Multi-Scaled Socio-Ecology of the Everglades FCE III Conceptual Framework

FRESH WATER SUPPLY 1 Multi-Scaled Socio-Ecology of the Everglades FCE III Conceptual Framework Global Climate Change Regional Climate Modulation 2 B O Carbon Cycle P T Organic Matter EXTERNAL DRIVERS LOCAL RESPONSES Global Socioeconomic Change Regional Water Management and Land Use Everglades Coastal Gradient 1 Geochemistry Carbon Cycle Consumers Primary Production Socio-ecological feedbacks South Florida Urban Gradient Resource Demand, Use, Stewardship and Management Decisions 1 MARINE WATER SUPPLY FCE III LTER Goals: 1 Water : How do water management decisions interact with climate change to determine freshwater distribution? 2 Carbon: How does the balance of fresh and marine water supplies regulate C uptake, storage, and fluxes by influencing water residence time, nutrient availability, and salinity? 3 Legacies: How does historic variability in the relative supply of fresh and marine water modify ecosystem sensitivity to further change? 4 Scenarios: What are alternative socio-ecological futures for South Florida under contrasting climate change and water management scenarios? Past 3 Present 4 Future

Party crashers: displaced marsh consumers regulate a prey subsidy to an estuarine consumer Ross Boucek & Jennifer Rehage Florida International University rbouc003@fiu.edu

Pulsed resource subsidies Resource pulse Instantaneous resource iincrease (Holt 2008) Subsidy Pulses across ecosystem b boundaries (Anderson et al. 2008) Yang et al. 2008 Bird guano Mass emergences of aquatic insects Salmon in Pacific NW Seaweed deposits on beaches

Pulsed resource subsidies Subsidies can fuel almost all biological activity within (Polis et al. 2004; Spiller 2010) recipient ecosystems Marine to terrestrial

Information gap What regulates the flow of resources from one system to another?? Energy Energy? Paetzold et al. 2008

Consumers from donor communities important Deplete resources locally Nothing to transfer (Epichan et al. 2010) Track resources across boundaries Compete with recipient consumers Energy Energy Paetzold et al. 2008

In the Pacific Northwest Salmon migrate up river to spawn Subsidizing upstream communities River Ocean

Sea lions Track Salmon Up River River Ocean

Sealions reduce salmon subsidies by 65% River Ocean Recycling marine energy to the oceans Leaving hungry bears

Leading to Aggressive Management Naughton et. al. 2011

depth (cm) Everglades Ecotone: Wet season Marsh Estuary Marsh water level ( SH1; 2005-2010) 80 60 40 20 0-20 05 06 07 08 09 10 Year

depth (cm) Everglades Ecotone: Wet season Marsh Marsh Prey Estuary Marsh water level ( SH1; 2005-2010) 80 60 40 20 0-20 05 06 07 08 09 10 Year

depth (cm) Everglades Ecotone: Wet season Marsh Marsh Predators Estuary Marsh water level ( SH1; 2005-2010) 80 60 40 20 0-20 05 06 07 08 09 10 Year

depth (cm) Everglades Ecotone: Dry Season Marsh Marsh Predators Estuarine predators Estuary Marsh Prey Marsh water level ( SH1; 2005-2010) 80 60 40 20 0-20 05 06 07 08 09 10 Year

Research questions (1) Does marsh drying push freshwater prey into the estuary? (2) How do consumers respond to the pulse? (3) Are freshwater consumers reducing marsh subsidies for estuarine consumers?

Focal taxa: 2 freshwater + 1 estuarine consumer Gar, bass, bowfin and snook dominate Electrofishing (#/100m) 14 12 10 8 6 4 2 0 Consumers show marked seasonality Largemouth Bass Wet Early Dry Late Dry Gar Bass Bowfin Snook Tarpon American eel Gray snapper Sheepshead Redfish Jack crevalle Ladyfish

Study system: ecotonal sites at ENP First and second order oligohaline estuarine creeks < 1.2 m depth < 10 PSU salinity 600 m

Hypotheses During drydown Prey abundance Post drydown Prey abundance Predator abundance Marsh prey consumption Diet segregation Predator condition Predator abundance Marsh prey consumption Diet segregation Predator condition

Marsh depth (cm) Tracking predator-prey abundance Data collection Continuously sampled 5 sites Nov 2010 to June 2011 Electrofishing Minnow traps 200 100 2.0 1.5 1.0 * sampling events water level Statistics Compared time & species using GLMs Predator abundance 0 0.5 0.0 * * * * * * * * * Prey abundance 4 functional groups -100 Sunfishes Cyprinodontoids Invertebrates Estuarine prey -0.5-1.0 Sep Nov Jan Mar May Jul Sep 10 Nov 10 Jan 11 March 11 May 11 July 11 USGS station SH1

Stomach contents Data Collection Pulsed gastric lavage Statistics 100% effective in bass & snook (Adams et al. 2009 Hartleb & Moring 1995) Compared effects of time & species using Scheirer-Ray-Hare test (Dytham 1999) Time partitioned into 4 hydrologic stages biomass of freshwater and estuarine prey consumed Numerical proportions of each prey functional group stomachs sampled Bass Bowfin Snook 247 159 99

# of prey per trap pair # of fish per 100 m Prey Predators Diet Fitness gains 40 30 Electrofishing Sunfishes Estuarine prey Sunfishes 20 10 Cyprinodontoids 0 160 120 80 Minnow traps Cyprinodontoids Invertebrates Estuarine prey Invertebrates 40 0 Species, p =.001 Time, p =.001 Species x time, p =.001 Not sampled Nov. Dec. Jan. Feb. Early Mar. Late Mar. April May June Estuarine Prey

# of prey per trap pair # of fish per 100 m Marsh water depth (cm) Prey Predators Diet Fitness gains 40 30 20 10 0 160 120 80 40 0 USGS station SH1 Electrofishing Minnow traps Not sampled Nov. Dec. Jan. Feb. Early Mar. Marsh water level Late Mar. Sunfishes Estuarine Prey Cyprinodontoids Invertebrates Estuarine Prey April May June Marsh drying 200 100 0-100 200 100 0-100 Species, p =.001 Time, p =.001 Species x Time, p =.001

# of fish per 100 m Prey Predators Diet Fitness gains Pre drydown Early drydown Late drydown Post drydown 14 12 10 8 6 4 2 0 Nov. Dec. Jan. Feb. Early Mar. Late Mar. April May June Species, p =.001 Time, p =.001 Species x Time, p =.001

Biomass (grams) consumed per 100 m Prey Predators Diet Fitness gains 100 100 80 80 Freshwater prey Species, p <.001 Time, p <.001 Species x Time, p =.568 60 60 40 40 20 20 0 0 100 Estuarine prey 12 8 4 0 Pre drydown Early drydown Late drydown Post drydown Species, p <.001 Time, p =.2915 Species x Time, p =.965

Numerical Proportion Prey Predators Diet Fitness gains 1.0.8.6.4.2 1.0 1.0 0.8.8.6 0.6.4 0.4.2 0.2 1.0 0.0.8.6.4.2 Species, p =.001 Time, p =.001 Species x Time, p =.01 Species, p =.001 Time p =.001 Species x Time, p =.47 Species, p =.001 Time p =.001 Species x Time, p =.85 Sunfishes Cyprinodontoids Invertebrates Pre drydown Early drydown Late drydown post drydown Dish = 10 cm

Condition Prey Predators Diet Fitness gains.03.025 Pre drydown Early drydown * Late drydown * Post drydown.02.015.01 * * * Nov. Dec. Jan. Feb. Early Mar. Late Mar. April May June Bass, p =.001 Snook, p =.001 Bowfin, p =.001

Summary of results During drydown Post drydown Prey abundance Prey abundance Predator abundance Predator abundance Marsh prey consumption Marsh prey consumption Diet segregation Diet segregation Predator condition Predator condition

Summary of results During drydown Post drydown Prey abundance Prey abundance Predator abundance Predator abundance Marsh prey consumption Marsh prey consumption Diet segregation Diet segregation Predator condition Predator condition

Summary of results During drydown Post drydown Prey abundance Prey abundance Predator abundance Predator abundance Marsh prey consumption Marsh prey consumption Diet segregation Diet segregation Predator condition Predator condition

Summary of results During Drydown Post Drydown Prey Abundance Prey Abundance Predator Abundance Predator Abundance Marsh prey consumption Marsh prey consumption Diet Segregation Diet Segregation

Summary of results During drydown Post drydown Prey abundance Prey abundance Predator abundance Predator abundance Marsh prey consumption Marsh prey consumption Diet segregation Diet segregation Predator condition Predator condition

Implications Marsh consumers regulate subsidy 36% Marsh consumers Estuarine consumers 59% 5%

Implications In a series of years with high rainfall Marsh consumers Estuarine consumers

Implications In a series of dry years Marsh consumers Estuarine consumers

Implications: Angler catches, Feb-June 40 snook bass Angler catch per day 30 20 10 0 Recaptured bass!! 1982 1983 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Fished nearly every full moon of every month at the Rookery branch since 1982 Anglers in group wear counters to record bass and snook caught per day. Using similar lures since 1982 2008 2009 2010 2011

Implications: Angler catches Feb-June Angler catch per day 40 30 20 10 0 Bass years 1982 1983 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 snook bass

Implications: Angler catches, Feb - June Angler catch per day 40 30 20 10 0 Snook years 1982 1983 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 snook bass

Everglades: World Class Snook Fishery Snook fishery maybe enhanced by subsidies 18,246 of anglers target snook at ENP /yr (Osborne 2006) Generating 4 million dollars per year (Fedler 2009 & Ault et al. 2010) Understanding and conserving snook High quality foraging opportunities important

Moving on to FCE III Trexler et al. 2005 increased freshwater flow increases marsh fish production Proportion of subsidy to snook does not change, but the subsidy increases Sea level rise Snook prey availability Increased freshwater flow Large subsidy Small subsidy Magnitude of subsidy

Please Visit Poster #216 Acknowledgements USGS RECOVER FCE LTER FIU Rehage Lab Aaron Adams Craig Layman Michael Heithaus Amy Narducci Dave Rose and the southernmost bass anglers