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Spring has sprung in Marin County- so have the wild flowers and wild baby Coho salmon!


Salmonid fry in San Geronimo Creek Watershed

It has been a rough winter for everyone. When you’re a live fast and die hard Coho salmon using every last ounce of effort to reproduce, constant winter rain storms are a terrible way to end things.

Fishermen tales are starting to circulate that 90% of the California salmon population has now been decimated by the tidal wave of high creek flows following too many years of a warm, nutrient-poor ocean and spawning grounds in drought.

These rumors make it  extra special to spy Coho fry zooming around our creeks this past week. A “fry” is the stage in a salmonid life cycle when the fish has graduated from feeding off it’s egg yolk, wiggled out of the redd, and begun feeding on zooplankton. It is a beginning to a crucial first year of constantly eating to grow strong enough for a sea voyage and the one year to imprint on natal freshwater streams in order to return to spawn at three years old.

Coho salmon fry

Biologists counted around two dozen Coho fry and two sticklebacks near Roy’s Pools last week.

Salmonids are difficult to differentiate when they are fry. Markings are not obvious until the parr stage, when fish begin eating insects. The immediate differences to look for between a baby Coho Salmon and a baby Steelhead trout are on the dorsal (top) fin and anal (bottom) fin. On Coho salmon, there will be no spots on the dorsal fin and the anal fin’s bottom-most ray will be slightly longer than the rest. On a juvenile Steelhead, spots will display on the dorsal fin and the anal fin will be the same even length. A juvenile Steelhead’s most defining characteristic is a red lateral line.

An instructional photo showing a Coho parr on the left and a Steelhead parr on the right.

An instructional photo showing a Coho parr on the left and a Steelhead parr on the right.

If you would like a better look at Coho fry, check out SPAWN’s Facebook page to watch a video of Coho salmon fry feeding .

Learn more about juvenile salmon migration in the Lagunitas Watershed from our Smolt Monitoring 2017 page.

SPAWN will begin 2017 Smolt Monitoring on Saturday April 8th with a training class to teach Citizen Scientist volunteers protocols and procedures.

Click here to find out more.