The Clean Water Act sets national goals of making all our lakes, rivers, streams, and estuaries swimmable and fishable, and restoring their ecological integrity. To tell if we are achieving these goals, EMAP-Estuaries is developing a monitoring program that will gauge conditions for ecological health, water contact, and fish consumption in most of the estuaries of the United States. EMAP-E checks water clarity and marine debris at each of the approximately 600 sampling locations in the Virginian and Louisianian Provinces.
Marine debris is examined by the presence or absence of debris on the bottom.
Presence of debris is an aesthetic indicator of the condition of estuarine resources. An estuarine water body is designated as poor with respect to marine debris if greater than 40 percent of its bottom sediments contain debris. A water body is considered marginal if 15-40 percent of its bottom sediments have marine debris and is considered in good condition if less than 15 percent of the bottom sediments have debris. Water clarity is measured by the proportion of surface light reaching 1 meter into the water column. Poor light penetration is defined as less than 10 percent of surface light reaching a depth of 1 meter.