1. Parker, C.A. and O’Reilly, J.E. (1991) Oxygen depletion in Long Island Sound: A historical perspective, Estuaries 14, 248–264.
2. Common Wadden Sea Secretariat (1996) Black Spots in the Wadden Sea, Wadden Sea Newsletters No. 2.
3. Prena, J. (1994) Oxygen depletion in Wismar Bay (western Baltic Sea) 1988, Arc. Fish. Mar. Res. 42, 77–87.
4. Gamenick, I., Jahn, A., Vopel, K. and Giere, O. (1996) Hypoxia and sulphide as structuring factors in a macrozoobenthic community on the Baltic shore: colonization studies and tolerance experiments, Marine Ecology Progress Series 144, 73–85.
5. Nichols, F.H., Cloern, J.E., Luoma, S.N. and Peterson D.H. (1986) The modification of an estuary, Science 231, 567–573.