Bears vs. salmon: Solving the McNeil River puzzle

Although brown bears kill more than half the chum salmon entering the world-famous McNeil River each year, state fishery biologists and managers don't believe the bears' predation is the primary reason for the river's stubbornly persistent weak salmon runs.

Consequently, although the state Board of Fisheries recently designated the McNeil chum fishery a stock of concern, the board also decided against shooing away or killing some of the bears or helping the salmon avoid them — opting instead to allow the chum runs, over time, to recover on their own.

McNeil River — named about a century ago for area rancher Charlie McNeil and bounded by McNeil River State Game Refuge and Katmai National Park — drains into the western portion of Kamishak Bay, approximately 100 miles west-southwest of Homer. The entire drainage lies within the McNeil River State Game Sanctuary, established in 1967, an exceptional bear-viewing area located near a cascading set of falls that has been drawing wildlife lovers since its creation.

Located only a mile above the river mouth, the falls were formed when local bedrock fractured along a fault line, causing the land downstream to sink. From just above the crest of the falls downstream to the first rapids, the elevation drops at least 20 feet.

Cagey bears

Brown bears that visit McNeil know how to best take advantage of this natural barrier and the river's abundant gifts. Frequently concentrating in the dozens at the peak of the chum run, the bears feast at the falls while the salmon attempt to forge their way upstream.

When the run wanes in late July or early August and most of the exhausted salmon try to spawn below the falls, the bears amble downstream to the three good gravel beds and gorge on spawning or spawned-out chums there.

A few bears, spread out and, less effective in their efforts, remain above the falls, where far more spawning areas exist.

State studies indicate the upriver spawning gravels are likely the key to increasing future escapements. When more chum salmon reach those grounds, spawning success is significantly higher. Stronger runs tend to push more salmon past the gauntlet of feeding bears.

According to a 2013 interagency report, "it appears likely that escapements above the falls may contribute disproportionately more to the stream-wide production of chum salmon at McNeil River than fish below the falls, even though they represent only 10-15 percent of the total run."

The report, citing a 12-year-old Fish and Game radio-telemetry study involving tagged McNeil River chums, said that 90 percent of the salmon swimming above the falls lived long enough to spawn, while only 41 percent below the falls survived that long. Fish and Game estimates that less than 10 percent of the river's spawning habitat exists below the falls.

McNeil chum runs have ranged from average to weak for more than 30 years. The 2013 report says there were, on average, twice as many chum salmon in McNeil River during the 1980s than in the 1990s and 2000s.

Since 1994, in an effort to boost declining escapement numbers, Fish and Game has shuttered commercial chum salmon fishing in the McNeil River subdistrict. Before the shutdown, commercial fishermen were allowed to harvest any surplus — chums exceeding the escapement goal of 13,750 to 25,750 fish.

No rebound

For decades, it seemed that McNeil chum runs mirrored the strength of chum stocks in other lower Cook Inlet drainages. Then in 1999, after a 10-year slump in all lower Cook Inlet chum runs, stocks rebounded — everywhere, that is, except the McNeil River.

Fish and Game had speculated that most downturns in lower Cook Inlet chum stocks reflected unfavorable rearing and feeding conditions in the ocean. When only the McNeil stocks failed to rebound, researchers contemplated other causes — the falls, the bears, commercial fishing.

State regulations made potential quick fixes used in other waterways unfeasable:

— Rules within the state game sanctuary restricted physical changes (such as fish ladders) that might allow more chums to avoid the bears congregated at the falls.

— The state sanctuary, a bear-viewing haven, also prohibited the hazing or shooting of bears.

— Emergency orders were already keeping the commercial fishery closed.

In 2007, fishery managers and biologists pored over nearly six decades of data concerning annual McNeil River chum runs and decided to raise their escapement numbers to a range of 24,000-48,000 fish. They hypothesized that natural fluctuations in the chum runs would eventually result in larger overall returns. When that happened, they reasoned, proper management could help keep the escapements strong.

In the last six years, however, Fish and Game has met its McNeil River escapement goal only twice — in 2011 and last year.

In fact, the actual McNeil chum salmon escapement for the last decade averaged 18,000 fish, 10 percent lower than the previous 10-year average and 33 percent lower than the average for all years surveyed, starting in 1950.

Still, state officials are cautiously optimistic.

Selective bears

Ted Otis, an Alaska Department of Fish and Game fish biologist for lower Cook Inlet, said the agency hopes a natural recovery will occur.

Achieving such escapements will provide the greatest opportunity for enough chum salmon to return each year to feed the bears, repopulate the chums and allow commercial fishing.

Regardless, the agency believes the bears will be just fine.

According to the 2013 report, it appears that in lean chum years bears kill more than half of the McNeil River chums before they spawn and may consume — or partly consume — nearly every salmon that remains below the falls, some before and some after they spawn.

During more robust salmon runs, however, the bears appear to be more selective about their meals, leaving behind more partially eaten carcasses.

Also, with greater numbers on their side, more chums evade the bears, ascend the falls and move to the upriver gravel beds.

Brown bears and chum salmon have reenacted this drama for thousands of years, achieving over time what Otis calls "a dynamic balance."

"Salmon are super-important to bear populations in coastal Alaska," said Otis. "(Bears that) eat those protein packets coming upriver are way better off for having done so. They're going to survive better through the winter, and they'll have more cubs."

According to official daily counts over the last 35 years, an average of 27 brown bears can be viewed at or below the falls during the 80-day viewing season (June 7 to Aug. 25). The peak of bear-viewing season is July, when the average climbs closer to four dozen.

The highest official number of individual bears counted at one time was 75 on July 19, 2011. As many as 101 mature bears (144 including cubs) have been identified at the game sanctuary within a 10-square-kilometer area during a single year.

During viewing season, up to 10 people a day, chosen in an annual state lottery, receive four-day permits to view bears.  Last year, 819 people applied for 175 permits.

‘Natural levels of fish’

Ed Weiss, project manager for McNeil River State Game Sanctuary, sides with the Board of Fisheries' decision.

"I try to look at things from the perspective of the sanctuary, and all the sanctuary resources, as a whole. In general, I feel we should try to allow the natural levels of fish production and bear use to take place within the McNeil River system. And where that natural production allows for a large surplus, we can allow for commercial harvest as long as it's not affecting the bear resources or public use of the sanctuary."

Still, maintaining the higher escapement goal and taking no other action is a gamble.

"We painted ourselves into this corner, one could argue," Otis said. "We knowingly set a high escapement goal for a stock that we fully recognized was unlikely to meet that goal regularly until it recovered to the point where the whole stream was producing fish, instead of just a small portion of it.

"And it's a bit of an experiment, if you will. In order to satisfy the sustainable fisheries policy, the guidelines for the sanctuary, and the McNeil River chum salmon fishery management plan, all of which strive to achieve maximum sustained yield, you need the whole system producing fish."

"Maybe what we're seeing now," Otis continued, "with lower escapements due to the limited spawning habitat available below the falls, is kind of what to expect most of the time, regardless of what sustainable escapement goal we set or manage for. It's possible. All we can do, though, is do our best to maximize stream-wide production there. It could be that 20 years from now — I'll be retired — but we'll have enough data to say, 'Yeah, it's kind of a lost cause to try and do that. You're just not gonna get there. So let's have the lower escapement goal, and accept that production in McNeil River is mostly from below the falls…' That's possible, too.

"With the bears there and the falls there, that may be the case. (But) I'm not ready to say that yet. I think that system can consistently produce a lot more fish."

Clark Fair, a Kenai Peninsula resident for more than 50 years, is a lifetime Alaskan living in Homer.