Thank you.
In terms of the factors responsible for the initial declines, I think it's fairly well established that habitat destruction and alteration were of key importance. It was the placing of dams, erosion, and land or river use issues.
Number two was over-exploitation, both in the freshwater and in the marine realm. Compounding that, in some areas, such as the Southern Uplands, we had issues associated with acidification. There were at least, depending on the region, two or three things that led to the decline.
Then once population has been reduced to a low level, the question then becomes, what affects recovery? One thing that has helped is a huge cutback on the commercial fishery for Atlantic salmon, beginning in 1984 in the Maritimes and in 1992 in Newfoundland. Also in 1992 was the cessation of the cod fishery. There was a lot of bycatch of salmon in that cod fishery, so if you look at Newfoundland, you actually see quite a positive response in survival of salmon and in returning salmon adults.
This is why I caution that we must place our arguments in the region we're discussing. In Newfoundland, for the most part, with the exception of the Conne River on the south coast of Newfoundland, there has been a fairly positive response to reductions in fishing pressure at sea in terms of salmon productivity.
In other areas, such the inner and outer Bay of Fundy and the Southern Uplands, we do have the issues of an increased proliferation of aquaculture sites. DFO, COSEWIC, and lots of scientific evidence point to issues associated with aquaculture operations, because salmon are at such low levels of abundance. In other words, I think it's a fact that they're at such low levels that they have become more vulnerable to threats that much larger populations in the past would not have been so vulnerable to.
In terms of the key issues, one reason I quite liked your question is that it reminds me that one of the reasons I identified this mathematical model idea is that what we'd ideally like to do from a science perspective is partition or break up the survival of salmon throughout their life cycle and determine where the bottlenecks and problems are.
We can identify fishing, seals, habitat alteration, dams, the Greenland fishery, striped bass, and a lot of different things, but what we need to do is have those management decisions guided by science in terms spending a lot of money and a lot of effort on something that maybe affects half a per cent of the survival rate of salmon. Wouldn't we rather focus on something that affects 10% of the survival rate of salmon?
That's why I would make the recommendation—it's one of the themes in the back of my mind—that science can help inform management and political decision-making by identifying where the bottlenecks are and what could potentially be done. In other words, if you took some mitigation measures in one particular realm, what's the best that could come out of that?
There have been about 22,000 or 23,000 papers published on Atlantic salmon.