温度对5种大型海藻氮磷吸收能力的影响

Effects of temperature on the uptake capacities of five large seaweeds for nitrogen and phosphorus

通过测定不同温度(20、25、30和35℃)下长茎葡萄蕨藻(Caulerpa lentillifera)、齿形蕨藻(Caulerpa serrulata)、线性硬毛藻(Chaetomorpha linum)、缢江蓠(Gracilaria salicornia)和芋根江蓠(Gracilaria blodgettii)等5种海南常见大型海藻对无机氮(dissolved inorganic nitrogen,DIN)和无机磷(dissolved inorganic phosphorus,DIP)的吸收速率,评估了其营养盐吸收能力。结果显示,温度对大型海藻的营养盐吸收速率具有显著影响,5种大型海藻吸收营养盐的最适温度范围均为30~35℃。在实验条件下,芋根江蓠和线形硬毛藻对营养盐的吸收速率显著高于其他3种海藻,其中,线形硬毛藻对DIN的吸收速率最高,为(5.078±0.666)μmol/(g·h),芋根江蓠对DIP的吸收速率最高,为(0.561±0.053)μmol/(g·h),表明这2种海藻对营养盐具有较强的吸收能力,可以作为高效修复富营养化水域的优选海藻。不同形态营养盐去除率的结果显示,在任何温度下,5种大型海藻均优先吸收NH+4-N,对NO-3-N、NO-2-N和DIP的吸收几乎同步进行。本研究筛选了适合中国南方地区的海水养殖尾水排放及海洋生态环境生物治理优势海藻种类,结果可为水产养殖尾水的生物修复提供理论基础。

The nutrient uptake capacities of five large seaweeds(Caulerpa lentillifera,Caulerpa serrulata,Chaetomorpha linum,Gracilaria salicornia,and Gracilaria blodgettii)were studied under laboratory condition.Seaweeds were held at the temperatures of 20,25,30 and 35 oC.After 5 h exposure,the nutrient uptake rates of five seaweeds in different temperature were determined and compared.The optimum temperature range for the absorption of dissolved inorganic nitrogen(DIN)and dissolved inorganic phosphorus(DIP)by five seaweeds were between 30℃and 35℃.The nutrients uptake rates of G.blodgettii and C.linum were significantly higher than that of C.lentillifera,C.serrulata and G.salicornia.The maximum DIN uptake rate was(5.078±0.666)μmol/(g·h)by C.linum and the maximum DIP uptake rate was(0.561±0.053)μmol/(g·h)by G.blodgettii,indicating that G.blodgettii and C.linum had high uptake capacities for nutrients,and were more suitable for the bioremediation of eutrophication area.Moreover,the removal efficiency of different forms of nutrients by five seaweeds was also determined and compared under the same experimental condition.Five seaweeds selectively absorbed NH+4-N prior to NO-3-N,NO-2-N and DIP,and the absorption of NO-3-N,NO-2-N and DIP were almost synchronous.Overall,the study screened the optimized seaweeds for marine aquaculture sewage discharge and marine eco-environment management,and will provide theoretical basis for the bioremediation of aquaculture sewage in southern China.