ANCHORAGE, Alaska — COVID-19 outbreaks have shut down operations at two of Alaska’s largest seafood processing plants in the Aleutian Islands.

The plants owned separately by Trident Seafoods Corp. and UniSea Inc. are halting work as the lucrative crab and pollock seasons begin, Anchorage Daily News reported Tuesday.

The Trident Seafoods plant is a processing center for Bering Sea harvests of pollock, crab and cod in Akutan, about 750 miles (1,200 kilometers) southwest of Anchorage.

The plant has about 700 workers and is the largest Alaska location owned by Seattle-based Trident, the largest harvesting and processing company in North America.

Prior to the suspension, Trident said Monday it was assessing potential operational impacts after four workers at the Akutan plant, who were roommates, tested positive for the virus.

Coronavirus cases detected at Alaska seafood plant owned by Seattle-based Trident Seafoods

About 365 plant employees are waiting in Anchorage while the company contends with the outbreak, Trident said.

UniSea locked down its facility in Unalaska, 1,172 miles (1,886 kilometers) southwest of Anchorage, after 55 workers tested positive for the virus. About two-thirds of the positive test results occurred during a travel quarantine intended to identify positive cases.

The UniSea outbreak began with four cases but 20 more surfaced last weekend. Company officials said the outbreak resulted from a New Year gathering in company housing.

The plant, with 700 employees in Dutch Harbor and another 60 waiting in Anchorage, took one delivery of cod before shutting down. All processing is halted at least until the end of the month, company President Tom Enlow said.

Crab season started last week and the plant was gearing up for the winter pollock fishing season that opened Wednesday, Enlow said.

The earliest the UniSea plant could take a delivery now is Jan. 27, depending on the outcome of virus testing of about 450 employees Tuesday, Enlow said.

The seafood industry had Alaska’s largest coronavirus outbreaks over the summer as thousands of workers streamed into the state to catch and process salmon and other species.