Number of algal blooms							Algal bloom occurrence area
	2011	2012	2013	2014	2015		km2	2011	2012	2013	2014	2015
Bohai sea	13	8	13	11	7		Bohai sea	217	3869	1880	4078	1522
Yellow sea	8	11	2	2	1		Yellow sea	4242	1333	450	19	48
Average	10.5	9.5	7.5	6.5	4		Average	2229.5	2601	1165	2048.5	785