Though the slogan “Save the Whales” has, these days, something of a sepia-toned sound to it, we aren’t doing a terribly good job of it, a new study suggests. In the last 40 years, the study says, humans were implicated in the majority of whale deaths with known causes.
Researchers from Woods Hole Oceanographic Institution looked at government reports of whale strandings, fatalities, and necropsies along the Eastern coast of the US and Canada from 1970 to 2009. Their sample included 1762 deaths involving eight species of whales. Of all those deaths, 502, or 28 percent were attributable to “human interaction,” with 323 whales mortally entangled in fishing gear and 171 whales hit by boats. 248 whales died of natural causes. The cause of death was only known in under half the cases (43 percent). (A cause of death would be unknown if, for example, a whale was spotted floating dead in the water but was not examined.) Of the 750 deaths with known causes, humans were responsible for 67 percent.
There are laws to protect whales from these fates. In particular, the researchers point to a 2008 US law, the Ship Strike Rule, that restricts boat speeds in certain coastal areas and certain times of year in order to protect whales. The researchers mention that after the first year of the law, only 20 percent of boats were respecting the speed limits, according to the Marine Mammal Commission’s 2010 annual report. The researchers also mention a 2011 paper showing that there was little evidence that the law had any effect over the course of its first two years.
The Woods Hole analysis itself, however, only goes through 2009, and thus says little about how the 2008 law is working to protect whales. In order to examine that with greater clarity, the researchers recommend that next year, when the Ship Strike Rule is due to expire or be renewed, their analysis be updated with as much new data as are available so that it will be possible to compare whale deaths before and after passage of the law.
Whale photo via by Evadb; Edited by jjron/Wikimedia Commons