Juvenile salmon found in the Garcia River watershed.
Jennifer Carah, Conservancy ecologist
Conservancy ecologist Jennifer Carah spotted juvenile coho salmon in the Pardaloe Creek of the Garcia River watershed. This is a first sighting of endangered coho on the creek, and it’s a significant distance upstream from where the salmon have previously been seen. This sighting is a very positive indication of the improving health of the stream and the river.
“It’s pretty exciting,” said Carah. “It’s definitely encouraging that this endangered fish is finding conditions suitable to allow its rearing all the way up into the headwaters of the watershed.”
“We’ve also had nine other sightings in this watershed where salmon haven’t been seen since the mid-’90s. This is very good news,” Carah concluded.
Located in the coastal mountain range of southwestern Mendocino County, the Garcia River Forest has been the site of an ongoing experiment to prove that sustainable timber production can go hand-in-hand with not just maintaining but actually improving the ecological health of the area.
The Conservancy is closely monitoring the experiment’s results for the impact on the area’s struggling coho salmon population, which, according to some sources, is a mere 1% of what it was in the 1940s.
“Coho salmon are listed as both state and federally endangered,” said Carah. “They’re particularly sensitive to water quality, requiring colder and cleaner waters than many other native salmon species. In that way they are sort of the ‘canaries in the coal mine’ in northern California coastal watersheds. If there are water quality problems, their numbers will reflect it.”
Deep in the forests, poorly planned logging roads are being upgraded as part of the river’s rehabilitation. Built in the 1950s and 1960s, these roads run through the forest and transport sediment to rivers and streams. This fine sediment can smother salmon nests, and fill the pools that are vital to salmon rearing.
As the pools have filled in and become shallower, the streams have been forced to widen, resulting in water temperatures that are too warm for successful coho rearing. Repairing and decommissioning some of the roads will lead to a permanent reduction of the sediment and a deepening and cooling of the pools.
Another strategy for river rehabilitation is to build natural wood structures in the streams that encourage scour and create the deep pools that coho need to rear. Because many of the larger, older trees near the streams have been harvested, not much significant debris is left to fall into the waters and form these natural structures.
The team has begun building these structures, and they plan to eventually release logs and large tree debris into the river system to see if the structures will happen naturally.
According to Carah, the initial data coupled with this coho sighting is promising. The research indicates that there is now good winter and summer rearing habitat, with low temperatures in some areas of the watershed. But for the ecologists working in the field, it’s sightings like Carah’s that really validate the efforts.March 11, 2013