基于环境DNA技术探究海南文昌海草床-珊瑚礁连通性生境的鱼类多样性OA

Seagrass beds and coral reefs are highly productive nearshore ecosystems that play critical roles in maintaining regional fish diversity and ecological functions through their ecological connectivity.However,comprehensively mapping biodiversity distributions and identifying key biological linkages across such habitat continua using traditional survey methods present substantial logistical challenges.Recent advances in environmental DNA(eDNA)metabarcoding offer a revolutionary,non-invasive approach to characterize biodiversity and elucidate intricate ecological networks across large areas.This study leveraged eDNA technology to conduct a detailed assessment of fish diversity and quantify habitat connectivity along the seagrass bed-coral reef continuum within the coastal waters of Wenchang,Hainan,China.eDNA analysis of the Wenchang continuum revealed remarkably rich ichthyofauna diversity,with 193 fish species A majority(133 species)were shared between seagrass beds and coral reefs,indicating strong biotic connectivity,while each habitat also harbored unique species.Community composition differed significantly at the order and family levels between the two habitats,with Gobiiformes dominating both..Seagrass beds exhibited greater potential species richness(Chao1),whereas coral reefs exhibited superior species evenness and diversity(Pielou,Shannon,and Simpson).Principal coordinate analysis(PCoA)and PERMANOVA confirmed distinct community structures(P=0.01,R2=0.356).Linear discriminant analysis effect size(LEfSe)identified habitat-specific indicator species,including Lutjanus fulviflamma and Gerres oyena(LDA＞3.0),which were highly associated with seagrass beds,and Trachinotus mookalee and L.argentimaculatus,for coral reef habitats.Co-occurrence network analysis highlighted Mugil cephalus as a critical"keystone connector,"and G.filamentosus and Hyporhamphus quoyi as notable"bridging species"across both habitats,implying functional linkages in this coastal ecosystem.These findings directly translate the shared species list into a dynamic understanding of species that actively contribute to habitat linkages.In conclusion,this study unequivocally demonstrates that eDNA metabarcoding technology serves as an exceptionally powerful and sensitive complementary tool to conventional surveys.It provides unique advantages,particularly in identifying elusive,cryptic,or transient species often missed by traditional methods,and in deciphering complex biological connectivity pathways between habitats.By unveiling distinct fish assemblages,highlighting key indicator species,and pinpointing crucial connector and bridging species like M.cephalus,G.filamentosus,and H.quoyi,this study generates critical empirical evidence for the existence and potential mechanisms of habitat connectivity along the Wenchang seagrass-coral reef continuum.These results provide foundational scientific data and novel methodological insights essential for developing effective evidence-based strategies for fishery management and for the conservation of these vulnerable and economically vital coastal ecosystems in Hainan and beyond.