald Islands, 4000 kms south-west of Perth. The waters surrounding the islands out to 200 nm are part of the Australian Fishing Zone and this area is managed by AFMA.
Fishing gear & environmental impacts
Fishers use trawl nets when fishing for mackerel icefish.
When fishing for mackerel icefish, sometimes bottom trawling can catch other species of fish. This is known as bycatch and it is monitored by on-board fishery observers who assess the environmental impact of the trawling.
There are low levels of bycatch, caught when fishing for mackerel icefish, but some sharks, seabirds and other species may be caught.
Although it is not physically possible to trawl on reef structures, significant long-term damage can occur if sensitive habitat areas like corals, sponges and seagrass beds are trawled. To ensure these sensitive habitat areas are protected from trawling, management arrangements such as area closures are used.
Ecological risk assessments are done for the Heard Island and McDonald Islands Fishery to find out if the fishing of mackerel icefish is harming other species. The most recent assessment was done in 2009 and the risk to other species was assessed as low.