非投饵网箱鲢鱼、鳙鱼对藻类的遏制效果

Inhibiting Effect of Silver Carp and Bighead Carp on Algae in Bait-free Cage Culture

利用鲢鱼(Hypophthalmichthysmolitrixi)、鳙鱼(Aristichthysnobilis)滤食藻类生物的特殊功能,在相同水体条件的围隔网箱内投放不同数量的鲢鱼、鳙鱼,观测其对水中藻类生物滤食的强度与作用。结果表明:未养鱼的对照网箱内,藻类数量逐渐增加,到第16天时数量比箱外增加45.29%;网箱内放养鲢鱼、鳙鱼能够有效地抑制藻类的增加,第4天时放养鲢鱼、鳙鱼各处理的藻类数量比对照减少73%～83%,第7天时减少比例达到82%～88%。网箱养殖鲢鱼、鳙鱼与否的水色和藻类优势种群都有明显的改变。

The effect of silver carp (Hypophth almichthys molitrixi) and bighead carp (Aristichthys nobilis) on algae in cage culture was studied. The results showed that algae increased gradually in no culture cage, and on the 16th day algae increased by 45.29% over outside the cage. But culturing silver carp and bighead carp could inhibit algae from increasing. Compared with control treatment, culturing silver carp and bighead carp in cage decreased algae by 73%～83% on the 4th day and 82%～88% on the 7th day under different fish densities. The water color and algae dominant population in the cage under culturing the fishes were also obviously different from those under culturing no fishes.