LONG-TERM BENTHIC MONITORING OF A DENSE EFFLUENT DISCHARGE TO SEA

The paper describes and discusses the effect on the local benthic comm unity of the discharge of a dense, saline, effluent into a nearshore a rea of the North Sea. The monitoring programme continued through the t wenty-year period from 1970 until 1989 and includes effectively five y ears pre-discharge data. Samples were taken from fixed stations with a grab sampler and the invertebrate fauna were identified, wherever pos sible, to species. In addition, the particle size distribution of the sediment in each sample was determined. The discharge has had a clear effect on the benthic community. This extensive dataset, with its clea r gradient of effect, also offers the opportunity of comparing the eff ectiveness of species and family level identification when studying th e effect of disturbance. In this case the impacted area was as readily identifiable from the family as the species level data.