Investigations In Benthic In Benthic Environmental Effects Of Mariculture Activity Based On The Analysis Of Three Biotic Indices In Sansha Bay

In order to investigate the potential benthic environmental impacts of offshore mariculture activities in Sansha Bay.It evaluated the community health and ecological environment quality of macrobenthos in the Sansha Bay of China quantitatively.A typical aquaculture bay in the East China Sea,three ecological indices including Shannon-Wiener index(H'),AZTI's Marine Biotic Index(AMBI)and M-AMBI(Multivariate—AMBI)were employed.Based on the newest obtained from a cruise in August of 2016,we calculated the three indices,analysed their variability among four kind of waters as well as the correlations of indices with typical environmental parameters.The applicability of each biological index was discussed,and the reasonable index selection was given.The main results were as follows.(1)The value of Shannon—Wiener index(H')was between 0 and 3.51.The value of thirteen stance was minimum(H'= 0).showing its extreme disturbance.The waters were disturbed lightly and in a good condition.The value of AMBI index was between 0 and 4.13.The value of thirteen stance was at the lowest AMBI index(AMBI = 0),it was not obvious disturbance,showing the ecological quality was high.AMBI value between 3.30 and 4.30(a total of 8 stations,19.51%)was on behalf of the benthic habitat disturbance and moderate ecological quality medium.The value of M-AMBI index was between 0.30 and 0.77.The value of thirteen station M-AMBI index was the lowest(M-AMBI = 0.30).It was in poor ecological quality and significantly disturbance.M-AMBI in the three evaluation results than those of AMBI's were more in line with the actual situation of environmental quality.Evaluation of M-AMBI—15%and M—AMBI showed the highest similarity.(2)The square root,the four square roots and the logarithmic results of the AMBI index showed that the quality of the whole habitat was in good condition.The results were basically the same.There was no obvious difference and high similarity.The AMBI index's results had a strong positive correlation with the numerical values calculated on the basis of the three indexes(P<0.01).But the mean value of the three was less than the result of the AMBI.At the same time,there was a strong positive correlation between BAMBI and AMBI(P<0.01).(3)The three indices implied that the environmental quality of Sansha Bay was good and only slight disturbances were present.Kruskal-Wallis test showed that among three studied indices,only H' differed among four kinds of waters(P<0.05).Supplementary pairwise test revealed that H' in cage farm water were statistically higher than those in seaweed farm area(P<0.01).Spearman correlation coefficient showed that significant correlation between indexes and environmental parameters were slight present,only occurring between TP and H',and between TP and M-AMBI(P<0.05).Cluster analysis revealed that sampling stations were randomly distributed,which did not correspond to differences of the farm categories.In conclusion,on the basis of biotic indices,the present paper considered that mariculture operation in Sansha Bay only had minor impacts of benthic environment.