SUSAN PHILLIPS/WHYY – New Jersey’s back bays, those lush wetlands that sit between the barrier island beach towns and the mainland, are home to unknown numbers of baby sharks that feast on the American eel, crabs and small fish that thrive in the coastal salt marshes. Giving birth to litters in those food-rich shallow waters like Little Egg Harbor is just about all the maternal care given to the shark pups by their mothers, who swim back out to the Atlantic Ocean soon afterwards …