The ecological effects of clam harvesting by mechanical means in St Mary's Bay, Nova Scotia

Description

Traditional hand harvesting is not considered to be a sustainable practice for providing seed for the development of clam aquaculture in Nova Scotia for various reasons, including social and economical factors. The clam aquaculture industry has experienced major challenges in the recruitment and retention of clam diggers, as well as a lack of interest from the younger employable population, resulting in an aging employee-base. Additionally, traditional hand harvesting is very labour-intensive and involves the use of a clam hake - with tines that measure about 15 cm in length, to dig up and turn over the sediment. A mechanical clam harvester has been used in Washington and British Columbia, and there is increased interest in utilizing a modified version of this harvester to compliment hand harvesting of quahogs (Mercenaria mercenaria) in St Mary's Bay, Nova Scotia. This project will compare the ecological effect of traditional hand harvesting and a mechanical clam harvester. It will investigate the effects of each harvest technique on the ecological health and production of the area through the monitoring of the clam population, associated fauna and flora, and various physical and chemical parameters. Methods for reducing the ecological impact of harvesting, such as replanting pre-recruits on size-class plots and reducing repeated harvesting efforts, will also be investigated.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2012 - 2014

Ecoregion(s)

Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Thomas Landry
Email: Thomas.Landry@dfo-mpo.gc.ca