Toxin levels in shellfish drop at Pania
13 April 2006
Toxin levels in shellfish drop at Pania but too early yet to lift warnings on the collection of shellfish
Hawke's Bay District Health Board advises that despite reducing levels of Paralytic Shellfish Toxin (PSP) being found in shellfish samples taken this week, the coastline between the Mohaka River mouth in the north and Cape Kidnappers in the south needs to remain closed to the collection of shellfish.
Results from shellfish samples collected on Monday from Pania Reef, Napier have returned with a Paralytic Shellfish toxin level of 46 micrograms of toxin per 100 grams of shellfish flesh. This is below the Food Safety Authority’s level at which an area is closed for shellfish collection - being 80 micrograms per 100 grams of flesh but it is important though to remind the public that further low shellfish and water results are needed before the closure can be lifted.
Levels of the toxin in shellfish can increase, and decrease, very quickly as the toxic algae levels change in the water. A water sample taken at the same time as the shellfish sample from Pania Reef, Napier has returned showing that PSP toxin causative marine phytoplankton species Gymnodinium catenatum was still present.
Shellfish samples collected from Portland Island, Mahia late last week returned this week showing low levels of the PSP toxin below the Food Safety Authority’s safe level. The water sample taken at the same time was negative for PSP producing phytoplankton species.
Shellfish and water samples collected this week from the Porangahau and Waimarama regions have returned negative for both the presence of PSP toxin, or any PSP producing phytoplankton algae.
Further shellfish samples will be collected over Easter and into next week providing sea conditions allow it, and the public will be advised of results and any changes to the area affected by the PSP toxin.
Kina, mussels, toheroa, pipis, tuatua, oysters and cockles in affected areas should not be eaten.
Paua, crab, and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed its contents could contaminate the meat during the cooking process.
Cooking affected shellfish does not remove the toxin.
Fish, such as snapper, gurnard, and terakihi are not affected by the algae and are still safe to eat.
It needs to be stressed that anyone eating toxic shellfish in closed areas could be at risk of serious illness.
Symptoms of Paralytic Shellfish Poisoning can occur within 12 hours of eating affected seafood and can include:
- Numbness and a tingling (prickly feeling)
around the mouth, face, and extremities first.
- Difficulty swallowing, or breathing.
- Headache, dizziness, and double vision.
Severe cases may suffer respiratory arrest resulting in death if medical treatment is not immediately available.
If anyone becomes ill after eating shellfish from any Hawke’s Bay area (not just the closed area) they should contact a doctor immediately and also advise the Public Health Unit on (06) 878 1329.
Anyone wanting further information can phone the Hawke's Bay District Health Board's Toxic Shellfish Information Line on (06) 878-1329. There is a pre-recorded message giving the latest sampling results, the status of the closure, and a facility for people to leave their contact details and a message if required.
Information on the closure will be posted and updated on Hawke’s Bay District Health Board’s web site www.healthinhawkesbay.co.nz in the Public Health Unit’s area of the site.