Benthic Repopulation of the Raritan River Estuary Following Pollution ABATEMENT1

摘要: A total of 69 samples benthic animals was taken in the lower 20 km Raritan River estuary from 1957 to 1960. During 1957, under heavily polluted conditions, no frcshwater spccics wcrc discovered. Of I7 marinc species found, barnacle BaEanus improuisus extended 8.5 above river mouth; remaining were confined seaward 4.6 river. In January 1958, a trunk sewer system began operation Valley, and pollution abated Rapid repopulation occurred. The sequence numbers freshwater invading colonizing bottom sediments followed 1959, most obvious change 1958 distribution density Balanus improuisus. Thcsc barnacles coated all firm substrata previously uninhabited section, extending upriver limit salt penetration. 12 stations sampled both 1959 yielded 6 21 marine 8 28 1959. 1960, frcshwatcr continued increase, but there slight decrease number species. Dominant components fauna oligochaetes Limnodrilus spp., leech Erpobdella punctata, bivalve Sphaerium sp. 7,102 organisms/ma found at one Marinc that invaded following abatement aro placed five groups -three pioneers, secondary invaders, progressive pcnetratorson basis their year arrival, penetration, length stay. By end study, biotic recovery had so progressed plot quantitative illustrated classic V-shaped curve for estuaries. similarly shaped obtained population clensitics.