CFF researchers Natalie Jennings, Samir Patel, and Farrell Davis pose with a tagged loggerhead sea turtle. Photo: CFF/NEFSC
The Mid-Atlantic sea turtle biology and behavior project utilizes acoustic telemetry, satellite telemetry, biological sampling, remotely operated vehicles, and oceanographic sensors to collect data on sea turtles in the Mid-Atlantic region and learn about their environment.
The Coonamessett Farm Foundation (CFF) is a fisheries research firm which largely focuses on studying the Atlantic offshore scallop fishery. CFF began studying sea turtles in 2007 to reduce the bycatch, or accidental capture, of sea turtles in scallop fishing gear. The sea turtle research at CFF has helped scallop fishermen to reduce bycatch by adjusting the type of gear they use. Today, this research has expanded to capture information about sea turtle biology, behavior, and movement, and even uses sea turtles as mobile data loggers to collect oceanographic data.
The project has been highly collaborative since the beginning. When CFF first started studying sea turtles, they worked with the National Oceanic and Atmospheric Administration (NOAA) Northeast Fisheries Science Center, who helped with carrying out the research and obtaining permits for studying sea turtles. The partnership has remained to this day. “It is an extremely collaborative, essentially one-unit entity that’s working together,” CFF Senior Research Biologist Samir Patel said.
They initially started using a remotely operated vehicle, or ROV, to observe turtles underwater in the Mid-Atlantic. Eventually, they expanded their research beyond remote observation and began capturing and tagging turtles to track their movements.
Catching a sea turtle is not easy work. In the mid-Atlantic, researchers like Patel will go offshore on a large boat and scan the horizon for surfacing sea turtles using binoculars. Once they have spotted a turtle, timing and communication are essential. A few people will board a small inflatable craft known as a Zodiac. Guided by the spotter, they will drive the boat up behind the turtle, being careful not to spook it and cause it to dive back down. The researchers use a large dipnet to scoop the turtle out of the water and return it to the main boat, where samples can be taken and the turtle tagged before returning it to the water.
The turtles that are a part of the CFF project are fitted with satellite tags, and some are also tagged with acoustic tags. Satellite tags mark the location of a turtle every time it surfaces, and acoustic tags are picked up on receivers along the Atlantic coast. In addition to their tracking abilities, the satellite tags serve another purpose: they log and transmit oceanographic data from where the turtle has been. This approach allows researchers to use turtles as mobile oceanographic sensors. CFF is using the data from these turtles to map out factors such as temperature in the mid-Atlantic Bight.
One of the things that makes this project unique is the integration of telemetry data with not only oceanographic data, but biological data as well. For every turtle that is captured, researchers take morphometric measurements, blood samples, scute samples, cloacal lavage samples, and skin stable isotopes. These data are used to answer questions about turtle health, diet, and behaviors in combination with telemetry data.
The use of acoustic tags in the project expanded in 2023 when CFF began working with the New Jersey Department of Environmental Protection Research and Monitoring Initiative. (RMI). With funding from RMI, CFF’s turtle research has shifted from a focus on preventing bycatch in the scallop fishery to monitoring the impacts of wind energy lease areas on their movements. With acoustic receivers in the wind energy lease areas, as well as passive acoustic monitoring equipment, they hope to see whether animals that currently pass through the New Jersey wind energy lease areas continue to do so after the wind farms are built. Acoustic receivers can detect turtles at a higher resolution than satellite tags, and Patel hopes that this ability can be used to track turtles’ movements on a finer scale.
The project has uncovered patterns in the way that turtles move. CFF has found that during summer foraging, turtles tagged in nearshore North Carolina behave differently than those tagged in the Mid-Atlantic. Specifically, those tagged nearshore tend to stay nearshore as they migrate and forage, however, they also tend to reach more northern habitats than their offshore counterparts. Despite these discoveries, they still have questions. For example, North Carolina turtles spend the winter in reefs. CFF wants to know which habitats they use in the summer throughout the Mid-Atlantic where reefs are not as common.
In addition to CFF, the NOAA Northeastern Fisheries Science Center, and New Jersey RMI, there are many other organizations that participate in this work. Collaborators from Massachusetts Division of Marine Fisheries, University of Florida, Roger Williams University, University of North Carolina, and Purdue University have all made important contributions to the project.
The CFF Sea Turtle Project will provide important information on the biology of sea turtles in the Mid-Atlantic and document their interactions with proposed offshore wind farms. It leverages telemetry in addition to oceanographic and biological data to provide essential information on the management of wind farms for sea turtle population health.
For more information, visit ACT Network Project CFFSTMAB.
by Gabriel Stephenson/SERC
Watch a turtle-mounted camera in action. Credit: CFF/NEFSC