Maruha Nichiro-owned Westward Seafoods has temporarily halted production at Alaska pollock processing plant Alyeska Seafoods, based on a cluster of positive cases of COVID-19 identified during surveillance testing of the workforce at the facility last week.

The company is the third major Alaska Bering Sea pollock processor to have shut down in the past week over COVID outbreaks, just as the critical A fishing season begins.

The Alaska pollock fishery is the second largest fishery in the world, worth an estimated $1.9 billion (€1.6 billion), according to NOAA. A and B fishing seasons are the primary time for vessels to catch and harvest fish in the state, with Unalaska's Dutch Harbor serving as a hub for production.

The City of Unalaska said Friday the company has launched its response plan for the outbreak,

"including isolating positive cases, assisting with contact tracing efforts, quarantining direct contacts, and activating a robust plan for additional surveillance testing."

Westward Seafoods processes nearly 1.2 million metric tons of pollock, cod, halibut, black cod, king crab, snow crab and Dungeness crab at its operations in Dutch Harbor.

Last week, Trident Seafoods announced it had suspended operations at its pollock processing plant in Akutan, Alaska, for three weeks to enable comprehensive testing and support a preventative quarantine for its 700 workers there.

There have been 30 workers who have tested positive for COVID in the Akutan seafood industry so far, according the regional tribal healthcare provider Eastern Aleutian Tribes.

UniSea President Tom Enlow told IntraFish last week 59 workers at its pollock processing plant in Unalaska have tested positive since the start of this year, with operations shut down until further testing is conducted.

Only two plants remain operational on the island, according to local Alaska news site KUCB.

One is Westward's other processing facility, and the other is Icicle Seafoods' floating Northern Victor plant — a 380-foot vessel docked permanently on Unalaska's spit.

Read more on the Alaska pollock A season: