Lake Worth Lagoon
Lake Worth Lagoon (LWL) is a 20-mile-long body of water located just west of the Atlantic Ocean along the coast of Palm Beach County, Florida. The lagoon was historically a freshwater lake but is now a moderately polluted estuarine waterway that receives ocean water from two man-made inlets, the Boynton Inlet and the Lake Worth Inlet. Concern about the lagoon’s health prompted Palm Beach County’s Department of Environmental Resources Management (PBCDERM) to implement a habitat restoration and enhancement plan in the mid 1990’s. One of the goals of this plan is to attain and maintain the biological integrity of the ecosystem which supports the diversity of fisheries and wildlife, including endangered and threatened species. This directive specifically includes research that should be conducted to understand the extent of utilization of the LWL habitat by sea turtles. To implement this directive, PBCDERM asked Inwater Research Group (IRG) to conduct preliminary surveys of marine turtles in LWL. IRG evaluated the abundance and species composition of sea turtles in the LWL by utilizing visual transects to identify areas where turtles aggregate. Then, netting and hand capture operations were conducted in areas identified by these transects as sea turtle hotspots.
Sampling in LWL began in 2005 and has been conducted annually since. This research project is the first in-water assessment of marine turtles ever conducted in the LWL. Throughout this study, IRG has gathered substantial information on species distribution, abundance, size class structure, diet, sex ratio, and genetic origin of sea turtles within the LWL. We have also extensively studied the prevalence of fibropapillomatosis (FP), a potentially deadly disease that occurs at high rates among sea turtles in Indian River Lagoon and Florida Bay. Our goal is to better understand this disease, how it affects sea turtles, and its connection to the lagoon’s water quality.
Jupiter Inlet is located 12 miles south of the Lake Worth inlet and is the point where the Loxahatchee River flows into the Atlantic Ocean in Palm Beach County, Florida. The inlet was expanded in 1922, and an easterly channel was created, cutting through the historic sand barrier. Similarly to LWL, growing concern over the health of Jupiter inlet also prompted Palm Beach County’s Department of Environmental Resources Management (PBCDERM) to implement a habitat restoration and enhancement plan around the same time in the mid 1990’s with the goals to restore and maintain ecosystem integrity and ensure support of the biological diversity of this area, including the abundance of sea turtles that utilize the inlet.
This study site being an inlet is particularly unique as turtles are exposed to the environmental influences of the lagoon as well as from the Atlantic Ocean via daily tidal exchanges. Because of this, research on how these factors, such as freshwater runoff and turbidity levels, might influence water quality and resource availability in this habitat is critical for understanding how sea turtles may be affected. Since the project began in 2017, IRG biologists have found that green turtles captured at Jupiter inlet tended to be smaller in comparison to nearby LWL and gathered assemblage data indicating that this inlet may mostly consist of individuals that have recently come in from offshore, pelagic habitats. Multiple recaptured turtles at this site also display high residency for many of these juvenile green turtles. Future work here will involve more fine-scale tracking to monitor habitat usage within the inlet. Varying severity levels of FP on turtles sampled suggest that more long-term sampling will be needed to examine trends and further monitor water quality and habitat changes.
Green turtles on Florida’s nearshore hard-bottom reefs generally forage upon macroalgae. However, sea turtle stranding records indicate that a growing number of green turtles feed on fishing bait from recreational fisheries. Despite being the most frequently and repeatedly hooked sea turtle species in Florida, no studies have investigated green turtle interactions with fishing piers. As Florida’s green turtle population increases, the number of interactions with fishing piers is expected to increase as well. Therefore, it is important to quantify the impact of fishing piers on green turtles and to develop practices to minimize future interactions.
The goal of this study is to characterize and quantify green turtle interactions with a fishing pier in Florida. IRG biologists are studying how fishing pier interactions affect diet, behavior, and incidence of hooking by comparing turtles caught at a fishing pier to turtles captured on the Boca nearshore reef and at a control site without a nearby pier. This is the first study to quantify the impacts of a hook-and-line fishery on green turtles at the Deerfield Beach International Fishing Pier, which has the highest number of green turtle strandings in the state. This project is in collaboration with Florida Atlantic University, Sea Turtle Care and Conservation Specialists, and Gumbo Limbo Nature Center and is supported in part by the National Save the Sea Turtle Foundation and the Sea Turtle License Plate Grant.