Magaguadavic - Index River of Wild and Farmed Salmon Interactions
Monitoring of wild and escaped farmed salmon in the Magaguadavic, the North American index river of interactions, has now continued through almost an entire generation, since 1992. In 2014, 13 wild salmon returned, along with 27 aquaculture escapees. A chart of returns since the early 1990s shows the drastic decline in wild returns. (see chart at bottom of page)
Understanding the impact of escaping aquaculture salmon
Through the years there have been concerns about aquaculture escapees attempting to enter the Magaguadavic. In 2010, there were several escapes, including 13,000 from sea cages near Deer Island, another 33,000 from a site east of Grand Manan, and later an escape of 138,000 more salmon at Grand Manan. These indicated problems cages had with weather and ocean conditions.
In 2014, despite no escapes being reported to government, there were still 27 escapees appearing at the mouth of the Magaguadavic.
Human malice can also impact wild salmon. In 2005, cages vandalized near Deer Island through summer and autumn led to the escape of approximately 146,000 farmed fish, with some entering the Magaguadavic River and other streams in the area in November.
In freshwater, there have also been issues of fry and parr escaping from hatcheries and displacing wild Atlantic salmon. These are a component in reducing adaptation to natural conditions, as found in a 2011 study.
Read more on the issue of aquaculture
Chart of Magaguadavic Returns of Wild and Cultured Atlantic Salmon: