Counting Copper River Salmon at Childs Glacier

As Elliot Johnson of Alaska Department of Fish and Game explains in the video, the Childs Glacier monitoring station is responsible for counting the returning salmon as they complete their ocean migration back to their native spawning grounds in the Copper River Delta.

Their monitoring station uses sonar waves, essentially “echo location”; 26 beams form the pie shaped image that displays on the computer monitor capturing an image of the fish as they swim by.

These counts are incredibly important to the local commercial fishing fleet because they determine when the commercial season begins for each of the different salmon runs. The Chinook, Sockeye, and Coho runs occur from May through September, though the actual commercial fishing harvests are kept quite short.

“This first opener is usually around the middle of May”, says Johnson. He continues, “Well, in the case of this year [2013], we had a late ice-out and we didn’t start seeing fish until about the 30th of May; we usually start seeing fish up here around the 20th. So, how I mentioned earlier that they’re able to close the fishery if conditions aren’t, if we aren’t seeing numbers, well that’s what happened.

So at the first opener, it was marginal, I think they caught 60 or 70,000 total and it was a 12 hour period. 3 days later was the next opener, had about the same. The 3rd opener, it was 12 or 24 hours, they caught almost 400,000 fish. And they were like Whoa! Okay, hit the brakes and we still had zeroes here at that point and we still had zeroes for a whole other week. So here the fishermen are like, We just slammed them; There’s fish everywhere!; It’s going to be a great year!; but, zero – zero – zero – close fishing, close fishing. We haven’t seen any fish in River, so they’re not sure if they’re going to over-harvest.

Part of the management is spreading out the fish, the run, into spawning grounds. So, you don’t want to over harvest early and you don’t want to over harvest late, you want to take a little bit throughout, because part of the reason for that is maintaining that genetic diversity, so the early fish coming in typically run farther upstream and they’re going to spawn a little bit sooner. So if you lose the early run fish, you’re going to shorten the length of your fishing period because now you’ve lost those first 2 weeks of fish returning, and likewise on the end of it.”

First Bend of the Copper River at Childs Glacier

First Bend of the Copper River at Childs Glacier

According to the recent 2013 report by the Alaska Seafood Marketing Institute, the state of Alaska contributes over half of all fishery production in the U.S., creating tens of thousands of jobs, and generating almost 7 billion in annual revenue. Not surprising, the Alaska state constitution mandates that its fisheries operate in a sustainable manner consistent with careful monitoring, and reliance on science-based policies and procedures to protect and maintain its fish populations.

One of the defining characteristics of the Copper River Salmon (Chinook, Coho, Sockeye, Pink salmon, and Keta), is the buildup of fats (rich in Omega 3 fatty acids) needed for their arduous 300 mile journey from the mouth of the Gulf of Alaska near Cordova to their final spawning grounds in the Copper River Delta. As a result, the wild salmon caught in these pristine ocean waters are incredibly delicious, at their physical peak, and are (as previously noted) of high nutritional value to eat.

Copper River Basin illustration at Childs Glacier, near Cordova, Alaska.

Copper River Basin illustration at Childs Glacier, near Cordova, Alaska.
Click to enlarge image.

About the Copper River Delta and Ecosystem:

“The Copper River is not simply one river—it’s dozens of rivers, hundreds of streams, and countless mountain drainages, all tied together to form one coursing channel to the ocean.” —Mark Henspeter

  • The Copper River Delta encompasses 24,000 square miles, and is the 10th largest river in the United States.
  • The Copper River is 300 miles long, a mile wide, and flows at a swift average rate of 7 miles per hour at near freezing temperatures during the warmer months.
  • There are about 500 drift gillnet commercial permit holders that commercially fish the area in the Gulf of Alaska and Prince William Sound.
  • The Copper River Delta is a world-class spawning and rearing habitat for all 5 salmon species and cutthroat trout.
  • Considered the largest contiguous wetland on the Pacific Coast of North America, the Copper River Delta is also a critically important location for migratory birds.

Additional Resources:

Video transcript:

[Music; shots going up Copper River; see Childs Glacier & Million Dollar Bridge]

[Elliot Johnson, Alaska Fish and Game] We’re located here at Miles Lake Sonar site, in between Childs Glacier and Miles Glacier on the Copper River, uh, at the Million Dollar Bridge.

The importance of this location for our sonar site, is that it’s the first bottleneck in the River coming upstream from the Ocean. Here at this site we have a single channel with relatively high velocity which forces migrating salmon closer to the shore ensuring we get an accurate count with our sonar equipment.

Physically counting these fish involves counting them one by one with our tally-whackers, [pause; natural sound of counting] so in high passage we can see fish as much as, say, 90 fish a minute, and in low passage, it can be as little as 2 or 3 fish a minute.

The importance of counting the fish and getting accurate counts is to manage this fishery as sustainably as possible. The major goal of our hourly counts is to minimize and completely eliminate the potential for overfishing.

So from the daily salmon escapement counts, those numbers are directly applied to the regularly scheduled fisheries openers for the commercial fleet um here in the Copper River Delta.

We are primarily interested in Sockeye salmon escapement here on the Copper River mainly because it’s the largest run of salmon this River sees. There’s also Chinook salmon run and a Coho salmon run. Both are of commercial interest but their numbers are very little in comparison, um, for instance we’ve seen over a 1,000,000 Sockeye salmon return this year and it’s looking like it will be 50,000 Chinook salmon this year.

The Copper River commercial fishing fleet depends on the data we collect here at this site. Ultimately, because this is the only management tool used on the Copper River and it’s written into the Alaska State Constitution that the State must manage fisheries for sustainability. so if at any one point in time, this sonar site goes down and we happen to be not operational for a technical issue and we aren’t able to count fish then it’s written into the law that they must close the fishery until we could properly manage that therefore it is highly important to maintain this fishery.

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