Marine animals to be tested for 1080 poisoning in wake of rat deaths

Tuesday, 12 November 2019

Hundreds of dead rats have washed up on a West Coast beach.

Dead Westland petrels, weka, octopus, starfish, a goat, crabs, crayfish and skate fish were amongst the rat carcasses washed up on a West Coast beach.

The Department of Conservation (DOC) is presuming the rats died from an aerial 1080 drop in the Lewis Pass National Reserve recently washed down with the help of over half a metre of rainfall on the West Coast over the past week. The results of toxicology tests on the rats and a sample of the marine life washed up were due back by the end of this week.

The carcasses were picked up by volunteers and DOC staff and samples sent for testing.

DOC had been given $81.2 million in new funding to deal with the biggest beech mast this year for more than 40 years. It had previously announced it would scale up its 1080 programme to eradicate rodent and stoat plagues which would come with the mega mast and pose a serious threat to native birds.

The recent 1080 drop at at Maruia was 2kg of bait per hectare, which was an increase from 1.5kg per ha earlier this year.

An octopus washed up on a Westport beach after a 1080 drop and heavy rain.

A goat washed up on a Westport beach after a 1080 drop and heavy rain.

* No dead native birds found in Egmont National Park following 1080 drops**

Westport man Trevor Reid said he went for a walk on a Westport beach on Saturday morning after seeing reports about the dead rats on Facebook.

Black Westland Petrels were among animals washed up on a Westport beach after a 1080 drop and heavy rain.

He said he counted 385 rats on North Beach between Derby St and the Westport tip head.

'I saw sea life which is not usually seen washed up. Some of that could have an explanation, like the crayfish could have been thrown back by a fishing boat for being undersized and same with the skates. But the octopus, they are really opportunistic and would grab something floating by and eat it. The rats I found were definitely poisoned,' he said.

A number of skate fish were washed up on a Westport beach along with hundreds of rats.

Some of the rats and a goat found had lost their fur, indicating they had been dead for a week or more.

Reid, along with some friends, spent two hours loading a trailer full of dead animals on the beach.

This supplied video outlines DOC's efforts to measure the long-term effects of 1080 in New Zealand. It claims bird numbers have doubled in one West Coast valley. (Video first published in January 2019)

'It was a smelly job that needed doing. A DOC ranger came down and put a sign up to beware so I got him to help us get rid of them. He made some phone calls and got a digger and buried them above the high tide mark,' he said.

He believed DOC should make more effort to collect carcasses in the bush after 1080 drops.

DOC Western South Island operations director Mark Davies confirmed there had been an aerial 1080 drop at Te Maruia in the Lewis Pass National Reserve recently.

About 600 rat carcasses had been removed from Westport's North Beach, along with dead fish and birds.

'However, until we know otherwise, we have to presume the rats have been poisoned by 1080 and take a cautionary approach,' he said.

The poison operation was also more than 140km away from Westport's North Beach, where the rats washed up.

'However, until we know otherwise, we have to presume the rats have been poisoned by 1080 and take a cautionary approach. Rats and a sample of marine life have been sent for testing to check whether they contain 1080. While it is possible that the rats have been washed down from an area where rats have been targeted in a recent predator control operation, it's unclear what would have cause the marine life deaths. We expect results of these tests by the end of the week,' he said.

Davies said six rats had been collected on Monday from a beach near Waimangaroa, north of Westport.

'As a precaution warning signs advising people to keep dogs on a lead have been placed at beach entranceways. Dogs are susceptible to poisoning from 1080, and with their propensity to scavenge, people do need to be careful and keep their dogs supervised on leads or keep dogs away from beaches until the results of the toxicology tests come back.'

He warned against people handling the dead rats.

'If they do contain toxin, naturally occurring bacteria will break this down overtime as the carcasses disintegrate, there is no threat to human health.'

NZ Federation of Freshwater Anglers president and retired veterinarian Peter Trolove warned against eating fish caught in Buller rivers after a 1080 drop because they eat mice and can eat 1080 pellets. He had caught a fish in South Westland whose insides were dyed blue after a 1080 drop.

He said the only study done on trout eating 1080 showed that the poison was present in the fishes' flesh five days after ingestion. He disputed an MPI assessment of the research which found that the 1080 in trout flesh posed no risk to human health.

'The work hasn't been done and the MPI risk assessment is little better than a guess. I wouldn't take my dog into an area that had a 1080 drop for months after,' he said.