| In this paper,based on the spring of 2011 and spring 2011 nekton survey data obtained in Wenzhou Bay.We can comprehensively study the function relationship between the different populations of the main nekton in Wenzhou Bay.Analysis of the interactions between species under the same community ecological relationship,the common features between resource utilization.The main results are as follows:Wenzhou Bay in the spring of 2013 and the spring of 2014,Two trawl surveys were conducted in the survey area to identify a total of 104 species.The three dominant species were Amblychaeturichthys hexanema,Harpodon nehereus,and Pampus argenteus,which had large spatial niches,accounting for 52.78% of the total mantissa of the catch,accounting for 32.98% of the total weight of the catch.The biodiversity index was between 0.195 and 2.630,with an average of 1.752,the overall degree of the general.Richness index value was between 1.685 ~ 5.202,the average value of 3.601,the overall level was better.The uniformity index was between 0.007 and 0.857,with an average of 0.550 and the overall degree of uniformity.A total of 33 species of nekton were used to divide their functional groups according to their feeding habits.There were 7 functional groups and the detritivores had not appeared.Among them,the functional group of benthivores was in the absolute dominant position,accounting for 70.86% species of the major nekton.The average trophic level of each functional group is between 3.02-4.35,The nekton in the secondary and intermediate consumers account for an important proportion of senior consumers in the community is too low proportion.The bait is too simple and the nutrient structure tends to be simple.In general,there were large differences in the niche breadth values among the major nekton populations,with a maximum value of 5.60 and a minimum of 0.07.The specie with the largest niche breadth was Amblychaeturichthys hexanema(5.60),The specie with the smallest niche breadth was Muraenesox cinereus(0.07).The niche overlap value was between 0.00-0.93,the change was relatively large and the distribution was not uniform.Among them,the largest species pair with niche overlap values were Gastrophysus spadiceus and Palaemon pacificus.The niche overlap value of this community is low,and some species may have predator relation.And the niche overlap value of relatively high kind of pairs,mostly shrimp and crabs,cephalopods some of the poor athletic ability type.The VR value was greater than 1 at7.87,and the W value was 291.25,which was considerably greater than the confidence interval.There were significantly positive correlations between the major nekton community species.The results showed that the community structure and species composition stability of Wenzhou Bay was strong,the trend of positive succession,the stable development of community,the structure and composition of the community were relatively perfect,the structure of the ecosystem was relatively mature,and the whole community had better ability to withstand the change of the external environment.The chi-square test showed that 88.64% of the species had no association,and the distribution coefficient showed 61.74% of the species had no association.The percentage of co-occurrence showed that 17.42% of the pairs had weak positive association.The correlation coefficient showed 56.25 % Of the species of non-associative;Ochiai index showed 8.33% of the species of non-associative.Indicating that the degree of intercropping with the succession increased,the degree of association decreased.In conclusion,the community structure of nekton of Wenzhou Bay was relatively stable,but low degree of diversity,some traditional decrease in the number of dominant species,due to overfishing,oceanic engineering artificial factors such as Marine environmental change is bigger,the overall resources current situation still not optimistic,resources present the trend of recession. |
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