Researching the habitat
For 23 years the company has researched the impact of its wild-stock rotational harvesting system on habitats, refining its operations accordingly. As well as the intrinsic importance of sustaining the littleneck clams’ environment for future generations, the company’s livelihood depends upon it. Over two decades of research and resource surveys have examined the impact of harvesting at Blueskin Bay and Papanui Inlet. The results show that clam beds harvested by Southern Clams tend to recover over 50% of their clam biomass a year after harvest. The impact on other species (macrofauna generally) is almost undetectable after 30 days, as is any effect on the sandy substrate of their habitat. Indeed, evidence shows that reducing the
shellfish density by 60% (analogous to thinning carrots) has a positive impact on the growth and health of the remaining shellfish.
How the harvest takes place
Southern Clams’ unique wild-stock rotational harvesting system uses a ‘body dredge’ in the water. Body dredge harvesting uses a light dredge with a ‘riddling’ basket pulled by each harvester. Body dredging is a ‘wet’ harvesting system, and the process causes less damage to shellfish and is gentler on the habitat. All unwanted material brought in with the harvest, including dead shells, other shellfish species (small numbers of pipi, oyster, mussels, for example) seaweed, sand, and any undersize or unwanted grade clams, are returned to the bed. Up to eight harvesters and two or three small vessels work in shallow water over the beds for two or three hours.
Harvests (which usually take place six days a week) are timed according to the tides, and market demand.
The future
While all harvesting is ‘to order’, when demand exceeds supply it remains unfilled as the supply level is set by The Ministry of Fisheries. Currently, the total allowable commercial catch of 1,475 tonnes set by The Ministry of Fisheries is not harvested, and the company harvested 956 tonnes of that in the 2005-6 fishing year.
Southern Clams deliberately adopts a conservative approach to harvesting, as it has sought to increase its knowledge of managing the resource. The company believes that as humans, we all modify our environment. The important thing is to be careful about how we do it.
Come and see what we do!
We have a number of open days throughout the year. If you would like to attend one of our open days, give us a call (03) 477-1505.
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In the 1980s, inspired by anthropology studies and an interest in food as a cultural resource, Roger Belton, had a vision to sustainably harvest native shellfish from selected areas in Otago and to take the delicacy to the food plates of the world. After years of practical hard slog and reflective research to develop sustainable management systems for both the shellfish and its habitat, Roger’s company Southern Clams has carved out niche markets in Europe and North America (servicing demand in a place where there is a strong tradition of clam cuisine) to become a thriving southern business that Otago can be proud of.