Toxic bloom returns to northern Hawkes Bay coast

A potentially deadly toxic bloom has returned to the northern Hawkes Bay coast, prompting health officials to warn people not to eat shellfish collected in the area.

The warning applies to all shellfish gathered between Whareongaonga, about 20km north of Mahia, and the Wairoa River mouth, and comes a year to the day since the last appearance of toxic algae forced a shellfish ban along much of the coast.

Mussels from the Portland Island-Mahia coastline were found yesterday to contain 161mcg of paralytic shellfish poison per 100g of flesh, double the Health Ministry's safe limit.

Health protection officer Noel Watson said the algae gymnodinium catenatum, which caused closures along the coast in the past two winters, was thought to be responsible.