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Research On Fish Species And Community Present Situation And Potential Prediction In The Liao River Basin

Posted on:2016-07-14Degree:MasterType:Thesis
Country:ChinaCandidate:H ZhangFull Text:PDF
GTID:2283330461490899Subject:Aquaculture
Abstract/Summary:PDF Full Text Request
This paper takes the Liao River basin as the research object and biome as a unit. The present situation of fish germplasm resources, the main environmental characteristics, and the influence of environment on fish individuals and communities in the Liao River have analyzed. On the basis of above, every species of potential distribution and community structure of potential is analyzed. The research results could provide the scientific reference for breeding new variety development, germplasm resources protection and natural water with a single species or hybrid species ecological breeding of Liao River basin. The main research contents and conclusions are as follows.The fish germplasm resources and current community structure, as well as the most significant environmental variables that influence fish in each ecological zone of Liao River were analyzed, the results showed that:(1) Sixty-two fishes existing in Liao River currently, most of them were Cyprinidae, Cobitidae and Gobiidae. However, species of Petromyzonidae, Siluridae, Bagridae, Eleotridae, Cichlidae, Channidae, Gasterosteidae,Oryziidae, Hemiramphus, Salangidae, Osmeridae, Cottidae, Mugilidae, Clupeidae and Synbranchidae were small in numbers.(2) The overall status of fish assemblage in this river basin were that: the average species richness is 7.40, with an maximum of 18 species;the average and maximum value of Shannon-Wiener diversity index are 1.22 and 2.35respectively; when compared with the ecological zones, we found that the overall condition of East Liaohe River and Liaohe River mainstream were better than Huntai River,however, the latter was better than West Liaohe River.(3) The biological integrity index of fish was used to evaluate the ecological zone of Liaohe River, and the relevant environmental variables that affect the fish assemblage health of each ecological zone were discriminated, moreover the protection limit values of environmental variables that influenced by human activities were calculated: the protection values of proportion of forestland, proportion of construction land, conductivity, dissolved oxygen of Huntai River are 58%, 1.5%, 179μS/cm, 8.5mg/L respectively; the protection values of proportion of waterland and proportion of forestland of East Liaohe River and Liao River mainstream are 31% and 24%; the protection values of nitrate, conductance, proportion of unused land and grassland are 0.36mg/L, 531 μS/cm,15.5% and 37% respectively.The effect of natural environment to fish species’ distribution in Liao River basin have been analyzed by using logistic regression method. Specific results are as follows:(1) thechoice of environmental factors, model construction, ROC curve assessment and prediction of species distribution were explained in detail by Odontobutis yaluensis.(2) fish potential distribution models of 24 fish species in the Hun Tai River basin, 32 fish species in the east and main stream of Liao River basin and 22 fish species in the west of Liao River basin have been built by using logistic regression method. most of the models can forecast the distribution of fish species by ROC curve assessment.The relationship between natural environment and community structure of fish have been built by using multiple linear regression methods, and the results showed that:(1) In the Hun Tai River basin, the altitude, mean annual precipitation and temperature have a significant effect on the species abundance; River levels can affect Shannon-number of nasdaq significantly; Sediment percentage and average flow velocity have a marked influence on the fish biological integrity.(2) In the east and main stream of Liao River basin, the pebble percentage has significant influence on the fish biological integrity.(3) In the west of Liao River basin, mean annual precipitation can have an obvious influence on the species abundance, Shannon-Weiner index and the fish biological integrity.
Keywords/Search Tags:Liao River basin, F-IBI, protection limit, potential distribution prediction, logistic regression model, multiple linear regression
PDF Full Text Request
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