Estimates of early-industrial inputs of nutrients to river systems: implication for coastal eutrophication

Although coastal eutrophication is generally recognised as a recent phenome non related to the well-documented increase in riverine nutrient delivery d uring the last 30 or 40 years, a few historical records paradoxically show that, in some places like the Southern Eight of the North Sea, or the North ern Adriatic, algal proliferation as intense as presently observed was alre ady regularly occurring at the end of the 19th century. Estimated riverine nutrient loads from diffuse sources or from domestic point sources of waste water at that time are too low to account for these observations. We attem pted a retrospective evaluation of the possible contribution of industrial activity to nutrient river loading. The figures indicate that, by the end o f the last century, large scale use of traditional processes in textile and paper industries, in tanneries, candles factories and others was responsib le for a dominant part of the nutrient load carried by rivers in Western Eu rope and could have caused nutrient inputs to coastal zones similar to the present ones. (C) 1999 Elsevier Science B.V. All rights reserved.