Horseshoe Crabs
Although there may officially be no mascot for the Delaware Bay, a perfect, arguably the best, candidate for this position would be the Atlantic Horseshoe Crab. These ancient creatures exit the waters of the Delaware Bay every year in mind-boggling numbers to breed at their highest concentration anywhere in the world. That's right, despite having a range from Maine to Mexico, the Delaware Bay is home to the largest concentration of these creatures in the world. Despite this, their population is a fraction of what it used to be. Not only have we noticed this decline, but the ecological recipients of their services have felt this blow as well.