Environmental threats induced heavy ecological burdens on the coastal zone of the Bohai Sea, China

The environment of the Bohai Sea is under enormous pressure because rapid economic and urban development associated with increased population inhabiting coastal zone. Environmental threats to ecosystem were analyzed using 2006–2017 statistical/monitoring data from State Oceanic Administration, China. results showed that harmful algal blooms occurred a total 104 times during period 2006–2017, for cumulative area more than 21,275 km 2 . main environmental came offshore oil gas production in form hydrocarbon pollution extraction, as well wastewater sewage. Oil pollution, mainly generated spills, platforms large number vessels/ports, was found cause very severe negative impacts on environment. Another threat excessive groundwater exploitation which has resulted seawater intrusion soil salinization occurrence 90% areas around Sea. maximum distance by 40 32 inland, respectively. Contamination terrestrial pollutants identified another affecting quality Approximately 840,000 t carried into sea major rivers annually 2010–2017. standard discharge rate terrestrial-source sewage outlets did not exceed 50%; however, only 13.12% adjacent (rivers) met requirements functional marine areas. also frequency storm surges 8.83 per year resulting annual direct losses reached (RMB) 1.77 billion 2006–2017. highlight urgent need implement an ecological management strategy reduce heavy burdens zone eco-environmental come wastewater, eco-environment. have eco-environment Chinese Yuan • pressure. A caused frequent spill accidents vessels/ports. ?90% coast input one important threats.