Fuente: Rutgers Media Relations
Expuesto el: viernes, 18 de mayo de 2012 19:09
Autor: Rutgers Media Relations
Asunto: Some Good News About the Ocean from Rutgers
| Rutgers marine scientists have discovered that creatures living in seafloor sediments near the New Jersey coast are doing better than scientists had believed. Researchers Patricia Ramey, Michael Kennish, and Rose Petrecca have conducted a comprehensive community assessment, and constructed a “biotic index” – a measure of an environment’s health – by cataloging invertebrate animals living in the ocean bottom from Sandy Hook to Cape May, from the beach to three miles offshore.
“We wanted to find out what effect hypoxia (insufficient oxygen) was having on benthic invertebrates,” Kennish said. “The DEP had declared the near-shore ocean 100 percent impaired in 2004 based on the level of dissolved oxygen, but we didn’t really know how this would affect the animals living in those waters.” The DEP and the EPA funded this study. Kennish and his colleagues turned to the benthic invertebrates because they are relatively long-lived, sensitive to pollution and, unlike fish, can’t swim away if the environment proves hostile. If the waters were seriously impaired, the impact would be toughest on them. The method was straightforward but painstaking. During August and September in 2007, 2009 and 2010, a team of marine The scientists did not find that the waters were clean, but they were cleaner than expected. The biotic index and the statistical results indicated that 28 percent of the stations sampled in 2007 and 2009 were rated unpolluted, based on the high percentage of pollution-sensitive animals living there. The remaining 72 percent were considered slightly polluted. “The environmental quality is actually quite good at most of the stations we sampled,” said Kennish, a research professor in the Institute of Marine and Coastal Sciences in the School of Environmental and Biological Sciences. “In fact, we had trouble finding impaired stations – only six out of 153 stations showed signs of initial degradation.” Media Contact: kbranson@ur.rutgers.edu
|
Their report casts doubt on the usefulness of dissolved oxygen as the only criterion for assessing the health of coastal ocean waters. In 2002 and 2004, the New Jersey Department of Environmental Protection and the United States Environmental Protection Agency declared the near-shore waters 70 percent (2002) and 100 percent (2004) impaired based on levels of dissolved oxygen below 5 milligrams per liter of water. And yet, Kennish, the Rutgers lead investigator of the project, noticed there were no reports of massive fish kills or loss of bottom-dwelling animal life off the coast in those years. 
scientists sampled a total of 153 randomly chosen sites from Sandy Hook to Cape May. They collected samples from a research vessel equipped with a Van Veen Grab – an underwater shovel designed to take precisely measured bites of the bottom. In this case, each sample measured 0.04 meters squared. The scientists washed each sample through a 500-micron sieve. All invertebrates remaining on the sieve were preserved in jars and brought back to shore for sorting, counting and identification. The researchers collected approximately 113,000 organisms, belonging to 273 species. Armed with a list of species, and knowing how abundant each species was at each sampled site, scientists used a variety of statistical methods to assess the ecological status of New Jersey's coastal marine waters. 
