Research Of Fish Resources And Fish Functional Diversity In Minjiang River Estuary

Environmental changes and human activities may have strong impacts on biodiversity and ecosystem functioning.Based on the survey data collected by bottom trawl research in May 2016,August 2016,November 2016 and December 2016 in the Minjiang River Estuary,we have got these conclusions:(1)A total of 125 species belonging to 47 families,13 orders were collected during the study.The species diversity changes conspicuous during the seasonal,there is a highest value during the summer and the lowest value during the winter.The migration species is the main ingredient of fish assemblies in the Minjiang River Estuary,so that,it changes obviously.During the research,based on species diversity value,the worst stations are S08 and S10,it is the result of environment disturbance.(2)Fifteen major fish species were determined by the IRI,including 4 dominate species Thrissa kammalensis,Coilia mystus.Chaeturichthys hexanema,Harpodon nehereus and 11 important pecies olichthys lucidus,Odontamblyopus rubicundus,Cynoglossus abbreviate,Trypauchen vagina,Thrissa kammalensis,Polydactylus sextarius,Trichiurus savala,Parargyrops edita,Pampus argenteus,Leiognathus ruconius,Chelidonichthys kumu,Argyrosomus argentatus.The ecological niche of major fish species in the Minjiang River Estuary had obvious seasonal changes.Results also showed that really high percentage(17.1%)of species pairs of major fish species on spatio-temporal niche overlap showed the meaningful level.A total of 6 species pairs of them reached significant ecological niche overlap,indicating that major fish species in the Minjiang River Estuary had similar distribution on the spatial and temporal scale and resource utilization competition between major fish species might exist.(3)Based on the fish samplings collected by bottom trawl in May,August,November and December 2016 in the Minjiang River Estuary,functional diversity of Minjiang Riven Estuary was quantified by a trait-based approach using morphological characters,as well as the spatialtempol variation.The functional diversity varied corresponding to the change of species richness.The species richness was 17.82±5.08 species in spring,22.36±5.63 in summer,17.73±6.33 in autumn and 12.09±2.26 in winter,while the functional diversity was highest in summer as 33.94×105±28.70×105,followed 19.05×105 ±19.32×105 in autumn,11.30×105±7.55×105 in spring and 9.93×105±8.83×105 in winter.The seasonal variation of fish species function was determined by its life history and the interactions with other species.