Nimbus Hatchery Steelhead Numbers Rebound From Last Year

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(Rancho Cordova) The number of steelhead showing now at Nimbus Fish Hatchery has improved greatly from last season, in spite of continuing low releases of 500 cfs from Nimbus Dam.

This year is much different from last season, when a total of only 154 steelhead were trapped from December through mid-March.

In contrast, the hatchery has trapped over 148 steelhead to date as of December 22. Last season only10 steelhead had been trapped by December 29.

There are lots of steelhead in the hatchery now,” said Gary Novak, Nimbus Fish Hatchery manager. “I’m floored.”

The hatchery has spawned a total of 27 pairs to date compared with only 31 pairs all of the last season.

“The males are above average size and the females are also large,” he said, leading to speculation that some of the steelhead may have stayed out in the ocean for an extra year and have come up the river as 4-year-olds.

We won’t know for sure until scale samples of the steelhead are analyzed. Most steelhead return to spawn as three-year-olds on the American River.

The number of eggs taken from the fish to date is 198,278. That’s more than total for the entire season last year, 192,278 eggs.

We averaged about 6,000 eggs per female last season,” he said. “This year we’re seeing over 7,000 eggs per fish.”

However, to put the current steelhead run in perspective, banner years for steelhead on the American have seen up to 2,000 adult steelhead counted by this time of year.

The numbers of fall-run Chinook salmon, including jacks and jills (two-year—old fish) showing at the hatchery are now also above those trapped last year. The facility has trapped 9,716 salmon, including 7,326 adults and 2390 jacks and jills this season.

Last year hatchery staff counted a total of 8,343 salmon, including 7,048 adults and 1,295 jacks and jills.

The hatchery has taken 8 million eyed salmon eggs. “Overall, the numbers of salmon are typical of those we’ve seen here in recent years,” said Novak.

“The water at the hatchery was warm in the beginning, but the cold snap we got cooled the water down and brought up fresh fish from the Sacramento,” he said.

He noted that they have already sent 2 million eggs to the Mokelumne River Fish Hatchery; in addition to the eggs they have on hand at Nimbus, as insurance against any unforeseen disaster.