San Mateo Creek Survey
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San Mateo Creek Survey Date: December 4th, 2003
Participants: Tim Hovey CDFG Biologist
Walt Wilson MBCP Biologist
Jenny O’Brien CDFG Scientific Aide
Purpose: During the spring of 2003, heavy winter storms provided enough rain to open
the sand berm at the mouth of San Mateo Creek (SMC). This allowed immigration and
emigration opportunities to southern steelhead trout. The prolonged period in which the
creek was accessible and the time of year, also created speculation that the opportunity
for anadromous upstream migration was promising. Summer snorkel surveys revealed no
trout in the larger pools of SMC. Since it has been determined that the original
anadromous adults that entered in 1997, spawned in DCC, a survey to determine trout
presence was scheduled for this tributary. We decided to wait for a low water period in
late fall to survey to allow the fish to obtain a detectable size. Our objective on this
survey was to electroshock as much available water on DCC, to determine if adult,
anadromous southern steelhead trout entered DCC to spawn. Towards the end of the year,
the water level would allow us to shock most of the lower portion of DCC and if
spawning occurred, the juveniles would be at an easily detectable size.
We began the survey at the USGS gauging station at 09:20. We hiked to Pool one on San Mateo Creek (SMC) and took water temperature and DO readings. We spent 235 effort seconds spot-shocking the pool. We collected 26 green sunfish, (Lepomis cyanellus) and a single specimen of Largemouth bass, (Micropterus salmoides), all were juveniles. We did not want to waste battery power removing exotic fish, so we moved on to Pool two At pool two we again spot shocked the shore. We spent an additional 350 effort seconds at this pool removing exotics. We removed large specimens of largemouth bass, green sunfish, bluegill (Lepomis macrochirus), black bullhead (Ameiurus spp.) and bullfrog (Rana catesbeiana). All specimens were sacrificed. We stopped at this pool on the way out of the drainage and collected several more specimens of the above listed species, including a 4-pound, 19-inch largemouth bass.
San Mateo Creek Pool Data (Data collected by MBCP base biologist Walt Wilson)
Pool 1 had a water temperature of 7.9 C at 09:15 and a dissolved oxygen level of 11.01
mg/l. The pool size at the time of the survey was approximately 5 square yards and is
obviously filled by subsurface flow. The depth was speculated to be 8-10 feet at its
deepest. The total effort seconds expended at Pool 1 was 235 seconds. We removed 26
juvenile green sunfish (Lepomis cyanellus) and one juvenile largemouth bass
(Micropterus salmoides). The deeper portions of the pool could not be effectively
sampled and we speculated that a great deal more fish currently occupy this pool.
Pool 2 had a water temperature of 9.4 C at 09:40 and a dissolved oxygen level of 9.7
mg/l. The pool size was approximately 3 square yards, with a depth of 4.5 feet. The total
effort seconds expended at Pool 2 was 350 seconds (200 at the beginning of the survey
and 150 at the end of the survey). We removed 5 large green sunfish, 1 large bluegill, 2
adult (male) bullfrogs, 9 adult bass to 19-inches and 6 adult bullhead (see photos).
Pool 3 had a water temperature of 13.8 c at 10:10 and a dissolved oxygen level of 4.7
mg/l. The pool size was approximately 15 yards X 60 yards. A total of 200 effort seconds
were expended at this pool, with no exotic fish being collected. A number of juvenile
green sunfish and bass were observed in the shallows.
We arrived at the Devil Canyon Confluence at 10:30 and began spot shocking all
available water on DCC. Water temperature and DO readings were taken at lower pools.
Although it was difficult to get accurate GPS information (see attached map), we were
able to collect waypoint data on our end point of the survey. The trout collection
waypoint was not accurate and we can speculate, with reasonable accuracy on which area
of the drainage it was observed.
Water temperature throughout the drainage ranged from 9.1 to 10.1 C. Dissolved oxygen
levels ranged from 9.3 to 9.7 mg/l. Most pools encountered on Devil Canyon had still
green terrestrial plants on the bottom, indicating that the pool had been recently filled.
We reached the pool where we observed the trout at approximately 11:45. The pool was
filled to capacity and over-flowing. I shocked the entire length of the pool, including
some of the deeper portions without success. When I reached the upstream limit of the
pool, I terminated the shocking and waded back downstream. About half-way back, I
noticed two small western pond turtles on the bottom of the pool. Approximately two feet
from the turtles was a large trout. I spot shocked above the fish and collected it and took
it back to a shallow area for work up.
Trout Data:
Length: 13.5 inches (337 mm TL)
Weight: Est. at 24 oz (1 ½ lbs)
Sex: Possibly a male
Genetics: 1cm X 1 cm sample taken from upper lobe of caudal fin
Condition: Appeared healthy, markings indicative of a resident trout (see photo)
The individual was released back into the same pool it was collected.
We shocked a few pools farther upstream without detecting fish and the survey was
terminated at 13:15. A total of 2027 effort seconds was expended on DCC during the
survey.
Notes: The size of the fish (13.5 inches) indicates that it is likely a holdover fish and not a
new immigrant into the system. The coloration (rainbow trout coloration) also indicates
that it is likely a resident fish. In fact, I strongly believe that this fish is a cohort of the F2
juvenile individuals discovered in the lower portion of the drainage in 2000. The
Department has been monitoring this group for over 3-years and we feel confident that
the size and location point to a holdover individual. This would put the age of the trout at
3 ½ years. The size of the fish is well within the growth rate of a three plus year resident
trout. With this discovery we can state that the San Mateo Creek drainage, including
Devil Canyon Creek has had uninterrupted trout presence on the drainage from spring of
1997 to present.
Base biologist Walt Wilson holds resident steelhead/rainbow trout for photographs.
The trout was discovered during a survey of Devil Canyon Creek in December of 2003.
Photo by T.E. Hovey (CDFG biologist)
California Department of Fish and Game Fishery biologist Tim Hovey collects
genetic material from the caudal fin of the Devil Canyon trout. Photo by Walt
Wilson (MBCP biologist)
Biologists Tim Hovey and Walt Wilson take measurements of steelhead/rainbow
trout discovered on Devil Canyon Creek on December 2003 Survey.
Photo by Jenny O’Brien (CDFG scientific aide)
Released trout displaying rainbow-like markings, indicative of resident trout.
Photo by T.E. Hovey (CDFG Biologist)
Shocking lower portion of Devil Canyon Creek during December 2003 survey.
Photo by Jenny O’Brien (CDFG scientific aide
Electro-shocking Pool two on San Mateo Creek, removing exotic fish species.
Note largemouth bass and green sunfish at surface, stunned by electro-shocker.
Photo by Jenny O’Brien (CDFG scientific aide)
During a follow up exotic removal survey conducted by Walt Wilson of Camp Pendleton and Tim Hovey of the California Department of Fish and Game On December 10th, 2003, a total of five largemouth bass, one bluegill, nine juvenile green sunfish, one black bullhead and 2 adult, female bullfrog were removed from Pool one on San Mateo Creek. The pool had not increased in size since the December 4th survey and was too deep to effectively shock. A total of 548 effort seconds were expended in Pool one. Pool One showing water level during exotic removal survey conducted on December 10th, 2003. Photo by Tim E. Hovey
We continued to Pool two and noticed substantial amounts of water in the creek between Pool one and Pool two. This section had been completely dry the previous week (December 4th, 2003). When we reached Pool two we observed it filled to capacity and overflowing.
Now shocking attempts were made here due to the water
depth.
Pool Two showing water level on December 4th, 2003. Note reference mark (arrow).
Photo By Jenny O’Brien
Pool Two as it appeared during the December 10th, 2003 survey. Photo by Walt Wilson.
Largemouth bass collected from Pool one during exotic removal survey on December 10th, 2003. The largest fish is 15-inches in length.
Photo by Tim E. Hovey
Note: the population of southern steelhead trout and their offspring occupying San
Mateo and Devil Canyon Creeks is protected by California Fish and Game
regulations and is listed as a federally endangered species. Take is prohibited.
Download a PDF file of this survey
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