Study Title: Impacts of Hydrological Restoration on Three Estuarine Communities of the Southwest Florida Coast and on Associated Animal Inhabitants
Study Start Date: 2000 Study End Date: 2004
Web Sites: http://www.fcsc.usgs.gov/basis/Greater_Everglades/4535/
Location (Subregions, Counties, Park or Refuge): Total System Everglades National Park (Monroe County)
Funding Source: USGS Priority Ecosystems Science (PES) Initiative: Additionally, ENP supplied research houseboat first 4 years. Hart salary: Human Resources grant to the FISC. Half Silverman's salary (a contractor) has been paid off Global Climate Change.
Principal Investigator(s): Carole C. McIvor
Study Personnel: Kathleen Kuss, (0.5 FTE), Kristen Hart (SCEP, PhD candidate Duke University), Noah Silverman (MS student, USF Marine Sciences), Gary L. Hill (0.5 FTE years 2-4), Lauren Yeager (intern, Eckerd College)
Supporting Organizations: Everglades National Park, Duke University
Associated / Linked Studies: Effects of Global Climate Change on mangrove forests & associated fauna in SW Florida (T.J. Smith, C.C. McIvor). Distribution & biochemical characteristics of submerged aquatic vegetation along Shark River (subcontract to J. Fourqurean, FIU, final report in review, 8/2004).

Overview & Objective(s): The overall goal is to provide baseline data on mangrove-associated fauna and on submerged aquatic vegetation in Shark River and Big Sable Creek prior to hydrological restoration upstream in the former location. Specific objectives are to: (1) quantify species composition, density, & biomass of fishes & decapod crustaceans in intertidal mangrove forests along salinity gradient in Shark River: relate these distributional patterns to hydrological & environmental factors; (2) describe the submerged aquatic vegetation (SAV) of Shark River in relation to sediment & water quality parameters; (3) quantify species composition, density, & biomass of fishes & decapod crustaceans in intertidal mangrove forests and hurricane-derived intertidal mudflats in replicate creeks of the Big Sable Creek complex: relate these distributional patterns to hydrological & environmental factors; and (4) describe the population structure & habitat use of diamondback terrapins in the Big Sable Creek complex.

Status: In final year of original funding cycle. Shark River fishes: 4 yrs of data; Big Sable Creek fishes: 1.5 yrs of data; terrapins 2.5 yrs of data; SAV in Shark River: 1 yr of data. Data collection and data entry has been completed for all tasks. Data analysis and interpretation coupled with manuscript preparation is ongoing for all tasks.

Recent Products: Access database of fish species, numbers and biomass at 3 fixed sites in fringing mangrove forests along a salinity gradient in Shark River, March 2000-Apr 2004. Access database of fish species, numbers and biomass at 3 fixed forest sites and 3 fixed mudflat sites on 3 creeks in the Big Sable Creek complex, Oct 2002-Jan 2004. Excel datasets of terrapin morphological parameters, capture and re-capture locations, PIT tag numbers, genetic analysis from 2001-2003. GEER Conference 2003: two papers, 1 poster. Draft final report from Fouqurean (SAV), 8/2004. Other invited or offered presentations from McIvor, Hart: approximately 10.

Planned Products: Thesis and dissertations: Comparative ecology and population dynamics of diamondback terrapins in a saltmarsh and a mangrove dominated estuary (PhD title of Kristen Hart, Duke University, defense 12/04), Fisheries impact of hurricane-induced habitat conversion in the Big Sable Creek complex, ENP, FL (MS title of Noah Silverman, USF, defense 12/05). Peer-reviewed papers: Modification of the bottomless lift net for use in mangrove forests (in prep, Silverman & McIvor); Ecology of Mangrove rivulus (Rivulus marmoratus) in mangrove forests along Shark River, Everglades National Park (in prep, McIvor); Ecology of frillfin goby (Bathygobius soporator) in mangrove forests along Shark River, Everglades National Park (McIvor); Community structure of mangrove forest fishes along Shark River, Everglades National Park (McIvor, Kuss, and Silverman); Gross export of macrodetritus from two mangrove systems in South Florida (in draft, Yeager, Silverman & McIvor). Additionally there will be at least 1 paper each from the SAV task, another strictly relating to ENP from the terrapin dissertation, a third from the mangrove versus mudflat thesis. Factsheet: Mangrove-associated aquatic fauna of Shark River and Big Sable Creek, Everglades National Park, due 11/15/04.

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan):

This study supports a primary activity of DOI in providing information to "ensure that hydrological performance targets protect threatened and endangered species and promote fish, wildlife and Park values". More specifically, tasks 1 (fishes of mangrove forests along Shark River) and 2 (submerged aquatic vegetation of Shark River) seek to provide current baseline conditions in the mangrove transition zone of the SW coast prior to hydrological modifications upstream. Restoration is occurring against a backdrop of ongoing global climate change. Task 3 (hurricane-induced habitat conversion and effect on fisheries) seeks to quantify one of the effects of GCC, i.e., increasing frequency and intensity of hurricane landfall. Finally, task 4 seeks to provide specific ecological and genetic information about listed diamondback terrapins at Big Sable Creek. Information gained under task 1 relates to another candidate species, mangrove rivulus. Our data may contribute to a reassessment of the status of this species and prevention of listing.

Key Findings:

1. Composition of the forage fish community using flooded mangrove forests along Shark River is largely explained using a combination of salinity (mean, variance), and depth of tidal flooding.
2. A specialized fish mangrove rivulus (Rivulus marmoratus), a species of special concern, is a common forest floor inhabitant all along the salinity gradient sampled in Shark River, a fact that may contribute significantly to the decision about whether to list it as endangered.
3. Submerged vascular vegetation (SAV) along Shark River is largely limited to Ponce de Leon Bay (seagrasses Halophila decipiens, Halodule wrighti), and Tarpon Bay (Ruppia maritima).
4. Diamondback terrapins, increasingly rare in developed portions of the Atlantic and Gulf of Mexico coasts, are abundant in the headwater portions of the mangrove-lined tidal creeks of the Big Cape Sable Creek (BSC) complex.
5. The species composition of fishes occupying forested and mudflat sites within the BSC complex is substantially different, suggesting that hurricane-induced conversion of forests to mudflats has fisheries consequences.