长江口盐沼潮沟水生动物群落动态及优势种生态位特征OA

Tidal creeks serve as crucial habitats for the migration,foraging,and nursery functions of aquatic animals in estuarine salt marsh wetlands.To clarify the annual spatiotemporal dynamics and maintenance mechanisms of aquatic animal communities in estuarine salt-marsh tidal creeks,this study conducted synchronized sampling over 12 consecutive months(from May 2024 to April 2025)in the tidal creeks of the Chongming Dongtan salt marsh,Yangtze Estuary,covering both day and night tides as well as flood and ebb phases.We systematically analyzed species composition,succession of dominant species,diversity indices,community structure differences,and characteristics of niche breadth and niche overlap. The results indicated that:(1)A total of 71033 aquatic individuals were collected annually,with a total biomass of 51.81 kg,belonging to 82 species from 29 families and 13 orders,including 68 fish species and 14 crustacean species.Species richness peaked in August(41 species)and was lowest in February(10 species).(2)Based on the index of relative importance(IRI>100),11 dominant species were identified.The ridgetail white prawn(Exopalaemon carinicauda)was the overwhelmingly dominant species throughout the year and acted as a core species with broad niche breadth.Acanthogobius ommaturus,E.carinicauda,and Eriocheir sinensis occurred in all 12 months.(3)The aquatic animal community structure in the tidal creeks exhibited significant monthly variation over the year.Differences were most pronounced in April-May,primarily due to the substantial abundance of larvae,juveniles,and young-of-the-year fish.Species diversity showed a distinct seasonal pattern,being higher in summer and autumn and lower in winter.(4)Overall,differences in community structure between day and night tides were weak,with significant differences detected only in November.In most months,species richness and abundance at night were slightly higher than during the day.(5)Ecological niche differentiation among dominant species was evident:Three species were classified as broad-niche species,six as intermediate-niche species,and two as narrow-niche species.Interspecific niche overlap was generally low,and significant resource competition was observed only among a few species. These findings demonstrate that the aquatic animal community in the tidal creeks of the Chongming Dongtan salt marsh,Yangtze Estuary,displays significant monthly variation but relatively weak diel differences.Its dynamics are closely associated with seasonal fluctuations in environmental factors(e.g.,water temperature and salinity),species reproduction and recruitment,and ecological niche differentiation.This study provides a scientific basis and data support for wetland ecosystem conservation,fishery resource restoration,and biodiversity maintenance in the Yangtze Estuary.