Gulf Coast researchers answer questions about dolphins

By Steve Phillips - bio | email

GULFPORT, MS (WLOX) - The largest population of dolphins in the United States can be found right off the coasts of Mississippi and Louisiana. And that gives scientists at the Institute of Marine Mammal Studies in Gulfport the perfect opportunity to study these smart, energetic sea animals.

Dolphins make people smile.  Those old enough will recall the playful antics and intelligent behavior of the dolphins in the TV series "Flipper." But dolphins are also an important species for providing clues about the health of our environment.

The challenge on any dolphin research trip is first finding them.  In the summertime, that's not usually a problem.  Up to 2,000 dolphins spend the summer in the warm waters of the Mississippi Sound.

"We do think they go where the food is. That's probably one of the reasons there's less, the population diminishes in the winter here in the sound and they go out to deeper waters where it's a little bit warmer and there's more abundant food. We also notice it's a great nursery here. There aren't a lot of predators for them in the sound. The waters are very warm in the summer, spring and summer, which is their calving season," said research leader Dr. Delphine Vanderpool.

As we approached Ship Island, we spotted the first pod of dolphins.

Megan Broadway uses a large lens to photograph the marine mammals.  But these aren't just pictures to capture the moment. She's aiming to create images that can be used in a dolphin identification project.

"We take pictures of the dorsal fins of dolphins. Over the course of their lifetime, they collect nicks and notches on the fin in the center of their back. And we can look at those fins and determine individual dolphins," said Megan Broadway.

The research team has already collected enough digital photos to create a database of dorsal fin images.

"The pattern is unique, sort of like our fingerprints.  And we can track individuals, determine where they like to hang out and spend their time and which dolphins they associate with. The tissue on the back of their dorsal fin is pretty soft tissue, so if they bump into things or if they're in a fight with another dolphin or animal, they can get a little nick or notch and it's like a scar. And it just stays there and we can map the notches," Broadway said.

While Broadway stays focused on sight, other team members concentrate on sound.

"We've known for a long time that there's a variety of vocalizations that each dolphin can produce, but we just don't really know exactly what, if anything, each one means," researcher Shea Eaves said.

"We'll put the hydrophone in the water and the hydrophone is directly linked to a computer program that will record the vocalization, should there be any activity going on in the water," Eaves said.

"We've studied behavior in the past on many of our research programs, research studies. We've also studied the vocalizations. But we've never actually tried to put the two together."

Studying dolphins in the wild is actually a relatively new field of marine science. The Institute for Marine Mammal Studies is a pioneer in that ongoing research effort.

"We're even comparing how they're doing now compared to how they were doing prior to Katrina, because we had started our studies before Hurricane Katrina. So it's interesting to see. In fact, we determined with one of our studies that they have actually had great reproductive success since Hurricane Katrina. Which is a good indication," Dr. Vanderpool said.

Man is the biggest threat to dolphins, both directly and indirectly. Pollution runoff hurts their habitat, while close encounters on the water can also be disturbing.

"We also study how human activity affects them, like the shrimp boats and jet skis and that sort of thing. And we have determined with another study that they do try to avoid boats and jet skis and it actually does change their immediate behavior," Dr. Vanderpool said.

"There has been a significant change in the ecology after Katrina, Gustav and Ike. And it's important for us to see if there's been an impact. Visually, it's fine. But you have to look at a comprehensive analysis to get an estimate of what their health is," said Dr. Moby Salangi, who heads the Institute for Marine Mammal Studies.

The institute will continue to support dolphin research, because the long term health and survival of these animals, is critical to our well being.

"These dolphins are on top of the food chain. And they're a good biological indicator of the environment. And their health is as important as ours. When we know something's wrong with them, it will ultimately affect us," Dr. Salangi said.

Along with being a hub for research projects, the Institute for Marine Mammal Studies is also an education center. The facility includes a museum, gift shop, touch tanks for the children, a variety of aquariums and various other marine life exhibits.

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