Florida Hawksbill Project Surveys Continue in Jupiter, Expand to Florida Keys
Larry Wood, Ph.D.
The National Save The Sea Turtle Foundation’s Florida Hawksbill Project has had a busy and productive summer. We have been fortunate to work at both ends of the SE Florida Reef Tract, having continued our surveys in the northernmost part of Palm Beach County (Jupiter) and also undertaken a new effort in the lower Florida Keys.
Ongoing surveys for hawksbills in the Jupiter area (Northern Palm Beach County, Florida) have provided further evidence that a substantial number of sub-adult hawksbills take up residence on these relatively high-latitude 60-90’ reefs.
So far this year, five new hawksbills have been tagged during fifteen SCUBA surveys (seven field days), and several more previously-tagged individuals have been encountered repeatedly (Figure 2).
We’ve been able to confirm that the surprising hawksbill abundance we found on the reefs just to the south of Jupiter in the Town of Palm Beach does continue northward into the Jupiter area, further underscoring the importance of Palm Beach County’s coral reefs for the regional recovery of this highly endangered species.
Ongoing surveys for hawksbills in the Jupiter area (Northern Palm Beach County, Florida) have provided further evidence that a substantial number of sub-adult hawksbills take up residence on these relatively high-latitude 60-90’ reefs.
So far this year, five new hawksbills have been tagged during fifteen SCUBA surveys (seven field days), and several more previously-tagged individuals have been encountered repeatedly (Figure 2).
We’ve been able to confirm that the surprising hawksbill abundance we found on the reefs just to the south of Jupiter in the Town of Palm Beach does continue northward into the Jupiter area, further underscoring the importance of Palm Beach County’s coral reefs for the regional recovery of this highly endangered species.
Figure 1. A hawksbill turtle forages at the
MG-111, a popular artificial reef site in Jupiter,
Florida
One of the most important aspects of the study is using our abundance data to determine what features of the habitat the turtles find most attractive, and then use this information to estimate hawksbill abundance in other locations along Florida’s SE coast. This information also helps us detemine where to target new survey efforts. Clearly, prey availability will have a major influence on hawksbill
abundance, but our work has shown that underwater topography may also play an important role in habitat choice. The hawksbills we’ve studied so far have centered their activity around a particular place of shelter that serves as nightly refuge; in some cases a shipwreck, in others a rocky ledge or underwater cave. In fact, two of the five new turtles tagged in Jupiter were found at an artificial reef site known as the MG-111, a broken up sunken barge (Figure 1).
The preference for protective shelter as a secondary habitat characteristic has steered our new efforts in the Lower Florida Keys. For several weeks in June, we utlized both of the National Save The Sea Turtle Foundation Research vessels;
the “Hawksbill” and the “Hawksbill II” to survey the reefs of Key West (Figures 3 and 4). We were joined on our maiden voyage(s) by Intern Stephanie Anderson, Captain Mike Osborne, and Key West Community College student Kaleb Jemison as we sought the most likely places to find hawksbills along the barrier reef sites just south of Key West Island known as Western and Eastern Dry Rocks, Sand Key, the Sambo Keys, and Pelican Shoals.
Figure 2. One of several hawksbill
turtles recently tagged in the
Jupiter area waits to return to the
reef after capture
These beautiful finger-like spur-and-groove reefs support a great variety of marine flora and fauna, and very likely hawksbill turtles as well. Other researchers have reported hawksbills in the area, as have local divers and fishermen. When we arrived at the target locations, our strategy was to first calmly wait on lookout for surfacing turtles. As air breathers, the requirement for surfacing gives away the turtles’
presence and, using an observer’s sharp eye, the species as well.
Figure 3. The Hawksbill II served as our dive boat during snorkel surveys
along the barrier reefs south of Key West
Figure 4. The shallow, spur-and-groove barrier reefs to the south of Key West were the
focus of hawksbill surveys aboard the Research Vessel Hawksbill II in June
We then conducted snorkel/dive surveys in broad circles around the main shoals, focusing on the places we had seen the turtles’ heads popping up. After several long days of searching, we were able to identify some surfacing turtles as hawksbills and catch a glimpse of just a couple of turtles rapidly swimming away during our snorkels and dives, but none ended up in-hand for tagging. The results so far confirm the turtles’ presence on these shoals, but it will take more time in these areas and others to determine their relative abundance along the barrier reefs of the Lower Keys.
Many thanks go to Captain SL8R and the Crew of the Kyalami, all my dive assistants in Jupiter, the great Captain Mike aboard the Hawkbill II, Kaleb Jemison, and everyone who has provided information and insight concerning hawksbills in the Keys. This project is sponsored by the National Save The Sea Turtle Foundation.
