西太平洋M2海盆区巨型底栖动物分布及其与结核赋存条件的关系研究  

Distribution of benthic megafauna in the M2 basin of the western Pacific Ocean and its relationship with nodule storage conditions

作　　者：刘莉红 何雪宝 吴燕红[1] LIU Lihong;HE Xuebao;WU Yanhong(Minzu University of China,Beijing 100081,China;Third Institute of Oceanography,MNR,Xiamen 361005,China)

机构地区：[1]中央民族大学,北京100081 [2]自然资源部第三海洋研究所,福建厦门361005

出　　处：《应用海洋学学报》2024年第3期395-404,共10页Journal of Applied Oceanography

基　　金：国家重点研发计划(2022YFC2804003);北京先驱西太多金属结核勘探项目(121166202001)。

摘　　要：深海平原和海盆是地球上最大的生态系统,其部分区域海底沉积物上赋存有大量的多金属结核,结核不仅增加了海底栖息地复杂性和空间异质性,也为附着生物提供硬质基底,形成了特殊的深海底栖生态系统。本研究利用深海摄像技术获取的高清海底图像,分析了西太平洋北京先驱多金属结核合同区M2-B1区块巨型底栖动物生物多样性、群落结构及其对结核大小和覆盖率的响应。结果发现了9门25个类群巨型底栖动物,包括多孔动物门、棘皮动物门、节肢动物门、刺胞动物门、脊索动物门、环节动物门、苔藓动物门、软体动物门、原生动物门等,平均密度为0.19 ind./m^(2)。西太平洋巨型底栖动物主要类群与东太平洋克拉里昂-克利珀顿区(CC区)基本一致,平均密度略低于CC区。多金属结核的覆盖率和结核粒径大小是该区动物类群密度的主要环境驱动因素,巨型底栖动物密度整体与多金属结核覆盖率呈正相关关系,与结核粒径呈负相关关系;而不同动物门类密度与结核覆盖率和粒径的关系存在多种模式,多孔动物和棘皮动物密度随结核覆盖率增加而增加,刺胞动物和软体动物在结核覆盖率大于64%后随结核覆盖率增加而增加,棘皮动物和刺胞动物密度在粒径大于3.15 cm后保持稳定不变。本研究结果初步揭示了该区域巨型底栖动物分布格局及其驱动因素,将可为未来深海采矿环境影响评估提供重要的科学支撑。Deep-sea basins and plains,the most extensive ecosystems on Earth,harbor vast areas whose seafloor sediments are stored with numerous polymetallic nodules.These nodules not only enrich the spatial complexity and heterogeneity of seafloor habitats but also offer hard substrates for sessile organisms,thereby fostering a unique deep-sea benthic ecosystem.Utilizing high-resolution seabed imagery captured by advanced deep-sea underwater camera,we conducted a comprehensive analysis on the diversity and community structure of benthic megafauna in the M2-B1 region of Beijing Pioneer Hi-Tech Development Corporation s Polymetallic Nodule Contract Area in the western Pacific Ocean,along with their responses to nodule size and coverage.Our findings revealed 25 megabenthos taxa of 9 phyla,including Porifera,Echinodermata,Arthropoda,Cnidaria,Chordata,Annelida,Bryozoa,Mollusca,and Foraminifera(Xenophyophore),with an average density of 0.19 ind./m^(2).The megabenthos phylum list in this region generally same with those found in the Clarion-Clipperton Zone(CCZ)of the eastern Pacific Ocean,albeit with slightly lower densities.Our results indicate that polymetallic nodule coverage and size are the major environmental drivers influencing megabenthos taxa abundance in this area.Specifically,we observed a positive correlation between overall megabenthos abundance and nodule coverage,and a negative correlation with nodule size.However,the relationship between different megafauna taxa abundance and nodule coverage/size exhibits complex patterns,i.e.,the abundance of sponges and echinoderms increases with nodule coverage,while the densities of echinoderms and molluscs rise with coverage above 64%.Furthermore,the abundance of echinoderms and cnidarians remains stable when nodule size exceeds 3.15 cm.These results preliminarily reveal the distribution pattern and driving factors of megafauna in this region,which will provide important scientific support for future environmental impact assessments of deep-sea mining.

关 键 词：海洋生物学 巨型底栖动物 分布特征 多金属结核覆盖率 海底影像分析 西太平洋 

分 类 号：P735[天文地球—海洋生物学]