Federal, state and Humane Society attorneys continued legal arguments during the past few weeks over Congress' intent in allowing the lethal removal of sea lions only if they are having a "significant" negative impact on protected salmon.

The closing legal briefs set up oral arguments in U.S. District Court in Portland next week. The HSUS says a March NOAA Fisheries Service decision to allow the states of Oregon and Washington to remove California sea lions from below the Columbia River's Bonneville Dam is arbitrary and capricious under the federal Administrative Procedures Act and contrary to the Marine Mammal Protection Act and the National Environmental Policy Act.

Before activity was stalled this year, the states managed to capture seven California sea lions for relocation to zoological facilities. Six sea lions were flown to SeaWorld facilities in Orlando, Fla., and San Antonio, Tex. A seventh sea lion died when it failed to resume breathing after being sedated for a health examination.

Trapping was ended after four California and two Steller sea lions would found dead May 4 in floating traps below the dam that had been used to capture the animals. The cause of death has been identified as heat prostration but is unknown how they became trapped. The traps were left open overnight but the doors were somehow triggered.

This year's live removal was allowed under a legal agreement struck by the litigants. The authorization was granted under Section 120 of the MMPA.

An Aug. 8 HSUS brief says NOAA does not in its decision documents or legal briefs "point to any studies, reports or other evidence in the record to indicate that sea lions are actually having a 'significant negative impact' on the decline or recovery of salmonid stocks…" as the MMPA requires.

Congress also "unequivocally instructed that 'current levels of protection afforded to seals and sea lions under the Act should not be lifted without first giving careful consideration to other reasons for the decline'" of salmon populations, the HSUS filing says. A lack of consideration of other causes of salmon mortality such as harvest and the Columbia/Snake hydro system are among legal NOAA's failures, HSUS says.

The sea lions congregate each spring below the dam, feasting on spawning salmon and steelhead as they seek fish ladders. A total of 13 salmon and steelhead stocks that originate in the Columbia basin are listed under the Endangered Species Act.

The HSUS says the federal agency has not proven that the observed take below the dam of from 0.4 to 4.2 percent of the salmonid run annually has a significant impact and cannot extrapolate the take elsewhere in the river to produce "post hoc" inflated numbers not included in the administrative record of the decision. The sea lions must swim 146 miles from the Pacific Ocean to the dam.

The states and federal government argue that the extrapolated predation numbers are indeed valid, and in the record.

"That AR clearly contains evidence that CSL are taking salmonids at a rate that both science and common sense would define as 'significant,'" according to a brief filed Aug. 18 by the state of Oregon.

An Aug. 22 federal filing refutes the HSUS contention that the California sea lion take of the spring run is 4.2 percent "at most."

"… that unobserved take could occur in different locations, hours, or outside the vision of the observer; that the bioenergetic needs of the species could cause take as high as 22.1 percent of Chinook; and that as many as 37 percent of salmon and steelhead show signs of pinniped scarring)," federal attorneys say.

A state analysis indicates that a sea lion eats 15 to 30 pounds per day during the swim upriver and, on the Columbia, 85 percent of that diet is salmonid.

HSUS' Aug. 8 brief says the lethal take approval should be overturned because of administrative miscues alone. The filing says that NOAA failed to consider other impacts to salmon and improperly left documents from the administrative record related to previous ESA decision allow harvest and hydro system impacts on listed fish.

Federal attorneys say that "NMFS appropriately considered the effects of the Columbia River power system and fishing on these species in the context of their MMPA decision process." And NMFS's MMPA Section 120 finding does not "swerve from prior precedents" as HSUS contends.

"… Plaintiffs' comparison of the MMPA Section 120 analysis of sea lion take to NEPA and ESA decisions regarding fishing and hydropower is inappropriate both because the standards set forth in the statutes are separate and distinct and because the facts of each case are complex making a simple comparison misleading."