- 3.9.7. Pressure impact on coastal waters and the wider marine environment of the Black Sea

Since the early 1960s, noticeable and well documented alterations have been observed at various trophic levels of the Black Sea ecosystem. Marine research carried out in the late 1990s81 indicated that the changes of the ecosystem were the result of a combination of human interventions, occurring simultaneously in the Black Sea drainage basin and in the marine environment: (a) the manipulation of the hydrological regimes of the outflowing rivers, (b) the increasing discharge of nutrients from rivers and direct land-based sources, (c) the introduction of exotic species (such as the jellyfish Mnemiopsis), and (d) selective and excessive fishing. (4.9.7. Coastal waters and the wider marine environment of the Black Sea - p.144)