Fishing: Tabs kept on succulent swimmer

Scallops shucked and eaten on the boat count as part of the daily limit. Photo / Geoff Thomas

As the dinghy slid over the wavelets little puffs of sand squirted up and small round shells seemed to dance in the clear water, suspended above the seabed. Then they sailed away, rising and falling in graceful arcs.

The creatures were scallops, the only bi-valve shellfish which swims, and these scallops had been disturbed by the boat. It was of a wooden clinker-type construction, a replica of the long boats which served the sailing ships that left Nantucket Island 200 years ago to roam the oceans in search of whales.

The grey and white houses that dotted the shore of Nantucket and nearby Martha's Vineyard were built to the Cape Cod design, each with a widow's loft lookout where wives would sit for hours anxiously searching the horizon for a mast and sail bringing husbands home.

We were there to fish for bluefish, the predator which shoals like kahawai and chases small bait fish. The wooden dinghy was the only boat available, but a pair of oars, and a short stump of a rod found fossicking under the house were soon put to good use. There was no bait or lure, but a scrap of rag tied to a hook was sufficient to attract the bluefish.

The rod bucked and the fish came to the boat, with gleaming silver flanks and blue backs they resembled a cross between a trevally and a kahawai.

But it was the scallops which impressed me. I was fascinated by their ability to detect a threat and squirt water by opening and closing their shells, propelling them to safety. Like everything in the sea, scallops are prey for other creatures. Starfish are the deadly enemy, as they clamp their powerful arms around the shell, forcing it open, and eating the flesh.

Snapper love scallops, and large fish can easily crush the shells in their powerful jaws. Canny anglers know that if they follow the big commercial scallop boats, dropping lures or baits in their wake, they will soon find snapper which are attracted to the heavy dredges as they crunch along the seabed, scooping up scallops but also smashing many and leaving a trail of broken shellfish and other creatures.

Scallops are found in harbours and on sand or mud bottoms out to about 50m deep. Like most other sea creatures scallops start life as a free-swimming embryo, but after about 48 hours they attach themselves to a rock or structure on the bottom where they live until reaching a few millimetres in size when they drop to the seabed. Like all bi-valves they are filter feeders, sitting on or just under the sand with their shells slightly open, straining water to extract plankton.

They grow quickly and reach 60mm across in about a year, when they start breeding.

Under a programme to monitor growth rates more than 9000 scallops were tagged earlier this year in Northland, Coromandel and the top of the South Island. Niwa scientists would like scallopers to return any tagged scallops, even if they are under size or in excess of the daily limit.

They should note the tag number and colour, when and where it was caught with GPS co-ordinates, and the shell dimensions. Such scallops can be kept in the freezer, and the catch reported by phoning 0800 RING NIWA (0800 746 464). All those reporting tagged scallops will go into a prize draw for fishing tackle.

For most of the country the scallop season opened on July 15, but in the top half of the North Island it now starts on September 1. The delay is intended to give the shellfish more time to regain condition after the cold winter. It also allows more fishing through the summer, as the traditional season ends on February 14 while in the north it now runs until March 31.

There have been other changes to the rules governing the collecting of scallops. Now a diver or divers may take a limit bag for up to two other people on the boat, which recognises the part played by boat operators. Also, scallops may be shucked and eaten at sea, but these must come from the daily limit. All other scallops must be taken ashore in the shell, so they can be measured.

When dredging for scallops, only those actively involved in fishing are entitled to a daily bag limit. The limit bag varies from 10 per day at Stewart Island, 50 per day in the Marlborough Sounds to 20 per day in the North Island. The minimum size which can be taken is 100mm across the widest part of the shell (but 90mm in Marlborough).

The Kaipara Harbour reopened to scallop fishing after a two-year closure following disease.