U.S. District Court Judge Michael H. Simon on Tuesday heard contradictory testimony about the effect of California sea lion predation on Columbia River salmon runs, and about the “harm” sustained by humans because of that predation – and, on the other side, the harm to humans resulting from lethal removal of the big pinnipeds.

The legal fight is about whether sea lions should be killed to reduce the mortality caused by the marine mammals’ feeding on protected salmon. The pinnipeds are also shielded by law under the Marine Mammal Protection Act.

The Humane Society of the United States, Wild Fish Conservancy and individual plaintiffs say that an ongoing program to remove salmon-eating sea lions results in the removal of their right to observe and enjoy the animals in their natural environment.

Defendants in the lawsuit, the federal government joined by the states of Idaho, Oregon and Washington and treaty tribes, say they and their constituencies are harmed by the fact that predatory sea lions thwart efforts to revive salmon populations that are protected under the Endangered Species Act.

Simon called nearly four hours of oral argument Tuesday at the federal courthouse in Portland “a good briefing.”

“You’ve given me additional things to consider” in deciding whether to grant a request for a preliminary injunction that would immediately halt sea lion removals, Simon said. Those arguments were waged by HSUS attorneys, the U.S. Department of Justice, the states of Idaho, Oregon and Washington and the Umatilla, Warm Springs and Yakama tribes.

The HSUS has filed a lawsuit that says an ongoing effort to lethally remove California sea lions that feed on salmon is illegal under the Administrative Procedures Act, the Endangered Species Act and the Marine Mammal Protection Act.

The lawsuit challenges a decision made March 15 by the U.S. Department of Commerce’s NOAA Fisheries Service granting the three states authority to remove “identifiable” California sea lions that the federal agency says are having a “significant” impact on the recovery of five wild salmon and steelhead stocks that are protected under the Endangered Species Act. The tribes have joined the lawsuit in defense of the federal decision as amicus or friend of the court.

The states were granted lethal removal authority under the federal Marine Mammal Protection Act’s Section 120 via a March 15 decision by NOAA Fisheries. That decision was immediately challenged with a complaint filed March 19 by HSUS. Soon after the HSUS soon after filed a request for a preliminary injunction to stop sea lion trapping and removal activities being carried out at the dam under the authorization from NOAA Fisheries.

To earn a preliminary injunction, plaintiffs must prove they have a reasonable chance of success in the lawsuit to be argued and that action in the interim – in this case sea lion removal – would cause greater harm to them than those represented by the defendants.

That trapping effort has been ongoing since late March with a total of 12 animals removed, including two this week. Of that dozen California sea lions, 11 were euthanized and one was accepted for residence at the Shedd Aquarium in Chicago.

The judge on Tuesday said that he would render a decision on the injunction request by the end of May.

Ongoing research conducted over the past decade has shown that most, if not all, of the California sea lions that visit the dam have left by end of May, and the upriver salmon run by that time is at a springtime ebb.

The sea lion contingent, which is entirely male, swims north in late summer to forage. For more than 10 years a certain portion of those sea lions have swum upriver in winter and spring to feast on the spring salmon run, which stalls briefly below the dam before finding fish ladders. Many of the big animals in late spring answer nature’s call and head for breeding grounds off the coast of southern California and in Mexico.

The injunction request is intended to halt action while legal briefing is conducted regarding the complaint filed by HSUS, which asked that NOAA Fisheries decision be declared illegal. The letter of authorization issued by the federal agency allows the removal of up to 92 California sea lions per year through a five-year period.

The judge on Tuesday asked the parties involved to reach agreement on a lawsuit briefing schedule. He adopted the suggested schedule, calling for the federal government to file the “administrative record” related to the decision by June 22. HSUS would then have until July 23 to file a motion for summary judgment which presumably, like its complaint, would ask that the NOAA Fisheries decision be invalidated. The schedule calls for briefing to be ended by Sept. 21. The idea is to complete the legal arguments and get an opinion on the legality of NOAA’s decision before next spring when the sea lions and salmon begin once again to funnel into the Columbia.

Congress in approving the MMPA allows NOAA Fisheries to authorize the lethal take of “individually identifiable” sea lions that are having a “significant negative impact on the decline or recovery” of listed salmon and steelhead.”

The agency first issued such authorization on the Columbia in March 2008. That decision was upheld in U.S. District Court but later overturned in the U.S. Court of Appeals for the Ninth Circuit, which said NOAA had “not offered a satisfactory explanation for its action. First, the agency has not adequately explained its finding that sea lions are having a ‘significant negative impact’ on the decline or recovery of listed salmonid populations given earlier factual findings by NMFS that fisheries that cause similar or greater mortality among these populations are not having significant negative impacts.”

The Nov. 23, 2010 Ninth Circuit ruling also said “the agency has not adequately explained why a California sea lion predation rate of 1 percent would have a significant negative impact on the decline or recovery of these salmonid populations.” The 2008 decision had said the removal program would be discontinued if observed predation on salmon in the area below the dam dropped below 1 percent.

HSUS in briefing has stressed that the impact on salmon from predation below the dam has ranged between 1 and 4 percent; and said that fish mortality caused by NOAA Fisheries-endorsed harvests and operation of the rivers’ hydro system is much higher. The organization has said that the federal agency has issued decisions under the ESA and APA that deem harvest and hydro impacts as insignificant, while branding the sea lion predation is significant under the MMPA.

To earn a preliminary injunction plaintiffs must prove they have a chance to later win a decision on the “merits” of the dispute -- that they have reasonably viable arguments. Another requirement, Simon said, is that the harms – i.e. loss of sea lion viewing vs. salmon availability – is greater.

In dollars and cents, the HSUS has stressed and continued to do so Tuesday that the observed take of salmon at Bonneville Dam has over the past 10 years amounted to 4 percent or less, and more often nearer 1 percent, of the spring chinook salmon run. That run includes Snake River and Upper Columbia fish that are protected under the Endangered Species Act, as well as threatened winter steelhead.

The U.S. Army Corps of Engineers had since 2002 monitored, via observers stationed atop the dam, the activities of sea lions that patrol tailwaters at Bonneville. The goal of the research is to evaluate the impact of marine mammals on listed salmon and steelhead.

The tribes, states and federal government say that the toll is much greater when taking into account activity beyond the observed area, which amounts to a quarter mile downstream of the dam. Bonneville is located about 146 miles upstream of the Columbia’s mouth at the Pacific Ocean.

Brent Hall, an attorney representing the three treaty tribes at the hearing, said it is “not fair” to compare predation in the quarter mile of river below the dam to harvest totals for the entire basin, above and below Bonneville dam.

HSUS has said harvest totals have been as high as 17 percent of the upriver spring chinook run. Tribal testimony, based on statistical modeling related to the sea lions biological needs, have estimated that sea lions take from 7 to 18 percent of the run over the entire 146 miles of the Columbia River from Bonneville Dam to the river mouth.

HSUS attorney Ralph Henry faulted the modeling effort produced by the states and tribes, saying it wrongly assumed a 100-percent salmon diet up and down the river. Whereas the pinnipeds at Bonneville had a diet made up 95 percent of salmon, Henry said that ratio is much lower elsewhere.

Defense attorneys, and declarations filed by the states and tribes, insist that the modeling effort did take into account the fact that sea lions downriver were likely to include a smaller proportion of salmon in their diet.

Significance remains a key issue. The 2008 NOAA Fisheries decision included the 1 percent impact threshold for significance. Last year’s decision, produced in response to the Ninth Circuit’s request for more explanation, dropped the 1-percent standard and replaced it with a seven-criteria judgment of how sea lion predation might be judged significant.

For more information, see:

CBB, May 4, 2012, “Humane Society: Feds Fail To Provide ‘Cogent’ Explanation Of How Sea Lion Predation ‘Significant'  http://www.cbbulletin.com/420177.aspx

CBB, April 27, 2012, “Briefs Filed Defending Sea Lion Removal; Oral Arguments May 15 On Preliminary Injunction Request” http://www.cbbulletin.com/419991.aspx