Shellfish may not be ready

HARBOUR CARE: Rodney Local Board member Tracey Martin, left, congratulates Hamish and Robyn Alexander for restoring their Whangateau Harbour frontage.
HARBOUR CARE: Rodney Local Board member Tracey Martin, left, congratulates Hamish and Robyn Alexander for restoring their Whangateau Harbour frontage.

The Whangateau Harbour cockle and pipi gathering ban is due to end on March 25.

But there's concern the shellfish may not have recovered sufficiently to sustain harvesting.

Adecision may be made in February after the Ministry of Primary Industries assesses all relevant information, including public feedback from a consultation document due for release shortly.

The cockle beds were decimated in early 2008 when about 60 per cent of the cockles died, including 85 per cent of larger "harvestable" shellfish over 30mm which are also breeding stock. The shellfish may have been weakened by some very hot days then succumbed to a rare combination of a parasite and bacterial infection.

A three-year ban was introduced in March 2009 by the then Ministry of Fisheries, but not before residents had set a voluntary ban after frustrations with official reaction.

As the ban comes up for review, those residents are again anxious about the department's assessment as they say the cockles haven't recovered.

In January, ministry team leader Allen Frazer was encouraged the cockles were no longer in decline and the large number of young shellfish were continuing to mature. But nearly a year later the larger cockles have not reached former numbers.

Studies by National Institute of Water and Atmospheric Research on Whangarei Harbour commercial cockle beds show the shellfish there grow quickly as youngsters but growth slows as they near the 30mm "harvestable" size, marine biologist Karen Tricklebank of the Whangateau HarbourCare group says.

Auckland University studies in the four years since the die-off show shellfish in the 24mm-29mm length are increasing and suggest the beds will return to normal if left to grow-on for another two to three years, Dr Tricklebank says.

Marine biologist Roger Grace, also with the harbour care group, has concerns the Ministry of Primary Industries may use other shellfish populations in the Auckland area as a benchmark rather than the previous high numbers found in Whangateau Harbour.

Even in its current depleted state, the harbour's adult cockle population is still above levels the ministry usually finds acceptable to harvest in other shellfish populations, Dr Grace says.

This could see them agreeing to lift the ban, jeopardising the population's ability to recover to its former robust state, as gatherers will likely take the immature shellfish as the big ones get harder to find, he says.

The Rodney Local Board has picked up on the concerns and will make a submission, after board member Tracey Martin gave an award at the opening of a Whangateau HarbourCare photographic exhibition for this summer at the Leigh Marine Laboratory's Public Interpretive Centre. The award went to horticulturists and Southern Paprika owners Hamish and Robyn Alexander for their efforts to restore and protect their property's harbour edge.

Rodney Times