New Zealand, or Hooker's sea lion only breeds around the
New Zealand sub-Antarctic Islands. The population was estimated at around 11,000
to 15,000 animals, prior to the mass die-off in 1998, which affected pups and
some adults. Smaller numbers of pups were affected in 2002 and 2003 when 25%
of pups died. Of these, 95% breed on two small islands off the Auckland
Islands - Enderby and Dundas Islands. Dundas Island, where 75 % of the
animals breed, is only the size of two football fields. A small population lives
around Campbell Island and occasional vagrant pupping occurs on Snares Islands
and on the Otago Coast.
The seal specialist group of the Species Survival Commission
(a group of 7000 international specialists) of IUCN (the World Conservation
Union), ranks the New Zealand sea lion as a vulnerable threatened species (see http://www.redlist.org).
The Minister of Conservation has gazetted the New Zealand sea lion
as a threatened species under the Marine Mammals Protection Act. This was opposed
by the fishing industry.
Population Problems
Each year dozens of sea lions die a painful, terror-filled
death in the gigantic trawl nets of the Auckland Islands squid fishery. These
sub-Antarctic Islands are the birth place of 95% of the world's
New Zealand sea lion pups. Since the squid fishing season coincides with the
sea lions' breeding season, many of the victims are pregnant and nursing mothers
whose unborn pups die with them, and whose pups on shore starve to death.
The population may have been reduced by over 20% in the
1998 disease event. The actual extent of mortality of adults may never be known
but over 50% of the pups died. In 2002 the reduction in the number of
pups born, by around 20%, and deaths of up to 25% of pups further
threatens the sea lion. In 2003 around 25% of pups died before the end of February.
Since trawl fishing for squid commenced in the Auckland
Islands in the early 1980s, over 2000 New Zealand sea lions have drowned in
trawl nets. The population has suffered a steady decline, with an adult breeding population of just 5000 in recent years. Pup production has declined 30% since 1998.
Though sea lion deaths were recorded in the first
experimental squid trawls undertaken near the Auckland Islands in 1978, sea
lions are still referred to as an "accidental bycatch" of the squid
fishery. In fact, sea lion deaths are an inevitable consequence of trawling
near the Auckland Islands.
An Historical Perspective
Early nineteenth-century sealers hunted populations
of sea lions to near extinction. In 1830 Benjamin Morrell, skipper of the schooner
Antarctic, recorded in his journal that;
"Although the Auckland Isles once abounded with numerous herds of fur and
hair-seal [the old name for sea lions], the American and English seamen engaged
in this business have made such clean work of it as to scarcely leave a breed."
Sea lions were later eaten by sailors who were frequently
shipwrecked on the Auckland Islands. When the schooner Grafton was wrecked there
in 1864 the crew subsisted on sea lion meat, and the captain Thomas Musgrave
wrote his journals using sea lion blood for ink.
New Zealand sea lions were killed for pelts by sealers in the
early 1800s and reduced to very low levels. It is likely that the population
has not yet recovered to pre-European levels. Evidence indicates that sea lions
bred in Northland, the Nelson area and on the Chatham Islands in the last 1000
years but were eliminated by Maori harvests.
Sea Lion Facts
World's rarest sea lion - with an estimated adult breeding population of only 5000.
Auckland Islands home - 95% of the world's New Zealand's sea lions breed
in the sub-Antarctic Auckland Islands, about 300km south of Invercargill.
Sea lions killed - in the last ten years at least 1000 sea lions have been
killed in squid and other fisheries in this area.
Drowned in trawl nets - sea lions are drowned in the enormous nets used
to trawl for squid. The nets resemble giant socks, with openings around 60-80
metres high and 150-200 metres wide. Sea lions have also been killed in fishing
nets for orange roughy, oreo, southern blue whiting and scampi.
There have been three significant mortality events in the last six years:
In 1998 sea lions were afflicted by a disease that killed around 50% of
pups and up to 20% of adults.
In 2002 pup numbers were down around 20% and 25% of pups born have died
from a disease.
In 2003 pup numbers were also down and 25% of pups born died from a disease.
Sea lions were later eaten by sailors who were frequently
shipwrecked on the Auckland Islands. When the schooner Grafton was wrecked there
in 1864 the crew subsisted on sea lion meat, and the captain Thomas Musgrave
wrote his journals using sea lion blood for ink.
