An assessment of the ecological condition of Long Island Sound, 1990-1993

摘要: Data from the Environmental Protection Agency's (EPA) Monitoring and Assessment Program (EMAP) 1990 to 1993 were used assess condition of Long Island Sound (LIS) estuary. Ambient water, sediment biota collected during summer months 53 LIS stations using an unbiased sampling design. The design consists two subunits, proper, small estuaries (<2.6 km2) at margins Sound. Selected indicators included: benthic species composition, abundance biomass; fish composition gross external pathology; physical chemical characterization toxicity; water clarity quality. Results four-year indicated that 28(±11)% areal extent proper had a index < zero (impacted) 51(±12)% area was impacted. Analysis results other also shows particularly affected. For example, 42(±10)% exhibited toxicity, significant contamination evident in 22% estuaries. Low dissolved oxygen (D.O.) concentrations (<5 ppm), however, appeared affect only deeper open waters western LIS. Approximately 48(±12)% documented exposure least moderate D.O. stress ppm). overall this monitoring study indicate anthropogenic impacts have occurred if remediation take place, specific localized problems would need attention. Point source non-point nutrient inputs Sound, which are believed be primary causative factor for observed hypoxic conditions,