Northern Indian River County Reefs

Project Type(s):capture

Site Name:Northern Indian River County Reefs

Site Reference Number:26

Region(s):Southeast

Counties:Indian River

Approximate Latitude: 27.8 Approximate Longitude: -80.4

Principal Investigator(s):Bagley, Dean; Ehrhart, Llewellyn; Redfoot, William

Point(s) of Contact:Bagley, Dean - Phone Number: (407) 765-5250, Email: de315786@pegasus.cc.ucf.edu

Organizations Involved:University of Central Florida

Organization Type(s):university

Project Status: Active

Start Date: 1988

End Date: n/a

General Method(s) Used:set net

	Visual	Capture
Sampling regime:	annually	annually
Measure of effort:	unknown	cap/area

Bottom Type(s):worm rock

Water Type Zone: neritic Water Type Environment: marine

Min. Depth (m): 9.9 Max. Depth (m): 14.1

Mean Depth (m): 12.6

Species	No. of Captures	No. of Sightings	Min Size* (cm)	Max Size* (cm)	Mean Size* (cm)	FP Observed	Life Stages**	Comments
Green Turtle (Cm)	1052	n/a	23.0	88.8	41.9	Yes	n/r
Loggerhead (Cc)	18	n/a	49.7	92.9	65.9	No	n/r
Kemp's Ridley (Lk)	0	n/a	0.0	0.0	0.0	n/a	n/a
Hawksbill (Ei)	2	n/a	24.8	60.2	42.5	No	n/r
Leatherback (Dc)	0	n/a	0.0	0.0	0.0	n/a	n/a

*All size measurements are SSCL unless otherwise indicated
** For Cm, Cc, Lk, & Ei: O - Oceanic-stage juvenile; N - Neritic-stage juvenile; S - Subadult; A - Adult. For Dc: I - Immature; A - Adult. n/a = not applicable; n/r = not reported.

blood chemistry

diet

growth rates

satellite tracking

sonic tracking

The worm reef on which the study is taking place is nearly continuous along the Atlantic coast of Florida from Biscayne Bay north to Jupiter, then is patchy northward to Cape Canaveral. The reefs are built by aggregations of polychaete worms in the family Sabellariidae that cement sand grains and fragments of shells into their tubes. The reefs extend from the intertidal zone to a depth of approximately 10 m in a series of linear structures parallel to the shoreline and they provide a substrate for at least 109 species of marine algae. This study has captured mainly juvenile and subadult green turtles, as well as some subadult loggerheads, a few adult female loggerheads, and two hawksbills. The small number of loggerhead captures is somewhat odd because divers report sightings of the species over the reefs farther south along Florida’s east coast. CPUE for green turtles during summer is higher over the reef than it is in the IRL, suggesting that there is either a greater summer population of green turtles on the reef or that turtles are more concentrated in the sampling area there. A female-biased sex ratio has been documented using Radioimmunoassay (RIA) titrations from green turtles on the reef. Recapture data suggest that turtles may emigrate to the western Caribbean as they undergo ontogeny. Green turtles from the reef have been captured locally at St. Lucie Power Plant, and turtles tagged by other projects near IRC have been captured on the reef. The turtles consume mostly algae in the Divisions Chlorophyta and Rhodophyta. Green turtles show an 8-32.9% prevalence of FP in this habitat, far lower than that in the nearby IRL. This is possibly due to the “oceanic” nature of the reef system. Haplotype analysis of green turtle mtDNA indicates that turtles in this population originate from Florida, Mexico, Costa Rica, and Aves Island.

File Name	Type	Description
Hirama_etal_2014.pdf	Journal Article
Kubis_etal_2009.pdf	Journal Article

* This document is available from FWC by request. Email SeaTurtleData@MyFWC.com if you would like a copy. Please include both the project name and file name in your email.
** This document has been provided to FWC but is unavailable for download. Please contact the project PI if you would like a copy.

Kubis, Stacy, Milani Chaloupka, Llewellyn Ehrhart, Michael Bresette. 2009. Growth rates of juvenile green turtles, Chelonia mydas from three ecologically distinct foraging habitats along the east central coast of Florida, USA. MEPS 389:257-269.

Hirama, S, L. Ehrhart, L Rea, R. Kiltie. 2014. Relating fibropapilloma tumor severity to blood parameters in green turtles Chelonia mydas. Dis. Aquat. Org. 111:61–68.