Of all the remarkable species that inhabit the Amazon river basin, few are as iconic or as threatened as Amazon river dolphins. For decades, the pinkish hued dolphins have been targeted by fishermen who view the skilled aquatic hunters as competitors for food -- leading to thousands of the animals to be poached every year by villagers, who often then use their meat as bait. But despite a campaign to save the river dolphins, researchers say that they're continuing to be killed at a troubling rate -- with some populations showing a decline of 10 percent annually.