Liz Slooten and Steve Dawson: Save our sea lions and hector's dolphins too

It was excellent to see a strong New Zealand delegation at the International Whaling Commission meeting last week. We've been involved with the IWC on and off for the past 15 years, and know that it's a tough job that requires real grit.

Japan and the other whaling nations are making steady progress towards the end of the "moratorium" on commercial whaling.

There is, however, a certain hypocrisy at work when New Zealand takes the moral high ground at the IWC because our performance at protecting our own marine mammals has been patchy at best, and is currently miserable. We'll give two brief examples.

Two marine mammal species, New Zealand sea lion and hector's dolphin, are found only in our waters. Both species are classified by DoC as "threatened", and are routinely killed in fishing gear. The Marine Mammals Protection Act (1978) states that bycatch for threatened species should be managed so that the species reaches non-threatened status as soon as possible and in any case within 20 years.

New Zealand sea lions are considered threatened mostly because 95 per cent of the breeding occurs within a 5km radius on the Auckland Islands. If a disease, oil spill, or similar local disaster hits the Auckland Island population, the species will be in serious trouble. This is not scaremongering - a disease "event" in 1998 killed 60 per cent of the pups and an unknown number of adults. The latest scientific information indicates that the population is declining partly as a result of this. Additional sea lion deaths in the squid fishery cannot be helping.

The sea lions receive less protection now than they did a decade ago. Indeed the catch limit for the Auckland Islands squid fishery has recently been raised from 62 to 150. This increase has been justified on the basis of a new population model initially developed by the fishing industry.

Given that the required goal for all "threatened" species is population recovery, it is inadequate that the fishing industry model does not address that issue. It models the Auckland Islands population only. This amounts to saying that New Zealand sea lions are managed sustainably as long as the population does not decline further. This ignores history.

Originally, New Zealand sea lions ranged the length of the country. By the mid-1800s they were reduced by sealing to a very small, remnant population on the Auckland Islands, and a few stragglers at other southern islands. Even now, there is still only one substantial breeding population.

Given the statutory goal of population recovery, this is not good enough. Obviously, increasing the "quota" for sea lion bycatch is a step in the wrong direction.

Hector's dolphins are in an even worse predicament than New Zealand sea lions. They have a much smaller population and breed less than half as fast. Most populations appear to be declining. Like other dolphins worldwide, they are routinely killed in commercial setnets, and occasionally by trawlers.

New Zealand is unusual among developed nations in allowing recreational fishers to use setnets, and each year several hector's dolphins die as a result. Last November, four Hector's dolphins were caught in one recreational gillnet in Jackson Bay.

Securing a bright future for hector's dolphins is easy; in dolphin habitat we need to avoid using the fishing gear that catches them. Two such protected areas have been set up at Banks Peninsula and off the North Island west coast. This was good progress, but they are not enough on their own.

Considering our strong pro-conservation stance internationally, one might wonder - as some delegates to the IWC have - why we don't do more to reduce impacts on our marine mammal populations. The usual answers to these questions are peppered with terms like "stakeholder discussion groups", "voluntary codes of practice", "threat reduction plan".

One could be forgiven for interpreting these as intricate constructions to avoid grasping the nettle.

The fact remains that hector's dolphins have been caught in fishing gear routinely for more than 30 years, we have known about it for at least 25 years, and in South Island waters, the last solid action taken was the establishment of Banks Peninsula Marine Mammal Sanctuary, 18 years ago.

"Could do much better" the report card would read. As biologists, we feel compelled to urge for more concrete action to deal with human impacts on New Zealand marine mammals. It's time for New Zealand to put its money where its mouth is.

* Dr Elisabeth Slooten and Dr Steve Dawson are senior lecturers at Otago University. In 2004 they received the New Zealand Royal Society's Sir Charles Fleming Award for outstanding contribution to conservation science.