Recently, the United States District Court for the District of Oregon issued a decision (pdf) denying the motion of plaintiff environmental groups for a preliminary injunction to halt lethal removal of California sea lions (Zalophus californianus) from the Columbia River to reduce predation pressure on salmonids as they migrate past the Bonneville Dam.  The decision is the latest chapter in a long-running dispute over efforts to protect salmon runs in the Columbia River system.

The States of Oregon, Washington, and Idaho applied for and obtained authorization from the National Marine Fisheries Service (NMFS) to remove the sea lions.  Plaintiff environmental groups challenged the decision to authorize removal, and Native American tribes intervened in support of the States.

Plaintiffs argued that NMFS acted unlawfully by authorizing the action without making a determination regarding incidental take of Stellar sea lions (Eumetopias jubatus) listed under the Endangered Species Act (ESA) and that NMFS also acted unlawfully by authorizing lethal take under the Marine Mammal Protection Act (MMPA).  With respect to the first argument, the court held that plaintiffs failed to show that harm to Stellar sea lions is likely to occur and so failed to demonstrate irreparable injury, which is a prerequisite for preliminary relief.  With respect to the second argument, the court held that the plaintiffs made a showing or irreparable harm but concluded that the public interest would be more harmed by issuance of an injunction than denial.  The court reasoned that issuing the injunction would harm defendants’ ability to protect ESA listed salmonids.