Ministry of Fisheries officials say 51 New Zealand or Hooker's sea lions have drowned in squid nets since the beginning of the sub-Antarctic squid fishing season in January.
When the toll reaches 75 the 2000-2001 squid season will be declared closed.
The ministry has official observers on all boats thisseason.
A sea lion exclusion device developed by the fishing company Squid Management, is being put to trial by the Department of Conservation and the ministry.
It is designed to prevent sea lions from becoming enmeshed in the squid nets.
In the past, the Auckland Islands squid fishing season has been closed by the Government when too many of the sea lions, which are native to southern New Zealand waters, have drowned in squid nets.
Between 11,000 and 15,000 of the marine mammals survive, but fewer than 10,000 are thought to be adults.
Yesterday, the umbrella group Environment and Conservation Organisations of New Zealand said the New Zealand hoki fishing industry drowned more than 1000 fur seals and more than 1000 seabirds, including many albatrosses, in trawl nets each year.
The group, which includes representatives from 65 environmental organisations, said no environmental assessment had been made of the impact of the fishery on the marine ecosystem.
