Fishes of the Laguna de Santa Rosa
Then, Now, and...Tomorrow?
Teejay O’Rear
Graduate Group in Ecology
Wildlife, Fish, and Conservation Biology
U.C. Davis
Fishes of the Laguna de Santa Rosa
Outline
•Quick Laguna tour
•Then
•Now
•Tomorrow
Fishes of the Laguna de Santa Rosa
Sebastopol
Rohnert Park
Santa RosaSanta Rosa Creek
Fishes of the Laguna de Santa Rosa
Background
•Pond-like stream
Main Points?
•Very fertile
What fish are in there?
Fishes of the Laguna de Santa Rosa
Then (1988)
•Only one known study of the Laguna’s aquatic community
•CH2MHill – 1988
•7 reaches
•Spring, summer, autumn
•Gillnets and seines
•Zooplankton, invertebrates, water quality
Fishes of the Laguna de Santa Rosa
Then (1988)
Fishes of the Laguna de Santa Rosa
Then (1988): Gillnets
Fishes of the Laguna de Santa Rosa
Then (1988): Seines
Fishes of the Laguna de Santa Rosa
Then (1988)
Main point? Fish community dominated by species that are tolerant of
•Low dissolved oxygen
•High water temperatures
•Still water
Fishes of the Laguna de Santa Rosa
2008 Aquatic Community Survey
Purposes
•See if the fish community has changed since 1988
•Determine environmental factors affecting the fish community
•To provide baseline data for management activities
Fishes of the Laguna de Santa Rosa
Now (2008)
Surveyed
•3 sites in 2 reaches
•On 2 days in August
Collected
•Water-quality data
•Invertebrates via net sweeps
•Fishes via gillnets and seines
•Fishes for gut-content analyses
Fishes of the Laguna de Santa Rosa
Now (2008)
map
Fishes of the Laguna de Santa Rosa
Now (2008): Gillnets
Fishes of the Laguna de Santa Rosa
Now (2008): Seines
Fishes of the Laguna de Santa Rosa
Then and Now: Gillnets
0
5
10
15
20
25
CARP SBF BC SS GSF BG
Species
20081988
Fishes of the Laguna de Santa Rosa
Then and Now: Seines
0
50
100
150
200
250
300
MQF LEP LMB SBF SS SC ROA BC STBK BLB CYP FHM
Species
20081988 All Sites1988 ORP and SRLC
Fishes of the Laguna de Santa Rosa
Now (2008): Gut Content Analyses
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Fathead Minnow Sacramento BlackfishYOY
Mosquitofish Black Crappie Bluegill YOY Bluegill Age 1+
Species
Bosminidae Cyclopidae Daphniidae Chironomidae larvae Chironomidae pupaeCorixidae Talitridae Poeciliidae Other
Fishes of the Laguna de Santa Rosa
Now (2008)
Main points?
•Fish community – changed little
•Like 1988, dominated by hardy fishes
•Low DO
•Warm, still water
•Spawn in/on vegetation
•Young/small fishes – feed on zooplankton
•Larger fishes – feed on aquatic insects
Fishes of the Laguna de Santa Rosa
Now (2008)
Factors structuring fish community
•Low dissolved oxygen
•High water temperatures
•Lack of spawning riffles
Fishes of the Laguna de Santa Rosa
Tomorrow?
•A little warmer?
•More Ludwigia BHM?
•No restoration?
Fishes of the Laguna de Santa Rosa
Tomorrow?•A little warmer?
•Less Ludwigia?
•Better water quality?
Fishes of the Laguna de Santa Rosa
Big-Time Thanks
Bill Cox Amber Manfree
Jason Moore