Climate change impacts on fish and fisheries in the Florida Keys National M arine Sanctuary
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Transcript of Climate change impacts on fish and fisheries in the Florida Keys National M arine Sanctuary
Climate change impacts on fish and fisheries in the Florida Keys National
Marine Sanctuary
Barbara MuhlingJohn Lamkin
NMFS: Southeast Center
Potential impacts of climate change on marine fish and fisheries
Warming sea temperatureso Changes in species dominance, occurrence and distributiono Changes in reproductive behaviors and spawning effort
Changing current patternso Alteration of larval dispersal pathwayso Changes to larval survival and recruitment to adult
populations, and fisheriesRising sea levels
o Loss or degradation of nearshore habitatChanging precipitation regimes
o Changes in nearshore water quality
The Florida Keys National Marine SanctuaryLinked to the Dry Tortugas, Gulf of Mexico and
Caribbean via the Loop CurrentThe degree of northward penetration of the Loop
Current is highly variableFlow from the intra-American seas
through the Gulf of Mexico and onto the Florida Keys
The Loop Current and Tortugas Gyre
The Florida Keys National Marine SanctuaryFreshwater inflow enters Florida Bay from the
EvergladesWater quality in Florida Bay and the Florida Keys
influences the health of seagrass meadows and coral reefs
These are important habitats for adult and juvenile fishes
Mean surface salinity across Florida Bay in summer, and winter
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Salinity
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Climate change impacts of primary concern to fish and fisheries in the FKNMS
1) Changes in species occurrence and distribution2) Changes in spawning behaviors and recruitment3) Changes in larval supply to nursery habitats
Potential changes are most likely to be linked to changes in water temperatures, Loop Current dynamics, and health of fish habitats
Examples demonstrating these mechanisms follow, highlighting research capacity at the SEFSC
Potential impacts on fish and fisheries - 1
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Changes in species dominance, occurrence or distributions
Example: Increasing abundances of tropical Lane Snapper (Lutjanus synagris) in the northern Gulf of Mexico
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NMFS Trawl survey area: Northwest GOM Changing abundance of L. synagris in summer trawl surveys
y = -0.00x3 + 0.03x2 - 0.70x + 4.85R² = 0.83
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Potential impacts on fish and fisheries - 2Changes in spawning behaviors and thus
recruitmentExample: Spawning habitat of bluefin tuna (Thunnus
thynnus) in the northern Gulf of MexicoProbability of collecting larval
bluefin tunavs. sea surface temperature
Change in suitable spawning habitat with 2°C increase in SST
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Potential impacts on fish and fisheries - 3
Changes in larval supply to nursery habitats in the FKNMS
Example: Changes in magnitude and timing of connection between Yucatan Peninsula, Dry Tortugas and Florida KeysSnapper larvae collected off Yucatan Generalized Loop Current
flowEddies provide retention and transport mechanisms for larvae
Data and modeling needs1) To predict and quantify the types of
mechanisms described, we need better information on how climate change would affect:Water temperaturesCurrent patternsFreshwater inflows
A downscaled climate model would be very helpful in addressing these points
2) To help explain past trends and predict future trajectories, access to historical datasets and collaboration with scientists within and outside of NOAA is essential
Downscaled climate modelsCoarse-scale (~100km) climate models have already
been produced through the IPCCDownscaling these to a regional level allows the
predictions of temperature, rainfall, and regional oceanographic conditions under various climate change scenarios
A downscaled model covering the Gulf of Mexico and Florida Keys would help to predict water temperatures, precipitation and Loop Current flow across the region under future CO2 emission scenarios
These parameters are highly important for predicting future stressors to the FKNMS, and fish populations