Health professionals are warning holidaymakers to take care when collecting shellfish this summer, with paralytic shellfish poisoning warnings in place for much of the North Island's west and east coasts.
This month 26 people have been hospitalised in Tauranga and Rotorua, including two people who ended up in intensive care, after eating pipi or tuatua gathered around Papamoa.
Another warning remains in place on the west coast from Taranaki to Kaipara Harbour and the Auckland Regional Public Health Service has warned that the risk of shellfish poisoning in Auckland and Northland is high.
Cooking shellfish does not remove the toxin, which is created naturally from algae growing in the sea water.
Symptoms of paralytic shellfish poisoning usually occurred within 12 hours after eating shellfish containing the toxins.
* Numbness and tingling around the mouth, face or extremities
* Difficulties in swallowing or breathing
* Dizziness, double vision
* In severe cases, paralysis and respiratory failure
Monitoring of toxin levels will continue along the coasts over the summer.