The fishing vessel Skipjack unloads its catch of red sea urchins in Ketchikan, Alaska. Divers commercially harvest the urchins for their roe, known as uni. Over the past several decades, the fishery has faced challenges. Most recently, market demand for uni has decreased. But more significantly, rapidly increasing numbers of sea otters in Southeast Alaska are moving closer to existing stocks of red sea urchins. Red urchins are a favorite food of the sea otter.