Jeff Piercey

MSc Candidate

Jeff PierceyBSc Hon., Memorial University

Research: "The role of blue mussel (Mytilus edulis), kelp (Laminaria saccharina) and biofouling on the dissolved oxygen budget of integrated (salmon-mussels-seaweed) aquaculture"

The Quoddy region of the Bay of Fundy has been an area of active aquaculture development for the last 2 decades. The high concentration of monoculture within this area has raised several ecological concerns and interest of late has focused on developing an integrated ecosystem approach to aquaculture.

Studies to date have shown that "extractive" organisms cultured along with "fed" organisms can help decrease the possible environmental loading of salmon aquaculture. However, the increased biomass associated with multi-trophic aquaculture may exceed the carrying capacity, relative to oxygen demand, of the area.

Dissolved oxygen has been a persistent concern as the Quoddy Region shows an annual autumnal reduction in dissolved oxygen concentrations to levels that may cause concern for salmon farmers. Existing dissolved oxygen models have incorporatedsalmon biomass, hydrography and benthos components but none have looked at the oxygen demand of a culture of mussels, kelp or fouling organisms.

The objective of this project is to better develop a dissolved oxygen demand model for multi-trophic aquaculture sites. Mussel socks, kelp lines and sections of mesh for biofouling have been placed on three salmon sites in this region. Preliminary respiration trials have begun and suggest kelp and mussels respire 10% and 60% of the salmon respiration rate respectively.