The EPA has compiled ten methods that have the potential to assess sediment quality relative to chemical contaminants (EPA 1989). Some of the methods involve chemical analyses that allow for the establishment of chemical specific criteria (e.g., an acceptable level of phenanthrene in sediments). These methods should allow risk to be assessed using the Quotient Method with sediment concentrations rather than water concentrations. Other methods involve only biological observations that limit the results to assessment of whether a sediment is toxic. Still others combine chemical and biological measurements. Brief descriptions of the ten methods are given in Table 4.4.
Aesthetics. Adverse aesthetic impacts include unpleasant sights, noxious odors, and unpleasant tactile sensations (such as from contact with the algae Pillayella litoralis). Adverse aesthetic impacts discourage recreational uses and thus can have significant economic impacts. Multiple sources of materials, including combined sewer overflows (CSOs) and urban runoff, as well as commercial ships, recreational boaters, and beachgoers can cause aesthetic offense. Aesthetic impacts can be quantified, albeit through indirect methods. For example, many jurisdictions survey beaches for plastics and other floatable solids and report numbers of objectionable items per unit length per time period.
The range and volume of plastic wastes that end up in the world's oceans are enormous. Typical are a variety of bottles, ropes, and fishnets. There are no reliable estimates of the total volume of such wastes nor the contribution from urban areas to the marine environment. Beach surveys finding condoms and plastic tampon inserters do not identify reliably the source of debris as wastewater, stormwater, recreational boaters, or beachgoers. Plastic debris is not only of aesthetic concern but also can carry pathogens, be mistaken for food and harm marine animals that ingest it, or entangle organisms and strangle them. The Center for Marine Conservation's Coastal Cleanup program cleared 4,347 miles of beaches and waterways of almost 3 million pounds of trash in 1991. Approximately 60 percent of the debris was plastic (Younger and Hodge 1992).
Some of the materials that cause the most aesthetic offense in the coastal marine environment are those that both mobilize public concern and cause significant environmental threats. Floatables, oil and grease, and materials that wash up on shorelines are visible signs of patterns of waste disposal and general human conduct that may also have other impacts on coastal water. As such, they are powerful symbols of more widespread problems. Garbage and syringes washing up on the New Jersey beach in the summer of 1987 did more to alarm the public than did numerous scientific studies. Similarly, when a lawyer jogging along Quincy Bay realized he was treading in human feces, the lawsuit that led to the beginning of the effort to