GRANTS PASS - Increasing salmon and steelhead returns in the past three years appear to be due mostly to a temporary cycle of more food in the ocean and do not signal any lasting victories in saving the fish from extinction, federal fisheries scientists say.

None of the 27 populations of salmon and steelhead evaluated appear to warrant coming off the threatened or endangered species list, and three appear to have declined from threatened or candidate species status to endangered, the scientists indicated.

The conclusions were made by a team of biologists for NOAA Fisheries, formerly known as the National Marine Fisheries Service, the federal agency in charge of restoring salmon. Their findings were included in a preliminary report distributed Tuesday to state and tribal fisheries agencies in California, Oregon, Washington and Idaho.

The report is the beginning of a process to be concluded by the end of the year with recommendations on whether to change the Endangered Species Act status of salmon and steelhead, said NOAA Fisheries Northwest Regional Administrator Bob Lohn.

NOAA Fisheries still has to evaluate conservation efforts, such as habitat improvements, hatchery reforms and harvest limitations, before making those decisions, Lohn added.

"The rebuilding is far from even," said Lohn. "In those areas where there have been good habitat conditions and/or major reforms such as harvest reforms or other improvements, we are often seeing a quicker rebound."

The review of all 26 runs of Pacific salmon and steelhead listed as threatened or endangered since 1991, plus one candidate for protection, was prompted by a 2001 federal court ruling that temporarily struck down threatened species status for Oregon coastal coho salmon.

U.S. District Judge Michael Hogan had ruled that NOAA Fisheries erred when it included both wild and hatchery salmon in the same population group, and then granted threatened species protection only to the wild fish. Protection for Oregon coastal coho was restored pending appeal.

Still to come as a result of the ruling is a review of NOAA Fisheries' policies on whether hatchery fish should be protected along with wild salmon and how hatcheries should be used to help restore depleted runs.

Based on the abundance, reproduction success, distribution across a home range and genetic diversity of each population, the review found that eight appeared endangered, or in danger of extinction, and 19 threatened, or likely to become endangered. The current status is five endangered, 21 threatened and one candidate for protection.

The scientists suggested changing three populations from threatened or candidate species to endangered: Central California coho salmon, lower Columbia River/Southwest Washington coho, and California Central Valley steelhead. None warranted upgrading or being taken off the list.

Increasing returns over the past three years have helped alleviate immediate fears of extinction for some populations, such as Snake River spring/summer and fall chinook and Sacramento winter chinook, the report said.

Lohn said four other populations showed improvement, though not enough to change their status: upper Columbia River spring chinook, Oregon coast coho, upper Columbia river steelhead, mid-Columbia River steelhead and upper Willamette River steelhead.

The scientists said increasing returns remain well below targets for recovery and have not been sustained for more than one generation. They appear primarily due to a temporary cycle of improved food availability in the ocean, were the fish spend most of their lives before returning to native rivers to spawn.