Bear Valley Fish Monitoring 10/9/07

Bear Valley Fish Monitoring

Tuesday, October 9, 2007

Davis Allen

Purpose: The fish project is designed to monitor the fish in the Point Reyes National Seashore watershed. For this specific survey twenty percent of the pools in Bear Valley Creek (a tributary of Paper Mill Creek) were e-fished. This particular survey is completed once a year in Olema Creek, Pine Gulch Creek, Redwook Creek, and Cheda Creek in order to count all the juvenile fish. The idea is that the pools are home to the vast majority of fish living in the creek; therefore, by getting the tallies therefore by getting the tallies for resident fish in a portion of the pools one can project the total number, and what species of fish are in the creek.

Hypothesis: If the vast majority of the fish population actually do inhabit the pools then it is probable that the projections for the types and number of fish will be approximately accurate. Following strict procedures, and taking multiple surveys will help to create a solid theory of fish populations in the Bear Valley Creek.

Procedure: A net is placed at the bottom downstream side of the pool that is to be fished. Water measurements including dissolved oxygen, temperature, conductivity, and salinity are taken and recorded for the pool being fished. Next a net is placed at the upstream end of the pool being fished, effectively shutting off all escape routes for the fish in the pool. Next the electric probe is calibrated for the conductivity of the water. Once the shocking begins the probe is moved in a methodical motion from bottom to the surface covering the entire pool. Two netters stand on either side of the shocker in order to scoop up the fish being shocked. The fish are put in buckets, then they are identified, weighed, and measured. All information is recorded. The procedure is then repeated for all the sites being sampled.

Observations: The fish we recorded in the creek included Stickleback, Steelhead, Sculpin, and Cojo Salmon fry.

Conclusion: Working on a larger project does not bring immediate closure, but rather helps to gather knowledge for a future conclusion or finding. Most excitingly was the finding of a Cojo fry in Bear Valley Creek. This was the first Cojo seen in the creek in at least the last three years. Although one fish isn’t enough to draw the conclusion that salmon are now spawning there, it is an interesting finding, and deserves future inquiry.