浙江中南部近海鱼类群落功能多样性时空变化及其与ENSO的关系OA

The coastal waters of central and southern Zhejiang constitute a key component of the fishery ecosystem in the East China Sea,where changes in the functional structure of fish communities play a pivotal role in influencing ecosystem stability.Based on survey data collected from these waters spanning 2014 to 2024,this study incorporated both the El Niño-Southern Oscillation(ENSO)indices and various environmental factors to analyze the spatio-temporal patterns of fish functional diversity.The results revealed significant interannual fluctuations in the functional richness index(FRic),with notably high values occurring primarily in 2014,2015,and 2022-2024.Spatially,FRic exhibited a distinct gradient,characterized by lower values in nearshore areas and higher values offshore.Functional evenness(FEve)was relatively stable overall,yet showed a notable decline in nearshore areas after 2021.Functional divergence(FDiv)increased substantially during the period 2020-2022,with persistent high-divergence zones observed in offshore waters over the long term,indicative of enhanced niche differentiation.Redundancy analysis demonstrated that environmental factors had strong explanatory power for the observed variations in functional diversity.Among these factors,sea surface temperature(SST)emerged as the dominant driver,followed by sea surface salinity(SSS),while chlorophyll a(CHLA)exhibited a relatively weaker influence.Notably,a significant negative correlation was detected between FDiv and SST,suggesting that elevated temperatures may constrain functional differentiation.Overall,this study indicates that fish functional diversity is highly sensitive to environmental stress and anomalous climatic events,with SST playing a crucial regulatory role in shaping the functional structure of the community.