(AP) ATLANTIC CITY, N.J. -- A new study by Rutgers University finds that New Jersey's coastal waters are not as polluted as scientists had thought.
Marine scientists studying pollution-sensitive sea creatures on the ocean floor since 2007 found their numbers and types indicate healthier water conditions than expected. The study involved scooping small animals from 153 ocean floor sites along New Jersey's 127-mile coastline from Sandy Hook to Cape May.
"Conditions were actually pretty good, pretty healthy," said Michael Kennish, the project's lead investigator.
While state and federal officials declared New Jersey's near-shore waters as 100 percent impaired in 2004, there were no major die-offs of fish or bottom-dwelling sea creatures. That prompted the Rutgers team to wonder why, and to look more closely at exactly what type of animals were on the ocean floor.
The scientists did not find that the waters were clean, but that they were cleaner than expected. The survey found 28 percent of the sites sampled in 2007 and 2009 were rated as unpolluted, based on the high percentage of pollution-sensitive animals living there. The remaining 72 percent were considered slightly polluted.
"We just didn't find a heavily impacted environment," Kennish said. "What we saw was typical of what you would see in a healthy community."
The researchers collected samples from a vessel equipped with an underwater shovel called a Van Veen Grab, designed to take precisely measured bites of the bottom. The scientists washed each sample through a sieve, preserved all the animals that remained, and brought them back to shore for sorting, counting and identification. They collected about 113,000 organisms from 273 different species.
Other research techniques were used as well to complement the ocean floor data.
The key was seeing what types of small bottom-dwelling animals are present in a given location. In healthy areas, animals like clams, snails and shrimp can be expected, along with tinier invertebrates. In contrast, in heavily polluted areas, one would expect to find different types of animals dominating the environment, like certain species of worms that not only tolerate but thrive on sewage sludge, for example. That sort of environment was rarely encountered, Kennish said.
He said the study also shows that dissolved oxygen levels are not the only way to determine the health of coastal waters.
The study was funded by the New Jersey Department of Environmental Protection and the U.S. Environmental Protection Agency. A DEP spokesman did not immediately return a message seeking comment on the results of the study.