GILLS ARE GOOD IN FLOODS : MOST FISH ARE FARING JUST FINE.

Byline: BRETT PAULY

Anglers fretting over the impact of the serious flooding of Northern California may find solace in assessments by Department of Fish and Game officials.

``Fish like water. They've got to have it. And the more they have, the better off they are,'' said Tim Farley, chief of the DFG's Inland Fisheries Division.

The DFG did have casualties.

The flooded San Joaquin River Hatchery northeast of Fresno lost its entire crop of 2 million trout and kokanee salmon. At Nimbus Hatchery near Rancho Cordova on the American River, crews were forced to release 290,000 steelhead yearlings three weeks early because of high flows, turbidity and debris cascading from Folsom Dam.

But while throngs of fish perished in the dramatic confluence of rain runoff and snowmelt in the winter warming trend, the losses will be short-term and there is reason to assume fisheries will actually benefit in the long run.

``If you had to generalize, it's probably good for the fish,'' Farley said. ``During flood years, lakes and reservoirs fill up and are enriched by vegetation and nutrients, which improve spawning and survival.''

Black bass and other lake dwellers reap the greatest rewards from the food-rich flows.

Salmon are generally not hurt by floods because the timing is usually fortuitous.

Adult salmon spawn in September, October and November. When the rivers are most subject to flooding, in winter, the offspring range in length from 1 to 6 inches and are readying to swim to their ocean home - normally from December through April.

Their flight to the sea may indeed be aided by high waters, because the fish are less likely to run into pumping systems that feed aqueducts and wind up dying on agricultural fields.

Steelhead usually don't spawn until later, in late January through early March, when there is less of a threat of flooding.

``Flooding is not a big-time problem for fish,'' said Bruce Barngrover, senior hatchery supervisor for the DFG's Sacramento Valley-Central Sierra Region. ``Steelhead were swimming up fish ladders on the American River during the height of the flooding.''

Some species, like sturgeon, thrive in high water.

Trout in rivers and streams are hardest hit, Farley explained, but even the worst floods rarely wipe out entire populations.

``They hug the bottom, get behind logs and boulders and find eddies to hold in,'' he said. ``And the reproductive success of the survivors will be excellent.''

Floods act as massive flushing flows, restructuring rivers and cleaning out debris. Anglers on the American, Yuba and Truckee rivers may notice slight decreases in catches this year, but by trout season in 1998 their creels will be as full as ever, Farley said.

``And in areas where we plant fish, there won't be any problem at all,'' he said.

Contamination from sewage, mud, silt and other pollutants did affect fish in a few localized areas, but, in general, it becomes so diluted in flood conditions that most fish aren't threatened, Barngrover said.

Farley noted that no studies are planned to determine the impact of the latest floods on state fisheries.

The San Joaquin River Hatchery, which produces 10 percent of the state's catchable trout, will soon be stocked with excess fingerlings from other hatcheries. Farley expects it will return to its normal rearing operation within a month.