藍藻(zao)(zao)水(shui)(shui)(shui)主要(yao)呈(cheng)現(xian)出灰綠(lv)色(se)或(huo)(huo)藍綠(lv)色(se)，主要(yao)是(shi)(shi)由于水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)底(di)質(zhi)老化或(huo)(huo)有(you)(you)(you)機(ji)(ji)物(wu)(wu)(wu)大量(liang)(liang)增加，水(shui)(shui)(shui)溫升(sheng)高，水(shui)(shui)(shui)體(ti)營養不平衡(heng)，該(gai)種水(shui)(shui)(shui)體(ti)中(zhong)缺少氮環境(jing)導(dao)致其他藻(zao)(zao)類不能存活，唯(wei)有(you)(you)(you)藍藻(zao)(zao)可以大量(liang)(liang)繁(fan)殖。藍藻(zao)(zao)初期，水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)顏色(se)為翠綠(lv)色(se)，很快水(shui)(shui)(shui)面會浮(fu)一(yi)層(ceng)綠(lv)膜，如不及(ji)時(shi)(shi)處理，藍藻(zao)(zao)會很快漫布(bu)整(zheng)個水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)。藍藻(zao)(zao)的(de)(de)(de)危害：消耗(hao)水(shui)(shui)(shui)體(ti)溶解(jie)(jie)氧(yang)。當水(shui)(shui)(shui)體(ti)中(zhong)的(de)(de)(de)藍藻(zao)(zao)形成水(shui)(shui)(shui)華時(shi)(shi)，一(yi)方(fang)面嚴(yan)重抑(yi)制了浮(fu)游植物(wu)(wu)(wu)因光合作(zuo)用(yong)所產生(sheng)(sheng)(sheng)的(de)(de)(de)氧(yang)氣(qi)，另一(yi)方(fang)面也阻隔了空氣(qi)中(zhong)的(de)(de)(de)氣(qi)體(ti)進入水(shui)(shui)(shui)中(zhong)，因而導(dao)致水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)中(zhong)溶解(jie)(jie)氧(yang)嚴(yan)重不足，長時(shi)(shi)間(jian)出現(xian)缺氧(yang)或(huo)(huo)者亞缺氧(yang)狀(zhuang)態(tai)，使水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)水(shui)(shui)(shui)體(ti)持續(xu)惡化，抑(yi)制了水(shui)(shui)(shui)體(ti)中(zhong)有(you)(you)(you)益(yi)浮(fu)游生(sheng)(sheng)(sheng)物(wu)(wu)(wu)的(de)(de)(de)生(sheng)(sheng)(sheng)長繁(fan)殖、阻礙(ai)了其它藻(zao)(zao)類的(de)(de)(de)光合作(zuo)用(yong)，使水(shui)(shui)(shui)體(ti)中(zhong)的(de)(de)(de)絲狀(zhuang)藻(zao)(zao)類和浮(fu)游藻(zao)(zao)類等不能合成本身所需要(yao)的(de)(de)(de)營養物(wu)(wu)(wu)質(zhi)而死亡。產生(sheng)(sheng)(sheng)有(you)(you)(you)毒(du)(du)有(you)(you)(you)害物(wu)(wu)(wu)質(zhi)。藍藻(zao)(zao)大量(liang)(liang)死亡時(shi)(shi)會產生(sheng)(sheng)(sheng)藍藻(zao)(zao)毒(du)(du)素、大量(liang)(liang)羥胺及(ji)硫化氫(qing)等有(you)(you)(you)毒(du)(du)有(you)(you)(you)害物(wu)(wu)(wu)質(zhi)嚴(yan)重敗(bai)壞(huai)水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)環境(jing);另外死亡的(de)(de)(de)藍藻(zao)(zao)釋(shi)放大量(liang)(liang)有(you)(you)(you)機(ji)(ji)質(zhi)，散發腥臭味，刺激了化能異(yi)養細菌(jun)的(de)(de)(de)滋生(sheng)(sheng)(sheng)，其中(zhong)大部分化能異(yi)養細菌(jun)對水(shui)(shui)(shui)生(sheng)(sheng)(sheng)動(dong)物(wu)(wu)(wu)及(ji)植物(wu)(wu)(wu)來說并不是(shi)(shi)有(you)(you)(you)益(yi)菌(jun)，而是(shi)(shi)致病菌(jun)，從而進一(yi)步對水(shui)(shui)(shui)生(sheng)(sheng)(sheng)態(tai)系(xi)統(tong)構成威脅。