A Delta Renewed; SFEI Aquatic Science Center 2016

Special Oral Session: Re-envisioning the Delta with New Knowledge from the Past

Reinvesting in the Delta’s Food Web Portfolio

Charles (“Si”) SimenstadUniversity of WashingtonEmily HoweThe Nature Conservancy

Delta Food Web Portfolio

?

Cloern: Output = Annual Primary Production by Five Groups Then and Now

Delta Food Web Portfolio

“…even the absence of ecological interactions, statistical effects can cause greater species diversity to lead to lower oscillations in community biomass” …analygous to “effects of the diversity of a portfolio of investments on the stability of its valuation…”Tilman et al. 1998. Diversity-stability relationships: Statistical inevitability or ecological consequence? Am. Nat. 151: 277-282.Doak et al.1998. The statistical inevitability of stability-diversity relationships in community ecology. Am. Nat. 151:264-276.

Portfolio Concept as Applied to Population Resilience

“…ecological resilience is generated by diverse, but overlapping, function within a scale and by apparently redundant species that operate at different scales, thereby reinforcing function across scales.” Peterson et al. 1998; Ecosystems 1:6-18

Wall and Nielsen. 2012. Biodiversity and Ecosystem Services: Is It the Same Below Ground? Nature Education Knowledge 3:8

Delta Food Web Portfolio Portfolio Concept as Applied to Population Resilience

Source: Schindler et al. 2010. Population diversity and the portfolio effect in an exploited species. Nature Letters 465: 609-613.

“Variability in annual Bristol Bay salmon returns is 2.2 times lower than it would be if the system consisted of a single homogenous population rather than the several hundred discrete populations it currently consists of.”“Portfolio effects are also evident in watershed food webs, where they stabilize and extend predator access to salmon resources.”

Delta Food Web Portfolio

1. Diverse sources of organic matter2. Spatial/temporal scales of variability3. Quantity vs. quality4. Evidence of organic matter sources to pelagic food

web from Delta and specifically Cache Slough complex• Organic matter budget• Biogeochemical biomarkers

o Stable isotopeso Fatty acids

5. Implications for Delta ecosystem restoration

A “Portfolio Context” to the Delta’s Food Web

Regulating Factors Biome Structure

Primary Producerspeciesgrowthsurvival

Direct Consumption

(grazing)

Primary Producer

compositionEmergent

Marsh Macrophytes

Riparian Woody

Submerged / Floating

Macrophytes

Benthic/Epiphytic

Microalgae

Phytoplankton

Producer Assemblages

Marsh Surgeplain

Tidal Channel

Distributary Channel

Mud Flat

Biogeography

Detritus Consumption (detritivory)

Light

Nutrients

Salinity

Flooding Regime

Precipitation

SedimentStructure

Disturbance

Temperature

High surgeplain/

riparian

Flooded Island

Hydrology

Delta Food Web Portfolio Portfolio Composition of Primary Producer Assemblages and Source

Biomes in Delta, with Factors Regulating Productivity and Availability

Biotic Regulation Direct

Consumption (detritivory)

Direct Consumption

(herbivory/omnivory)

Allochthonous Input(import from watershed)

Autochthonous(internal)

phytoplankton consumers

Export to Suisun Marsh/Bay(passive particle and active organism

transport at different spatial/temporal scales)

organic matter

Abiotic Regulation

“Microbial Loop”

DETRITUSPOC DOC

Delta

burial respiration

NET PRIMARYPRODUCTION

phytoplankton consumersorganic matter

Delta Food Web Portfolio Conceptual Model Framework for Delta Scale Food Web Processes

Delta Food Web Portfolio Scales of Variability in Types and Quantities of Organic Matter Sources and Consumer Access to Food Web

Temporal• Fine-scale

o Tidal (pumping)—neap/spring• Broad-scale

o Seasonal floodingo Dry-wet years

Spatial• Fine-scale

o Tidal ecosystemo Channel hierarchyo Connectivityo Consumer life history

• Broad-scaleo Estuarine gradiento Consumer distribution

DRY year

Marsh Surgeplain Habitat Types

Delta Food Web Portfolio Variability in Temporal Production, Processing and

Delivery of Food Web Sources

WET year

Lakes, Ponds and Riparian Habitat Types

Marsh Surgeplain Habitat Types

Delta Food Web Portfolio Variability in Temporal Production, Processing and

Delivery of Food Web Sources

Delta Food Web Portfolio

Source: Kendall, C., Young, M.B., Silva, S.R., Kraus, T.E.C., Peek, S., and Guerin, M., 2015. Tracing nutrient and organic matter sources and biogeochemical processes in the Sacramento River and Northern Delta: proof of concept using stable isotope data. U.S. Geological Survey, Data Release, http://dx.doi.org/10.5066/F7QJ7FCM

Temporal and Spatial Variability in the Ratio of Chlorophyll-a to Total

Chlorophyll Concentration

=

Cache/Yolo SRWTP 3/10 Chi-a/ 2/10 Chi-T

1/10 "T1 (ppb)

r-12/09 0

~ 0 .9

.c ..... c 0 .7 0

== 8/09

7/09 0 .5

6/09

5/09 0 .3

4/09

3/0 -40 0 1 0 .1

Angel Island RIVER MILE Rio VIsta

Delta Food Web Portfolio

Data for figure from: California Department of Water Resources Dayflow and California Department of Fish and Game Report, 2010 (Quantifiable Biological Objectives and Flow Criteria for Aquatic and Terrestrial Species of Concern Dependent on the Delta).

Source: The Bay Institute. 2016. San Francisco Bay: The Freshwater-Starved Estuary; How Water Flowing to the Ocean Sustains California’s Greatest Aquatic Ecosystem.

Temporal Variability in Life Cycle Occurrence of Fishes in San Francisco

Bay and the Delta, 2009-2012

Light blue bars indicate when a life stage may be present; dark blue bar indicated the life stage is definitely present at that time; amber shading indicates when flow volume was significantly reduced by water diversions and exports

POM

DOM

flocculationfragmentationdissolution

AutochthonousSources

phytoplankton and POM/DOM

AllochthonousSources

free-living bacteria

agricultural discharge,

wastewater, and urban

runoff

flagellates

“microbial loop”

attached bacteria

and fungi

ciliatesriparian and floodplain

POM/DOM

Emergent Marsh

Macrophytes

Riparian Woody

Submerged/Floating

Macrophytes

Benthic/Epiphytic

Microalgae

Phytoplankton

Delta Food Web Portfolio Transformation and Loss of Organic Matter Sources in Delta Food Web

Pathways of food web transfer:1. Direct grazing on phytoplankton (herbivory)2. Direct feeding on particulate detritus (detritivory)3. Predation on bacteria that consume POC or DOC (bacterivory), including

feeding bactiverious microzooplankton

Delta Food Web Portfolio Bioavailability Budgeting of Organic Matter

Source: Sobczak et al. 2005. Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary’s freshwater delta. Estuaries 28:124-137.

DOC and POC bioavailability phytoplankton and bacterioplankton biomass

phytoplankton and bacterioplankton net primary production

Delta habitats: SR = Sacramento River at Hood; RV = Sacramento River at Rio Vista; TI = San Joaquin River at TwitchellIsland; MR = Middle River at Clifton Court Forebay; X2 = export to SF Bay at salinity = 2 psu; YB = Yolo Bypass drainage; FT = Franks Tract; MI = Mildred Island; SJ = San Joaquin River at Mossdale

Delta Food Web Portfolio

York Hudson

Fresh Mesohaline RiverMouth

Autochthonous (phytoplankton FW/estuarine)TerrigenousEmergent (marsh)Chesapeake Bay DOC

% C

ompo

sitio

n

km 244 km 122 km 25

Fall Spring/Fall Nov Oct

Autochthonous (phytoplankton FW/estuarine)TerrigenousEmergent (marsh)

Jun Oct Jun Jun

% C

ompo

sitio

n

100

75

50

25

0

100

75

50

25

0

Source: McCalliuster et al. 2004; L&O 49: 1687-1702

Proportions of Allochthonous (subsidized) and Autochthonous (internal) Sources of Organic Matter Assimilated by Bacteria in

York and Hudson Rivers Estuaries Estimated from Average Dual Isotope, Three-Source

Mixing Models of Nucleic Acid ẟ13C and Δ14C

Delta Food Web Portfolio

Source: SFCWA Cache Slough Complex unpubl.

Bayesian Mixing Model (MixSIAR) Estimation of Primary Organic Matter Sources to

Zooplankton in Cache Slough Complex

filamentous green algaeBenthic diatomsSAV species: Egeria densa, Ludwigia peploides, Cabomba canadensisSAV species: Myriophyllum spicatum, Ceratophyllum demersumPhragmites australis, Schoenoplectus acutusphytoplanktonTypha spp., Schoenoplectus californica

(Important caveat: sampling dates differ)

See: Lori Smith, Tue., 4:35pm; Room 306

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See: Lori Smith, Tue .. 4:35pm; Room 306

Delta Food Web Portfolio

Source: SFCWA Cache Slough Complex unpubl.

diatoms/terrestrial POM/fungidinoflagellates

HUFAPUFAPUFA HUFAMUFA MUFAMUFA SFA SFA SFASFA SFA MUFA PUFASFA MUFA MUFA

Fatty Acid Composition of Primary Organic Matter Sources (top) and

Zooplankton (bottom) from Five Sites in Cache Slough Complex

Dominant zooplankton: Pseudodiaptomus forbesi (nauplii, copepodids, adults) and Sinocalanus doerrii (see Cordell et al. poster, “Trophic Ecology of Zooplankton and Larval Fish the Cache Slough Complex”)

bacteriamacroalgae

wetland emergent/SAV/fungi

(ALA)

FA (fatty acid): SFA = saturated; MFA = monounsaturated; PUFA = polyunsaturated; HUFA = highly unsaturated

Delta Food Web Portfolio

Source: SFCWA Cache Slough Complex unpubl.

Non-Metric Multidimensional Scaling (ordination) of Fatty Acids in

Zooplankton from Five Sites in Cache Slough Complex, March-June 2015

Dominant zooplankton: Pseudodiaptomus forbesi (nauplii, copepodids, adults) and Sinocalanus doerrii (see Cordell et al. poster, “Trophic Ecology of Zooplankton and Larval Fish the Cache Slough Complex”

vegetal detritus?

vegetal detritus?

diatomsfungi?

macroalgae bacteria

dinoflagellates

protozoa?diatoms

dinoflagellates

Delta Food Web Portfolio

Source: Young, Howe, et al. manuscript in prep.

Multiple Stable Isotope Estimates of the Contribution of Organic Matter Sources

Supporting Cache Slough Complex Fishes

See: Matt Young, Wed., 1:35pm; Room 311-313

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0.75 0.75

0.50 0.50

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0.00 L.......,.-~~~~---==:;=--~~~~~~--.---> 0.00 g.

See: Matt Young, Wed., 1:35pm; Room 311-313

r}"~:g'j $covrJ.co0~~~«09..~.P~4 « ~v CD 0 '=v ~ ,<.;.0 0 0 ~~ '<

OM Category 0 Phyto 0 SAV - EM. GFA. BD

Delta Food Web Portfolio

• Despite historic reduction in tidal wetlands, surge- and floodplains, food web contributions from their non-algal sources is non-trivial, varying by time and location

• Although quality of organic matter sources differs between algal and detrital pathways to consumers, both contribute variably over different time and space scales

• Management and restoration of the Delta landscape needs to consider the contribution of ecosystem diversity, and resulting robust food web, to the resilience of species, populations, communities

• Resilience of consumer production would benefit from expansion of tidal wetland and surge/floodplain restoration, especially bridging periods of low algal contributions, from spatial and temporal diversification of organic matter sources

• Re-investment in diversifying the Delta’s food web portfolio would benefit broad spectrum of higher trophic levels, even those based on pelagic food web pathways

Take-Home Message

Delta Food Web Portfolio Thank You!

Charles (“Si”) Simenstadsimenstd@u.washington.eduhttp://depts.washington.edu/wet/

Emily Howeemily.howe@tnc.org