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

taorear@ucdavis.edu

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