New methods for assessing the re-suspension and transport of aquaculture wastes

PARR-2008-M-05

Description

Modeling programs like DEPOMOD deal primarily with the initial deposition of aquaculture wastes but fail to predict their subsequent resuspension and dispersal due to an inability to parameterize erosion shear stress and the grain size of the eroded material. The development of predictive models for transport of aquaculture wastes that could be used to assess the potential for far-field impacts requires both concentration and size of the resuspended material. A pilot study was carried out in Charlie Cove and Maces Bay, New Brunswick in November 2008 using new methodologies to determine the erosive dynamics of fin-fish aquaculture wastes. A specially designed erosion chamber that applies increasing shear stress to the sediment surface was fitted to a slo-core to determine the critical erosion shear stress of bottom sediment and to capture the resuspended material for analysis of grain size and contaminant load. The characterization of the resuspended material (i.e., grain size, organic carbon and trace metals) may lead to far field indicators for the transport of aquaculture wastes and determine appropriate critical erosion shear stress values for incorporation into resuspension models.

Program Name

Program for Aquaculture Regulatory Research (PARR)

Year(s)

2008 - 2009

Ecoregion(s)

Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Brent Law
Email: Brent.Law@dfo-mpo.gc.ca