Some interesting salmon articles over the last few days.

Carrying capacity? (Victoria, BC circa 1977)

Figure this one out… Mark Hume in the Globe and Mail yesterday:

Sports anglers in British Columbia have asked the federal government to charge them more to go salmon fishing.

But the 300,000 anglers who annually buy salt-water licences on the West Coast just can’t get the Department of Fisheries and Oceans to agree to a fee hike, a federal commission appointed by Prime Minister Stephen Harper heard Monday.

“We have been enormously frustrated by the Department’s inability to charge us more money,” Gerry Kristianson told the Commission of Inquiry into the Decline of Sockeye Salmon in the Fraser River.

Mr. Kristianson, Chair of the Sport Fishery Advisory Board (SFAB), said salt-water-fishing licences haven’t increased in price since the mid-1990s, and anglers are prepared to pay more if the money will be returned by the government to help manage the resource.

He said his board, which advises DFO on a voluntary basis, has been told the request for higher licence fees is caught up in government red tape.

Mr. Kristianson said it seems odd any group “is unable to have the government collect more money from it,” and urged Commissioner Bruce Cohen to look into the situation.

…

Mr. Kwak [also from SFAB] said the province is considering hiking its fresh-water licence fees, and urged Mr. Cohen to keep that in mind should he make any recommendations concerning increases to the federal salt-water licence.

He also told the Commission “upward of 5,000 fishermen a day” can be seen on the Fraser during the sockeye run, but said it is not clear how many fish they catch, because DFO doesn’t have a comprehensive or rigorous way of collecting catch data.

Mr. Kwak questioned whether an accurate count of anglers can be made from patrol flights over the Fraser. And he said DFO workers, who ask anglers on the river how many fish they have caught, in an onsite survey, can get misleading data, because fishermen exaggerate how many fish they have caught…

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And so sport fishers are asking DFO to charge them more for licenses… and… DFO does not get accurate information on how many fish sport fishers are catching.

Hmmmm… I think I sense one potential solution here… maybe charge sport fishers more and then use those fees to better monitor the sport fishery itself?

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Two related articles. One also from Mark Hume at the Globe and Mail:

The Fraser River is heating up because of climate change and an increasing number of salmon are dying in the warmer water from diseases or parasites or are simply dropping dead from cardiac collapse, a federal judicial inquiry has been told.

Scott Hinch, an expert witness on aquatic ecology, told the Commission of Inquiry Into the Decline of Sockeye Salmon in the Fraser River that sometimes 50 per cent of the salmon that return to the river die before they reach the spawning beds.

Dr. Hinch said because the Fraser has increased in temperature by about 2 degrees C, salmon are changing the timing of their spawning migrations, to enter rivers weeks earlier or later, in an effort to avoid warm water. And once in the river they are seeking out cold-water refuges, sometimes going up tributaries to sink to the bottoms of lakes or schooling where cold streams enter the Fraser.

As water temperatures continue to climb (predictions suggest an increase of between 2 and 4 degrees over the next 60 to 80 years), more and more Fraser River salmon are likely to die before they have a chance to spawn, said Dr. Hinch, a fisheries researcher and professor at the University of British Columbia.

“Certainly we’re gong to see higher en route mortality [in the future],” he said. “We’re going to have to forsake more harvest on these fish.”

Dr. Hinch said the warmer water doesn’t kill fish directly, but once the temperature of the Fraser has climbed above 18 degrees C, as it does for several weeks every summer, the fish are subject to stresses which increase the chances of death.

…

Higher water temperatures also increase the rate of development of pathogens, exposing salmon to disease.

The research, one of 12 scientific papers being prepared at the request of Commissioner Bruce Cohen, says the phenomenon of en route loss of salmon was first reported in 1992 for three distinct runs of sockeye, which come back to the Fraser in the spring, early summer and summer. A fourth run of sockeye, which returns to the river in the fall, didn’t exhibit the problem until 1996.

The paper states that since 1996 “en route loss of at least 30 per cent has been observed for at least one run-timing group in each year,” and many stocks have had losses of 50 per cent or more.

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Gee… sure makes sense to me then, that we should be harvesting upwards of 80% of these runs as one other pre-eminent scientist has suggested to the Cohen Commission and spouted off on radio, tv, and wherever else his voice could be recorded last year.

Bring back maximum sustainable yield…!

kidding.

Dr. Hinch and Dr. Martins, who synthesized decades of salmon research in their paper, said warmer water temperatures appear to be decreasing the survivability of salmon at nearly all life stages, not just when the fish are adults returning to spawn.

But Dr. Hinch said there is “shockingly little information” on the early life stages of salmon.

He also noted that one run of sockeye, which goes up the Fraser and then into the glacial-fed Chilko River, have adapted to handle dramatic temperature ranges.

He said it is important to protect a wide variety of salmon stocks, because it is not clear which fish may hold the genetic key to survive in the warmer water of the future.

I’ve noted this before… in asking DFO they really only investigate about two sockeye nursery lakes in the entire Fraser system. Some estimates suggest there hundreds of nursery lakes.

Sounds like biodiversity and protecting all runs is important — and even more important as every organism has to become more rapidly adaptive to climate change. Human communities are sure as hell having to become more adaptive — especially coastal communities. There’s only so much boulder rip-rap armoring of coastlines that can be done to protect infrastructure…

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The Tyee has also ran a related article:

An expert in aquatic ecology told the Cohen Commission that a retrovirus is having a more devastating effect on salmon smolt as rising water temperatures put stress on them.

Dr. Scott Hinch, expert in aquatic ecology and forestry professor at the University of British Columbia took the stand as a witness accompanied by Eduardo Martins, UBC population ecologist at the Federal Judicial Inquiry in to the collapse of the 2009 Sockeye Salmon runs yesterday and today.

Hinch said the optimal average temperature for salmon is around 13-15 degrees. Over the last 20 years the Fraser River has increased by about 2 degree, often causing salmon to seek thermal refuge in cold water at the bottoms of stream or lakes.

“Survival decreases as temp increases,” said Martins, whose research showed that an increase in water temperatures would likely a higher die off rate among smolts and older salmon.

“Mortality got to be a problem at about 18 degrees in the river. When things got up to about 19 degrees stocks survived very poorly,” said Hinch.

Climate change has been showed to be a major stressor for returning salmon. But far less is known about how climate change is affecting salmon while they are at sea.

“This life stage is the most poorly understood of the salmon, there is a major data gap when they are in the open ocean,” said Hinch.

“It’s possible to keep fish alive [in warmer water temperature], if the water is pathogen free,” explained Hinch.

But the water in which B.C. salmon swim isn’t pathogen free. In fact a mysterious retro-virus that has been shown to be killing off large numbers of salmon before they have spawned. Salmon showing a certain genomic predisposition were 13.5 more likely to die before spawning than their healthier counterparts.

“Warm water highly increases the mortality rate of pre-spawning salmon,” explained Hinch. “Stress hormones impede their ability to spawn, and develop eggs and sperm. And higher temperatures, are making it harder for the fish who are experiencing disease to cope.”

Also of central concern are early entry patterns of returning salmon. Some runs are not holding in the mouth of the river as long, and are spawning as early as two months earlier that their usual run time.

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This is an important point:

“Climate change has been showed to be a major stressor for returning salmon. But far less is known about how climate change is affecting salmon while they are at sea.”

Well… we will never know much about what is going on out at sea… and we will never be able to accurately predict the impacts of climate change, nor rates of rapid change.

And what does this mean?

More precaution. Give the wild salmon a chance…

climate change isn’t going anywhere… it’s here to stay.