Only a few coho were spotted and only 20 egg nests, called redds, were counted in the Lagunitas Creek watershed's two main tributaries during the annual winter survey of fish, the San Francisco Chronicle reported Saturday.
The decline is being blamed on the lack of winter rains.
"It's just frightening, actually," Paola Bouley, conservation program director for the Salmon Protection and Watershed Network, or SPAWN, told the newspaper. "We were expecting 70 redds, which is still a 63 percent decline. It's definitely a crisis situation."
The declining numbers in Marin County add to what it being called a near catastrophic drop in the overall population of salmon along the West Coast, biologists said. State wildlife officials last year banned ocean salmon fishing in the Sacramento-San Joaquin river system because the fish population had declined so dramatically, the Chronicle said.