Sub-Antarctic lanternfish (Electrona
carlsbergi)
Distribution
This species has a circumpolar distribution between the Subtropical Convergence and the
waters just south of the Antarctic Polar Front. Dense aggregations have been found around
South Georgia and Shag Rocks. Sub-Antarctic lanternfish are found mostly in the upper 200
m of the water column, but at greater depths towards the Subtropical Convergence.
Size and Age
The maximum size and weight rarely exceed 10 cm and 14 g respectively. Fish live four to
five years.
Biology
The main components of the diet are copepods, pelagic amphipods and
euphausiids. Fish attain sexual maturity at 75 to 78 mm. Spawning is
likely to take place between the sub-Antarctic and the Subtropical
Frontal Zone in the austral summer–autumn. Egg diameter is from 0.7 to
0.8 mm. This species spawns several batches of eggs over the season. It
is not known when the larvae hatch.
Exploitation
The Soviet Union began a trawl fishery for lanternfish (reported indiscriminately as E. carlsbergi)
in the Antarctic Polar Front in the 1980s, with annual catches initially
varying between 500 and 2 500 tonnes. Catches increased from 1987/88 by
14 000 to 23 000–29 000 tonnes in the two subsequent seasons, and peaked
in 1990/91 (78 000 tonnes) and 1991/92 (51 000 tonnes) (Figure
2). The fishery lapsed in the 1992/93 season, as it was no longer considered to be
economically viable.
Status
The status of the stock(s) is unknown. A TAC has been imposed by CCAMLR on the fishery in
the South Georgia region (Statistical Subarea 48.3).
Humped rockcod (Gobionotothen
gibberifrons)
Distribution
The geographic distribution of this species is confined to the Atlantic Ocean sector
(northern part of the Antarctic Peninsula, islands of the Scotia Arc). Humped rockcod has
been found down to 750 m, but is most abundant between 100 and 400 m depth.
Size and Age
This species may grow to 55 cm in length and 1 800 to 2 000 g in weight. At South Georgia,
fish may live from 15 to 20 years.
Biology
Humped rockcod eat primarily benthic prey, such as tube worms, brittle stars, sea urchins
and molluscs. The fish becomes sexually mature at 34 to 36 cm at South Georgia and at a
slightly smaller size on the more southerly grounds. Spawning occurs at the end of the
austral winter, but with latitudinal differences between stocks. Fecundity ranges between
21 000 and 130 000 eggs. Egg diameter is 2.0 to 2.5 mm. The larvae hatch in
spring and early summer. Juveniles change from pelagic to benthic life at the end of the
austral summer.
Exploitation
The first catches of this species were reported in 1976/77. Together with some icefish
species, humped rockcod has been primarily a by-catch of the bottom trawl fishery
targeting mackerel icefish. Only in some years, such as in 1977/78 at South Georgia, was
this species targeted by the fishery, taking annual catches of more than 5 000 to 10 000
tonnes. The directed fishery on this species was closed by CCAMLR in 1989.
Status
There is evidence that the stock around South Georgia has partly recovered from depletion.
The status of the stock near the South Orkney Islands is unknown. The stock around
Elephant Island appears to have been little affected by fishing.
Wilson’s icefish (Chaenodraco
wilsoni)
Distribution
Wilson’s icefish has a circum-Antarctic distribution, with northernmost
records coming from the South Orkney and the South Shetland Islands. It
is found down to 800 m depth.
Size and Age
Maximum size and weight observed are, respectively, 43 cm and about 700 g. Ages have not
been estimated.
Biology
Wilson’s icefish feeds primarily on krill, and to a lesser extent on
fish. It becomes sexually mature at 23 cm and spawns in
October–November, but its spawning grounds are unknown. Fecundity is 300
to 2 000 eggs in individuals of 30 to 32 cm in length. Egg diameter is
from 4.4 to 4.9 mm. The larvae are likely to hatch in the austral
autumn–early winter.
Exploitation
Polish and former East German trawlers reported catches of 10 100 tonnes
and 4 300 tonnes respectively from Statistical Subarea 48.1 in 1978/79
and 1979/80, when concentrations of Wilson’s icefish were detected north
and northeast of Joinville Island at the tip of the Antarctic Peninsula
(Figure 4). In the 1980s this species
was taken regularly in an exploratory fishery of the Soviet Union off the coasts of the
Antarctic continent. Depending on the ice conditions and the availability of fish
aggregations, between 270 and 1 800 tonnes were caught each year. The fishery lapsed at
the end of the 1980s when it was no longer considered to be economically viable.
Status
The status of the stock(s) is unknown.
Scotia Sea icefish (Chaenocephalus
aceratus)
Distribution
The geographic distribution of this species is confined to the Atlantic Ocean sector
(northern part of the Antarctic Peninsula, islands of the Scotia Arc, Bouvet Island).
Scotia Sea icefish has been found down to 770 m, but is most abundant between 100 and 350
m depth.
Size and Age
Females attain 70 to 75 cm and up to 3 800 g, males attain 55 to 58 cm and 1 300 g. At
South Georgia, they may live for 13 to 15 years.
Biology
Post-larvae and juveniles up to 30 cm in length feed primarily on pelagic and
benthopelagic organisms, such as krill and mysids. Older juveniles and adult fish are
bottom-dwelling and prey mostly on other fish. Males reach maturity at 35 to 45 cm and
females at 45 to 55 cm. The species spawns from April to July in coastal waters. Fecundity
ranges from 3 000 to 22 000 eggs. The diameter of ripe eggs is 4.4 to 4.7 mm.
The larvae hatch between August and October.
Exploitation
Catches of the species have been reported since 1976/77. Scotia Sea icefish has primarily
been a by-catch species in the bottom trawl fishery targeting mackerel icefish. Only
occasionally, such as in 1977/78 at South Georgia, has the species been targeted by the
fishery. Annual reported catches never exceeded a few thousand tonnes per statistical
subarea. However, there is evidence that part of the by-catch in other fisheries was not
reported. The fishery was closed by CCAMLR in 1989 when stock assessments indicated that
some stocks had been depleted to below 50% of their sizes before exploitation.
Status
Research surveys suggest that the stocks around South Georgia and Elephant Island have
largely recovered from depletion. The status of the stock near the South Orkney Islands is
unknown.
South Georgia icefish (Pseudochaenichthys
georgianus)
Distribution
South Georgia icefish is found off islands of the Scotia Arc and the northern part of the
Antarctic Peninsula down to 475 m.
Size and Age
The species attains a length of 55 to 60 cm and a weight of 2 000 to 2 500 g. Specimens up
to 15 years of age have been reported; however, age determinations differ widely between
researchers.
Biology
South Georgia icefish feed almost exclusively on krill and fish. At South Georgia, they
spawn in the austral autumn (March to May). Fecundity ranges from 5 000 to 11 000 eggs;
the eggs are up to 4.8 mm in diameter. The larvae hatch between August and October.
Exploitation
The first catches were reported in 1976/77. The species has been a regular by-catch in the
bottom trawl fishery, but has been targeted only in some years, such as 1977/78 at South
Georgia and in 1979/80 in the South Orkney Islands. Annual reported catches exceeded a few
thousand tonnes per statistical subarea in 1977/78. However, there is evidence that part
of the by-catch in other fisheries was not reported. The fishery for this species was
closed in 1989 after it became evident that the stocks at South Georgia and off the South
Orkney Islands were depleted.
Status
The stock at South Georgia appears to have partly recovered from
exploitation in the late 1970s–early 1980s. The status of the stock
around the South Orkney Islands is unknown.
Stone crabs (Paralomis
spinosissima, P. formosa)
Distribution
These species have been found at the South Orkney Islands, but appear to
be most abundant in the South Georgia–Shag Rocks area. They are found at
depths between about 100 m to more than 1 000 m.
Size and Age
Maximum carapace length is 122 mm in males and 112 mm in females of P. spinosissima
and 102 mm in males of P. formosa at South Georgia. No age estimates have yet been
made.
Biology
Information on the biology of the two species is limited to estimates of length at sexual
maturity. Female P. spinosissima mature at 62 mm carapace length, male P.
spinosissima at 66 mm (Shag Rocks) and 75 mm (South Georgia), and male P.
formosa at 80 mm carapace length (South Georgia).
Exploitation
P. spinosissima was the main species in the experimental crab
fishery in the Shag Rocks–South Georgia area between 1992/93 and
1995/96. The fishery used crab pots; all other bottom gear was
prohibited. It was limited to sexually mature male crabs. A TAC of 1 600
tonnes per annum was imposed on the fishery. The one US fishing vessel
that entered the fishery removed a total of 835 tonnes of crabs over
three seasons (see section 1.2). The fishery was discontinued after the
1995/96 season because it was not viable.
Status
The impact fishing has had on the stocks is unknown.
Martialia hyadesi
Distribution
The squid Martialia hyadesi is a circum-Antarctic species whose distribution is
linked to the Antarctic Polar Front. It appears to be particularly abundant in the
southwest Atlantic Ocean sector, but is also found near the Kerguelen Islands and
Macquarie Island.
Size and Age
The species attains a maximum mantle length of 50 cm. Its life span is probably two years.
Biology
M. hyadesi feed largely on mesopelagic fish, such as lanternfish. The species
reproduces once during its lifetime. Its spawning areas are not known, but the catch of a
few small juvenile specimens on the edge of the Patagonian shelf suggests there is some
spawning there. This species is a large part of the squid diet of toothfish, southern
elephant seals, grey-headed and black-browed albatrosses, and white-chinned petrels.
Exploitation
M. hyadesi are regularly caught in small quantities on the extreme eastern
edge of the Patagonian shelf in the fishery for the squid Illex argentinus. In some
years, when oceanographic conditions are favourable, it is present in much larger
quantities in this fishery. About 26 000 tonnes were caught in 1995 on the Patagonian
shelf edge to the northeast of the Falkland/Malvinas Islands. There is currently an
exploratory fishery for M. hyadesi in Statistical Subarea 48.3 (South Georgia),
where about 80 tonnes were caught in 1996/97.
Status
The status of the stock(s) is unknown.
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