龙须菜海藻场构建及其对水环境因子的影响

Structure of Gracilaria lemaneiformis bed and its effect on the factors of water environment

2010年2月～2010年5月,在汕头南澳岛海域,通过设计不同的主绳间距和苗绳间距研究了龙须菜(Gracilarialemaneifomis)海藻场的构建模式及其对养殖附近海域环境的影响。结果表明,在不同的筏式养殖密度中,主绳间距在0.3～0.4m,苗绳间距在0.1～0.2 m之间,龙须菜的生长速率较高。龙须菜海藻场构建后,养殖海域的无机氮(IN)平均值为133.40±15.18μg·L^(-1),对照海域的无机氮平均值为153.81±11.97μg-L^(-1),养殖海域显著低于对照海域(p<0.05);养殖海域的无机磷(IP)平均值为13.16±1.38μg·L^(-1),对照海域的平均值为15.55±1.05μg·L^(-1),养殖海域的显著低于对照海域的(p<0.05)。养殖海域叶绿素(Chl-a)的平均值为1.86±0.23 mg·m^(-3),对照海域的平均值为2.44±0.30mg·m^(-3),养殖海域显著低于对照海域(p<0.05);养殖海域的透明度平均值为1.76±0.09 m,对照海域的透明度为1.41±0.15 m,养殖海域显著高于对照海域(p<0.05):养殖海域的溶解氧(DO)平均值为9.55±0.46 mg·L^(-1),对照海域的平均值为8.90±0.37 mg·L^(-1),养殖海域显著高于对照海域(p<0.05)。研究表明,构建龙须菜海藻场可以显著增加海水中DO浓度,抑制微藻生长繁殖,吸收水体营养盐,改善水质质量。

We investigated the structure of Gracilaria lemaneiformis bed and its effects on water environment from February to May, 2010. The results showed that the growth rate of G. lemaneiformis was the best in the condition of thick distance ranging from 0.3 to 0.4 m and seedling distance from 0.1 to 0.2 m. The structure of G. lemaneiformis affected the water quality. In the cultural area, the average concentrations of inorganic nitrogen （IN）, inorganic phosphorus （IP）, Chlorophyll-a （Chl-a）, dissolved oxygen （DO） and average transparency were （133.40±15.18） μg.L1, （13.16±1.38） μg.L1, （1.86±0.23） mg·m^-3, （9.55±0.46） mg.Ll and （1.76±0.09） m, respectively. In the control area, they were （153.81±11.97） μg.L1, （15.55±1.05） μg.L1, （2.44±0.30） mg·m^-3 and （8.90±0.37） mg＇L1 and （1.41±0.15） m, respectively. The concentrations of IN, IP, Chl-a were significantly lower in the culture area than those in the control area, but dissolved oxygen concentration and transparency were significantly higher in the culture area than those in the control area. Hence, the structure of G. lemaneiformis bed may improve the water quality by increasing the concentration of DO, restricting the growth of microalgae and reducing the concentration of IN and IP.