Live

Watch CBSN Live

Sonar Suspect In Dolphins Wash-Ups

Investigators are trying to determine whether two different types of sonar used by a nuclear-powered submarine training off the Florida Keys played a role in last week's stranding of dozens of rough-tooth dolphins.

When the massive stranding occurred near Marathon, the submarine was 39 nautical miles away, Navy officials say. Nearly half of the stranded dolphins have since died, and at least two dozen are being cared for by researchers and volunteers at rehab centers around the Florida Keys area.

Some theories suggest marine mammals may have a sensitivity to active sonar, which enables vessels to spot targets by emitting sound waves that bounce off other objects, revealing distance and location. Marine mammals rely on sound for everything from feeding to finding a mate to communicating.

"It's way too early for us to know what caused this, and our scientists are collecting as much data as possible," said Laura Engleby, a biologist with the National Oceanic and Atmospheric Administration.

Necropsies and tests are underway on the dead animals, a process that may take months to complete.

Pamela Sweeney, the Stranding Director for the Marine Animal Rescue Society, explained to The Early Show co-anchor Hannah Storm that sonar is "just one of many theories about why animals strand. And from what I understand, that Navy ship was near Key West, which is quite a ways away from where these guys were.

"(Sonar signals can) cause these animals to rise to the surface sooner than they would normally. So, in essence they have what in humans would be the bends. And that can be fatal or cause hemorrhaging. So that definitely throws them off, and we can look for evidence of that. But right now, it's just one of many theories."

Sweeney was in the water at the Southeast Fisheries Science Center in Key Biscayne, Fla. with two of the dolphins who washed up, nicknamed Notch and Naia. She tells Storm efforts to save them are going "as well as can be expected." The main concerns involve dehydration and infection.

"Volunteers," Sweeney points out, "do get attached. They name them, things like that. So it's a little bit personal. You do get attached a little bit. But our focus remains clear."


The Marine Animal Rescue Society says items beachgoers commonly carry can help stranded dolphins. For instance, beach towels: After immersing the towel in water, it can be laid on the dolphin for skin protection. Dolphin skin burns very easily. Umbrellas, for shade, also may be used to protect the dolphins' sensitive skin.

The society is "in urgent need" of supplies: Pedialyte, gallon-sized purified water, wetsuits, Baytrol, Gentamyacin, multivitamins, Vitamin E, Silinium, gallon-sized Zip-Loc bags, sizes C & D batteries, gift certificates for Home Depot, hydrophone, ice, banners, food for volunteers.

Supplies can be delivered to MARS' site on Virginia Key. For more information, call 305-546-1111.

Monetary donations for supplies can be sent to:
Marine Animal Rescue Society
PO Box 833356
Miami, FL 33283

View CBS News In