More than 130 bottlenose dolphins have washed ashore in the Gulf of Mexico's mysterious die-off, but the deeper question for many has been, how many more go unrecorded? Marine animal corpses that wash ashore are widely regarded as the "tip of the iceberg," notes the NRDC, and new research shows that that iceberg is likely vast—that the real carnage is likely 50 times greater.
The Conservation Letters study used five years of stranding data for 14 different Gulf species and measured that against known population sizes and survival rates. The results vary widely by species—one in 30 dead sperm whales are thought to wash ashore, while that number is one in 200 for a striped or spinner dolphin. (The bottlenose dolphin isn't assigned a number because of the intricacies of its population.) "To be sure, the Conservation Letters paper is a first take," notes the NRDC's Michael Jasny. But if the oil spill is determined to play a role in the die-off, the feds will again have to come up with an undiscovered-deaths multiplier with which to hold BP accountable. Click here for more. (Read more dolphins stories.)