Larger fish were able to swim away from the oil during the spill. Mummichogs Also known as killifish, mummichogs can break down petroleum hydrocarbons and excrete them as carbon dioxide and water molecules through their digestive system. Their egg has a tough outer membrane, which may keep oil from penetrating and damaging the embryo. Fish that feed on creatures that are directly affected by the oil spill will be more at risk for toxin-related problems than fish feeding on plankton within the water column. Horseshoe Crabs Most adults have migrated to the continental shelf in the Atlantic. When the water warms, they will return to spawn in the Delaware Bay. Adult and juvenile crabs that do not move offshore could encounter tarballs on the bay’s floor and become oiled. If oil or tarballs are on the beaches or in the sediment during spawning, they could affect the survival and development of the crabs’ eggs and larvae. Green alga Golden brown alga Herring egg Oyster larvae Striped bass larva Giant water flea Barnacle nauplius larva Copepod Crab zoea larva Sea nettle ephyra Snail larva Diatom American eel Blue heron Silver-haired bat Bald eagle Osprey American shad Flounder Oyster Bed Catfish New Jersey chorus frog Coastal plain frog Mud turtle Horseshoe crab Atlantic sturgeon River otter Diamondback terrapin Tiger salamander Belted kingfisher Benthic community species magnified Species are not to scale Mallard duck River herring Menhaden Red drum Sheephead minnows Mummichog A Drop of Fresh Water Plankton are tiny plants, animals or bacteria and serve as the basis of the food web. They float in the water column and are sensitive to changes in water quality. There are many different species in the Delaware estuary. Phytoplankton are capable of photosynthesis and live in the part of the water column that light can penetrate. They are single-celled organisms that include diatoms and other algae and are consumed by zooplankton. Contaminants can enter the food web at this level. Zooplankton are filter feeders that get food from particles suspended in the water. Since zooplankton consume phytoplankton, they are an important link in the food web and can convey contaminants to fish. Birds More than 300 species of birds are found in the Delaware estuary. Only a fraction of the birds immediately affected by the oil spill were recovered and cleaned, and survived to be released. During the nesting season, oil that comes in contact with an egg can permeate the shell and kill the embryo. Oil was seen on some of the three pairs of nesting bald eagles along the Delaware River. The nesting area, hard hit with a heavy coating of oil, was given a priority status for the cleaning. Larger Water Fowl Canada geese that are slightly oiled may be able to fly away from the spill area. During preening or feeding, they can ingest oil and become sick. Mussels function as biofilters. This can lead to a toxic concentration of oil byproducts in their fatty tissue. As with oysters, mussels can be affected by direct exposure to their tissue and smothered by heavy crude oil. Vegetation The wetlands that ring the Delaware estuary are vital to maintaining clean water and a healthy ecosystem. They are a spawning and nursery area for fish and help remove nutrients from the water column. Mallards and wood ducks feed on small invertebrates and submerged vegetation by sifting sediment through their bills. Fiddler Crabs Studies of the fiddler crab after an oil spill in Massachusetts uncovered behavioral problems. The crabs live in burrows in marsh areas. During warm weather, they come out at low tide to eat and mate. In the winter, they burrow deeper to hibernate. After the oil spill, the crabs studied did not burrow deeper and froze over the winter. Oyster Bed Eastern oysters were in a period of inactivity during the colder months, so they were not feeding as much at the time of the spill. As with mussels, the oysters can ingest oil particles during feeding. Red Knots The endangered bird eats the eggs of the horseshoe crab during a stopover on its migratory path to the Arctic. Canada geese Loggerhead turtle Migratory Turtles The loggerhead, Kemp’s ridley, leatherback and green turtles will migrate to the bay area in the spring. Any effect from the oil would most likely come from eating contaminated prey. Loggerheads’ diet includes horseshoe crabs. Benthic Community Benthic algae, microorganisms growing on the bottom sediment of the water body, are a source of food and habitat in the marsh area. The benthic community includes tiny worms, isopods, clams, mussels, shrimp, snails and crabs that live in the bottom sediment of the estuary. Filter feeders, such as oysters, siphon their food from the water. Deposit feeders, such as snails and shrimp, sift through the rich soil and feed on the organic matter. The eggs and larva of fish that spawn on the river bottom or in vegetation where there are still concentrations of oil may be killed or suffer deformities and impaired growth from the toxic effects of the oil. Some oil can seep into holes left by burrowing worms, mussels and plant roots. Once in these subsurface areas, the oil will be covered by the sediment during the back-and-forth motion of tides. ▼ 95 76 295 295 676 476 130 322 TACONY-PALMYRA BR. BETSY ROSS BR. B. FRANKLIN BR. DEL. MEM. BR. WALT WHITMAN BR. 70 PENNSYLVANIA 40 49 73 NJ. TPK. A 10-mile stretch of the shipping lane was closed and restrictions were temporarily placed on larger vessels in the river after the oil spill. Ships in the area at the time needed to be cleaned before leaving the river. 1 Delaware River Shoreline Oiling Light Very Light Medium Heavy Unsurveyed Oiling MILES 0 5 *Map represents data as of Feb. 23; map does not represent precise amounts or locations of all the oil spill SALEM Delaware River GLOUCESTER CAMDEN BURLINGTON PHILA. DELAWARE CHESTER DELAWARE NEW JERSEY 495 Site of oil spill Oil trench sites N ■ Command center closed in April. ■ Various vessels are continuing to monitor and maintain the affected areas. ■ 221,910 gallons of oily liquid have been recovered. ■ 17,761 tons of oily solids (cleanup materials and oil) have been collected. ■ 389 birds have been released and 186 birds are reported deceased. ■ One year after the spill the Coast Guard has declared the spill cleaned except for a 200-yard stretch in Paulsboro, the site near the spill. Oil Spill Facts The Venezuelan crude from the Athos I spill is very viscous and sticky, like peanut butter. It is used to make asphalt and weathers slowly. Oil will rapidly spread to a thin film on the water surface. Pooled oil accumulates in subsurface depressions. In the Athos I spill pooled oil was found at the collision site. Cleaning Up the Spill 0 50 100 150 200 250 300 350 (1975–2004) In thousands of gallons Major Oil Spills in the Delaware River and Bay Athos I ’04 B-115 ’99 Coastal Oil Eagle ’95 ’89 Grand Eagle ’85 Corinthos ’75 Presidente Rivera Fiddler crab (male) Evaporation Looking Ahead Before The oil binds with sediment particles as it saturates the ground. This requires cleanup crews to remove particles and the oil together. During After Ground-Saturation Removal oil soil particle Booms Within a week of the spill, 91,100 feet of booms were set out along the shoreline and in sensitive areas to combat spread. Skimming Boats used booms to collect oil from the water surface. V-SORS The Vessel-Submerged Oil Recovery System is a pipe with attached chains and snares, composed of thin sheets of absorbent polypropylene. It is lowered into the water and towed at low speeds by a boat to collect oil on the river bottom. Submerged oil recovery A work platform with a crane and a submersible pump is lowered to the site of pooled oil. A diver uses a maneuverable nozzle and siphons the oil into decanters on the adjacent barge. The oil is then stored in containers, and the water is discharged into a boomed area. Warmer Weather When the temperature rises, oil becomes softer and “re-oiling events” or “seeping” may occur. Cleanup officials consider dredging the oil to be a last resort, since it would likely reintroduce pollutants from sediment such as lead and mercury into the water column. The cost of cleanup is $175 million, of which $125 million is from Tsakos Shipping, owner of Athos I. The remaining $50 million is from the Oil Spill Liability Trust Fund. Responders were allowed to use various removal methods. ▼ ▼ The oil’s chemical ingredients, hydrocarbons, will change to a gaseous form and evaporate shortly after the spill. This can contribute to air-quality issues. The smell of oil at the scene is evidence of this evaporation. Precipitation will return the hydrocarbons back to the land. The National Oceanic and Atmospheric Administration Damage Assessment and Restoration will release a technical data report scheduled for release in 2006. Absorption Oxidation, a chemical reaction that occurs when the oil is exposed to air, will increase the density of oil and cause it to sink. Oxidized oils are more toxic to aquatic life. Tarballs may persist for several months. Some have reached the shoreline as far as the outer coast of the Delaware Bay. Tarball The effects of the Athos I oil spill: On Thanksgiving weekend last year, the Greek tanker spilled an estimated 265,000 gallons of a thick Venezuelan crude oil into the Delaware River • More than 215 miles of shoreline in the Delaware estuary were contaminated with oil • The spill happened when most animals were prepared for winter and many plants were dormant • Migratory fish, birds and dolphins had already left for warmer climates • While some of the damage was seen immediately, scientists worry that the hidden effects could harm the environment for decades. Imbalanced A Natural World Turtles Adults can survive a spill if steps are taken to clean them. Not so for baby turtles. Offspring that were cleaned and rehabilitated in the February 2000 oil spill at the John Heinz National Wildlife Refuge at Tinicum were born deformed or died. SOURCES: Thomas L. Bott, Ph.D., Stroud Water Research Center; Delaware River Basin Commission; Dr. Susan E. Ford, Haskin Shellfish Research Laboratory; Susan Soltau Kilham, Ph.D., Department of Bioscience and Biotechnology, Drexel University; Danielle A. Kreeger, Ph.D Delaware Estuary Program; Dr. Richard Larsen, Professor Emeritus, Department of Natural Sciences and Environmental Resources, University of Illinois at Urbana- Champaign; Ed Levine, James Hoff, NOAA; O'Brien & Gere; Christopher K. Sommerfield, College of Marine Studies, University of Delaware; James Spotilla, Ph.D., Department of Bioscience and Biotechnology, Drexel University; Suzanne Thurman, Marine Education, Research and Rehabilitation Institute (MERR); Tri-State Bird Rescue & Research, Inc; Maya K. van Rossum, Delaware River Keeper; U.S. Coast Guard; U.S. Fish & Wildlife Service ■ BOOKS DataStreme Ocean, American Meteorological Society, 2004; Life in the Chesapeake Bay, Alice Jane Lippson & Robert L. Lippson, 1997; Living Resources of the Delaware Estuary, Delaware Estuary Program, 1995; The Scientific Characterization of the Delaware Estuary, Delaware Estuary Program, 1996; Sources, Effects and Sinks of Hydrocarbons in the Aquatic Environment, The American Institute of Biological Sciences, 1976; Angler's Guide to Fish, 1997; The Audubon Society Field Guide to North American Birds, 1977; Atlantic & Gulf Coasts, 1988 KEITA S. SULLIVAN and MARI A. SCHAEFER / The Philadelphia Inquirer Soil The soil is made of more complex material than a rocky or sandy shoreline and is a source of nutrients for plants. A6 B www.philly.com THE PHILADELPHIA INQUIRER Monday, November 28, 2005 THE PHILADELPHIA INQUIRER www.philly.com A7