Have decades of protection allowed the endangered humpback whale (Megaptera novaeangliae) to recover? That’s the question asked this week by the National Oceanic and Atmospheric Administration (NOAA). On Monday the agency proposed removing most of the species’s population sites from the protection of the Endangered Species Act (ESA).

Specifically, NOAA proposes a change in the way it classifies humpback whales. Instead of looking at the species as a whole, the proposal would break the whales into 14 distinct population segments, an ESA indication of significant and discreet groups for a given species. Ten of those would no longer be covered under the act. Two population segments, one in the Arabian Sea and one off northwestern Africa, however, would continue to be listed as endangered. Two more segments, off the coast of Central America and in the western North Pacific, would be listed as threatened.

The move comes in response to petitions from the state of Alaska and the Hawaii Fishermen’s Alliance for Conservation and Tradition, both of which argued that humpback whale populations in their regions of the world have increased and become stable. (The same whales actually migrate in Pacific waters between the 49th and 50th states.) Each petitioner has its own agenda: Removing ESA protections could make it easier to authorize offshore oil drilling around Alaska. The Hawaiian group, on the other hand, based their petition on opposing federal oversight rather than supporting local fishing rights.

NOAA calls the proposal an ESA “success story,” although the truth is actually more complicated. Decades of overexploitation forced the international whaling community in 1946 to limit hunting of humpbacks and then to ban it completely 20 years later. The U.S. followed suit in 1970 by protecting the species under a law that preceded the ESA, which came into being three years later. In 1991 NOAA put a recovery plan in place to “increase humpback whale populations to at least 60 percent of the number existing before commercial exploitation or of current environmental carrying capacity.” Later, with exact historic population levels remaining unknown, the goal was revised to doubling the population within 20 years.

These protection plans have worked, at least to a degree. Although the exact number of humpbacks that swim the world’s oceans is still a mystery, and some counts are at least a decade old, we do know that many of the populations are growing. Most of the distinct population segments (DPS) have a few thousand whales. The West Australia DPS has more than 21,000. On the other extreme, the two DPS groups that NOAA still considers endangered each have fewer than 100 humpbacks.

Even if the whales lose their endangered species status, they will remain covered under the Marine Mammal Protection Act (MMPA) as well as by the international ban on commercial whaling, but is that enough? The Center for Biological Diversity called NOAA’s proposal “premature,” saying ESA protection of humpbacks from threats such as climate change, ocean acidification, ocean noise and habitat disruption could still be valuable. The MMPA fails to cover those conditions.

As with any ESA proposal, the announcement is just the beginning. The public has until July 20 to provide feedback as to whether or not humpback whales should remain protected.

Main photo by Gregory Smith. Used under Creative Commons license. Map courtesy of NOAA