New research from the University of Hawai’i has found that dolphins may be one of the most important food sources for a group of marine creatures called sea turtles, a study has found.
The finding may have implications for the conservation of some sea turtles found in the Pacific, such as the endangered Indo-Pacific sea turtle (Osteoporca sexta).
It also raises the possibility that the animals might play a role in protecting ecosystems, said co-author Michael G. Schleicher, a marine biologist at the University at Buffalo and the University’s Center for Marine Science.
The study was published online May 13 in the journal Proceedings of the National Academy of Sciences.
The dolphins were found in Hawaii in the 1960s, and the research was based on underwater footage taken by the U.S. Navy’s Whidbey Island Research Center from 1962 to 1971.
Researchers studied a variety of species of dolphin in the area, including dolphins and humpback whales, as well as sea turtles.
Schleicer and his team collected data on the dolphins’ movements and feeding habits, which were captured in a series of underwater video footage.
The footage, which lasted about seven minutes, revealed a group that included three different types of dolphins — two that live in the water and one that lives on land.
“The dolphins are a big source of food for the whales,” said Schleick, who was a postdoctoral research associate at the UH-Boulder’s Marine Mammal Research Institute.
“There is an interesting correlation between the size of the dolphin and the amount of food it eats.”
Scientists found that the dolphins that lived on land tended to eat more squid, which are often eaten by humpback whale, as compared to the dolphins on land that eat squid.
They also found that a group called the “sea turtle herd” of dolphins lived in the same area, although it was not known whether the dolphins were members of the same group or had different members.
The researchers also found a group known as the “humpback whale group,” which were larger, had shorter tails and had smaller ears than the humpback group, which tended to be smaller and lighter-bodied.
Schlesicher said the research suggests that some of the dolphins could be part of a group where they eat other animals, such the sea turtles that live on the Pacific coast of North America.
“They’re very close to other marine mammals, and it makes them a great source of information,” Schleican said.
Schlichick said that the discovery may help researchers understand how the sea turtle community may change as sea turtle populations decline in the United States, but the findings do not change current theories about the evolution of sea turtles in the ocean.
“There are a lot of theories out there, but I think the best way to study these things is through data,” Schlichick added.
Schlick said the findings will likely be used to study the evolution and dispersal of other groups of marine animals, including whales and dolphins.
“These things can change so quickly, and these species can move very quickly, that it’s a really difficult thing to study,” he said.