North Atlantic right whales now grow smaller than they did 40 years ago, and new research suggests a leading cause is the damage human activity inflicts on the critically endangered mammals.
The findings, published today in the journal Current Biology, reveal that when fully grown, a North Atlantic right whale born today would be expected to be about one meter shorter than a whale born in 1980. Currently, full-grown members of the species average 13 to 14 meters in length (43 to 46 feet).
"The first inkling that we had came from the folks who were collecting the data in the field, where, as the story goes, they saw what looked to be a really young whale, a calf, or maybe one- or two-year-old," said Joshua Stewart, a postdoctoral researcher with the National Oceanic and Atmospheric Administration's (NOAA) Marine Mammal and Turtle Division and lead author of the new study. "But it turns out that they were actually 5-year-old or 10-year-old whales that were smaller than a typical 2-year-old."