Environmental Decision Support Tools for Performance Based Management of Organic Waste Dispersal and Dissolved Oxygen Depletion Associated with Salmon Farm Sites in SWNB

Description

The finfish aquaculture industry in southwestern New Brunswick and the government regulatory agencies responsible for habitat and environmental protection do not have predictive environmental impact models that robustly relate farm production and operation to environmental impacts and regulatory environmental performance measures, either those in existence (e.g. sulphide) or those being considered (e.g. dissolved oxygen). This knowledge gap hinders the proactive estimation of environmental impact and finfish holding capacity. This in turn hinders the ability of industry to plan and implement its farming operations and hinders the government's ability to assess the potential for sustainable development, marine resource planning scenarios and environmental regulation policy. At present there are two models that are considered to have some potential for filling this gap in the southwestern New Brunswick area - a benthic deposition model (DEPOMOD) and an oxygen reduction model. The utility of these models need to be evaluated for the SWNB area before they are incorporated into industry and regulatory decision making considerations such as the proposed of approach of management by Performance Based Standards.

The present regulatory framework governing fish farms in SWNB monitors the environmental impact of the farming by empirically measuring the Eh and sulphide levels within soft bottom sediment samples collected under and within close proximity of each fish farm. In the future dissolved oxygen may become a second variable to be monitored as it is recognized as being of fundamental importance to ecosystem function and fish production.

Unfortunately, there are no robust relationships or models relating soft-bottom environmental conditions or dissolved oxygen concentrations within and near farms to farm production levels and the physical characteristics of farm sites (e.g. water current speed). The lack of such relationships hinders the ability of farmers to plan site production levels and for farmers and regulators to devise environmental remediation plans when undesirable impacts occur.

The purpose of the proposed research is to evaluate the utility of the DEPOMOD and Page dissolved oxygen models as cause and effect tools for relating farm production to benthic deposition and oxygen depletion in the vicinity of fish farms within the macro-tidal environment of the Bay of Fundy. Although the models explicitly deal with near-field effects a by-product of their evaluation will be insight into the likely magnitude of far-field concerns.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2005 to 2008

Ecoregion(s)

Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Fred Page
Email: Fred.Page@dfo-mpo.gc.ca