Tuesday, August 18, 2009

Tetrodotoxin and North Shore Beaches...

The ARC had a formal briefing from environmental experts at its Environmental Management Committee meeting today. So I thought it useful to share the report....

While the science is somewhat tentative, there does appear to be strong evidence to support the opinion that the dog deaths and problems experienced at Cheltenham and Narrowneck beaches, are unrelated to reports of penguin, pilchard and dolphin deaths elsewhere in the Hauraki Gulf.

The dog deaths that occurred after ingesting substances found on NarrowNeck or Cheltenham beaches were neurological. The dogs died very quickly - less than an hour afterward. There have been other reported dog deaths in Auckland Region, but these have been lingering deaths accompanied by vomiting, and sometimes these sick dogs have had to put down after being sick for some time.

The cause of death of the dogs that died after eating something on Narrowneck or Cheltenham beaches have been attributed to tetrodotoxin - often referred to as TTX for short. TTX was confirmed in the stomach of one of the dogs that died.

ARC specialists have been working with other Government specialists intensively. Last week 150 Sea Slugs were collected off NarrowNeck and Cheltenham beaches, between high and low tide marks. Of these Sea Slugs, four were confirmed contaminated with the TTX poison. It is suspected that the dogs ate or tasted a Sea Slug poisoned with TTX.

Rapid death is associated with TTX poisoning.

ARC specialists visited North Shore beaches yesterday (Monday 17th August) and found 5 Sea Slugs at NarrowNeck Beach and 2 at Cheltenham. These Sea Slugs are now being tested at the Cawthron Institute in Wellington - where the others were tested. So there is still a risk that poisoned Sea Slugs may be being washed onto these beaches.

A Public Health Warning is still in force for North Shore beaches, but it appears that Cheltenham and NarrowNeck beaches are where the TTX poison danger has been localised.

Apparently TTX is produced from a reasonably common bacterium which can infect quite healthy sea animals. It appears that this bacterium lives happily in soft bodied animals like Puffer Fish and Octopus, in a sort of parasitic arrangement. It doesn't harm them. However if another animal attacks the host and bites it, then the bacterium emits TTX which can either kill the attacker or repel it. Scientists believe that Sea Slugs - which are carniverous and eat pretty much anything - ate a sea animal which was contaminated with TTX.

Then these Sea Slugs themselves became contaminated with the TTX poison, died, and got washed up on beaches, where they have tempted local dogs.

We were advised that adult Sea Slugs are about 80 - 100 mm long. They are soft, smooth to the touch, and coloured pale grey, with brown/black stripes. It appears that Sea Slugs go through a boom/bust breeding cycle where a proportion of mature healthy Sea Slugs commonly die - after spawning - and may get washed up on the beach. What was uncommon with the present situation, was that a proprtion of those that were washed up were around 40mm long - ie young. This supports the view that the Sea Slugs themselves were poisoned.

ARC experts stated that this was the first time TTX had been detected like this, in the Hauraki Gulf, but were quick to point out that this may have happened before - it was a natural event - but may have not come to anyone's attention before this event.

1 comment:

Anonymous said...

Tetrodotoxin is such a powerful poison and its found in the puffer fish. I know that in Japan a chef has to have a special certificate to cook this kind of fish for the customers. A small amount can kill anyone. With the case in NZ its nothing to do with the fish. Some ship has probably dropped a whole sack with this poison. Who had the intensions to do that and why, noone knows. In my opinion someone did it, in order to damage our 'clean' and 'green' country. This is sad news not only for the people but for everything and everyone. Also its sad that its not announced to people by the news on TV. I think people should know about it in order to keep themselves safe.

Tuesday, August 18, 2009

Tetrodotoxin and North Shore Beaches...

The ARC had a formal briefing from environmental experts at its Environmental Management Committee meeting today. So I thought it useful to share the report....

While the science is somewhat tentative, there does appear to be strong evidence to support the opinion that the dog deaths and problems experienced at Cheltenham and Narrowneck beaches, are unrelated to reports of penguin, pilchard and dolphin deaths elsewhere in the Hauraki Gulf.

The dog deaths that occurred after ingesting substances found on NarrowNeck or Cheltenham beaches were neurological. The dogs died very quickly - less than an hour afterward. There have been other reported dog deaths in Auckland Region, but these have been lingering deaths accompanied by vomiting, and sometimes these sick dogs have had to put down after being sick for some time.

The cause of death of the dogs that died after eating something on Narrowneck or Cheltenham beaches have been attributed to tetrodotoxin - often referred to as TTX for short. TTX was confirmed in the stomach of one of the dogs that died.

ARC specialists have been working with other Government specialists intensively. Last week 150 Sea Slugs were collected off NarrowNeck and Cheltenham beaches, between high and low tide marks. Of these Sea Slugs, four were confirmed contaminated with the TTX poison. It is suspected that the dogs ate or tasted a Sea Slug poisoned with TTX.

Rapid death is associated with TTX poisoning.

ARC specialists visited North Shore beaches yesterday (Monday 17th August) and found 5 Sea Slugs at NarrowNeck Beach and 2 at Cheltenham. These Sea Slugs are now being tested at the Cawthron Institute in Wellington - where the others were tested. So there is still a risk that poisoned Sea Slugs may be being washed onto these beaches.

A Public Health Warning is still in force for North Shore beaches, but it appears that Cheltenham and NarrowNeck beaches are where the TTX poison danger has been localised.

Apparently TTX is produced from a reasonably common bacterium which can infect quite healthy sea animals. It appears that this bacterium lives happily in soft bodied animals like Puffer Fish and Octopus, in a sort of parasitic arrangement. It doesn't harm them. However if another animal attacks the host and bites it, then the bacterium emits TTX which can either kill the attacker or repel it. Scientists believe that Sea Slugs - which are carniverous and eat pretty much anything - ate a sea animal which was contaminated with TTX.

Then these Sea Slugs themselves became contaminated with the TTX poison, died, and got washed up on beaches, where they have tempted local dogs.

We were advised that adult Sea Slugs are about 80 - 100 mm long. They are soft, smooth to the touch, and coloured pale grey, with brown/black stripes. It appears that Sea Slugs go through a boom/bust breeding cycle where a proportion of mature healthy Sea Slugs commonly die - after spawning - and may get washed up on the beach. What was uncommon with the present situation, was that a proprtion of those that were washed up were around 40mm long - ie young. This supports the view that the Sea Slugs themselves were poisoned.

ARC experts stated that this was the first time TTX had been detected like this, in the Hauraki Gulf, but were quick to point out that this may have happened before - it was a natural event - but may have not come to anyone's attention before this event.

1 comment:

Anonymous said...

Tetrodotoxin is such a powerful poison and its found in the puffer fish. I know that in Japan a chef has to have a special certificate to cook this kind of fish for the customers. A small amount can kill anyone. With the case in NZ its nothing to do with the fish. Some ship has probably dropped a whole sack with this poison. Who had the intensions to do that and why, noone knows. In my opinion someone did it, in order to damage our 'clean' and 'green' country. This is sad news not only for the people but for everything and everyone. Also its sad that its not announced to people by the news on TV. I think people should know about it in order to keep themselves safe.