渤海湾
Pollution: Severe eutrophication caused by polluted runoff has made red tides in the Bohai Bay common. Combined with overfishing, this has put pressure on once-abundant fish stocks. Biological pollution is also a problem, with illegal ballast water discharges creating a strong danger of invasive exotic species. Habitat destruction caused by reclamation has damaged coastal wetlands, intertidal flats and shallow water hatcheries essential for many fish and bird species.