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  • Eco-Profile: Delaware Bay

    Delaware Bay

    Photo Credit: Common Good Productions

    The Delaware Bay is New Jersey’s largest estuary, mixing fresh water from the Delaware River with the saltwater of the Atlantic Ocean.

    The Bay makes up New Jersey’s southern border, beginning with Cape May in New Jersey and Cape Henlopen in Delaware, and stretching northwest to the Delaware River, touching on Wilmington, Delaware; Philadelphia, Pennsylvania; and Trenton, New Jersey.

    Like all of New Jersey’s coastline, the Delaware Bay is important both economically and ecologically.

    One of the world’s largest freshwater port systems, approximately 85% of all oil shipped to the East Coast of the United States passes through the Delaware Bay.

    Every year, more than 70 million tons of cargo is also moved through these waters.

    Wildlife Spotlight: Horseshoe Crabs and the Red Knot

    Horseshoe crabs spawning in Delaware Bay

    Photo Credit: Common Good Productions

    The Delaware Bay is a site of hemispheric importance for wildlife migration. Each year, hundreds of thousands of migrating birds pass through, stopping along the shore.

    Westerly wind currents act as a funnel for migrating birds, carrying them over Delaware Bay. The marshes and tributaries of the Delaware River also provide a stopover and wintering habitat for more than 200 species of migrating birds, including Canada geese. This area attracts eco-tourists from around the world.

    Air currents aren’t the only reason that migrating birds stop here. The bay is home to the world’s largest horseshoe crab spawning event. Tens of thousands of horseshoe crabs climb onto the bay’s beaches to lay their eggs in the spring.

    One female crab can lay as many as 90,000 eggs each season, creating an important food source for hungry migrating birds like the Red Knot.

    A Red Knot in Delaware Bay

    Photo Credit: US Fish and Wildlife Service

    Red Knots winter in the Antarctic and summer in the Arctic, and they stop in the Delaware Bay to refuel on crab eggs in the middle of their annual global trek.

    These small birds fly from pole to pole each year, making one of the longest migrations of any animal species on earth.

    Horseshoe crabs also play an important role in protecting human health. Horseshoe crab blood is used by the medical industry in a test to determine whether IV drugs, vaccines, and medical devices contain harmful bacterium that can withstand regular methods of sterilization. The test can also detect contagions like spinal meningitis and urinary tract infections.

    NJ Wildlife Spotlight: Crabs

    A female blue crab

    Photo Credit: South Carolina Dept of Natural Resources

    Blue Crabs

    Crabs are abundant all along the New Jersey coast, from the Hackensack River to the Delaware Bay. However, blue crabs seem to be the most beloved and sought-after species in New Jersey. The blue crab's scientific name is Callinectes sapidus. When translated from Latin, this means 'beautiful savory swimmer.' Males have blue claws and females have red-tipped claws.

    A study by Rutgers University reports that nearly three-quarters of the state's saltwater fishermen go crabbing and that crabbing comprises roughly 30 percent of all marine fishing activity.

    Other crabs that can be found in the Delaware Bay include hermit crabs, horseshoe crabs, rock crabs, spider crabs, ghost crabs, and mole crabs.

    Delaware Bay and Oil Spills

    The Athos I leaking oil

    Photo Credit: Delaware Estuary Watershed Database
    and Mapping Project

    Given its rich biodiversity and importance as a commercial hub, the Delaware Bay is uniquely vulnerable to oil spills.

    This vulnerability was exposed in 2004, when an oil tanker named the Athos I stuck a submerged anchor, spilling 265,000 gallons of Venezuelan crude oil into the Delaware River near Philadelphia, PA. Some 115 miles of shoreline were affected.

    Waterfowl were covered with oil and killed by the spill, which occurred near Little Tinicum Island and the John Heinz National Wildlife Refuge. These areas are used year-round by some waterfowl and are occupied even more extensively during the fall and spring migrations along the Atlantic Flyway. Delaware's Pea Patch Island, which contains the largest heronry north of Florida on the East Coast, was also threatened by the spill.

    A diver covered in oil from the Athos I Spill

    Photo Credit: Delaware Estuary Watershed
    Database and Mapping Project

    Because the Delaware Bay is a migratory hub, the impact of an oil spill or pollution event varies depending on the time of year. The bay is most at risk during the fall and spring, when the most wildlife migrates through.

    In the wake of this disaster, citizens and lawmakers called for tougher fines and penalties for oil spills in New Jersey waters.

    In 2005, the State of New Jersey raised the cap on oil spill liability to 1,200 dollars per gross ton for vessels, with a maximum of 50 million dollars.

    The Athos I is just the most recent ship to spill oil into the Delaware Bay.

    The Mystra spilled 10,000 gallons of crude oil in 1997
    The Anitra spilled 42,000 gallons of crude oil in 1996
    The Kentucky spilled 13,000 gallons of crude oil in 1994