Sea lion task force makes recommendations for fish

Lethal removal of sea lions at Bonneville Dam is likely not reducing predation on salmon and steelhead at the dam by California sea lions (CSL).

That is the general opinion of the NOAA Fisheries’ Pinniped-Fishery Interactive Task Force that met for the fifth time since 2008 in March. The task force was assigned by NOAA to review lethal removal of California sea lions and hazing operations aimed at reducing salmon predation at Bonneville Dam.

Although the task force of 14 people agreed that the program to lethally remove sea lions at the dam is “effectively eliminating pinniped predation by individual CSLs,” it couldn’t agree on whether the program has actually reduced overall predation by the sea lions, according to the Final Report And Recommendations Of The Bonneville Pinniped-Fishery Interaction Task Force report published Friday, April 21.

(For the full report, see http://www.westcoast.fisheries.noaa.gov/publications/protected--species/marine--mammals/pinnipeds/sea--lion--removals/2017/bonneville--pfitf--march--2017--report--final.pdf.)

As many as 3,000 California and Steller sea lions were present last year in the Columbia River from Astoria to Bonneville Dam with three to five sea lions at any one time upstream of the dam in the Bonneville pool from January and into June, when the males leave for California breeding grounds.

The task force met March 1 and 2 in Portland to consider ways to improve lethal removal and hazing of the sea lions authorized by NOAA Fisheries in a March 15, 2012, Letter of Authorization.

The authorization allows the states of Oregon, Washington and Idaho to “lethally remove individually identifiable California sea lions that are having a significant negative impact on ESA-listed salmon and steelhead in the vicinity of Bonneville Dam,” according to NOAA Fisheries information announcing the Task Force meeting.

The task force was asked to consider four questions and the first was whether the current lethal removal program is effectively reducing pinniped predation on at-risk salmonids and what to do about it.

While the task force agreed that killing an individual California sea lion eliminates the impact that sea lion has on salmon, “the data on the total number of sea lions present at the dam, the continued addition of new CSL to the list of animals approved for lethal taking, and the trend in annual-predation rates indicate that new sea lions continue to arrive at Bonneville and prey upon salmonids,” the report says.

Although sea lions stayed for a shorter period at the dam the past few years, their overall abundance and the percentage of available fish they ate last year rose, taking some 3.9 percent of the spring chinook run. Some task force members believe their removal prevents additional carnage, while others believe that no fish are actually saved as more sea lions come in behind the removed animals, simply replacing them.

Among the recommendations offered by the task force are:

-- enhance the ability to identify animals that are to be removed by changing the number of days a sea lion must be present from five to three before being tapped for removal, automatically marking for removal animals that make it upstream of the dam, and even to trigger Section 109 of the MMPA, which could allow removal of animals throughout the Columbia River.

-- prioritize removal early in the season to protect more of the run of fish listed under the Endangered Species Act, as the earliest run of fish are the most at risk, according to NOAA.

-- enhance the ability of federal agencies to expedite the approval of animals to be removed.

-- find additional resources to hire removal and observation crews.

-- identify “trap-shy” sea lions and determine their impact on salmonids.

-- NOAA should work with coastal cities to discourage sea lions hauling out at docks.

-- determine how to estimate predation downstream of Bonneville Dam in other areas of the river.

The task force was also asked to consider three more questions:

-- Does non-lethal hazing appear to be an effective aid in reducing sea lion predation on salmonids in the area? Should non-lethal efforts be modified (increased, reduced, or re-directed) to improve effectiveness?

It determined that hazing was ineffective at reducing predation. The only recommendation the full task force agreed on was to cease hazing in the river, but to continue and increase at-dam hazing. Other recommendations included dropping the requirement of hazing in order to target a sea lion for removal and explore other non-lethal alternatives.

-- Do the criteria in the authorization for identifying predatory sea lions remain appropriate? If not, how could these criteria be modified to improve effectiveness?

The task force said that some aspects of the criteria may not be appropriate, but only came to a consensus on one recommendation: “Add the latitude to use additional measures to mark and identify individual CSLs when appropriately and scientifically implemented.” The task force suggested using temporary markers, such as paintballs, using PIT tags or other methods of tagging to mark animals, and to increase the observation staff’s ability to observe from multiple locations.

The majority of members said that a number of changes might increase the effectiveness of the overall lethal removal program and some felt that these changes might best be made in the terms and conditions portion of the LOA.

Now that the task force has submitted its recommendations, NOAA will determine a course of action and let the Task Force, the states, and the public know of its decisions.

Task Force members are Daryl Boness, scientist; Bruce Buckmaster, Salmon For All; Joyce Casey, Corps;