Sept. 18, 2021 — As the summer wanes and the tourists start to move on from most areas of the Oregon Coast, spots like Westlake Resort and Darlings on Siltcoos Lake look forward to the annual fall boost of visitors when wild coho season arrives on Oct. 1. 

Siltcoos and Tahkenitch, along with Tenmile, about 45 miles south of Florence, are the major coho producing lakes on the Oregon Coast and the only three lakes in Oregon where fishing for wild coho salmon is legal. 

The coho, or silver salmon, is one of the five Pacific salmon species. It is listed under the U.S. Endangered Species Act as threatened and only since 2003 have rules been in place that allowed catching and keeping the fish from freshwater fisheries. 

From Oct. 1 to Dec. 31, each angler may take one wild coho and one wild coho jack per day and no more than a total of five per year. 

Wild coho are identified by inspecting the fins and checking to see if the adipose fin is removed. Hatchery fish’ adipose is clipped before they are released to the wild, permanently marking them to indicate they are nonnative. 

When fishing was allowed by Oregon Fish and Wildlife (ODFW) and National Oceanic and Atmospheric Administration (NOAA) fisheries officials in 2003, it was the first time in 10 years that nonhatchery coho could be kept at Siltcoos and Tahkenitch lakes.

Though numbers have remained stable since fishing was opened, most anglers on the two lakes agree that a few factors continue to hurt the coho habitat on Siltcoos and Tahkenitch. 

In 1963, International Paper (IP) in Gardiner was one of the major employers in the area. The plywood business was booming, and operations required a significant increase in water needs for the mill. It was estimated at the time that the mill would guzzle some 8,500 gallons of water a minute. At the time, that was nearly equal to the water needs of an average winter day for the entire city of Eugene. 

IP owned the water rights to both Siltcoos and Tahkenitch and built dams on each in order to collect the water for use at the mill. At the south end of each lake, giant pumps were installed to draw water and send it to Gardiner. The mill closed in the late 1990s and in 2016 Industrial Harbor USA, LLC of Centralia, Wash., bought the site and the water rights to the two lakes. They maintain and operate the dams to this day.

The hope was that the dams would keep water levels for both lakes nearly constant the year around and also provide plenty of water to the mills. Some hope was lost when fish numbers seemed to steadily decrease and the consensus among locals who fish for wild coho on Siltcoos and Tahkenitch is that the dams are the number one reason the coho fishery is so precarious. Each dam is equipped with fish ladders for spawning salmon to transverse the structures though that is far from foolproof. 

In 2015, ODFW Fish Passage Program Coordinator Ken Loffink said, “Both sites (Tahkenitch and Siltcoos) have dams that can be partial barriers to native migratory fish migration. Both sites also have fish ladders that provide (or offer) fish passage at low flows when the dams are not open. I’ve been to both sites and inspected the fish ladders associated with each site several years ago, and while not perfect, I found the ladders to provide fairly good fish passage conditions at both dams. Both fish ladders are currently operational and in good working order, and fish have the ability to travel up those if they choose. Many fish choose not to use the ladders, though, and instead wait for a rain event and travel through the dam when the dam is subsequently opened.”

Some locals believe the dams keep the lake at an unnaturally low level, in turn creating less than optimal conditions for coho. 

Loffink believes this to be partially true.

“Yes, the dams contribute to some delay in the lower river, but I believe a combination of factors is going on. In dry years (such as this year and last year), there may not be a strong environmental cue for fish to travel upstream until a significant pulse of freshwater comes down the system. This also occurs in a lot of our coastal estuaries, though it is likely more pronounced and more visible in the smaller basins such as Siltcoos, Tahkenitch, Tenmile, etc.,” said Loffink.  “Significant rains also signal the time that the dam operators need to open the gates at each site to maintain the proper lake levels. In general, when fish get a strong environmental cue to move upstream from a rain event, the dam is usually open to allow for free passage. When the dam is closed, the fish ladders still provide a viable option for passage as well. The biggest issue is at Siltcoos Lake, where the high tide can flood out the fish ladder entrance, eliminating much of the attraction flow. However, once the tide goes out again, the ladder will flow normally again and produce good attraction flow.”

These factors, along with eutrophication caused by runoff of land from construction around the lake and introduction of nonnative warm water species, have certainly created a less hospitable environment for wild coho but that doesn’t mean all hope for success is lost. 

Coho average 8 pounds but can grow significantly larger. The largest wild coho ever caught in Oregon was caught on our own Siltcoos Lake in 1966 by Ed Martin. It tipped the scales at 25 pounds, 5.25 ounces. 

Even in the best of times, wild coho are a difficult catch. It is said that, on average, it takes 40 hours of fishing to catch a wild coho on Siltcoos Lake. But, as Scottish author John Buchan once said, “The charm of fishing is that it is the pursuit of what is elusive but attainable, a perpetual series of occasions for hope.”

With another fall coho run approaching, hope springs eternal this fall on Siltcoos and Tahkenitch Lakes.