New tech could unveil the secret life of Bristol Bay red king crab

Fishery researchers in Alaska are using cutting-edge technology to track migratory patterns of one of Alaska's tastiest catches -- the red king crab.

Biologists tagged 150 mature male crab in Dutch Harbor in June. The tags transmit acoustic readings back to an unmanned saildrone equipped with an accoustic receiver. This allows researchers to track movement across the ocean floor and monitor changes in water temperature.

NOAA fishery biologist Leah Zacher says this one-year study is the first of its kind. Its mission is to better understand the crab's year-round migration and habitat to inform fishery management.

"It's an exciting project," Zacher said. "Managers really need to understand where crabs go in all seasons, and what habitats are essential to make effective rules for fishing."

Researchers already know a little about their movements. According to Zacher, Bristol Bay red king crab generally come closer to shore during their summer mating season. The fishery opens in Oct., when the crab have moved out to deeper water.

"But the spring is a little bit more of a mystery," Zacher said. "I think it depends a lot on what the water temperature is and exactly where they're moving."

Zacher says the one-year experiment will not provide enough data to know how, or if, climate change will impact their migratory patterns.

"It's a new project, but if it's successful we would like to continue it," Zacher said. "That will allow us to compare movement now and into the future under potentially warmer conditions."

According to NOAA's most recent stock assessment, Bristol Bay's red king crab population is not over-fished. However, the total catch dropped over 35 percent between 2014 and 2018, from 11.92 million lbs to 7.67 million lbs.