BONNEVILLE — NOAA Fisheries Service announced last Wednesday that the “eastern distinct population segment” of Steller sea lions has recovered and can be removed from the list of threatened species under the Endangered Species Act.

The decision is the first species NOAA Fisheries has delisted due to recovery since the eastern North Pacific gray whale was taken off the list of threatened and endangered species in 1994.

It will be viewed as good news for several reasons, not least of which is that Stellers are blamed for substantial predation on white sturgeon below Bonneville dam, as well as migrating salmon.

“We’re delighted to see the recovery of the eastern population of Steller sea lions,” said Jim Balsiger, administrator of NOAA Fisheries’ Alaska Region. “We’ll be working with the states and other partners to monitor this population to ensure its continued health.”

NOAA has concluded delisting is warranted because the species has met the recovery criteria outlined in its 2008 recovery plan and no longer meets the definition of a threatened or endangered species under the ESA.

A threatened species is one that is likely to become endangered within the foreseeable future throughout all or a significant portion of its range. An endangered species is one that is in danger of extinction throughout all or a significant portion of its range.

Big recovery

The best available scientific information indicates the eastern Steller sea lion has increased from an estimated 18,040 animals in 1979 to an estimated 70,174 in 2010, the most recent year for which data are available.

This increase corresponds to an estimated annual growth rate of 4.18 percent, which exceeds a 2008 recovery plan’s demographic recovery criterion of 3 percent. NOAA Fisheries also conducted an analysis of possible threats, finding none likely to cause the eastern DPS to become in danger of extinction in the foreseeable future throughout all or a significant portion of its range.

Eastern Steller sea lions will continue to be protected under provisions of the Marine Mammal Protection Act.

The listing reconsideration was prompted by a 2010 petition signed by the directors of the Oregon and Washington departments of fish and wildlife, as well as one from the state of Alaska, that said the eastern Steller population is robust.

“… the Oregon Department of Fish and Wildlife has conducted abundance surveys from northern California to Washington that demonstrate continued population growth at nearly 4 percent through 2008,” the states’ delisting request said. “In addition, Washington Department of Fish and Wildlife has conducted Steller sea lion surveys along the Washington coast that show both increasing Steller sea lion numbers at haul out areas as well as increasing numbers of newborn pups….”

“Of particular concern to state fish and wildlife management agencies are the increasingly negative interactions that the growing Steller sea lion population is having with other very important marine and anadromous fish resources,” the states said in their August 2010 letter to NOAA Fisheries.

Sturgeon predation

Of growing concern is the predation of Steller sea lions on white sturgeon that huddle together in midwinter below the lower Columbia River’s Bonneville Dam.

Stellers are known to inhabit the Columbia but have until recent years seldom ventured as far as far upriver as Bonneville (river mile 146) in any great number. Sturgeon, while not ESA listed, are a popular game fish that have shown marked population declines in recent years in the lower river.

Since 2002 when research began to evaluate California sea lions impact on, primarily, migrating salmon and steelhead spawners, no Stellers were seen in the neighborhood and only three individuals were seen in each of the next two years.

But the number of Steller sea lions that congregate at the dam each winter and spring has grown steadily through the years. In 2011 the total number of individually identifiable Steller sea lions at the dam reached 89 and they ate, according to observers keeping a tally, more than 3,000 white sturgeon in the area immediately below the dam. That’s the most white sturgeon taken by sea lions since the researchers have been keeping track.

Estimates are that more than 98 percent of the predation on white sturgeon below the dam was by Steller sea lions, while the California sea lions concentrated on salmon.

That ratio has changed to considerable degree, with Stellers bagging nearly as many salmon this past spring as did California sea lions.

The states sought via a 2006 application under provisions of the MMPA, and received from NOAA Fisheries in March 2008, permission to remove California sea lions from the Columbia that were known to prey on salmon and steelhead populations that are listed under the ESA. The California sea lions, while protected under the MMPA, are not ESA listed.

The most recent state estimates of legal size — 3 ½ to 5-feet long — sturgeon in the lower Columbia declined steeply, from 131,700 fish in 2007 to an estimate of 66,400 fish in 2010. The Oregon Department of Fish and Wildlife initiated an additional survey in 2010 using research setlines during July-August to recover white sturgeon tagged in May and June. The “in-year” approach produced an estimate of 87,000 fish in 2010 and a preliminary estimate of 80,500 for 2011.

Over the past two years, Steller sea lions have increased their focus on salmon headed over Bonneville in the springtime.

More management options

The delisting decision gives the states and others “more management options for the future,” said Guy Norman, director the Washington Department of Fish and Wildlife’s Southwest Region.

“There’s an increasing concern about Stellers’ impact on salmon,” as well as on white sturgeon, in the lower Columbia, Norman said.

Taking any action, beyond non-lethal “hazing” now being carried out, would require another application, as was done California sea lions, for an authority under the MMPA to remove Steller sea lions known to be having a significant impact on efforts to recover ESA-listed salmon stocks.

Steller sea lions were first listed as a threatened species under the ESA in 1990. In 1997, NOAA scientists recognized two distinct population segments of Steller sea lions: a western and an eastern segment. The eastern segment includes Steller sea lions from Cape Suckling, Alaska, south to California’s Channel Islands. The western population segment remains classified as endangered. NOAA is not proposing any changes to the status of the western Steller sea lion.

On June 29, 2010, NOAA Fisheries provided notice that it was initiating a status review of the eastern Steller sea lion and requested public comment. During the comment period, NOAA Fisheries received two petitions to delist the eastern Steller sea lion: one from Washington and Oregon; and one from Alaska.

On April 18, 2012, NOAA released a draft status review, which underwent independent peer review and proposed to remove eastern sea lions from the list of endangered and threatened wildlife. NOAA requested, received, and considered 1,144 public comments during the 60-day comment period.

With the delisting, federal agencies proposing actions that may affect the eastern Steller sea lions are no longer required to consult with NOAA Fisheries under section 7 of the ESA. However, NOAA Fisheries will continue to monitor the effects of proposed projects on the eastern population to ensure existing measures under the MMPA provide protection necessary to maintain recovered status.

NOAA Fisheries says it is proceeding carefully to ensure the eastern population segment remains strong. Working with affected states and other partners, NOAA has developed a post-delisting monitoring plan for this population. As a precautionary measure, the plan will be in effect for 10 years—twice the five year time requirement under the ESA. If implemented as intended, this plan takes the important steps necessary to maintain the recovered status of the eastern Steller sea lion.

The delisting of the eastern Steller sea lion will take effect 30 days after publication of the final rule in the Federal Register.

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