Australian officials were initially so concerned about the invasion of the tropical algae Caulerpa taxifolia that they banned most recreational activities around the West Lakes waterway system. Now, according to this article from The Advertiser, the restriction has been lifted in some areas, and beaches were opened for swimming just in time for the start of summer. Authorities aren't concerned with beachgoers spreading the algae, because so little of it grows near the edge of the water. But they may have another reason not to worry, at least for now: barely anyone is showing up to swim. Fishing and other boating bans remain in effect.