Epidemic devastates coastal kina colonies

By ANGELA GREGORY

LEIGH - A mystery epidemic is killing off kina colonies in some coastal areas of New Zealand.

Scientists fear the sea urchin could be devastated by what is thought to be an infectious disease.

Auckland University researchers at the Leigh Marine Laboratory, northeast of Warkworth, have found kina populations badly affected in a survey of 20km of coastline near Leigh.

There have also been reports of the disease at Kerikeri, north of Whakatane and Kaikoura.

A senior lecturer in marine biology, Dr Russell Babcock, said some of the reefs resembled a kina graveyard as the animals gradually lost their spines and died.

More than half of the kina in the surveyed area had shown signs of infection, and in some places more than 90 per cent were affected.

The problem was first noticed late last year when scientists were researching the size of fish populations at the Mokohinau Islands, 60km off Bream Bay, in Northland.

Dr Babcock said they noticed a relatively small patch of sick kina, then in December spotted similar problems at Leigh.

He said the origin of the epidemic was not known and it had not been seen in New Zealand before.

Ngatiwai iwi were shocked to hear of the danger to one of their favourite foods.

The customary fisheries officer, Perry Watts, said he would be concerned if a disease was killing the kina colonies.

"Every Maori would be. We all love it," he said.

Mr Watts said doctors advised Maori to eat kina as the roe was a good source of iron.

He said he had not noticed the problems around Leigh.

"But I usually send the boys out to dive for them."

Overseas sea urchin species have been almost wiped out in Nova Scotia, Scandinavia and Norway.

Causes of the disease included bacteria, protozoa or even extreme oceanographic conditions.

Dr Babcock said it was critical to establish the cause of the New Zealand deaths.

So far, disease seemed the most likely reason.

"Without some knowledge of the cause, we will not be able to predict where the epidemic will strike next, and how long it will last."

Dr Babcock said sea urchins were a valuable food resource for many people on the coast, and there was also a small commercial fishery.

"But more than this, the urchins are an important part of the marine ecosystem, grazing down algae, providing space for some animals and food for others, such as crayfish and snapper."

The disappearance of kina would mean big changes to coastal ecosystems, as many species of fish fed on them.

He said there was a need for a wider approach to the investigation, with more help required to survey coastlines in the different regions.

Scientists needed to discover how widespread the epidemic was, and whether the urchins could recover.

Talks were under way with the Ministry of Fisheries to determine how that could be achieved.

A ministry spokesman said a report had been received from Dr Babcock and the ministry was considering what response was required.