Teejay O’Rear ([email protected]) and Peter Moyle ([email protected]) UC Davis Center for Watershed Sciences and Wildlife, Fish, and Conservation Biology Cal-Neva AFS 2015 • Santa Cruz, CA North Delta Arc working group: Matt Young, Denise DeCarion, Thomas Handley, Amber Manfree, Brian Williamson, Jacob Montgomery, Kathleen Berridge, Kousei Martin Perales, Felipe La Luz, Chris Jasper, Teejay O’Rear, Randy Dahlgren, William Fleenor, James Hobbs, John Durand, Peter Moyle White Catfish and Adult Striped Bass Diets in Suisun Marsh
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Teejay O’Rear ([email protected]) and Peter Moyle ([email protected]) UC Davis Center for Watershed Sciences and Wildlife, Fish, and Conservation Biology
Cal-Neva AFS 2015 • Santa Cruz, CA
North Delta Arc working group: Matt Young, Denise DeCarion, Thomas Handley, Amber Manfree, Brian Williamson, Jacob Montgomery, Kathleen Berridge, Kousei Martin Perales, Felipe La Luz, Chris Jasper, Teejay O’Rear, Randy Dahlgren, William Fleenor, James Hobbs, John Durand, Peter Moyle
White Catfish and Adult Striped Bass Diets in Suisun Marsh
White Catfish and Adult Striped Bass Diets in Suisun Marsh
1. Key Suisun Marsh features
2. White catfish diets
3. Adult striped bass diets
Suisun Marsh
Water Clarity: Low
Win Aut Sum Spr
dry
wet wet
Managed Wetlands Water Management
Oxygen:Variable
a, b Year: 2009
Otter Trawl Rank: #2 (28,348 fish) of 54 spp. Beach Seine Rank: #6 (3,821 fish) of 38 spp.
Sacramento Splittail
Suisun Marsh – Why Do We Care?
a, c, d
a
Waterfowl!
Otter Trawl Rank: from #14 (1979-2001) to #5 (2002-2014) of 54 spp.
White Catfish
Adult Striped Bass
a
a
“They included Dorosoma petenense, Alosa sapidissima, Roccus saxatilis, Hypomesus olidus, Lampetra ayresi, Clupea pallasi, and Lepomis macrochirus.”
White Catfish – Delta (Turner 1966)
Striped Bass – Delta (Nobriga and Feyrer 2007)
e
f
White Catfish Diets in Suisun Marsh? Unknown
Questions: • What are white catfish eating? • Associated with habitat features? • Any habitat features explain piscivory of white catfish?
Methods: • Stomach-pump (deck hose!) white catfish from Suisun Marsh Fish Study trawls • Sampling period: June 2009 – May 2010 • Correlate habitat variables to diet items (sal, temp, clarity, depth, DO, diversion
density) • Test habitat variables on piscivory
White Catfish Diets in Suisun Marsh
• n = 304 fish • winter: 28 • spring: 135 • summer: 102 • autumn: 39
• 274 fish (90%) w/food
• mean SL: 216 mm (adults); few<182 mm
56
54 48 71
26
30
16
White Catfish Diets in Suisun Marsh
g
Eogammarus confervicolus
CA bay shrimp
overbite clam
shim. goby
stickleback Eogammarus confervicolus
Bio Photo Group, ON
Bio Photo Group, ON
Daphnia magna Daphnia magna Very Tiny Things
Very Tiny Things
wetland species bay/slough
species
(no smelt/salmon)
%Fish Mass in Diet of White Catfish: Correlates? Parameter Parameter Estimate t-ratio Probability > |t| Temperature 0.0063291 0.40 0.508 DO -0.078083 -2.54 0.014* Standard length 0.0013695 0.77 0.444 Temperature X DO 0.0053317 0.36 0.718 Temperature X standard Length 0.0003352 0.55 0.584 DO X standard length 0.0001548 0.22 0.829 Temperature X DO x standard length 0.0001271 0.38 0.706
Managed Wetlands Water Management
circulate water circulate water
dry
DO = 2.9 mg/L
g
Adult Striped Bass
• Sample period: October ‘09 – ongoing (opportunistic!)
• Adult striped bass: fish diet dominated by slow-moving benthic/littoral fishes…turbidity?
• Both species: no salmon/smelt eaten/identified
• Both species: most food from wetlands…trophic relay?
Thanks!
Funding provided by California Department of Water Resources and private donors
Mike Wigginton, Phil Antipa, everyone at the Suisun Marsh Branch of DWR, the Suisun Resource Conservation District, Melissa Riley (CDFW), the entire North Delta Arc Working Group (especially Brian Williamson), Alison Furler (CDFW), Tommy Agosta (UCD), Rachel Johnson (NMFS), Fred Feyrer (USGS), Alpa Wintzer, Rob Schroeter, Jason Moore (DWR), Patrick Fuller, Amy Chandos, Nick Buckmaster (CDFW), Miranda Bell (UCD), Nicky Bunn, Angie Munguia (DWR – formerly!), Eva Bush (UCD), Nick Corline (“Mudbug”; UCD), Carson Jeffres (UCD), Emma Davidson (UCD), Josh Porter (EB Parks), Lily Tomkovic (UCD), Scott McDonald (CSUSJ), Hailey Pexton (UCD), Paul Takemoto (UCD), Robert Dunn (UCD), Joe Rogers, Georgia Ramos (UCD), Karin Petrites (Putah Creek Council), Emma Cox, Thaddeus Hunt, Quoc Van, Ethan and Janet Kean...
References a. O’Rear, unpublished data b. Siegel, S., P. Bachand, D. Gillenwater, S. Chappel, B. Wickland, O. Rocha, M. Stephenson, W. Heim, C. Enright, P. Moyle, P.
Crain, B. Downing, and B. Bergamaschi. 2011. Final evaluation memorandum, strategies for reducing low dissolved oxygen and methylmercury events in northern Suisun Marsh. Prepared for the State Water Resources Control Board, Sacramento, California. SWRCB Project Number 06-283-552-0.
c. California Department of Fish and Game. 1996, 1997, 1998. Fishery monitoring program a component of the Suisun Marsh Diversion Screening Program. University of California, Davis, California.
d. Pickard, A. A. Baracco, and R. Kano. 1982. Occurrence, abundance, and size of fish at the Roaring River Slough intake, Suisun Marsh, California during the 1980-81 and the 1981-82 diversion seasons. Technical Report 3, California, California Department of Fish and Game.
e. Turner, J. L. 1966. Distribution and food habits of ictalurid fishes in the Sacramento-San Joaquin Delta. Pages 130-143 in J. L. Turner and D. W. Kelley, editors. Ecological Studies of the Sacramento-San Joaquin Delta, part 2. California Department of Fish and Game Fish Bulletin 136.
f. Nobriga, M. L., and F. V. Feyrer. 2008. Diet composition in San Francisco Estuary striped bass: does trophic adaptability have its limits? Environmental Biology of Fishes 83: 495-503. g. O'Rear, T. A. 2012. Diet of an introduced estuarine population of white catfish in California. Master's thesis. University of California, Davis.
