2种大型海藻养殖对水体DIC含量的影响

Impact of Aquaculture of 2 Macroscopic Algae on DIC Content in Seawater

为了解大型海藻养殖对水体溶解无机碳(DIC)含量的影响,明确其在光照、黑暗及光暗交替条件下水体DIC含量的变化过程,将取自温州洞头近海养殖的鼠尾藻、羊栖菜在实验室内进行养殖试验,设置光照、黑暗、光暗交替处理,测定了养殖水体DIC含量,并对DIC变化速率进行了分析。结果显示:在光照条件下,鼠尾藻DIC的消耗速率比羊栖菜高(P<0.05)。在黑暗条件下,鼠尾藻DIC释放速率比羊栖菜高(P<0.05)。随着光暗交替周期的延长,鼠尾藻、羊栖菜DIC的消耗速率均是先升后降,鼠尾藻DIC消耗速率比羊栖菜高。近海海藻养殖时随着光暗环境的交替进行,将发生光合作用消耗DIC、暗呼吸释放DIC的转换。总体而言,海藻养殖最终降低了水体DIC含量,能够促进大气CO2向海水转移,而且随养殖大型海藻的收获,形成一个"可移出的碳汇",大力发展大型海藻养殖具有重要的碳汇生态意义。

In order to understand the impact of macroscopic algae aquaculture on the content of seawater dissolved inorganic carbon（DIC）, and clarify the change process of DIC content in different conditions（light,dark, alternation of light and dark）, Sargassum thunbergii and Hizikia fusiforme collected from WenzhouDongtou offshore were cultivated in laboratory, three treatments（light, dark, alternation of light and dark） wereset in the experiment, DIC contents were measured and DIC change rates were analyzed. The results showedthat： DIC consumption rate of Sargassum thunbergii was higher than that of Hizikia fusiforme under lightcondition. DIC release rate of Sargassum thunbergii was higher than that of Hizikia fusiforme under darkcondition. DIC consumption rate of both Sargassum thunbergii and Hizikia fusiforme increased at first and thenreduced under the light and dark alternation condition, and DIC consumption rate of Sargassum thunbergii washigher than that of Hizikia fusiforme. With the carrying out of the light and dark alternated process,photosynthetic consumed DIC and dark respiration released DIC converted continuously. Overall, theaquaculture of macroscopic algae decreased the DIC content of seawater and promoted the atmospheric CO2 transfer to seawater. With the harvest of macroscopic algae, a＂removable carbon sink＂was formed. The development of macroscopic algae aquaculture had important carbon sink ecological significance.