Assessment of the Introduced Lionfish in Everglades and Dry Tortugas National Parks Tracy A. Ziegler, Ph.D. Fisheries Biologist National Park Service Everglades and Dry Tortugas National Park Problem • Sightings of lionfish at Dry Tortugas (DRTO) & Everglades National Parks (EVER) increasing since 2009 • Variety of threats to invaded ecosystem o Negative impact on native species through competition, predation, niche takeover o Few predators eat lionfish o Likely to establish w/in stressed areas within Florida Bay o Venomous spines – could harm visitors Everglades and Dry Tortugas National Park Limited Monitoring and Removal Efforts at EVER & DRTO • Respond to sightings in visitor use areas • Remove all lionfish reported or observed doing other natural resource work • Biscayne National Park lionfish interns visited DRTO for 10 days in 2012 • 80 dives completed; 118 lionfish removed • Still, no full time lionfish management efforts at DRTO or EVER Everglades and Dry Tortugas National Park Special Circumstances for DRTO • RNA (research natural area) • Lionfish could dramatically affect the performance measures of the RNA e.g., snapper and grouper size and abundance may be influenced by lionfish Everglades and Dry Tortugas National Park Reef Visual Census June 2011 142 lionfish reported Everglades and Dry Tortugas National Park Florida Current Everglades and Dry Tortugas National Park Project Goals • Minimize ecological impacts of lionfish to the marine resources within the parks by removing lionfish • Improve visitor experience and reduce threats to visitor safety Everglades and Dry Tortugas National Park Methods • Conducted timed surveys (total search time) via SCUBA or snorkel Search time began upon decent or when searcher could see the bottom/habitat • Slow, steady lionfish-focused search of all habitat during the dive or snorkel • All lionfish observed were removed or documented in not captured, with size estimates Everglades and Dry Tortugas National Park Results • DRTO: 141 timed surveys totaling 1493 min total search time (24.8 hours!) were conducted • 78 lionfish TOTAL were removed • 117 observed and not captured • EVER: 31 timed surveys totaling 1019 min (16.9 hours underwater) • 12 lionfish removed • NONE were left behind Everglades and Dry Tortugas National Park Habitat Type Distribution DRTO - Lionfish were found: High Relief Coral Reef – 52% Low Relief Coral Reef – 44% Other – 4% Low Relief Coral EVER - Lionfish were found: Hard Bottom – 56% Seagrass – 28% Sandy/Mud Bottom w/ Ledge – 8% Artificial Structure – 8% Everglades and Dry Tortugas National Park Dry Tortugas National Park Total number of fish captured = 78 Surveys conducted at 47 sites Everglades and Dry Tortugas National Park Dry Tortugas National Park Total number of fish observed but NOT captured = 117 Everglades and Dry Tortugas National Park Everglades, Florida Bay Area Total number of fish captured = 12 Surveys conducted at 31 sites Everglades and Dry Tortugas National Park Hot Spots Identified DRTO: Large groups of lionfish were found on high relief coral sites such as Texas Rock (pinnacle formation) and areas of White Shoal with high relief coral Everglades and Dry Tortugas National Park Hot Spots Identified EVER: • 7 of the 12 lionfish found in Florida Bay were removed from Arsenicker Bank and the southwestern portion of Florida Bay Everglades and Dry Tortugas National Park Conclusions: Dry Tortugas • Relatively small number of lionfish removed suggest that the presence of large predators (e.g., goliath grouper, groupers, snappers, sharks, etc.) may be influencing the number of lionfish • Possible predation? o TWO reports from fisherman that caught groupers at DRTO found lionfish in their guts Everglades and Dry Tortugas National Park Conclusions: Everglades • Many more lionfish were collected in Florida Bay than were expected • Lionfish were found in NON-TRADITIONAL HABITATS (seagrass beds, hard bottom, etc.) • Lionfish were found in areas with high salinity (between 36 – 39 ppt) and at shallow depths (anywhere from 2 – 4 ft) Everglades and Dry Tortugas National Park Science Need Hypotheses to test in the near future: Presence of larger, more abundant predators at DRTO are keeping lionfish population numbers low. Lionfish will recruit to stressed areas (e.g., high salinity, poor habitat) within Florida Bay in EVER Everglades and Dry Tortugas National Park THANK YOU!! South Florida National Parks Trust Grant Funding for interns Vanessa McDonough, Ph.D., Fisheries Biologist ALL our fabulous interns! Including Kara Wall, Amanda Lawrence, Ryan Lind, Lee Qi, Marc Fruitema David Fowler, District Ranger from Everglades Kayla Nimmo, Jason Osborne, Zach Fratto Numerous Volunteers! Everglades and Dry Tortugas National Park Any Questions? Catch and eat lionfish!!! Everglades and Dry Tortugas National Park .