Saturday, January 20, 2007

Dolphins give great opportunity to be observed by scientists

About 50 dolphins that have taken up residence in Kinko Bay off Kagoshima are providing researchers with a great opportunity to observe the mammals.

For two days each month, a team of researchers, led by Kagoshima University Prof. Akihiko Shinomiya and Kagoshima Aquarium official Jun Hirose, studies the dolphins' behavorial patterns.
To help them in their research, 28 of the dolphins that are distinguishable by their color and markings, such as scratches and cuts, have been given names--IK1, IK2, etc.

Although satisfied with their efforts to date, Shinomiya and Hirose admit there is still much to learn about the mammals. For example, they are not sure what kinds of fish they consume and where they mate.

Observations of the dolphins began in 1999, with researchers and students recording visual data from boats and small planes.

Looking out over the water from a research boat, Shinomiya said, "They swim over a wide area, so it's difficult to keep track of individual dolphins."

"I can see a dolphin over there," a student yelled, as the boat sailed slowly along the coast of the bay, 40 minutes after leaving Kamoike Port in Kagoshima. The dolphin's dorsal fin dipped and rose above the water about 50 meters away.

Shinomiya, 60, and Hirose, 31, hopped from the research boat onto a smaller craft, which took them to the other side of the dolphin.

Shortly after, Hirose called to those on the boat, "Look behind us," drawing their attention to the fins of three or four dolphins bobbing among the waves before they periodically dived and resurfaced a few minutes later.

The dolphins did not seem to be bothered by the researchers taking pictures of them.

Among those on the survey team was Yoshimi Miyagawa, 23, a senior currently analyzing the DNA of dolphins as part of her thesis before she graduates in March. She said she can identify 28 of the dolphins by their markings, which she has committed to memory.

"It's taken us eight years to get to this stage," said Shinomiya, who teaches marine ecology at Kagoshima University's faculty of fisheries. "There is a long way to go from here, but we are happy to live near the water that feeds these dolphins."

Quick "Facts about Dolphins"