Curtain of death


curtain of death

Watch an animated depiction of how Cook Inlet setnets move in the tide/Kintama Inc.


Two years after a bitter and unproductive fight to remove what are sometimes called the “curtains of death” in Alaska’s Cook Inlet, a new study is suggesting the answer to the old problem of how to clean up commercial, set gillnet fishing might be flowing in the tides.

Remote-sensing devices placed on Inlet nets have provided data to construct an animated depiction of how the nets actually fish, and what that animation shows is that the nets behave a lot like curtains flapping in the wind.

As fast-moving tides create drag on the monofilament webbing, the nets billow and the lead lines holding the bottoms down are pulled up and away from the floor of the Inlet. As the lead lines rise toward the corks keeping the tops of the nets afloat, space opens beneath for deep-swimming Chinook to pass while shallow-swimming sockeye continue to be snagged by their gills in the nets, the researchers said.

The long-running problem with the Inlet gillnets has been that they can’t tell plentiful sockeye salmon from prized Chinook salmon – or king salmon as Alaskans often call them – and will indiscriminately catch and kill either. That has created issues for a Kenai River king salmon fishery that is a key component of a regional sport fishing business the state a decade ago calculated to be worth almost $1 billion per year.

Over the years, scientists have recognized that the Kenai-bound kings headed up the Inlet from the North Pacific Ocean tend to be bottom huggers while sockeye travel closer to the surface of the water. The long-running conservation question focused on how to slip kings beneath the nets, which are anchored to the bottom of the Inlet at either end.

The Alaska Board of Fisheries tried encouraging commercial fishermen to use shallower nets, but those who’d invested a lot of money in deep monofilament netting were reluctant to modify their gear.

Now comes the study from Canadian scientists putting a whole new spin on the debate. Along with demonstrating conditions under which deep nets fish shallow, it indicates that shallow nets sometime fish deeper than standard nets because the smaller surface area of the former creates less drag.

Think of the short net as a short curtain in an open window when a gale is blowing. The wind pushes the curtain in and up, but it doesn’t billow and rise almost parallel to the ground the way a long curtain does.

The study argues setnetters might want to switch to shallower nets to increase their sockeye catches, or the state might want to coordinate fishing times to tides to avoid fishing at slack water when the setnet curtains drop. The latter move could minimize king salmon bycatch when fishing with what are now standard nets.

“This study provides the first concrete data on how setnets actually fish in Cook Inlet, and the specific technical methods we report here likely have much broader potential application to managing bycatch worldwide,” write authors David Welch, Aswea Porter and Paul Winchell. “The exceedingly shallow net depths we document in Cook Inlet were unexpected given the potential maximum depth of the nets. When tidal currents were strongest, the average leadline depth for all nets was less than 1.5 meters (approximately 5 feet) –  only 26 percent of the potential maximum fishing depth of a standard 45 mesh net – and leadlines sometimes reached as shallow as 0.6 meters – 11 percent of maximum depth – regardless of net construction. As current strength dropped, leadline depths gradually increased, but for half the tidal cycle all instrumented nets remained at less than half their maximum potential depth.”

The Fish Board’s “shallow net” plan called for about 12-foot deep nets. The study led by Welch, a scientist at a research company called Kintama in Nanaimo, British Columbia, Canada, concluded that when the tides are running strong in the Inlet, setnets already fish at a mere fraction of that depth.

The study concedes there is merit to going to shallower nets to protect king salmon if the state wants to continue with the same commercial fishing periods as in the past, but the scientists add their suspicion ” that large increases in both the overall economic value of the Cook Inlet salmon fishery and (spawning) escapement to various regions within Cook Inlet could be simultaneously attained by applying” new rules that tie net dynamics to the tides to enable commercial fishermen to catch maximum numbers of sockeye and minimum numbers of kings.

“The dynamics are relatively complicated and beyond our current goals,” the study says; “however, such a strategy could potentially enable managers to achieve high rates of (king salmon) population rebuilding while maintaining acceptable levels of (commercial fisheries) employment and revenue in the near-term.”


The issue of king salmon bycatch in the Inlet is old and much debated. Most of the approximately 1,100 people holding state limited-entry permits to fish commercially say they are primarily trying to catch sockeye salmon that return by the millions every year and not Chinook salmon that return by the tens of thousands.

Still, some like the extra money they get out of harvesting kings and don’t want the big fish considered bycatch, which is something of a dirty word in the 49th state.

In an editorial in the Alaska Journal of Commerce, editor Andrew Jensen wrote that “calling king salmon harvested by setnetters bycatch (is)…offensive to fishermen who’ve been setting their nets at the same sites for generations without a negative impact on Cook Inlet kings.”

The argument voiced by Jensen and some setnetters centers on the idea that Kenai king runs haven’t been wiped out by setnetting and as long as it is legal for setnetters to sell their kings, the fish technically aren’t bycatch. The National Oceanic and Atmospheric Administration currently defines bycatch as fish “that are not sold or kept for personal use,” either for economic or regulatory reasons.

Scientists, on the other hand, generally define bycatch as “nontarget species.” 

And everyone involved in the debate over Cook Inlet kings seems to agree kings are not specifically targeted by eastside setnetters, even though the setnets sometimes catch large numbers of the fish.

During the 2015 fishing season, approximately seven out of every 11 dead, Kenai late-run king salmon died in gillnets. It was a bad year for the big fish, and the anglers who live to pursue them.

Only about 18,000 kings over 34 inches made it back into the river that year, the Alaska Department of Fish and Game later estimated. Still, this was way better than the year before when the Kenai fell almost 3,000 fish short of the minimum spawning goal of 13,500 big fish.

The run was about the same in 2016 as in 2015, but jumped up over 22,000 this year. Part of the increase can be attributed to the way state fishery managers prosecuted the early Inlet sockeye season, and part can be attributed to the sockeye run being late.

Early in the season, managers used the commercial drift gillnet fleet to catch large numbers of sockeye far out in the Inlet. The gillnet fleet fishes in deep water and catches very few kings. The entire reported drift catch this year was less than 250 Chinook.

The catch of sockeye, however, was large, and because of that there were no extra fishing periods for the inshore setnet fisheries. In fact, it was more the opposite.

With 1.1 million of the year’s anticipated harvest of 1.7 million sockeye caught by July 22 and very few spawners yet in the Kenai River, state fisheries biologist ordered a week-long shut down in commercial fishing at a time when king returns to the Kenai were near their peak.

This alone could help explain why the commercial harvest of Chinook fell from about 7,000 last year to fewer than 5,000 this year.


A happy setnet crew with a nice catch of Chinook/photographer unknown

Money fish

The summer’s smallish king catch in the setnet fishery has not, however, quieted questions about the wisest and best use of these fish over the long run.

Anchorage businessman and avid Kenai king salmon fisherman Bob Penney, a thorn in the side of setnet fishermen for years, is now questioning whether the significant harvest of kings in the setnet fishery is constitutional.

Penney two years ago pushed the initiative to ban setnets in “urban areas.” The initiative would have eliminated setnets in the Inlet if approved by voters. It won the signatures of enough Alaskans to qualify for the ballot, but the state and commercial fishermen sued, arguing Alaska voters shouldn’t be allowed to decide what kind of gear can be used to kill salmon.

Only the Board of Fisheries or the Legislature can determine the tools for salmon harvest, the state Supreme Court eventually ruled.

Although the biggest beneficiaries of the initiative would have been the Inlet’s drift gillnetters, the justices wrote “that the initiative in question was a give-away program because it was ‘designed to appeal to the self-interests of (the masses of) sport, personal, and subsistence fishers, in that those groups were specifically targeted to receive state assets in the circumstance of harvestable shortages.”

Penny is now questioning the “give-away” aspects of the Board of Fish allocating thousands of kings to set netters when the fish are worth 10 times as much or more in-river.

Article 8, Section 2 of the Alaska Constitution says “the legislature shall provide for the utilization, development, and conservation of all natural resources belonging to the State, including land and waters, for the maximum benefit of its people.”


Penney questions how getting $60 to $90 out of a 30-pound king salmon caught in a commercial net can qualify as a “maximum benefit of its people” when a decade-old state study concluded the average, guided non-resident angler spends $770 per day in Alaska just trying to catch one of those fish.

Adjusted for inflation that would amount to about $950 per day in 2017. A state already suffering through a major recession is taking an economic hit because of the way it manages Kenai kings, according to Penney and others who note the value of the Kenai sport fishery has fallen significantly as the number of kings getting into the river has declined.

Dozens of guides have gone out of business in recent years, and the ripple effect has hit restaurants, hotels, bed and breakfast businesses, and even supermarkets and gas stations.

The number of late-run fish entering the river in July has dropped from 40,000 to 70,000 in the first years of the new millennium to about half of that in recent years. The actual counts since 2013 have ranged from 11,000 to 22,000, but those are the counts of only fish over 34 inches. The Alaska Department of Fish and Game only recently went to the “big” fish count in an effort to buttress the return in poor years when more little fish usually show up.

Why king returns have fallen remains an unanswered question. Speculation has centered strongly on ocean survival, and commercial fishermen in Cook Inlet are clearly not to blame.

But as the runs have trended downward and Kenai guides have gone out of business, the issue of king salmon allocation has become ever more contentious than when there were more of the fish.

Guides and anglers pay the price when kings fail to make it back into the river in significant numbers, and the setnetters pay the price when the state maximizes the offshore harvest in the driftnet fleet to try to minimize the bycatch of kings in setnets.

In an ideal world, most sockeye bound for the Kenai and Kasilof rivers would be caught in what are called “terminal fisheries” near the mouths of the waterways where they were hatched to minimize the mixed-stock problems of drift gillnet fishing, and most Chinook bound for the Kenai and Kasilof would be caught in-river to maximize the value of the 49th state’s most prized salmon.

The Kintama study could point the way to a win-win situation for both setnetters and anglers, but its authors note, more information is needed.

“Although most Chinook are probably captured around slack water, it is unknown when during the tidal cycle most sockeye are harvested,” they note. “With their surface-oriented depth distribution, sockeye are potentially exposed to the nets over much of the tidal cycle, but their direction and speed of migration within the East Side Set Net (fishery) relative to net orientation may change with the stage of the tide or time of day, and net efficiency is probably affected by the dramatic changes in net shape that must occur over the tidal cycle.”

If most sockeye are caught at slack water, they suggest, shorter nets are the preferable solution. Any losses of overall sockeye catch due to shorter nets could be compensated by added fishing hours.

What the limited data does appear to have made clear is this: sockeye and Chinook travel at different depths in the water column, and the nets move in the current. These two facts could makes cleaner fishing a real possibility.

“During times of strongest tidal flow,”the study says, “the leadlines of all nets were lifted to slightly above the median migration depth of sockeye (about 1.8 meters or about 6 feet), but entered into only the top 10 percent of the Chinook depth distribution. It was not until slack water when the nets extend down close to their potential maximum depths that the deeper nets dropped significantly into the depth distribution of Chinook with the 44-mesh net approximately doubling Chinook exposure relative to the 29-mesh net.”

The study was funded by the Matanuska-Susitna Borough, which has issues with the mixed-stock interception of northern-bound coho salmon in the Inlet’s drift gillnet fishery.

The study’sauthors noted they were also supported by setnetters Gary Hollier, Ken Coleman, Brent Johnson, and Richard Person.

“We thank each of them for their willingness to explore the possibilities concerning how their nets actually fish, and placing their trust in us to represent the results in a frank and open-minded manner,” Welch wrote. “Gary Hollier deserves particular credit for his leadership in the complex and frequently fraught world of Cook Inlet fish politics.”

Whether the study will change the minds of any setnet fishermen remains to be seen. Change never comes easily, and it is especially difficult to institute in Alaska fisheries that cling to the old ways of doing things as if they were a badge of honor.





7 replies »

  1. Steve: there’s no doubt that sizing mesh to the salmon in question will increase the selectivity of gillnets. 8-inch mesh will probably let all pink most sockeye salmon through and predomiinately catch kings. 4 3/4-mesh will catch humpies and reduce the number of sockeye/coho and likely increase the sockeye/coho drop out rate though no one has an estimate as to by how much. 5- to 6-inch mesh is considered optimum for sockeye. those nets won’t catch as many kings as 8-inch mesh, but will clearly catch kings. the smaller the net, probably the fewer of the kings, and the larger net, probably more, but the directed, northern district early season king fishery is limited to 6-inch mesh and seems to do ok on kings. 5- or 5 1/8-mesh seems to be the norm during the sockeye season, and it catches kings though it clearly isn’t what anyone would use if fishing specifically for kings. if you’re really interested, here’s an old study on 5 1/4- to 6 1/4-inch mesh in Southeast marine fisheries. it basically found they all caught chum, sockeye, pink and coho with some selectively on mesh size but not that much. there weren’t enough Chinook in the sample, however, to say anything about king catch. gillnets are simply not very selective.

  2. Gillnets catch fish in a couple of ways, the first and most common is by trapping the fish by the gill plate, hence the name gillnet. Fish are targeted by their size using different sized mesh, you don’t target herring with the same net as you would for sockeye, and you don’t target sockeye with the same sized net you would use to target king salmon. Most kings that are caught in gillnets are caught in the “bag” that the illustration you linked to show. Salmon, of all species, get caught in gillnets by the mouth, or as some sportsfishermen on the kenai might call it when they snag a sockeye in the mouth “willful biters”.

    • True, Sockeye gill net mesh size is small enough that mid to large Chinook cannot be hooked in the gill plates. Smaller ones can, however. The larger Chinook do get either tangled up
      in a loosely hung net or caught in the teeth. Problem is, and it is rarely addressed by ADF&G managers and never by the commercial fleet, that many large Chinook die in these nets only to drop out of them when they are hauled aboard the boats. And they are never counted as Chinook mortality and added to the commercial harvest. It is similar to the sports Chinook hook & release fishery on the Kenai that sometimes occurs. In that fishery the ADF&G recognizes that there is a mortality associated with the release of Chinook and around 7% of the total H & R catch, all of which are released, are presumed to be killed and that number is added to the sports harvest. Not so with the drop out of the fish from commercial nets. This might be interpreted as just another bias of the ADF&G in favor of the commercial fishery.
      The photo of the happy set net fishers holding those large magnificent Chinooks is very telling. The number of fishers shown is but a small percentage of the set net fleet. How many Chinooks were caught on that day by the rest of the fleet, one might ask. Were these fish reported as part of the harvest or left under a tarp?
      It might be time for new Board of Fisheries members and a new Commissioner to look at these issues.

      • Drop out rates from gillnets are a total unknown everywhere in this state, but if you notice a lot of gillnetters now carry a big, ole dipnet. That’s so if they see a king hanging by the mouth when they pull the net, they can try to dipnet it before it falls out of the net and drifts away. Give them credit for at least trying to lower dipnet dropout mortality.

      • No question that the gill net fleet is trying to harvest as many kings as their nets will catch. They get well for their Kings. My criticism is that there is no accounting for the ones that do drop off. And nobody can intelligently argue that there are not drop offs. Set net fishers use the big net more often than the drifters. They build a net bag that attaches to the stern right under the roller. Until the king is over the bag they are vulnerable to dropping out. Happens all the time. And by that time they are dead. A netted king is a dead king

      • Craig,

        That is an interesting study, and I will admit I am not a scientist, however the study was for 5.5 inch vs 6 inch mesh in freshwater comparing chum and king catch rates. I think comparing that study to sockeye vs king catch rate in saltwater with different size mesh with that study would be a non-starter for any scientifically minded person, once again I admit I am not a scientist so maybe I am wrong.

        I can only base my judgement on my own experiences, like any other person. When I commercial fished for salmon twenty something years ago in Bristol Bay (not Cook Inlet) we would target kings at the begining of the season as I recall. When we would target kings we would use bigger mesh for one reason and one reason only, it caught kings. When sockeye started showing we would change to the smaller mesh for one reason and one reason only, it caught more reds. We would even change mesh sizes between districts because some river systems return larger or smaller fish. Completely unscientific research on my part I admit, but it paid what limited bills I had at the time and helped finance a number of trips around the world, but I digress. When we fished for herring we would use much smaller mesh for one reason and one reason only…you guessed it, it caught more herring. Now Bristol Bay salmon, both king and red, are as a rule generally smaller than their Kenai cousin. On a side note herring in Bristol Bay (Togiak) are as a rule generally larger than their Cook Inlet cousin. Not having commercial fished in a couple decades I cannot recall specific mesh sizes and not knowing any CI or BB commercial fishermen I have no idea what net size they use here, or there, for salmon or herring now-a-days.

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