Impact of Man on Coastal Marine Ecosystems

Abstract

Dissolved Pb, ranging from 5 – 15 ng/kg in open-ocean surface waters up to 50 ng/kg in highly polluted coastal waters, enters marine food chains at the 10−8 g Pb/g fw level by adsorption onto surfaces of algae which are consumed by herbivores. Dissolved Pb and biological productivity tend to be inversely correlated in surface ocean waters. Benthic filter-feeders consume particles containing 10−6 g Pb/g wet wt, yet the 10−9 g Pb/g fw concentrations in their tissues are the same as those in benthic grazers whose food contains 10−8 g Pb/g fw. The isotopic composition of dated coastal basin sediment cores conclusively documents the increasing pollution of the marine biosphere by industrial Pb, derived primarily from gasoline Pb-alkyls.