Environmental and fishing groups are accusing an Oregon aquaculture company of contaminating Tillamook Bay by mechanically harvesting oysters contrary to the Clean Water Act.

The Northwest Environmental Defense Center and Northwest Guides and Anglers Association have filed a federal complaint seeking an injunction to block Pacific Seafood Aquaculture and affiliated companies from discharging pollutants through dredging.

The lawsuit alleges the company’s harvesting practices increase “suspended sediment and turbidity,” thus “releasing nutrients and other pollutants that would otherwise remain bound to the sediment,” which is unlawful without a Clean Water Act permit.

“Yet Pacific Seafood does not hold such a permit that would authorize and appropriately regulate those discharges,” the complaint said. “These discharges are ongoing and will continue to occur on each day that Pacific Seafood engages in mechanical oyster harvesting in Tillamook Bay.”

A spokesperson for Pacific Seafood said the company is “deeply committed to environmental stewardship” and considers the lawsuit “an unfortunate misuse of the legal system that mischaracterizes our operations in Tillamook Bay.”

The company’s oyster harvesting operations “have a positive effect on the bay’s ecosystem” but the lawsuit blames them for a “natural proliferation” of floating eelgrass, the spokesperson said.

“We have nothing to hide, and we stand firmly by our compliance with all applicable regulations and our long-standing commitment to sustainable practices,” according to Pacific Seafood.

According to the plaintiffs, mechanical harvesting relies on a “metal blade or dredge” being dragged behind a vessel, which scrapes the bottom of the bay, sending mature oysters tumbling into a bag.

The plaintiffs claim their members have “observed on numerous occasions” plumes of contaminants dredged up by the company’s oyster harvests, along with clumps of eelgrass that would otherwise provide habitat for endangered Coho salmon and other fish.

The lawsuit alleges mechanical oyster harvesting has raised concerns among Oregon Department of Fish and Wildlife officials, who have signed a memorandum of understanding with the Oregon Department of Agriculture disallowing the practice on oyster plats leases.

However, Pacific Seafood has continued to mechanically harvest oysters under its older “legacy” plat leases in Tillamook Bay, which are “unique” because they do not prohibit the practice, according to the complaint.

In addition to the injunction against discharging pollutants without a permit, the lawsuit wants a federal judge to impose civil penalties of about $66,700 per day of violation on Pacific Seafood and to order the company to “remediate the environmental damage” it allegedly inflicted.

Pacific Seafood’s spokesperson said “a comprehensive, science-based study” of the “factors impacting eelgrass health” in Oregon’s waterways would be a better use of resources than costly litigation.

“It is disappointing that this group has chosen to pursue litigation and mischaracterize our operations instead of working collaboratively on real solutions,” the spokesperson said.