The Effects of Sediment Phosphorus Types and Water Temperature on the Release of Phosphorus and Nitrogen from Freshwater Sediments in a Lake with Cage Fish Farming

Description

The development of the Canadian freshwater aquaculture is currently limited by perceived risk of altering the trophic status of lakes. This perception persist despite the operation of fish farms and extensive environmental monitoring by farms in the North Channel for more than 20 years that has yet to document detectable increased in nutrient concentrations. Behind this perception is the lack of sound scientific knowledge regarding aquaculture's potential effects on receiving waters and sediments. One of the major knowledge gaps in our understanding of the environmental effects of aquaculture in freshwaters is the quantification of nutrient fluxes from sediments to the water column. Organic loading from fish cage farms increases the total nutrient content of the sediments and it can also increase the concentration of soluble forms that can be released into the overlying water. However, the fate of those nutrients (burial or release back to the water column) and the factors regulating that fate in sediments affected by aquaculture wastes are poorly understood. The main objective of this project is to quantify the effects of sediment chemistry and water temperature on the nutrient release rates from the sediments affected by fish wastes.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2007 - 2008

Ecoregion(s)

National

Principal Investigator(s)

Paula Azevedo
Email: Paula.Azevedo@dfo-mpo.gc.ca