Species Focus - Coromandel Scallops (Pecten novaezelandiae)

The Coromandel Scallop fishery extends from Cape Rodney near Leigh in the north to Town Point in the Bay of Plenty in the south.

This area provides a fertile environment for scallops, with scallop beds found throughout much of this range.

Scallops in this area have long been popular with recreational and customary fishers who take their catch by diving, dredging or on occasion, by hand-gathering scallops washed-up after a storm.

A commercial dredge fishery developed in the late-1960s and early-1970s. At its peak during the early 1990s, this fishery supported 22 commercial fishers with landings in excess of 200 tonnes meatweight (the weight of the edible part of the scallop).

Status of the Stock

Like many other shellfish species, scallops are very sensitive to environmental conditions such as sea temperature, currents and availability of food. This means that scallop recruitment (the number of new scallops in the fishery each year) is highly variable and difficult to predict in advance. Because of this, scallop numbers can fluctuate significantly from year to year. To ensure that fishing is always at sustainable levels, the Coromandel scallop fishery is managed differently to most other fisheries in New Zealand.

In 2002, the total allowable catch in the fishery was set at 48 tonnes (meatweight), with the total allowable commercial catch set at a deliberately low ‘baseline’ level of 22 tonnes. The baseline can be reviewed and increased each year only after a survey has shown that a higher catch level would be sustainable. In this way, the catch limit in any given year is set at a sustainable level in response to the natural variations in scallop numbers in the fishery.

Commercial and non-commercial fishers generally fish different areas within the Coromandel Scallop fishery. Non-commercial fishers may fish anywhere within the fishery, though most of their effort is concentrated in the shallower areas closed to commercial fishers. In contrast, commercial fishers have tended to fish almost exclusively in the established beds around Little Barrier Island, Waiheke Island, Mercury Bay, Waihi and Motiti.

Current Management Issues

In 2005, MFish selected this fishery to test the concept of fishery plans. This saw MFish bring together fishers from the commercial, recreational and customary sectors, as well as representatives from the environmental sector to discuss what each wanted to see achieved in the fishery. Over the following 18 months, this group worked together to produce the Draft Coromandel Scallop Fishery Plan. This document combines many different goals and aspirations, including a desire to increase the stability of the fishery and to “maintain the mauri and sustainability of the fishery with a cautious respectful approach.”

In 2008, MFish intends to work with stakeholders and tangata whenua to develop this plan further and seek wider public comment. For more information and a copy of this draft plan see the MFish website.

Historically, an annual survey has been undertaken on the commercial beds only. However, for the past three years, four popular recreational beds in the Coromandel fishery have also been surveyed. It is hoped that this work will help provide more accurate estimates of total scallop abundance in the fishery. It should help us to find out if there is a relationship between scallop abundance in the commercial beds and in the non-commercial areas of the fishery.

Scallop catch limits and allowances

Over the past few years, this stock has been fished cautiously by the commercial sector, with annual commercial landings seldom exceeding 50 percent of the available yield. For example, in 2007 the stock assessment survey indicated that 338 tonnes was available from the commercial beds, yet commercial fishers opted to take only 108 tonnes of scallop.

Recent changes to non-commercial regulations in this fishery include an allowance for divers to harvest the daily bag limit for up to two boat safety people and a shift in the recreational scallop season which now runs from 1 September to 31 March.