From the Times-Transcript:
It’s that time of year when a large number of folk will be heading for beautiful rivers like the Miramichi, Nepisiguit, and Restigouche to angle for that king of fish, the Atlantic salmon that has made New Brunswick so famous worldwide.
The major item in that last statement is that only three rivers are listed as of 2011. Just 20 years ago, that list of rivers would have been as high as 30.
Unfortunately, something went very wrong starting in the 1980s. The Atlantic salmon presence in many rivers, in particular those that drained into the Bay of Fundy, rapidly declined. There were several theories as to what may be the "smoking gun," however events were happening faster than research could establish the problem.
It was the crash of the Atlantic salmon population in those rivers that drain into the Bay of Fundy that was most dramatic and perplexing.
The Atlantic salmon that use New Brunswick rivers as a nursery are of two distinct populations that were once thought to historically evolve separately. The Miramichi, Restigouche, and the Nepisiguit River population would spawn and grow to 2- to 3-year-old smolts, then head on a journey to the North Atlantic off Greenland to grow into mature reproductive fish and return to these rivers to reproduce, often to within metres of where they were originally hatched from the egg.
An absolutely awesome "homing" ability evolved, allowing them to travel from the Greenland Sea back to their natal site. Stop to reflect on the natural onboard GPS systems these creatures must have. No man-made computer magic here. Mother Nature evolved a perfect design system of navigation that man will have to work on for some time yet to match.
The Atlantic salmon population that uses the rivers that drain into the Bay of Fundy also successfully evolved, but differently. These fish are commonly believed to limit their migration the Bay of Fundy and Gulf of Maine region as smolts to find lots of growth fuel to allow them to mature and return to those Fundy rivers in which they were hatched.
It was a perfect scenario with a relatively short sea voyage to meet their needs to mature and often returned to spawn after only one winter at sea. Times were good.
The good times suddenly crashed to the point the Bay of Fundy Atlantic salmon was in jeopardy of becoming extinct. Whatever the culprit(s) was/were, their effect was alarmingly rapid. With the threat of permanent extinction of this population, the Department of Fisheries and Oceans (DFO) in co-operation with several other conservation groups devised a plan to collect as much remnant Bay of Fundy Salmon stock as possible and hold them in captivity in a "gene bank" at Biodiversity Facilities on both the New Brunswick and Nova Scotia side of the Bay of Fundy. The hope was to maintain enough genetic stock to restock rivers when and if the reason for their demise could be found.
Although the problem is commonly accepted to occur in the marine environment, many possible threats could be at play there. Some threats have been correlated to varying degrees of inner Bay of Fundy salmon decline and there are likely others yet to be identified. A take-home message may be "we really don’t know. The Bay of Fundy is a difficult environment to work in."
Originally applauded for reducing dependence on wild fish stocks and fisheries, an aquaculture industry developed in Scandinavia where Atlantic salmon were farmed in sea cages to supply demand. The industry soon was successfully adopted in Scotland, Canada, and Chile.
However, as the aquaculture industry developed, it was found that river estuaries with aquaculture sea cages were losing their wild salmon population. The correlation seemed more than coincidental. Research was suggesting that escapee farmed fish were crossing with wild stock to create offspring that did not have the evolved fitness to complete their life-cycle. There was also evidence of disease from farmed fish getting into the wild population. It appeared aquaculture was one possible reason for the Atlantic salmon decline.
However, the aquaculture industry is ongoing at the head of the Bay of Fundy and there is no question that aquaculture in that area should continue as it has become a significant source of livelihood and an economic driver to New Brunswick.
The Petitcodiac River causeway constructed in Moncton-Riverview stopped Atlantic salmon from ascending the Petitcodiac River to spawn in its many upper tributaries. Before the causeway was constructed, the Petitcodiac River and its upper tributaries was the fourth largest nursery for Atlantic salmon in North America and its stock was thought to be replenishing other Bay of Fundy rivers as well through a natural straying process for this species.
Were there possibly two significant factors to challenge the existence of the Bay of Fundy Atlantic salmon? There were certainly two, but likely many more known and unknown
If the Petitcodiac River causeway was indeed one of the factors, the recent opening of the causeway to let the river run free should start a potential remediation process as some of those saved gene banked fish are reintroduced into the Petitcodiac River headwaters.
A potentially significant recent development is in progress between the aquaculture industry, DFO, and Parks Canada that has the possibility to allow aquaculture and the existence of the wild Atlantic salmon to take place. Finger-pointing is of little value; however, co-operation of the accumulated knowledge and ability of research and industry may be a crucial factor.
The historic parallel already exists in New Brunswick. In the 1960s, DDT was used by the forestry industry to control spruce budworm. When research found it to be a major problem to the wildlife community, and very likely the human community as well, it was through the co-operation of the forest industry and research that the problem was addressed. The valued forest industry of New Brunswick was not about to be stopped by any stretch of the imagination, but co-operation allowed for the problem to be addressed. Will history repeat itself for the benefit of the co-existence of the valued aquaculture industry and of the valued wild salmon resource? In drawing this parallel, we must remember DDT was a one issue problem whereas with the Atlantic salmon, several issues may be at play.
We often think of our national parks as places to camp and commune with nature. While this is true, a significant role of national parks is often the incredible research work, often unseen by the public, which make these parks outstanding outdoor laboratories.
Two of those Bay of Fundy rivers that lost the Atlantic salmon happen to be in Fundy National Park.
With close co-operation between Fundy National Park and DFO, Parks Canada through gene banking activities has been able to keep the endangered Bay of Fundy Atlantic salmon in the Upper Salmon River (Alma River) to maintain a genetic presence. A Fundy National Park research program and some members of the Atlantic Canada Fish Farmers Association have pooled knowledge to start on a path of potentially groundbreaking trial efforts to allow better chances for the wild salmon population to exist with the farmed population.
As Fundy National Park researcher Corey Clark commented, "We have been able to learn a great deal from our industry partners that are showing tremendous dedication to this conservation effort."
Some members of the aquaculture industry have been co-operative and helpful beyond the call of duty to help mediate the potential problem. Research may be familiar with the genetics and biology of the Atlantic salmon, but it is the aquaculture industry that best know how to grow fish. With the co-operation of the aquaculture industry, an experiment to grow the gene-banked endangered fish in sea cages designed by the aquaculture industry has seen some early success.
It may be a wild dream but the possibility exists to grow enough wild fish in a sea cage to meet the numbers to sustain a whole river system.
But for that dream to come to fruition, there are still lots of hurdles to be cleared. When true co-operation happens, however, a lot of doors swing open.
* Nelson Poirier is a veterinarian by trade and a naturalist by nature from the Moncton area. His column appears each Saturday and he can be reached at P.O. Box 25091, Moncton, N.B. E1C 9M9, or e-mail firstname.lastname@example.org