The U.S. military's tech still isn't sophisticated enough to consistently tell Aunt Irma apart from Terrorist Jane. (Unless Jane is holding an AK-47, that is.) But what about telling a sea turtle apart from a dolphin? Yeah, um, the Army's still working on that one too.

In the Army's latest round of requests for research proposals, they're asking for sophisticated Sonar sensors that'll allow personnel in the Army Corps of Engineers to distinguish between a bevy of different underwater animals, including turtles, dolphins and sturgeon. (Marine biology degree, not required.)

See, the Corps has a bit of a problem on its hands: One part of its mandate is to clear American waterways that are used by military vessels, whether deploying to a warzone or headed to the location of a natural disaster. Without ongoing maintenance, the Army's new solicitation warns, those water channels "would represent a threat to national security."

But Corps personnel need to be extra careful when they're working in waterways. Two federal laws, the Endangered Species Act and the Marine Mammal Protect Act, prohibit them from negatively impacting any endangered underwater species – including "killing, injuring, or harassing" – during their projects. In the waterways where Corps typically work, the solicitation notes, they've got to watch out for six species of sturgeon and five species of sea turtle, along with the Florida Manatee and dolphins.

Enter Sonar. Already, the technique – which sends out sound waves and then uses the returning echos to detect objects or map locations – is widely used by the military, Army Corps included. Navy submarines, for example, rely on Sonar as a key navigational tool. Ships use the technique to spot underwater threats, like enemy subs. And the Army Corps of Engineers use Sonar to map waterway floors and monitor marine life.

But the Army Corps has been warned before that its Sonar detection systems don't pass muster where endangered species are concerned: In 2009, the U.S. Fish and Wildlife Service criticized current methods as "inadequate" and asked the Corps to develop "a significantly enhanced technique" that could more accurately spot at-risk marine life.

Right now, Sonar devices can easily detect underwater animals. When a Sonar sensor emits sound waves underwater, and those waves strike an animal, the difference in density between that animal and its surroundings translates to a different echo in return. The next stage of the process, and what the Army Corps wants, is a little tougher: It's after sensors that distinguish large marine life from small, and then determine whether the animal is an endangered species. In particular, the Army wants the device to classify "manatees, sea turtles, sturgeons and dolphins."

Tough, but not impossible. Already, Sonar can be used to evaluate the mass of an animal, by analyzing the echoes sent back from underwater to estimate both size and location. Adding yet another layer of sophistication to the devices, so that they can automatically distinguish massive, sluggish pairs of manatees from a sleek pod of dolphins, and tell human operators exactly where the animals are, seems like a viable order.

There is, however, one small problem: Active sonar, the kind the Army's solicitation suggests using, also interferes with the echolocation of whales and dolphins – sometimes with deadly results. Naval activities alone have caused more than 50 marine mammal strandings or beachings since 1986, and led to several lawsuits from conservation groups. Accurate detection and annihilation, all wrapped into one? At least this time, that's actually not the Army's ideal outcome.