牡蛎礁是蓝色碳汇的重要组成部分,其通过钙化作用、生物同化作用以及生物沉积作用等来完成对碳的封存,以达到碳中和的目的.目前我国关于热带天然牡蛎礁碳库储量的研究较少.文章评估了海南岛近岸4处典型天然牡蛎礁(文昌龙楼、文昌会文、昌江昌化和儋州海头)的碳库储量,并分析了其时空变化特征及其原因.结果表明,4处礁区的现存总碳库储量为18 734.6 t C,长期总碳库储量为16 883.08 t C.其中海头、昌化、龙楼和会文的现存碳库储量及单位面积平均碳库储量分别为15 923.42 t C(3.46 kg C/m2)、2 119.01 t C(6.09 kg C/m2)、494.53 t C(2.49 kg C/m2)和 197.63 t C(3.67 kg C/m2),长期碳库储量分别为14 334.11、1 898.99、460.08和189.91 t C.海头和昌化牡蛎礁单位面积碳库储量可能受到高温或低温的影响,在7月和12月出现下降趋势,而在水温适宜的10月和2月,牡蛎快速生长,同时导致单位面积碳库储量的上升,值得注意的是牡蛎的繁殖可能是10月份单位面积碳库储量上升的另一重要因素.2022年6～12月龙楼地区的牡蛎遗壳脱落导致牡蛎礁单位面积碳库储量连续下降,而2022年7月、10月和2023年2月会文地区牡蛎的死亡率升高,牡蛎活体壳和软体部分固碳量下降.研究表明,海南岛近岸天然牡蛎礁总体固碳效率较高,固碳潜力大,其碳储量受温度、海况及周边养殖活动的影响较大.研究同时发现上述区域仍面临人为干扰和系统退化的风险,亟需制订相关保护政策并开展有效的人工增殖,以保证其良好的固碳功能.
ASSESSMENT OF TOTAL CARBON POOL STORAGE AND CHANGES OF TYPICAL OYSTER REEFS IN THE EAST AND WEST COASTS OF HAINAN ISLAND
Oyster reef is an important component of blue carbon sink,which completes carbon sequestration through calcification,biological assimilation,and biological deposition,by which carbon neutralization is achieved.Currently,research on the carbon storage capacity of tropical natural oyster reefs in China is limited.The carbon pool of four typical oyster reefs(Longlou in Wenchang(LW),Huiwen in Wenchang(HW),Changhua in Changjiang(CC),and Haitou in Danzhou(HD))in Hainan Island was evaluated based on the oyster samples collected from June 2022 to February 2023,and the characteristics of temporal and spatial variation and their causes were analyzed.Results show that the total existing carbon pool storage of the four reef areas were 18 734.6 t C and the total long-term carbon pool reserves were 16 883.08 t C.The existing carbon pool reserves(average carbon pool reserves)in HD,CC,LW,and HW were 15 923.42 t C(3.46 kg C/m2),2 119.01 t C(6.09 kg C/m2),494.53 t C(2.49 kg C/m2),and 197.63 t C(3.67 kg C/m2),respectively,and the long-term carbon pool reserves are 14 334.11,1 898.99,460.08 and 189.91 t C,respectively.The carbon storage per unit area of HD and CC oyster reefs might be affected by high or low temperature,and the carbon storage per unit area decreased in July and December.However,in October and February,when water temperature was suitable,the oyster grew rapidly,leading to the increase in carbon storage per unit area.It is worth noting that the reproduction of oysters may be another important factor for the increase of carbon storage per unit area in October.From June to December 2022,the loss of oyster shells in LW area led to the continuous decrease of carbon storage per unit area of oyster reef,while the mortality rate of oysters in HW area increased in July,October 2022,and February 2023,resulting in a decrease in carbon fixation capacity of living shell and soft part of oysters decreased.Result shows that the carbon fixation effiiciency of natural oyster reef in Hainan Island was relatively high,and its carbon storage was greatly affected by temperature,sea conditions,and surrounding aquaculture activities.These areas are still facing the risk of anthropogenic disturbance and system degradation,calling for the urgent need for relevant protection policies and effective artificial proliferation to ensure their good carbon sequestration function.
万方数据
维普
