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Measure halibut before it's landed? There's an app for that.

  • Author: Carey Restino
  • Updated: September 27, 2016
  • Published October 19, 2013

As regulations tighten on the size of sport-caught halibut on charter boats in Alaska, sport fishermen are faced with a challenge of how to tell the size of a halibut without pulling it out of the water and applying a measuring tape. While accurate, holding a ruler up to a floundering fish can be dangerous to both the fish and the crew.

The solution may lie in an app being developed by the Halibut Angler Release Mortality Reduction Project for hand-held devices like smartphones and iPods that could make determining the size of a halibut as easy as snapping a photo from the side of the boat.

Richard Yamada is owner of Shelter Lodge in Auke Bay as well as a longtime advocate for recreational fishing in Alaska. He also has a background in computer technology. It was that marriage of backgrounds that spawned the idea of creating an app that could measure the size of a halibut without pulling it all the way out of the water, thus improving the chances that the fish would survive.

"We don't really have a method to measure fish now," said Yamada. "So we came up with the idea of using a smartphone application to determine the size of the fish."

Yamada said similar technology has been used in other areas of science. Digital cameras are used to record and count fish and there are even applications that use technology to do stock assessments of geese. So a grant was written and the Alaska Charter Association recently received $186,725 from the Bycatch Reduction Engineering Program to use digital imaging technology to reduce release halibut mortality in Alaska's recreational fishery. While the grant was only received this month, work has already started on the project, Yamada said.

The first challenge was finding a measurement that could scientifically be found to correlate with the overall size of the fish. From an initial survey of 250 samples performed this summer, various dimensions were examined, including the diameter of the eyeball socket and the distance between eyeballs, for example. But the dimension that rose to the top in accuracy for predicting the size of a halibut was a measurement from the eye to a nodule found on the gill plate.

Yamada said while initial results are promising, a software engineer firm in Juneau, Finsight LLC, developed a preliminary application for iPods designed to gather more data for study. A plastic jig was designed to attach to the iPod that will provide a consistent distance between phone and fish. These iPods will be deployed to Juneau, Petersburg, Seward and Homer for use during the remainder of the 2013 commercial fishing season through collaboration with the International Pacific Halibut Commission, which has agreed to participate in data collection through its port sampling program.

Yamada said getting samples entered from the commercial sector is important since many halibut caught by the charter fleet are smaller on average. For purposes of testing the scientific correlation between the eyeball-to-fin-node measurement and the overall fish weight, it is important to get a wider range of fish samples, he said. Also, measurements already accepted by fishermen relating fish weight to fish length seem to vary in accuracy by region, Yamada said, so one could extrapolate that similar head-measurement correlations might vary by region, too, so getting fish measurement data from various areas of the state is key.

Yamada said he hopes to collect a scientifically significant number of samples using the preliminary application and by next fall, if the measurement data proves the theory of this measurement as a predictor of fish weight, a second application will be created that translates the pixels on the screen to fish weight for charter operators. The application would be created for both Apple phones and Android operating systems, and would be free for download for anyone who wanted to use them.

Charter captains could even use the application to capture log-book data of fish caught on board, he said.

Beyond providing captains with a more accurate way of getting a fish measurement, Yamada said the application could also be used to allow measurement of trophy-sized halibut by anglers who wanted to release the fish. The phone app could even generate a thank-you letter for anglers practicing good conservation techniques, planners noted.

The application concept may also have possibly uses in other fisheries, and in the commercial sector, too, where measuring fish may sometimes be helpful for determining if the catch falls within quota limits.

"I think this is the tip of the iceberg," Yamada said, adding that technology like this holds potential in encouraging the sustainability of fisheries like the halibut charter sector.

For more information on the project, go to

Carey Restino writes for The Homer Tribune, where the preceding report was first published. Used with permission.

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