The horseshoe crab is in no danger of extinction. In fact, where I live, our local coastal restoration project has had 3 phenomenal successes. First, the cultivation of mangroves has reversed coastal erosion. Second, the water quality of the bay has improved to the point that consumption limits on local seafood have been lifted. Finally, third, the horseshoe population has increased more than 100 fold in the last 5 years. Unfortunately for harvesters, the crabs breed in protected mangrove preserves.