海水酸化与升温对孔石藻(Porolithon cf.onkodes)生长钙化的影响  

The effects of ocean acidification and warming on the growth and calcification in coralline alga Porolithon cf.onkodes

作　　者：杨芳芳[1,2,3] 肖志梁 韦章良[1,2,3] 黄怡 龙丽娟 YANG Fangfang;XIAO Zhiliang;WEI Zhangliang;HUANG Yi;LONG Lijuan(Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;CAS Tropical Marine Biological Research Station in Hainan,South China Sea Institute of Oceanology,Sanya 572000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院热带海洋生物资源与生态重点实验室(中国科学院南海海洋研究所),广东广州510301 [2]南方海洋科学与工程广东省实验室(广州),广东广州511458 [3]中国科学院海南热带海洋生物实验站,海南三亚572000 [4]中国科学院大学,北京100049

出　　处：《热带海洋学报》2023年第1期87-97,共11页Journal of Tropical Oceanography

基　　金：国家自然科学基金(42176157);中国科学院重点部署项目(ZDRW-XH-2021-2-06);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0402);中国科学院战略性先导科技专项(A类)(XDA13020203)。

摘　　要：钙化海藻作为一类重要的钙化生物,不仅能构建稳固礁体,而且部分藻株能诱导珊瑚幼虫附着变态,在珊瑚礁生态系统中具有极其重要的生态功能。但是,面对未来海水酸化与升温的共同作用,珊瑚藻生理过程会发生怎样的变化,目前尚不清楚。本文选取了广泛分布于珊瑚礁生态系统中的一种钙化海藻——孔石藻(Porolithon cf.onkodes)为研究对象,采用3个CO_(2)分压(pCO_(2):400μatm、1200μatm、1800μatm)和温度(27℃、30℃、32℃)对其培养1个月,通过监测藻体生长和钙化等参数的变化情况,探究海水酸化与升温对活体与死亡的孔石藻的影响。研究结果表明,当温度从27℃升高到30℃时,活体孔石藻生长钙化没有受到显著影响;但当温度提高到32℃时,藻体生长钙化显著下降,甚至出现溶解现象,净钙化速率从206.99nmol·cm^(–2)·h^(−1)(pCO_(2):400μatm;温度:27℃)降至–42.22nmol·cm^(–2)·h^(−1)(pCO_(2):1200μatm;温度32℃)。类似地,pCO_(2)增加也会显著抑制活体孔石藻的生长钙化,而且该抑制作用随着CO_(2)分压增加而增强。此外,升温与酸化对藻体叶绿素a含量和净钙化速率均具有交互作用。与活体孔石藻相比,死亡的藻体骨骼更易受到高温与酸化影响,当温度升高至30℃或pCO_(2)提高至1200μatm时,死亡藻体骨骼净溶解速率均显著增加,而且高温与酸化的交互作用加速了骨骼溶解速率。研究结果表明了酸化与升温不仅会影响活体孔石藻的生长钙化速率,而且会加速礁体主要组分(藻体碳酸钙骨骼)的溶解速率,进而影响到珊瑚礁生态系统。本文研究结果对预测未来气候变化对珊瑚礁生态系统的影响、制定珊瑚礁生态系统保护与修复策略均具有重要的理论价值和生态意义。Calcified macroalgae,an important calcifying group widely distributed in reef ecosystems,plays vital roles in the primary productivity and reef frameworks construction.Furthermore,several species of calcified algae can induce the coral larval settlement,which is closely related to the sustained development of coral reef ecosystem.However,it is not clear how calcified algae will response to ocean acidification and warming.In this study,healthy and bleached Porolithon cf.onkodes were exposed to different pCO_(2)(400μatm,1200μatm,1800μatm)and temperatures(27℃,30℃,32℃)for one month,respectively.The results showed that the growth rate and net calcification rate of living P.onkodes were not significantly affected when the temperature increased from 27℃to 30℃,however,these physiological parameters declined significantly at 32℃.The net calcification rate decreased from 206.99 nmol·cm^(–2)·h^(−1)(400μatm pCO_(2)+27℃)to–42.22 nmol·cm^(–2)·h^(−1)(1200μatm pCO_(2)+32℃).Similarly,the enhancement of pCO_(2)also significantly inhibited the growth and calcification in living P.onkodes.Additionally,warming and acidification had interactive effects on the chlorophyll a content and net calcification rate.Compared with living P.onkodes,dead or bleached algal skeletons were more susceptible to warming and acidification.When the temperature was 30℃or the pCO_(2)was 1200μatm,the net dissolution rate of dead algal skeletons increased significantly.Furthermore,the adverse effects of warming were exacerbated when high temperatures coincided with acidification.The results revealed that acidification and warming not only affected the growth and calcification rates of living algae,but also accelerated the dissolution rate of calcium carbonate skeleton,which can affect the coral reef ecosystem.The study may contribute to predict the impacts of climate change on reef ecosystem to protect reef ecosystems.

关 键 词：酸化 升温 孔石藻 钙化 生长 珊瑚礁生态系统 

分 类 号：P735.52[天文地球—海洋生物学]