湛江球形棕囊藻赤潮除藻试验

2005年4月,在广东湛江港赤潮区采集球形棕囊藻(Phaeoecystisglobosa),在室内用新洁尔灭和异噻唑啉酮两种除藻剂进行棕囊藻的杀灭试验。结果表明,新洁尔灭对赤潮水体中球形棕囊藻的72hLC50为0.96mgL-1;与新洁尔灭相比,异噻唑啉酮的除藻效果更为明显,其对球形棕囊藻的72hLC50为0.54mgL-1。新洁尔灭和异噻唑啉酮复配时具有协同作用,可提高除藻能力,新洁尔灭和异噻唑啉酮浓度比为1.3:0.3(配比为4.3:1)时除藻效果最优,2d的除藻率达到89%,协同指数为0.78。两种除藻剂对鲻鱼(Mugilcephalus)苗72h的毒性试验表明,新洁尔灭和异噻唑啉酮浓度分别在2.0和0.3mgL-1以下除藻是安全的。

Experiments in Removing Red Tide Alga Phaeoecystis globosa from Zhanjiang by Algicides

Algicides, bromogeramine (B) and isothiazolone (I), were used for removing Phaeoecystis globosa in the experiments in containers of 450 ml seawater with 109 cells L-1 of algae collected in April 2005 from Zhanjiang Seaport, Guangdong Province, where red tide had happened in January 2004. The results showed that LC50 of isothiazolone was 0.54 mg L-1 for the algae treated for 72 hours, which was more effective than that ofbromogeramine (LC50=0.96 mg L-1). Alga-removal effects of both algicides used in combination showed synergistic action. The proportion of bromogeramine to isothiazolone being 4.3 to 1 gave best result. Toxicity tests on little fishes (Mugil cephalus) showed that 2.0 mg L-1 bromogeramine or 0.3 mg L-1 isothiazolone were safe for fishes in the removal of algae in 72 hours.