Evaluating Effects of Climate Change on Florida s Freshwater Fisheries Mike S. Allen Mark W. Rogers Galen Kaufman Chris M. Horton
Methods Two parts: 1. Literature review to evaluate nationwide implications of GCC on freshwater fisheries nationwide 2. Assessment of what conservation agencies can do to mitigate impacts of GCC
Black Basses Courtesy FWC
Courtesy FWC
Panfish
Others
Uncertainty Forecasting climate and ecological interactions is very difficult (and some might say ) Climate studies have evaluated the past 100 years, and modeled future changes if trends persist Are predictions correct? No..
Uncertainty Despite high uncertainty, we must manage natural resources Climate change effects only amplify current threats; not new threats Actions to mitigate GCC already needed to protect fisheries from these same threats
Effects of Climate Change Changes in rainfall Higher temperatures Sea level rise Species interactions Effects are combined with alterations to aquatic systems by humans
Changes in Rainfall Climate models are forecasting more extreme events (consistent among studies) Past 100 years suggest this has occurred Rainfall patterns are the primary determinant of freshwater fish habitat quality in Florida
Droughts Droughts will be stronger in the future Water for human use already limited in Florida Droughts cause whole Droughts cause whole system changes to habitat
Droughts Agencies set MFL regulations Can we protect fish and wildlife and still provide the water we need? Will require difficult decisions and innovative solutions (reservoirs, basin transfers, trade offs)
Changes in Rainfall Flood and drought events play large roles in the numbers of freshwater fish Cycles are natural, and boom and bust fisheries occur naturally in Florida Orange Lake, Lake Okeechobee
Changes in Rainfall Variable fishing quality through time Stronger booms and busts Economic implications for fisheries Rivers..
Anadromous Fishes Temperature refugia for striped bass Flow requirements for American shad Changes in river flows and temperature threaten these populations Potential P i llong term impacts
Riverine Fishes Rare black basses Panfish P l i l l li k d Populations closely linked to flow conditions in rivers
Estuarine Fishes Altered flow will influence production in estuaries Could reduce recruitment of popular saltwater sport fish
Saltwater Intrusion Surface S f and groundwater saltwater t intrusion Reduced habitat for freshwater fishes
Aquatic Plants Primary fish habitat in Florida lakes Essential E lhbittf habitat for largemouth bass in large lakes Longer growing season under GCC Increased need for plant management
Stabilized water levels due to channelization Kissimmee Chain of Lakes, Lake Istokpoga More muck accumulation lti in the future Aquatic Plants
Exotic Species More M need for control of exotic plants (water hyacinth, hydrilla, etc.) Threats of new exotic plants Exotic fish
Summary Water availability stream fishes and MFL regulations anadromous fishes lake water levels Fish habitat aquatic plants boom and bust fisheries Exotic species new species new challenges
Management Responses How do we mitigate climate impacts for How do we mitigate climate impacts for fisheries?
Management Responses Actions to stabilize fisheries habitat restoration/enhancement harvest restrictions informed MFL regulations to protect riverine fish Water!
Management Responses Strategic water regulation to provide flows and water for fish habitat Trade offs (people vs. fish habitat), and sometimes winners and losers Prioritize must win battles for fish habitat (e.g., Lake Okeechobee, anadromous fish, rare black bass, major fisheries)
Management Responses Timely and appropriate scale habitat restoration Think big Aquatic A plant management Respond to losses in habitat
Management Responses Exotic species responses when found Measure impacts on native fish
Conclusions GCCpresents challenges that aren t unique Our responses to those challenges are critical Will be essential to protect Florida fisheries
Thank you!