All it takes is a license and a cutting rake to harvest rockweed anytime and anywhere along most of Maine's long coast. Other than in a large bay in far eastern Maine, there's no fisheries management plan for the common seaweed that grows along the shore. But work is now underway to develop a statewide plan to manage rockweed, which is processed in Maine into fertilizer, animal feed supplements, food and other products with an estimated value of $20 million a year.