Catch, release, kill fish


Part 1 of 2

If you believe the science, somewhere around 4.8 million sockeye salmon were likely caught and released in Bristol Bay last year and half them died before spawning. That’s 2.4 million dead fish.

Consider this the mother of all catch-and-release salmon kills in Alaska.

Nobody noticed, however, because it happened out of sight in a commercial fishery where the catch and release has a different name: “non-retention mortality.” Many things happen out of sight in Alaska’s commercial fisheries, and some odd terms are used to describe these things.

“Discards” is the word used for the highly valuable halibut caught and released in federally regulated offshore fisheries.  With 88 percent of the halibut caught and released in the pollock fishery – the biggest fishery off the Alaska coast – ending up dead, a reasonable observer might find the description a little disingenuous.

But as with commercial catch and release in Bristol Bay, discards happen out of sight of the general public so few really notice.

Instead, Alaskans fret about what they can see, the coolers full of fish tourists ship south in the cargo holds of passenger planes leaving  Ted Stevens International Airport in the state’s largest city.

At the same time, ships and cargo planes stuffed to overflowing with cooler-load equivalents of headed and gutted salmon are being shipped out-of-state to be processed.

China bound

As Undercurrent News, a publication covering the commercial fishing business reported in 2014, “American law requires that fish be landed by American citizens. But a high volume pipeline of H&G fish to China is the closest thing a foreign buyer can get to gain access to the US resource. This model is definitely attractive to foreign buyers.”

Silver Bay Seafoods in Sitka has been the leader in this new “model.”

“This company, now claiming to be one of the largest processors in Alaska, has two sales people, and a minimal staff in their corporate office in Sitka,” wrote John Sackton in Undercurrents. “They produce H&G frozen salmon.

“The business model is to attract the top producing harvesters, have them fish at full strength, pack the product in as quick and low-cost way as possible, and sell to China where further processing and distribution takes place.”

This is capitalism at work, and it is pointed out here not to bad-mouth the commercial fishing business, a valuable state industry, but to shine some light on how fishing functions in the 49th state where more than 95 percent of the catch is commercial.

An official figure on the exact percentage of salmon allocated to the commercial fishery is hard to come by. The Alaska Department of Fish and Game doesn’t track this in simple terms. You can’t just look it up.

Commercial fishermen last year landed about 1.1 billion pounds of salmon in Alaska. Exact figures for subsistence, sport and personal-use catches are not readily available but Fish and Game reports that subsistence accounts for 36.9 million pounds of wild food every year and residents of “urban areas harvest about 13.4 million pounds of wild food under subsistence, personal use, and sport regulations.”

The combined take of all subsistence, sport and commercial harvests would come to about 50.3 million pounds, which is about 4 percent of the commercial salmon harvest. But the subsistence, personal use and sport harvests include significant volumes of wildlife and non-salmon species of fish, so the actual percentage of salmon is somewhat less than that.

If you want to look at the issue another way, the state-wide sport harvest of salmon in 2014 was close to 1.5 million fish. The commercial harvest the same year was 157 million salmon. This pegs the sport harvest at about 1 percent of the total statewide harvest

The point here is this:

Salmon killing in Alaska is almost wholly a commercial operation. What happens largely out-of-sight in commercial fisheries is way more important than what happens in often highly visible sport and personal-use fisheries simply because of the huge difference in the volume of killing.

Catch-and-release is everywhere

So while some Alaskans worry about whether catch-and-release sport fisheries are wrong because people are “playing” with the fish, catch and release is underway at an industrial level in commercial fisheries.

The estimated 4.8 million salmon caught and released by gillnets in Bristol Bay went unnoticed last year, and yet some Alaskans are offended by the idea anglers catch and release on the Kenai River, the state’s most popular sport fishery.

Just over 1.7 million sockeye escaped commercial nets to make it into the that river in 2015. For anglers there to match the catch-and-release volume of commercial fishermen in Bristol Bay, they’d have to catch each Kenai salmon on average 2.8 times and release all of them. To match the Bristol Bay mortality, they’d have to work even harder.

A new study out of British Columbia does suggests that sockeye are more vulnerable to hook-and-line, catch-and-release mortality than previously thought. The study involving fish caught on rod-and-reel then stuffed with radio transmitters pushed down their throats found about 30 percent of the fish died before spawning.

This is a significantly higher mortality rate than show in previous studies.

Still, given the differences in mortality rates between sport and commercial fisheries, anglers would have to catch and release every Kenai salmon more than 4.5 times to kill as many fish as catch and release commercial fishing kills in Bristol Bay every year if one accepts the 50 percent gillnet non-retention mortality Matthew Baker from the University of Washington and others reported in the May 2011 issue of “Evolutionary Applications.”

The authors of that study themselves suggest some reservations about that number. They think it too low, writing that “pre-spawning mortality among disentangled fish likely exceeds our estimates (approximately 72 percent rather than 50 percent) and the effects of non-retention are likely greater than estimated.”

Killing doomed fish

But what if rod-and-reel fishermen are picking off the injured fish on the Kenai and eliminating waste?

Visit the Kenai during the height of the sockeye run, and you will witness plenty of anglers killing “net-marked” sockeye – those “disentangled” or “non-retention” fish cited in the Baker study. These harvests of already doomed fish without question diminish the non-retention mortality, because the fish that might die from it have now been caught and retained.

Plenty of the non-retention gillnet fish are also caught in the personal-use dipnet fishery at the mouth of the Kenai. Those harvests to some degree further reduce the non-retention mortality, although there is other mortality, probably small, from fish injured in dipnets.

Still, the non-retention mortality from fisheries is something in need of some consideration.

The Kenai sockeye escapement last year came under some criticism. Some Kenai commercial fishermen argued that it was too high, and that they were losing valuable sockeye upriver.

They had a valid argument. The 1.7 million sockeye that made it into the Kenai in 2015 were 500,000 fish more than the top of the spawning goal.

But some number crunching needs to be done given what is known from the Baker study and what happens in-river. If 30 percent of Kenai fish are net marked (ie. non-retention gillnet salmon) and if 50 percent of those fish are destined to die before spawning, as in Bristol Bay, the actual escapement needs to be adjusted downward.

For simplicity, let’s ignore hook-and-line removals of net-marked fish, and assume that however many they remove, they injure an equal number in other ways, either by active or accidental catch and release.

Do the math then, remove 255,000 sockeye doomed by injuries in various fisheries, and the actual numbers of spawners falls to something more like 1.45 mllion, but they’re not all going to spawn either because there is an active sport fishery on the river.

A lot of math is necessary to come up with a total sport catch for Kenai sockeye, a key number of which are returning to the popular Russian River, but if one goes through the numbers for 2014 (the last year for which data is available) the Kenai sport harvest now appears to be in excess of 400,000 sockeye.

Deduct this from the number of Kenai spawners corrected to account for the non-retention mortality, and you have an actual spawning escapement in the Kenai system last year of something closer to 1 million fish than 1.7 million fish.

A million fish is 300,000 above the minimum goal, but 200,000 fish below the maximum. Suddenly the financial loss to commercial fishermen and the dreaded “over-escapement” that could produce diminished returns of sockeye on down the road doesn’t look so “over.”

But again, it’s not this simple either. There are way too many unknowns:

How much is the gillnet non-retention mortality actually reduced by anglers catching and keeping gillnet injured fish?

Nobody is innocent

How much is the sockeye mortality increased by anglers catching and releasing sockeye either because they didn’t want the little ones or because they were just fishing for fun or because fish broke off?

How many Kenai sockeye fall in the catch-and-release category, and what is the actual catch-and-release mortality?

The study in British Columbia was done on the Fraser River in water temperatures ranging from 63 to 65 degrees. Water temperatures in the lower Kenai have been shown to get into that range, but are generally cooler. The normal range appears closer to 51-61 degrees.

Water temperature is a key factor in salmon survival in any stressful situation for the fish. The fish recover better, and thus are more likely to survive, in cooler water. But who knows? Survival could be lower on the Kenai for other reasons.

And water temps are just one survival factor.

There are also indications that where the fish are caught and released could play a key role in survival. A 1992 study on the Little Susitna River found that almost 70 percent of the silver salmon caught and released in intertidal waters died compared to only 12 percent of those caught upstream. But a 2002 study of silvers on the Unalakleet River found no such link.

Other studies of hook-and-release mortality are all over the place, showing death rates ranging from zero to 95 percent.

The only real conclusion that can be drawn from the data is that the Kenai fly fisherman who thinks he is holier-than-thou because he never directly kills a fish is fooling himself, and opponents of catch-and-release who think the practice evil because some fish die are doing the same given the reality that a lot of fish are injured and escape to die no matter how fishing takes place.

There are no clear-cut good guys and bad guys here. All salmon fisheries “waste” fish if you define waste as allowing salmon carcasses to stay in the river or ocean and naturally decompose. But that’s a purely human construct, because nature doesn’t really waste anything. Nature recycles salmon carcasses.

All of which leaves hanging only one philosophical question:  What does all of this mean to the fish? Is catch and release somehow “crueller,” for lack of a better word, than what we do to salmon in other Alaska fisheries?

Part II: Do the fish care?

3 replies »

  1. Interesting bit of number crunching, read your article couple times. Interesting to watch respective user groups cast their stones. Have friends in all of the arenas mentioned and indeed not with malice stones are cast, but, it still boils down to allocation.

    • well at least somebody got it. it does all boil down to allocation, and allocation boils down to economics. nobody in this debate is pure. everybody is taking advantage of the resource. that makes the state’s job simple: manage thw situation so all Alaskans get the maximum benefit. at the end of the day, fish are really no different than oil. they are a state resource that ought to be managed like a state resource not like some sort of deal where, “geez, you know, i really like Exxon so i’m going to give them this,” or “my buddy has worked for Conoco for 20 years, so we need to give Jack and Conoco special treatment,” etc.

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