Toxic Algal Blooms

Marine biotoxins are toxic chemicals released from various species of marine phytoplankton. These chemicals may then enter the marine food chain through the shellfish or other filter feeders and pose a health risk to humans who eat the contaminated seafood.

Phytoplankton are microscopic organisms that exist in the top layers of the oceans. Sometimes for unknown reasons, these growths will undergo a population explosion and create a “bloom” where the normally invisible phytoplankton cells may be in such numbers as to show a patchy green, brown or red colouration in the sea.

Not all phytoplankton produce biotoxins and the potentially toxic ones are well known, can be identified in the laboratory and their toxic effects on humans and animals are known. Sites around the coastline of Northland are monitored weekly for signs of toxic algae by Northland DHB Shellfish programme team.

                                                                              

Gathering of wild shellfish or kaimoana from areas affected by toxin algal blooms is dangerous. Warnings of toxic algae are issued by DHB staff and advertised on local radio stations and newspapers or you can phone the local public health service for further information.

Cooking of shellfish gathered from areas affected by toxic algal bloom, does not kill the poisons and can be very dangerous if eaten by people or animals.

Click here for WARNING MESSAGES.