Chesapeake Bay is an important foraging habitat for loggerhead sea turtles (Caretta caretta) throughout the summer.1,5 It also serves as a high volume port with commercial and military traffic.2,6 Routine maintenance of the various shipping channels typically requires dredging to take place on an annual basis.4
In 2015, the US Army Corps of Engineers contracted with the Great Lakes Dredge & Dock Company to dredge the York Spit Channel. Dredging commenced in late May 2015 using a trailing suction hopper dredge. Endangered species monitors were on board to provide 100% inspection of the draghead, deflectors, and inflow cages. During the project, a known total of six sea turtles were taken, all loggerheads ranging from 62 to 72 cm straight carapace length. Three were dead, but the other three were found alive, wedged in the teeth of the draghead. As a result, they suffered non-fatal, but life-threatening injuries.
Virginia Aquarium Stranding Response (VAQS) staff responded to the dredge-take turtles and admitted the live turtles into rehabilitation at the Marine Animal Care Center (MACC) in Virginia Beach, VA. These turtles suffered severe crushing injuries to the caudal marginal scutes with various additional involvements of the costal and vertebral scutes, multiple superficial abrasions, and severe swelling of the hind flippers and inguinal area. Fractures extended into or through the carapace to the underside, but did not penetrate the coelomic cavity. Additionally, two loggerheads had compound fractures of the caudal ribs, deep linear fractures in the plastrons, severe abrasions to the vertebral scutes, and one had severe, bilateral ocular swelling and dislocation of the left hip. Seventeen days after admission to the MACC, one loggerhead was transferred to the STAR center in Manteo, NC to continue and complete rehabilitation.
On admission, the patients were given pain management medication and fluids. They were treated systemically with antibiotics to prevent infection and locally with wound cleaning, debridement, and topical treatment initially three times a week and decreasing in frequency as healing progressed. Wound healing strategies included the use of raw honey and RediHeal, a biological glass-based veterinary wound care product. The carapace fractures were stabilized and apposed using eyehooks epoxied to the carapace and cable ties pulling the hooks together.
As the injury sites healed, non-viable areas of bone and soft tissue were recognized. Some areas were excreted passively through natural healing progression. Other areas required more active debridement and in some cases, surgical excision. Some of the fracture sites created marginal contours that were potential entanglement risks for the turtle after release. These areas of bone and tissue were reshaped surgically to reduce or eliminate the risk of entanglement at these fracture sites.
The transferred loggerhead was released at Cape Charles, VA after 16 weeks of rehabilitation. A Wildlife ComputersTM Spot tag attached to the carapace tracked the turtle's movements following release and it appeared to follow normal loggerhead foraging and migratory behavior.3 The other two loggerheads are still healing from their injuries and will also be outfitted with satellite transmitters once cleared for release.
The authors wish to thank the Virginia Aquarium Stranding Response Program staff, interns, and volunteers, Beach Pet Hospital, the North Carolina Aquariums staff and volunteers, Christian Legner, Dr. Mike Grafinger, East Coast Observers, and the US Army Corps of Engineers, Norfolk and Baltimore Districts.
* Presenting author
1. Arendt MD, Segars AL, Byrd JI, Boynton J, Whitaker JD, Parker L, Owens DW, Blanvillain G, Quattro JM, Roberts MA. Seasonal distribution patterns of juvenile loggerhead sea turtles (Caretta caretta) following capture from a shipping channel in the Northwest Atlantic Ocean. Marine Biology. 2012;159(1):127–139.
2. Barco SG, Lockhart GG, Lagueux KM, Knowlton AR, Swingle WM (Virginia Aquarium & Marine Science Center). Characterizing Large Vessel Traffic in the Chesapeake Bay Ocean Approach using AIS and RADAR. Virginia Beach, VA: Virginia Aquarium Foundation Scientific Report 2009-05. 2009.
3. Lockhart GG, DiMatteo A, Barco SG (Virginia Aquarium & Marine Science Center). Virginia and Maryland Sea Turtle Conservation Plan. Appendix A: Characterizing Foraging Behavior for Loggerhead Sea Turtles in Virginia and Maryland. Virginia Beach, VA; 2015.
4. Lockwood KB (personal communication). Norfolk, VA: US Army Corps of Engineers, Norfolk District; 2016.
5. Mansfield KL. Sources of mortality, movements and behavior of sea turtles in Virginia [dissertation]. Gloucester Point, VA: College of William and Mary, Virginia Institute of Marine Science; 2006.
6. US Department of Transportation. Vessel calls at US ports snapshot, 2007. Washington, DC: US Department of Transportation Maritime Administration; 2008.