Catching a glimpse of the largest animal ever to reside on our planet requires no foray into science fiction; it swims in our oceans to this day. The blue whale possesses a heart so large a child could crawl through its chambers. Kids can now do just that with last month's arrival at the American Museum of Natural History of a new exhibition dedicated to our great marine mammals.
The show, "Whales: Giants of the Deep," presents a gallery of models, films, fossils, and interactive displays illustrating the evolution and lives of whales, dolphins, and porpoises (referred to collectively as cetaceans) and their historic relationship to people and the culture of seafaring.
As anyone who read a certain whale tale in their high school English class will remember, that relationship has been fraught. Many whale species have been driven to the brink of extinction over the last centuries by commercial whaling fleets. During the second half of the 20th century, a global moratorium on whaling managed to slow and largely end the unrestricted killing of whales.
In that time, work by the International Whaling Commission (on whose scientific committee I serve), coupled with legislation enacted by a number of countries, has provided vital protection for a number of threatened and endangered species, including the blue whale. At the same time, whales became an important symbol of the environmental movement.
But whales face new challenges in today's oceans. While their industrialized slaughter has largely ceased, a number of direct and indirect human-generated threats have emerged that could jeopardize their long process of recovery.
One threat is man-made noise. Many cetacean species rely on acoustics and echolocation to communicate and find prey underwater. But the days of a quiet ocean are gone. Sounds from ships and military and industrial activities can interfere with these important behaviors. Sounds in a variety of frequencies often overlap with those of cetaceans, and can blanket large areas where whales breed or feed.
A changing climate may affect whales by changing the distribution of fish and other prey. During the last decade, melting sea ice has opened new shipping channels in previously unnavigable Arctic waters. This could put the bowhead whale and other species at greater risk from ship strikes and exposure to higher levels of noise and pollution.
Some of the most threatened cetaceans are smaller dolphins and porpoises, with relatively limited ranges in coastal and riverine habitats. A scale model of one such species, New Zealand's Hector's dolphin, is included in the show. This and other species have become threatened largely due to coastal development, fishing-net entanglement and, in some cases, direct hunting.
To counter these threats, conservation groups are working with local fishers and authorities across the globe. Fortunately, a key obstacle once thwarting the development of effective conservation measures for cetaceans -- a lack of knowledge about their essential biology, behavior and ecological needs -- is being addressed with a relatively new suite of research tools. Scientists are tracking whale movements using satellite tags, remotely monitoring whale communications and noise using underwater microphones and conducting genetic analyses. These strategies help us determine biologically important areas for whales and the levels of threats they face in unprecedented detail.
Using a mix of old and new methods, scientists can finally illuminate the largely hidden world of cetaceans and, most important, determine what they need to survive in their sometimes rapidly changing environments. These findings can in turn be used to create even more progressive policies and protections that reduce threats and protect the most important habitats for whales, dolphins and porpoises.
The new exhibit provides a fantastic opportunity to appreciate the complex behaviors, cultural importance and immense size of these amazing creatures. By capturing our imaginations, it both educates us and nurtures a deep desire to protect and conserve these giants of the deep.
Howard Rosenbaum directs the Ocean Giants program for the Wildlife Conservation Society and is a senior scientist with the Sackler Institute of Comparative Genomics at the American Museum of Natural History.