Property rights advocates, farm groups and development interests asked a federal judge Wednesday to lift Endangered Species Act protections from all threatened and endangered salmon across the West, arguing that the government failed to count fish spawned in hatcheries.

The federal government and conservation groups countered that the Endangered Species Act requires consideration of the best available science, which clearly indicates that depending on fish raised in hatcheries to boost salmon numbers will, over the long run, harm fish that spawn naturally in rivers.

U.S. District Judge Michael Hogan gave no indication when he might rule on the case, or how he might rule.

Pacific Legal Foundation, a property rights public interest law firm based in Sacramento, Calif., brought the lawsuit on behalf of the Building Industry Association of Washington, the Coalition for Idaho Water, farm bureaus in Idaho and Washington, the California State Grange and others.

The lawsuit builds on Hogan's 2001 ruling that NOAA Fisheries, the federal agency in charge of restoring dwindling salmon populations, violated the Endangered Species Act when it put wild and hatchery fish in the same group, known as an evolutionarily significant unit, or ESU, but then protected only the wild fish. The ruling led to lifting threatened species status for the Oregon coastal coho.

The plaintiffs want the court to lift threatened and endangered species listings for all 16 protected populations of salmon in Washington, Idaho, Oregon and California.

If they win, some restrictions on logging, irrigation and urban development could eventually be lifted around the West.

Several salmon populations are protected in the Seattle and Portland metropolitan areas. Irrigation water was shut off to farms in the Klamath Basin of Oregon and California in 2001 to provide enough water for threatened coho salmon in the Klamath River during a drought. Many timber sales on national forests have been blocked to protect salmon.

Restrictions on hydroelectric dam operations in the Columbia Basin would not be directly affected, because the case does not challenge 10 populations of steelhead, which overlap many of the protected salmon zones. Pacific Legal Foundation is challenging those listings, too, in a separate case in U.S. District Court in Fresno, Calif.

Pacific Legal Foundation lawyer Damien M. Schiff argued that NOAA Fisheries did not follow Hogan's 2001 ruling when it developed a new policy on hatchery fish and reconsidered its protections for salmon, because it made no effort to determine whether hatcheries could be relied upon as the principal means of assuring the survival of the fish.

He added that the need to consider the best available science stops once the hatchery and wild fish are put into the same population group, which NOAA Fisheries did.

Paul Lall, a U.S. Justice Department lawyer, countered that NOAA Fisheries had carefully considered Hogan's 2001 ruling, and that under the best available science, it had to consider more than just population numbers. It also had to consider whether salmon could reproduce effectively, if they were genetically diverse, and whether they were well distributed over their geographic range.

Science showed that fish raised in hatcheries eventually adapted to life in hatcheries, rather than the wild, and while they could help spread geographic distribution, they could sometimes harm genetic diversity and reproductive success, Lall added.

Jan Hasselman, representing Trout Unlimited, argued that the plaintiffs had not challenged the science behind the creation of the salmon population groups, and added that NOAA Fisheries' blue ribbon panel of scientists had declared it was "biologically indefensible" to count hatchery fish when deciding whether a group was in danger of extinction.

The judge's only question for lawyers was whether various runs of salmon within the same population group, such as spring chinook and fall chinook, could be expected to interbreed, given the fact that they spawn in different parts of the river and at different times of year.

The question was apparently in reference to the plaintiffs' claim that NOAA Fisheries had protected some salmon population groups that were too large geographically, said Schiff.

Lall told the judge that there was scientific evidence that over time, some different runs did interbreed - enough to make those within a larger group genetically similar.

He added that the alternative to creating broad population groups, known as evolutionarily significant units, would be to list each seasonal run of salmon in each little stream.