Our sea lion is a champion deep-sea diver, reaching depths of 600 metres and clocking up dives of up to 12 minutes.
NZ Sea Lion Facts
- Repeatedly hunted throughout history for their skin, meat & blubber, New Zealand sea lion populations were on the verge of extinction by the 1800s.
- Most New Zealand sea lions live in the sub-Antarctic islands.
- Sea lions travel huge distances for food – up to 175km from the coast.
- Sea lions once ranged throughout the North, South and Chatham Islands, but numbers have been drastically reduced due to hunting.
- Only recently have sea lions started breeding on the Otago Peninsula.
- In the last 10 years, squid trawl nets have killed between 14 and 123 sea lions every year.
- In 2001, sea lion exclusion devices (SLEDs) were introduced into the squid trawl fishery to assist sea lions to escape from nets. However, the effectiveness of SLEDs in increasing sea lion survival is unknown.
As well as holding the title as the deepest diver amongst sea-lions, these marine mammals can lay claim to a less trumpeted title - as one of the world's most endangered sea-lions.
The population demise of our sea-lions began in the 1800s, when they fell victim to sealers’ clubs bringing them to the brink of extinction and leaving only scattered populations on remote sub-Antarctic islands.
These populations have not been able to recover due to disease and continued pressure from the modern squid fishery, as many sea lions are killed as by-catch in nets.
Today, New Zealand sea lions are estimated to number less than 10,000, including fewer than 3000 breeding females. Most breeding (86%) occurs on the Auckland Islands.
Such concentrated populations of nursing mothers make these sea lions particularly vulnerable to epidemics such as the devastating bacterial infections that swept through these populations in 1998, 2002 and 2003. The worst of these events in 1998 killed more than 50% of pups and 20% of the adult population.
Over the last eight years, the number of pups produced has declined significantly – thought to be a knock-on effect from a decline in the number of breeding adults.
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).
Threats : Trawlers
As well as suffering a huge population blow from these recent epidemics, each year dozens of sea lions die in the gigantic trawl nets of the Auckland Islands squid trawl fishery. The nets resemble giant socks, with openings between 4 - 60 metres high and stretching 150-200 metres in length.
Since the squid fishing season coincides with the sea lions' breeding season, many of the victims are pregnant and nursing mothers. Unborn pups follow the fate of their pregnant mothers, and pups are left to starve onshore, significantly increasing the death toll from trawl fishing.
In 2006, all females captured in the squid trawl fishery had recently given birth and were pregnant again. And in the 2008-09 season, scientists on New Zealand’s sub-Antarctic islands reported a 31% decrease in the amount of sea-lion pups being born, heightening fears about the impact of by-catch deaths.
In the last 10 years, more than 700 sea lions are estimated to have been killed in the sub-Antarctic squid trawl fishery alone – this does not include pups on shore and unborn babies. And these are the recorded deaths from the squid fishery alone - there are other fisheries in the Auckland Islands area that also catch sea lions, but they are not restricted under current fisheries management.
Save our sea lions: what is being done.
Sea Lion Distribution
IN 1995, a Marine Mammal Sanctuary (MMS) was established in the Auckland Islands to help protect sea lions. Stretching for 12 nautical miles from nearest shore, this sanctuary will allow the government to implement fishing regulations in these areas.
In 2003, an overlapping no-take marine reserve was establishing in this area, giving further protection to our sea lions. However, neither the marine reserve nor the marine mammal sanctuary covers the whole range of any NZ sea lion.
Forest & Bird believe that the MMS should be extended so that it protects the areas where the only breeding strong hold of NZ sea lions are found.
The sanctuary should be extended to the 500m continental shelf edge. The fishing method of jigging, which does not harm sea lions, would still be allowed.
Extending the sanctuary would not only increase protection for New Zealand sea lions, but also enhance the protection of 52 breeding marine bird species – many of which are listed as vulnerable by the IUCN. It would also protect New Zealand fur seals, southern elephant seals and threatened southern right whales, all of which forage and/or breed around the Auckland Islands.
What we believe should be done
Forest & Bird wants to halt the decline in New Zealand sea lions and increase protection so that the species recovers to a non-threatened status
To do this, we believe the government needs to -
1. Increase the size of the existing marine mammal sanctuary
2. Reduce the fishing quota for killed sea lions closer to zero and apply to all fisheries
In addition the government should -
1. Establish a marine mammal sanctuary around Campbell Island
2. Make moves to switch to alternative fishing methods that do not kill marine mammals – e.g. jig fishing
• Ministry of Fisheries: Southern Squid trawl fishery Operational Plan. Each year an Operational Plan for the Auckland Islands squid trawl fishery (SQU6T) is set under the Fisheries Act to avoid, remedy or mitigate the effects of the fishery on New Zealand sea lions. This plan establishes an allowable ‘kill quota’ or number of sea lions allowed to be killed by the fishery each year, called a Fishing Related Mortality Limited (FRML).
In November 2011 the Ministry of Fisheries called for submissions on the squid (6T) Operational Plan for the upcoming 2011-12 fishing year (which normally starts 1 February every year).
Forest & Bird's submission can be viewed here:
The Department of Conservation Forest & Bird is very disappointed that a legally binding Population Management Plan was not written for NewZealand sea lions. Instead, the Department published a Species Management Plan. This plan fails to provide any new information or to commit to action to halt the decline of New Zealand sea lions. Forest & Bird continues to lobby for an improved plan and the implementation of a legally binding Population Management Plan for NZ sea lions.
For a copy of the sea lion Species Management plan – click here