Sonar fish counts on the Chignik River

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Myra Scholze steering ADFG’s skiff in Chignik, Alaska. Photo courtesy of Myra Scholze.

Field work is often seen as the glamorous part of science, where researchers get to experience the outdoors and be close to the subjects that they study. The sad reality is though that most scientists spend their time analyzing and processing data on computer screens at office desks. For Myra Scholze, a Fish and Wildlife Technician, for the Alaska Department of Fish and Game (ADFG), this is no unfamiliar territory.

Scholze began working for the ADFG seven years ago in the sport fisheries division in Kodiak. Two years ago, she began doing research for ADFG near Chignik, Alaska on the Alaskan Peninsula. The community of Chignik is primarily a fishing village that relies on the commercial and subsistence fisheries there.

Scholze’s work with ADFG helps manage those fisheries to maintain their sustainability. Her work is to count the salmon that swim up river between May and September.

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Myra Scholze on the Chignik River. Photo courtesy of Myra Scholze.

“Counting the fish is what tells fish and game when to open and close commercial fisheries,” Scholze said. “For each day of the month, in June and July, there’s escapement goals you’re supposed to meet that indicate that you’re going to meet your total number of fish that’s needed to maintain a sustainable run. We count the fish up and meet those goals then the manager at Chignik decides when and what areas to open and for how long.”

Specifically, Scholze is funded through a grant that is comparing and trying to find the correlation between fish counts made on a weir or on a sonar. The two fish counting methods generate a massive amount of data that must be processed.

Weir measurements are made by forcing salmon through a bottleneck in the river, the weir itself, and recording video of the salmon as they pass by. Researchers then go back and count how many individual salmon pass the camera lens.

Sonar doesn’t record video in a traditional sense, but rather records how sound moves through water. Sonar data is collected on both banks of the river and then a researcher must sit and watch back each of the videos and count how many fish blips they see on screen.

“We have two sonars and every ten minutes they create a file that looks kind of like a fish finder on a boat. That’s what you’re counting,” said Scholze. “Every bank creates 144 files per day, we have a sonar on each bank of the river, so we are creating 288 files a day. Over a month you’re creating about 10,000 files and that’s why we have such a back log and why I count files.”

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Myra Scholze adjusts the sonar in Chignik. Photo courtesy of Myra Scholze.

The massive amount of data and the nearly real-time nature (the videos can be sped up slightly when only a few fish are moving by) of watching back the files and counting fish makes for long work hours. Scholze has spent months outside of Chignik in the Kodiak ADFG office, in addition to long evenings at the bunkhouse in Chignik, just counting back fish on videos, so finding a correlation between weir and sonar counts may take years to come. The preliminary conclusions about correlation can’t even be made yet.

“They’ve looked at it [the correlation], but we don’t have enough done from 2016 yet.” Scholze said.

The work may be grueling to some, but to Scholze she loves being able to collect the data that helps inform management decisions for Alaskan fisheries. She intends to continue working for ADFG in Chignik for as long as they have files for her to count. She’s currently in Dutch Harbor, Alaska working for ADFG as a Fish and Wildlife Technician for the crab fishery there. Myra will return to Kodiak in the spring to restart her sonar counts before heading back to the field in Chignik as a Fishery Biologist.

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Myra Scholze collecting samples in Alitak, Alaska for a job she held with ADFG before working for ADFG in Chignik, Alaska. Photo courtesy of Myra Scholze.