WASHINGTON, June 7 (UPI) -- U.S. researchers say records of dead whales and dolphins washed up on the word's shores can be a useful tool to study the animals' global live populations.
Whales, although Earth's largest creatures, are incredibly hard to study in the open ocean, as are the globe's dolphins, and require boats and aircraft in attempts to conduct visual surveys.
However, recent work by paleobiologist Nick Pyenson of the Smithsonian's National Museum of Natural History has revealed a second, equally valuable, resource for information on cetaceans -- the record of dead whales and dolphins stranded and pushed ashore on beaches around the world.
"Some 30 years ago scientists got serious about the conservation of cetaceans, and began keeping records of strandings," Pyenson says.
Stranding information such as species type, sex, age, size and cause of death have been carefully collected, recorded and archived, a Smithsonian release reported Tuesday. By compiling and comparing data from stranding records and visual sighting records from nearly every ocean in the world, Pyenson said he verified that stranding records "faithfully reflect the number of species and the relative abundance" found in live surveys.
In fact, Pyenson said, stranding data from some parts of the world "almost always provides better diversity information about existing cetacean communities than the live surveys.
"A lot of rare species show up in stranding records that never appear in the live surveys," Pyenson adds.