2024-Aug-28
GBA’s Concerns Regarding Open-Cage Aquaculture
GBA’s aquaculture committee has held a watchful eye for 27 years and is very concerned by the potential environmental impacts of open-cage aquaculture in Georgian Bay and the North Channel. These high-density fish farms in open net pens rely on full exchange of the publicly shared water resource and bottomlands of the basin to both grow the fish and expel the fish waste between the farm and the surrounding aquatic environment, leading to several issues.
Open net cage aquaculture is not supported by any of the 8 U.S. Great Lake States, nor by Quebec.
GBA has highlighted 3 main environmental concerns with Ontario’s open-cage aquaculture which are:
Nutrient Loading: GBA has witnessed the effects of nutrient input, particularly phosphorus, on reduction in water quality, hypoxic events, water transparency and algae blooms (including cyanobacteria), and reliance on the benthic invertebrate community to break down the sediment (faeces) that accumulate on the bottom;- Potential effects on wild fish stocks by the inevitable escapements of the selectively bred domestic farmed fish competing for food and habitat, and disease pathogens they may carry as vectors to the wild;
- Possible effects of introducing therapeutants used at the fish farms, such as antibiotics, and/or other contaminants into the environment from medicated feeds or cleaning agents for the net pens.
These environmental concerns are not isolated from one another and can have cumulative effects on the ecosystem, coupled with other issues outside of open-cage aquaculture farming. There are too many un-researched potential impacts regarding open-cage aquaculture to allow for the expected growth of existing or addition of more open-cage farms. GBA is advocating for government funded research projects on the topics above and additional projects that are highlighted in the GBA Aquaculture Committee’s analysis document, “Environmental Effects of Open-Cage Salmonid Aquaculture in Ontario and Recommendation for Future Research”
GBA advocates for a move to land-based aquaculture – a growing trend globally and elsewhere in Canada to address a range of environmental issues. The technology and profitability of such aquaculture operations is steadily improving.