Fisheries Monitoring Report For Rush, Lee Vining, Parker and
Walker creeks, 1999
By Chris Hunter, Brad Shepard, Darren Mierau, Ken Knudson, Ross
This report presents the results of the first year of fish
population monitoring for Rush, Lee Vining, Parker and Walker creeks
pursuant to State Water Resources Control Board (SWRCB) WR
98-07. We evaluated four different techniques to estimate trout
populations: mark-recapture electrofishing; mark-recapture utilizing
electrofishing for the marking run and snorkeling (day and night) for
the recapture run; snorkeling and electrofishing depletion. We
concluded that mark-recapture electrofishing provided the most
reliable estimates for the larger waters (Rush and Lee Vining creeks).
Electrofishing depletion estimates provided reliable estimates for
Parker and Walker creeks.
We recommend that the methods described in the White Book (LADWP,
1997) be changed to reflect the results of the 1999 efforts.
Electrofishing mark-recapture should be used to estimate fish
populations in the Rush and Lee Vining creek main channels.
Electrofishing depletion estimates should be conducted on Parker and
Walker creeks and the Lee Vining side channels.
We compared the estimated fish population data for Rush and Lee
Vining creeks to the termination criteria adopted by the SWRCB. The
termination criteria are:
1. Lee Vining Creek sustained catchable brown trout averaging 8-10
inches in length.
2. Rush Creek fairly consistently produced brown trout weighing ¾ to
2 pounds. Trout averaging 13-14 inches were also regularly observed.
Lee Vining Creek does contain a small number of brown trout 8
inches and greater in length. However the numbers are so low, less
than 6 per 100 meters in the lower sampling section and less than 7
per 100 meters in the upper sampling section, that we don't believe
the population can be sustained in the face of harvest.
We collected two fish in Rush Creek that would meet the termination
criteria of weighing between ¾ and 2 pounds or attaining a length of
13 to 14 inches. We collected one fish that would meet these criteria
in each of the Upper and Lower sections of Rush Creek. We did not
sample any fish in the County Road section that would meet these
The SWRCB requires us to recommend additional quantitative
termination criteria for Rush and Lee Vining creeks as well as
quantitative termination criteria for Parker and Walker creeks. The
lack of historic fish population data makes it very difficult to make
recommendations for quantitative termination criteria with any
confidence that they are reasonable. We recommend that data collection
be continued for a few more years before we attempt to define
additional quantitative termination criteria.
We recommend that the two existing termination criteria be changed
to specifically state they must be met by self-sustaining trout
populations. We also recommend that the following two termination
criteria be adopted:
1. Fish population monitoring shall be terminated for any stream if it
is opened to any level of harvest or if fish stocking is
2. Fish population monitoring of Lee Vining Creek shall be terminated
because the stream has been opened to harvest. If the monitoring is
continued, then a creel census study should be conducted to evaluate
the effect of harvest on the trout population. If harvest is shown to
have a negative effect on the self-sustaining trout population, then
the harvest should be stopped or the fish population monitoring
End of Executive Summary