Escaped Atlantic Salmon Invade BC Rivers - John Volpe. NEW PAPER

Volpe has a new paper out on the invasion by leaked Atlantic farmed fish in Vancouver Island Rivers: https://www.academia.edu/17616905/Occupancy_dynamics_of_escaped_farmed_Atlantic_salmon_in_Canadian_Pacific_coastal_salmon_streams_implications_for_sustained_invasions?email_work_card=view-paper.

In a nutshell the results show: 37% of rivers have multiple year classes of Atlantics, meaning they are established breeding populations. In rivers with multiple Pacific Species, the results show 97% Atlantics, a staggering number.

Chronic low-volume escapes of salmon from farms into Pacific waters (‘‘leakage’’) are typically undetectable (Britton et al. 2011). Analysis of escape-reporting from farmers indicates that reports greatly underestimate the true number of Atlantic salmon inadvertently released from open-net pen rearing sites (Morton and Volpe 2002).

We systematically snorkel-surveyed 41 known Pacific salmon (Oncorhynchus spp.)-supporting rivers and creeks on Vancouver Island over a span of 3 years. We estimated and accounted for imperfect detections using multi-season occupancy models.

So what did they find?

Volpe says: "We detected Atlantic salmon in 36.6 % of surveyed rivers. After accounting for imperfect detection, occupancy models estimated that over half of surveyed streams across the study area contained Atlantic salmon, and that 97 %of streams with high native salmon diversity were occupied by Atlantic salmon.

And he offers a caution: "Even in intensive snorkel surveys, Atlantic salmon are detected in occupied streams only 2/3 the time, suggesting abundance and distribution of non-native salmon is greater than indicated by the only existing data."

Here is his most important point: "Further, Atlantic salmon are more likely to occupy streams with high native Pacific salmon diversity— and more likely to maintain occupancy across years— potentially increasing competitive pressure on native salmonids."

And this point is highly important as well: "These data for the first time show that Atlantic salmon occupy Pacific coastal rivers for multiple years. The impact of Atlantic salmon occupancy in British Columbia rivers must be factored into policy decisions regarding the future of salmon farming in the provincial waters.

And DFO aint doing this despite Minister Jordan's recent decison to move fish farms out of the Discovery Islands.

Just how bad is the DFO system? Volpe offers these comments: "The current Fisheries and Oceans Canada escapes-reporting system—the Atlantic Salmon Watch Program—has been effectively abandoned and was shown to under-represent Atlanticsalmon encounters by at least 40 % when it wasoperational (Morton and Volpe 2002). The lack of monitoring of salmon escapes and invasions indicates a failure of current management practices and a lack of oversight of escapes."