Phil Darby Rob Bennetts Unpublished Material http://sofia.usgs.gov/projects/workplans03/applesnail.html As the exclusive food of the endangered snail kite and prey to a variety of other wetland fauna, apple snails are generally recognized as a critical resource warranting monitoring in the context of the Greater Everglades ecosystem restoration. The overall goal of the project is to provide information to help predict the impact of changes in hydrology (and associated vegetation) to apple snail abundance following WCA-3A decompartmentalization. The apple snail is an important performance measure in Comprehensive Everglades Restoration Plan (CERP) because it is the exclusive prey of the snail kite, and information on apple snail production and spatial distribution under different water management is essential for CERP evaluations. The specific objectives for the project are as follows: 1) estimate apple snail abundance in wet prairie habitats (relatively short hydroperiod) relative to slough habitats (relatively longer hydroperiod) with potential linkages to snail kite foraging habitat selection; 2) estimate snail abundance in sites with foraging snail kites, and incorporate data from this study in to a larger coordinated effort to link snail kite habitat use and snail availability; and 3) document baseline seasonal apple snail egg production (not yet available in wetlands south of Lake Okeechobee) and assess the potential impacts of drying events on annual egg production. This project is no longer funded by the USGS Greater Everglades Science Program: Place-Based Studies 20020202 20050131 ground condition Complete As needed wet prairie habitats in the Greater Everglades -81 -80.375 26.375 25.5 none biology hydrology apple snail model ISO 19115 Topic Category biota environment inlandWaters 004 007 012 Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, D.C., National Institute of Standards and Technology United States US U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, D. C., NIST Florida FL Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology Broward County Miami-Dade County none Central Everglades Northeast Shark River Slough Water Conservation Area 3 WCA3 none animals invertebrates single species U.S. Department of Agriculture - Agricultural Research Service (ARS) U.S. Department of Agriculture - Natural Resources Conservation Service (NRCS) Department of the Interior - U.S. Geological Survey Department of Commerce - National Oceanic and Atmospheric Administration (NOAA) Environmental Protection Agency (EPA) Smithsonian Institution - National Museum of Natural History (NMNH) 2000 Database Retrieved from the Integrated Taxonomic Information System on-line database, http://www.itis.gov. http://www.itis.gov Snail abundance will be determined each year in five randomly selected wet prairie and five slough habitats using 1-m sq. throw traps. Estimates will be made of apple snail abundances in wet prairie habitats relative to slough habitats and in sites with foraging snail kites. Baseline seasonal apple snail egg production will be documented. Apple snails are identified to Species. Kingdom Animalia Animals Phylum Mollusca molluscs mollusks Class Gastropoda gastropods snails slugs Sub Class Prosobranchia Order Architaenioglossa Family Ampullariidae Genus Pomacea Species Pomacea paludosa Florida apple snail none Project data are subject to change and are not citeable until reviewed and approved for official publication. Phil Darby University of West Florida mailing address

Department of Biology, University of West Florida 11000 University Parkway

Pensacola FL 32514 USA 850 474-2647 850 474-2749 pdarby@uwf.edu Other project personnel include George Stewart and Don DeAngelis. Project personnel in FY 2003 include Jennifer DuPree and Jason Liddle. Bennetts, R. E. Kitchens, W. M., Dreitz, V. J. 2002 report Wetlands v. 22, no. 2 McLean, VA Society of Wetlands Scientists Burnham, K. P. Anderson, D. R. 1998 book New York, NY Springer-Verlag Darby, P.C. Croop, J. D., Bennetts, R. E., Valentine-Darby, P.L., Kitchens, W. M. 1999 report Journal of Molluscan Studies 65 Oxford, England, UK Malacological Society of London (Oxford University Press) Darby, P. C. Percival, H. F. 2000 report Final Report Research Work Order No. 182 Gainesville, FL U.S. Geological Survey White, G. C. Bennetts, R. E. 1996 report Ecology 77 Washington, DC Ecological Society of America not applicable not available We will conduct a 3-year study in Water Conservation Area-3A (WCA3A) and Northeast Shark River Slough (NESRS)(if accessible). Based on 2002 results, we do not plan to access NESRS in 2003. The trends observed in 2002 show a strong effect due to habitat type. This is coupled with the fact that the sites are much drier than the other sites and therefore, we will be less likely to given permission to enter the area. We will sample additional sites in WCA3A. We will determine snail abundance each year in five randomly selected wet prairie (same 5 sites each year) and five slough habitats (same 5 sites each year) using 1-m sq. throw traps (approximately 50-70 throw traps in a 50 x 50 m area) per Darby et al. (1999). The throw trap data will be used to test the hypothesis that apple snail abundance is greater in wet prairie versus slough habitats. Site selection and classification will be based on habitat structure and the best available hydrologic information for the areas. The timing of all sampling will depend, in part, on hydrologic conditions and seasonal patterns in egg cluster production. Most throw trap sampling should be conducted from approximately February through April. Sites that are dry during this period will be sampled following reflooding (surviving snails emerge from aestivation within 24 h). Egg cluster surveys will provide data to avoid sampling during the period of greatest post reproductive mortality. Protocol modifications may be warranted to document unusual hydrologic events (e.g., extended or atypically timed dry downs or floods). We will characterize plant community composition (per cent species coverage for the area), substrate composition, plant stem density (1-m sq. quadrat samples, n=7) and periphyton abundance in all sampling sites. We will attempt to control for variation in all aforementioned habitat characteristics during sample site selection. Three wet prairie/slough habitats known to support foraging snail kites (locations provided from our own surveys or by the snail kite monitoring field crew; P.I., Wiley Kitchens, USGS-BRD) will also be sampled for snail abundance using throw traps. Comparisons to the randomly selected sites within a wetland unit will be made to see if kites forage in sites with relatively higher snail abundance. However, understanding how snail kites respond to apple snail abundance requires comparisons to foraging habitats spread throughout the snail kite’s range. Snail kites are highly nomadic, even in generally high-water years (Bennetts and Kitchens 2000), but no snail abundance data has been linked to kite movements. Data from this 3-year study will be examined as part of a coordinated effort via concurrent studies in the Loxahatchee N.W.R., Kissimmee Chain-of-Lakes, and potentially other areas in order to correlate snail abundance with snail kite habitat use. Such coordination enables us to increase our scope of inference across areas with a range of hydrologic regimes and varying substrate types (e.g., sand versus peat) and over a temporal and spatial scale relevant to the nomadic snail kites’ foraging range. Apple snail egg clusters provide critical information about the timing of the annual post-reproductive adult die off (Darby and Percival 2000). A 1m x 2.5m PVC quadrat will be flipped end over end 20 times in order to count egg clusters in each transect. Two egg cluster transects will be established in all of the aforementioned throw trap study sites (thus incorporating a hydrology effect) and sampled monthly from February - September each year (n=26 transects each month). Finally, 2 egg cluster transects will be established in each of 3 sites subject to frequent drying events and known to contain apple snails (e.g., portions of NESRS and northwestern WCA3A) in order to quantify recruitment losses related to drying events and/or potential resumption of oviposition after water levels rise following a dry down. Apple snail density data from an approximately 50 m x 50 m area tends to be distributed as a negative binomial (Darby et al. 1999). A likelihood ratio testing approach (per White and Bennetts 1996, see snail data in Darby et al. 1999) will be used to model apple snail density as a function of community type, substrate type, snail kite presence or absence (or possibly some index of foraging success or extent of kite use, if data were available) and time (+ interactions). Final model selection will be based on comparing Akaike's information criteria (AIC) values from a suite of candidate models (Burnham and Anderson 1998). We will evaluate a suite of candidate models that include each main effect separately as well as all possible combinations of interactions. Egg cluster counts will be analyzed using a generalized linear models approach as described in Darby and Percival (2000). The model for egg cluster production will include temperature, water level, community type, substrate type, and time (+ interactions) as independent variables. Final model selection will be based on an AIC approach as described above. Not complete Phil Darby University of West Florida mailing address

Department of Biology, University of West Florida 11000 University Parkway

Pensacola FL 32514 USA 850 474-2647 850 474-2749 pdarby@uwf.edu WCA3 Phil Darby University of West Florida mailing address

Department of Biology, University of West Florida 11000 University Parkway

Pensacola FL 32514 USA 850 474-2647 850 474-2749 pdarby@uwf.edu snail abundance data There are no explicit or implicit warrantees for the data. unknown none Contact Phil Darby for data and information from this project 20070123 Heather Henkel U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext 3028 727 803-2030 sofia-metadata@usgs.gov Content Standard for Digital Geospatial Metadata Part 1: Biological Data Profile FGDC-STD-001.1-1999