PARR-2010-QC-05
Critical thresholds and dose-dependent relationships for biodeposition from farmed mussels and benthic responses

The development of a sustainable shellfish aquaculture industry requires the ability to predict impacts on the seabed by shellfish culture.

This project addresses knowledge gaps by using modeling approaches to: estimate biodeposit production and its influence on the seabed; evaluate predictions through a series of in situ experiments; and, parameterize an index of benthic condition for Eastern Canada conditions.

Results from large in situ mesocosm studies done in îles-de-la-Madeleine showed that sediment biogeochemical parameters and oxygen concentration change predictably with increasing organic loading from mussel biodeposition. Work in 2011 repeated and expanded upon this research in Prince Edward Island. Specifically, the mesocosm work was repeated and field work was conducted to obtain realistic estimates of biodeposit production. Sampling of sedimentation and benthic communities was also done in and around culture sites to evaluate the ability of a particle dispersion model to predict benthic loading and its impact on benthic conditions (sediment conditions and animal communities). Unfortunately, predation by starfish in the mesocosms destroyed the work in 2011 and efforts were then made to solve this problem. Analysis of biological communities, sedimentation data and sediment chemistry is on-going. Together, this work will contribute to the development of a model to predict benthic condition for different culture scenarios. The predictive model will enable mussel growers to manage bivalve densities within their farms to maintain a given benthic condition. Research efforts in 2012 will concentrate on redoing the mesocosm work in Prince Edward Island and sampling throughout the study site (St. Peter’s Bay) to evaluate the ability of the developed model to predict benthic conditions.

Project Leader: Chris McKindsey, Ocean and Environmental Science, Institut Maurice-Lamontagne, 850 route de la Mer, Mont-Joli, QC, G5H 3Z4, tel: (418) 775-0667; fax: (418) 775-0718;  chris.mckindsey@dfo-mpo.gc.ca.

Team Members: Andrea Weise, DFO-Quebec region, IML; François Roy, DFO-Quebec region, IML; Matthieu Huot, DFO-Quebec region, IML; Philippe Archambault, ISMER; Luc Comeau, DFO-Gulf region; Cédric Bacher, IFREMER; Gwénaëlle Chaillou, UQAR

3-year project: 2010/11, 2011/12, 2012/13