Tamanend’s Bottlenose Dolphin
Latin Name: Tursiops erebennus
Species: Mammal
Conservation Status: S4-5 - Secure
Previously thought to be Atlantic bottlenose dolphins (Tursiops truncatus), scientists recently determined through genetics that the dolphins in our Lowcountry estuaries are a distinct species, the Tamanend’s bottlenose dolphin (Tursiops erebennus). The Atlantic bottlenose dolphin is 8-9 feet in length on average, while the Tamanend’s is on the smaller end of that range. Otherwise, they are similar in appearance. The top of their body is grey while their belly is white. The thick, bottle-shaped snout gives them their name “bottlenose” and they have undistinguished, conical teeth. Dorsal fins become scarred and notched, which allows scientists to identify individual dolphins. They are mammals and have hair in the form of inconspicuous whiskers on their snouts.
Range & Habitat (map)
The Tamanend’s bottlenose dolphin range is described to be the inshore waters of the U.S. east coast.
Diet
The Tamanend’s bottlenose is a carnivore, hunting fish, squid, and crustaceans such as crabs and shrimp. Tamanend’s dolphins engage in a unique behavior called “strand feeding” where they will chase fish onto muddy shore banks at low tide and temporarily beach themselves to capture the stranded fish. Being marine mammals, dolphins acquire the freshwater their body needs through the fish they eat.
Life History
The Tamanend’s bottlenose is a social animal that lives in smaller groups, averaging around 4-5 individuals, as compared to the Atlantic bottlenose pods that can reach into the hundreds. They remain in inshore waters and although they may encounter migrating offshore Atlantic bottlenose populations, they will not interbreed. Females reach maturity at 7-10 years old. Breeding takes place in the spring and calves are born 12 months later. Mother Tamanend’s dolphins typically only give birth to one offspring and will nurse them for up to 20 months, but calves can begin eating fish as early as 6 months old. The life expectancy ranges from 40-60 years old.
Significance
Being a top predator and charismatic megafauna make the Tamanend’s bottlenose incredibly important to the ecology and the people of the Port Royal Sound. Tamanend’s dolphins are a saltmarsh keystone species, regulating their prey populations and thus regulating the entire food web. In addition to the ecological impact, they bring tourism to the Sound as people enjoy seeing these iconic dolphins within our inshore waters.
Threats & How You Can Help
The most pressing threats to the Tamanend’s bottlenose dolphin are mostly of human origin. Dolphins, like all marine mammals, are protected under the Marine Mammal Protection Act (MMPA) of 1972 which prevents the harassment and feeding of these wild animals nationwide. People breaking these laws to feed or interact with dolphins may lead to reliance on humans for food, more contact with humans, and ultimately a rise in boat strikes which are often fatal. They are also susceptible to land-based pollutants, biotoxins such as algal blooms, and entanglement with fishing gear. We can prevent harm and fatalities to our dolphins by following the guidelines of the MMPA, preventing the introduction of pollutants (pesticides, fertilizer, etc) into the Sound, properly disposing of fishing gear, and removing debris such as ghost nets.
Additional Resources
- Learn about some of the dolphin research funded in part by the PRSF