Flying back and forth over Cape Cod Bay, a survey plane spotted a half dozen of the world’s rarest creatures: North Atlantic right whales. Such sightings are good news. The species hovers near extinction—by one estimate, fewer than 360 remain. Each time researchers locate a whale, they take pictures...

The public display industry keeps many species of marine mammals captive in concrete tanks, especially whales and dolphins. The Humane Society of the United States believes that these animals are best seen in their natural coastal and ocean environments instead of being held captive simply to...