Catalogus

1. European estuaries and lagoons fall into three categories in respect of their conservation status and potential for ecological management. (i) Small lagoons, although greatly reduced by natural and man-made changes to the coastal environment, are relatively easily recreated behind longshore shingle barriers, but natural colonization of such habitats may have ceased and successful artificial introduction of species or whole assemblages is hampered by lack of knowledge of the processes structuring natural lagoonal communities. (ii) Small estuaries require very little conservation management, only control of further human exploitation especially in respect of the siting of marinas and other recreational usage. (iii) Large estuaries are in many cases already altered beyond recognition, and such is their economic importance that it is unlikely that the pressures for further reclamation, impoundment, and development will be resisted. Nevertheless, it is may be possible to protect areas within each such estuarine system that could serve as staging posts for migratory birds.