A battle is going on, and it seems to pit one species against another. There is great concern that one will win out over the other. Will this lead to both losing or is there a way to find balance in the ecosystem?
This current fight is north of the 49th parallel, but problems of favoring one species over another could happen anywhere popular sport fish exist or should I say co-exist. This particular instance involves Atlantic salmon and striped bass in New Brunswick’s Miramichi River system, with the impacts slowly spreading.
For years, these species have co-existed in this river system. In the past, the striped bass population was controlled by a combination of water temperatures and predation impacting their spawning success. As it has for millennia, the ecosystem and environment controlled the species populations.
Salmon have suffered some little understood population decreases in the high seas portion of their life cycle. While these issues have caused a slow decline with some cyclic variation, the interaction with striped bass has been demonstrably more detrimental.
In my 55 years fishing this river, the population was as high as 140,000 adult salmon and the river produced 50% of all salmon runs in the Western North Atlantic. Between 2010 and 2024, the population of salmon decreased 93% according to estimates produced by the Canadian Department of Fisheries and Oceans (DFO). During this same period, the population of striped bass experienced an exponential growth of 860% +/-.
Perhaps due to DFO’s mismanagement, the striped bass population had dropped to around 5,000 spawning adults (SSB) in the 1990s. There was a limited sport fishery at that time, but the commercial fishery was the main reason for the stock decline.
DFO closed all fishing for striped bass in 1996 and began a rebuilding program. Their initial target was 21,600 SSB, which they reached fairly quickly. The target was increased to 31,200. And finally, a 330,000 limit reference point (LRP), the population level below which management has concerns about the ability to reproduce enough fish to maintain their population.
The 330,000 SSB LRP is from a formulaic calculation that has been used for other species in the past. In 2017, DFO’s estimate had an SSB population at almost 1 million. There has been no scientific reasoning produced by DFO to explain their target increasing from a 10,000 to 330,000 SSB. At this level their management regime is in violation of the Canadian Fisheries Act which requires ecosystem balance for the species. They continue not to explain what is the basis for the concern for maintaining a viable SSB. It has been proven that the population grew from 5,000 +/- to almost 1 million in reasonably short order. It is hard to understand when there is silence.
The major detrimental interaction comes in the spring when the striped bass gather in the lower sections of the river to spawn. Unfortunately for the salmon, this happens when the salmon smolts, 3 year old fish, are on their out migration to the ocean. They form the “all you can eat” buffet that striped bass eagerly partake in.
Give or take 95% of the smolts are being consumed. While it is anecdotally obvious, there has also been some good scientific research on what is happening to the smolts. The Atlantic Salmon Federation, along with DFO, tagged smolts that could be tracked electronically over a number of years. The results show that the primary predator of smolts is striped bass. They consume 71% of the outward migrating fish. Other predation makes up the rest. Striped bass now inhabit the upstream river during the summer and consume salmon parr, predation that lowers the number of smolts.
What is the answer to this conflict? It is not easy since there are many parts to this and a number of constituencies. It should also be noted that salmon are not the only species suffering substantial decline during the timeframe of bass increases. There have been drastic declines in gaspereau (herring), smelt and shad.
In Miramichi Bay, the lobster fishery is also seeing problems. There are many impacted constituencies from First Nations, river communities, salmon and striped bass anglers, and commercial fishers. All these folks are not necessarily pulling in the same direction.
The first step is to recognize there is a problem. DFO refuses to do that. IMHO, the predominant problem is the striped bass population. DFO science has shown that with a striped bass level of 100,000 SSB, approximately 50% of the salmon smolts will make it out of the river and that is enough to sustain a salmon population. At that level, there would be a robust bass sport fishery and a salmon fishery.
This would support all user groups up and down the river. It would also mean that the river ecosystem would get back in balance rather than the monoculture it is becoming due to DFO’s mismanagement.
