ABSTRACT
The types and intensity of anthropogenic pressure in the same sea area may differ spatially and may change as time passes, but response of benthic biotic indices to different pressure is different, which makes it unreasonable to use the same benthic biotic indices in a large sea area. We provided a new way of thinking as to selecting benthic biotic indices according to pressure type. The study took six bays under eutrophication and sediment heavy metal pollution to different levels in Fujian coastal water, East China sea, as examples, analysed the response of five benthic biotic indices, namely AZTI marine biotic index (AMBI), multivariate AMBI (M-AMBI), Shannon-Wiener diversity index (H'), benthic opportunistic polychaetes amphipods (BOPA) and benthic polychaetes amphipods (BPA), to eutrophication factors and sediment heavy metal pollution factors firstly. The result indicated that AMBI well responded to dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP); M-AMBI responded soundly in the range of DIN >0.131 mg L-1 and DIP >0.022 mg L-1 and responded universally to heavy metals; H' responded to only Hg and Cd; BOPA has response to eutrophication condition of DIN >0.242 mg L-1; BPA had response to DIN, Cu and As. Then, suitable indices were selected based on the four pressure scenarios in the study area. AMBI was selected in no pressure scenario; M-AMBI was chosen under only eutrophication pressure and under dual pressure; H' was preferred in only heavy metal pressure scenario (mainly Hg pollution). At last, the density plot of the distribution of the selected indices in the evaluation grades under different pressure scenarios proved the proposal of selecting benthic biotic indices according to pressure types feasible. This study can offer some new insights into rapidly choosing indices to evaluate the coastal benthic ecological quality status.
Subject(s)
Amphipoda , Mercury , Animals , Cadmium , China , Ecosystem , Environmental Monitoring , Eutrophication , Invertebrates , Nitrogen , Phosphorus , WaterABSTRACT
With data for distributions and diversities of macroinvertebrates from 12 main subtidal zones in the bays of Fujian on August 2010, we investigated species composition, biodiversity and community structure, as well as their relationships with environmental factors. The results showed that 382 macroinvertebrates were recorded, which included 170 annelids, 75 crustaceans, 78 mollusks, 19 echinodermata, and 40 other species. The species richness, individual abundance, biomass and biodiversity indices showed significantly spatial variability. The average of species richness was (55±21), with the highest (92) in Luoyuan Bay and the lowest species (25) in Jiuzhen Bay. Polychaetes was dominant species in each bay, with an average percentage of (51.8±5.5)%. Zhaoan Bay had the highest average individual abundance with (1330±1094) ind·m-2, followed by Fuqing Bay, Xiamen Bay and Meizhou Bay, while Quanzhou bay had the lowest. Xinghua Bay had the highest average biomass with (821.2±2387.7) g·m-2, followed by Fuqing Bay and Xiamen Bay. Both richness index and Shannon diversity were much higher in Luoyuan Bay, Meizhou Bay, Shenhu Bay, Xiamen Bay and Dongshan Bay, and their values were low in Fuqing Bay and Jiuzhen Bay. The mean value for d and H across all bays was (0.80±0.09) and (2.73±0.64), respectively. The macroinvertebrates of the study area were divided into 14 groups using a criterion of 20% similarity. The stations in Luoyuan Bay had the highest similarity and the lowest spatial variability, and followed by Sansha Bay, Fuqing Bay, Shenhu Bay and Zhaoan Bay. The higher variability of community composition was found among the stations for the rest bays. On the basis of Spearman correlations among species richness, biodiversity indices and environmental factors, as well as PCA analy-sis, Cu in the sediment, water depth, and dissolved inorganic phosphorus in bottom water were the main factors driving the spatial variability of composition and distribution of macroinvertebrates in the study area.
Subject(s)
Bays , Biodiversity , Animals , Biomass , China , Environmental Monitoring , SeasonsABSTRACT
Three benthic biotic indices, AZTI marine biotic index (AMBI), benthic opportunistic polychaetes amphipods (BOPA), and benthic polychaetes amphipods (BPA), combined with Shannon diversity index (H) were applied in ecological quality status (EQS) assessment, to investigate their suitability at four bays and an estuary in Fujian Province. The results showed that there were substantial differences in the performance of these indices. There were only four sites with the same assessment grades using different indices, accounting for 8.7% of the applied sites. AMBI classified 76.1% of the sites as "Good", while 89.1% of the sites were classified as "High" using BOPA. The assessment results of BPA and H showed obvious gradient changes. For the bay areas, all the BOPA, BPA and AMBI values had no significant correlation with dissolved inorganic phosphate (DIP) and dissolved inorganic nitrogen (DIN) concentrations, suggesting that these indices did not respond to eutrophication pressure. The H value was significantly and negatively correlated with DIN concentration. For the estuarine area, the three indices, i.e . BOPA, BPA and AMBI, had significantly positive correlations with DIN and DIP, and there was no clear spatial variation in the assessment grades of these indices with the distance toward sea. The results suggested that BOPA, BPA and AMBI would overestimate the EQS and would show no response to the eutrophication pressure in estuarine area. Similar to the result from the bay areas,H value in the estuary area was significantly and negatively correlated to DIN. Meanwhile, the assessment grades of the seven sections in the estuary tended to increase with the distance toward the sea. In summary, our results suggested that BOPA, BPA and AMBI would not be suitable for the EQS assessment for Fujian coastal area, while H would be more suitable as it could respond to the main anthropogenic pressures.
Subject(s)
Ecosystem , Environmental Monitoring , Invertebrates , Animals , China , EcologyABSTRACT
In Dongshan Island, groundwater is the main resource of the local residents' drinking water, domestic water, agriculture irrigation and freshwater aquaculture. This study aimed to investigate the spatial distribution characteristic and its variation pattern of ammonia-N, nitrate-N and nitrite-N in groundwater, as well as its pollution source and influence factors. It is very important to understand the pollution level of ammonia-N, nitrate-N and nitrite-N in groundwater of Dongshan Island, the control and prevention of ammonia-N, nitrate-N and nitrite-N pollution, which is of great significance to the residents' health. In this study, the spatial variability characteristics of ammonia-N, nitrate-N and nitrite-N concentration in groundwater of Dongshan Island was analysed by geo- statistic method, the values of the non-observation points were determined by Kriging method, and the pollution characteristics of ammonia-N, nitrate-N and nitrite-N in groundwater of Dongshan Island was also analyzed. Our results showed that the ammonia-N and nitrite-N concentration in groundwater of Dongshan Island were at low levels, but their spatial variability were high, and their autocorrelation were poor; however, the nitrate-N concentration was general high, its spatial variability was moderate, and the autocorrelation was much good. The distribution characteristics of ammonia-N, nitrate-N and nitrite-N in groundwater of Dongshan Island were similar that the high concentration areas were all located in the coastal land. The domestic pollutants and human and animal wastes from towns and villages were the main sources of nitrogen pollution, which would be the first step to control the nitrogen pollution of Dongshan Island. Land use pattern, soil type, groundwater depth, pH, dissolved oxygen, season, and the existence of Fe2+, were the impact factors that influence the distribution and transformation of ammonia-N, nitrate-N and nitrite-N in groundwater, which could be the considerable factors in the control of nitrogen pollution in groundwater of Dongshan Island.
