The New Zealand sea lion (Phocarctos hookerii) is a remarkable animal. A highly localised species operating at the extremes of their physiological limits, NZ sea lions are recognised as the world’s deepest diving pinniped (eared seal), reaching depths of up to 600m. Unfortunately they are also one of the world’s most rare pinnipeds.
Once ranging throughout New Zealand waters, their population was massively depleted in the 1800s due to hunting for their once prized blubber. Such large scale depletion brought the species to the brink of extinction leaving only small, scattered populations in the cold southern extremes of New Zealand.
Today their population stands at only 12,000 individuals, with 86% of breeding occurring on two tiny and remote islands off Auckland Island in the Sub-Antarctic.
Whilst wildlife around the world is increasingly under threat from climate change, pollution and human interaction, the story of New Zealand sea lions paints a particularly dire and unacceptable trend.
Over the last 10 years, NZ sea lions have suffered a 48% decline in the number of pus born (including both live and dead pups). Whilst three cases of major disease outbreaks in the remote Islands had a significant effect on the population, another threat – one far more manageable – continues to operate unchecked.
New Zealand’s fisheries are legally allowed to kill NZ sea lions every year – on the basis of course that deaths are accidental – “bycatch”. However, the southern squid trawl fishery, which kills the most sea lions, is , in effect, endorsed in it’s killing by the setting of an allowable kill rate or number that can be killed each fishing season. Every year this fishery alone is allowed to kill up to 150 sea lions.
In addition to this direct impact, captures of sea lions in recent year’s shows a trend of increased female sea lion captures. Even more alarming is that due to the fishery operating during the sea lion’s breeding season, the number of lactating females (often pregnant and with a pup on shore) caught by the fishery is high. Sea lion pups are highly dependent on their mothers for food in the first few months of their lives, so as a result of their deaths at sea, the population potentially loses 3 individuals per fishing incident.
Other indirect effects of fishing include resource or food competition, damage to sea floor habitats from bottom trawling and potential decreases in the availability of sea floor associated prey species.
Surely something must be being done I hear you cry. Well, .. there is a marine mammal sanctuary and marine reserve that excludes fishing out to 12 nautical miles from the main Auckland Island. However these are far too small to protect most foraging sea lions. There are also devices inserted in the trawl nest to allow sea lions to escape – sea lion exclusion devices or SLEDs. Whilst good in theory, the survival of sea lions exiting the SLEDs is unknown plus dead sea lions continue to be landed on deck.
There is also the fishing limit on the number of sea lions that can be killed. But--- the model used to set the quota is subject to multiple assumptions, is being used inappropriately and has failed to halt or reverse the decline in the species.
This fishing year, the New Zealand government set a quota of 113 sea lions – 40% higher than the previous year. Just prior to the fishery operating, when most pups have been born, there was a 31% decline in the number of pups born compared to 2008 (50% compared to the number born in 1998). The squid trawl fishery voluntarily agreed to a reduction in the quota to 95 sea lions – still a value far greater than historical quotas set prior to their 10-year decline (around 30-60 sea lions).
Forest & Bird is New Zealand’s largest environmental NGO, dedicated to the protection and New Zealand’s native plants, animals and wild places – both on land and in our seas. Our petition to better protect NZ sea lions in 2006 was signed by over 25,000 people. There have been loud calls to reduce sea lion deaths in the fishery, extend the marine mammal sanctuary, avoid eating squid until action is taken, you name it. But still New Zealand’s government continues to push this species to extinction for the sake of economic gain.
Please help us before it is too late. Visit our website to learn more, write to the ministers and tell them it is not acceptable and find out other ways you can make a big difference:
The New Zealand sea lion (Phocarctos hookerii) is a remarkable animal. A highly localised species operating at the extremes of their physiological limits, NZ sea lions are recognised as the world’s deepest diving pinniped (eared seal), reaching depths of up to 600m. Unfortunately they are also one of the world’s most rare pinnipeds. 
Over the last 10 years, NZ sea lions have suffered a 48% decline in the number of pus born (including both live and dead pups). Whilst three cases of major disease outbreaks in the remote Islands had a significant effect on the population, another threat – one far more manageable – continues to operate unchecked. 
There is also the fishing limit on the number of sea lions that can be killed. But--- the model used to set the quota is subject to multiple assumptions, is being used inappropriately and has failed to halt or reverse the decline in the species. 
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