Spatial and seasonal pattern of macrozoobenthic assemblages and the congruence in water quality bioassessment using different taxa in artificial Mingzhu Lake in Shanghai

The spatial and seasonal pattern of macrozoobenthic structure and its relationship with environmental factors were studied from July 2006 to April 2008 in Mingzhu Lake,Chongming Island,Shanghai at the Changjiang River mouth.The congruences in water quality bioassessment based on diversity and biotic indices and using different taxonomic categories were also explored to find the best assessment method of water quality for the lake.All major structural characteristics of macrozoobenthic community,including species composition,abundance,biomass and four biomass-based diversity indices(Shannon's diversity,Simpson's diversity,Pielou's evenness and Simpson's evenness index) fluctuated significantly in season but in space.The above four abundance-based diversity indices plus abundance-based Margalef's richness index did not display significant spatial variations;and significant seasonal differences were found in three indices only.Water temperature was the key environmental factor responsible for macrozoobenthic spatio-temporal distribution patterns.Water quality assessed by Shannon's index(H_a') and biological pollution index(BPI) rather than the other four biotic indices were consistent with those by trophic state index(TSI).Results from chironomids and oligochaetes did not always agree to those from the whole community when H_a' or Hilsenhoff biotic index was applied to bioassessment.Therefore,combining multiple indices and avoiding a single taxonomic category to assess water quality are strongly recommended and in Mingzhu Lake using a mixture of H_a' and BPI will ensure the most effective investigation of water quality.Our results also show that the main structural characteristics of macrozoobenthic communities in the small lake may display consistent spatial patterns.

A Macroinvertebrate Multimetric Index for the Bioassessment of Wetlands Adjacent to Agriculture Fields in the Sanjiang Plain, China

Adjacent intensive agriculture disturbs the natural condition of wetlands.However, to assess the effect of this agriculture on wetlands, few studies have used indices based on aquatic invertebrates.Multi-metric indices(MMIs) have been successfully used to assess freshwater ecosystems worldwide and are an important management tool, but little is known about their applicability in the Sanjiang Plain, Northeast China.In this study, we developed a MMIs for aquatic invertebrates to assess freshwater wetlands in this region.The aquatic invertebrate assemblages were sampled in 27 wetlands in the Sanjiang Plain that included those in natural reserves and those affected by adjacent, intensive agriculture.Twenty-four candidate metrics were initially reviewed and screened before four core metrics were selected: total number of taxa, number of Hemiptera taxa, proportion of Gastropoda, and proportion of predators.Mann-Whitney U tests, Box and Whisker plots, correlation analyses, and redundant metric tests were used to assess the ability of metrics to distinguish among reference and impaired wetlands.Four ordinal rating categories for wetland were defined: poor, fair, good, and excellent.Of the impaired freshwater wetlands, 76.2% were in poor or fair categories.The MMIs was robust in discriminating reference wetlands from impaired wetlands and therefore have potential as a biomonitoring tool to assess the condition and to guide the restoration efforts of freshwater wetlands in Northeast China.

Spatial Distribution of Plant-Associated Invertebrates and Environmental Bioassessment in a Natural Riverine Lake (Lake Fibreno, Central Italy)

Lake Fibreno is a Mediterranean riverine lake located in Central Italy and fed by large flows of groundwater and characterized by the presence of a wide reed stand area and of the only floating island of the South Europe. It is enclosed in a Natural Reserve recognized as Special Area of Conservation (SAC-IT6050015) for the presence of habitats and species (92/43/EEC) of relevant scientific interest. In this paper, we compare the plant-associated meio-macrobenthic invertebrates among sites with different environmental characteristics. Both vegetation and invertebrates of Lake Fibreno were well diversified and abundant and were composed of a mixing of species typical of lentic and lotic waters. Our results show that a gradient of orthophosphate and nitrite contents and current velocity appeared to be the driver factors affecting the flora and fauna spatial distribution at the sampling sites. To obtain a bioassessment of the ecological quality of the vegetation zone, we compared the riverine Lake Fibreno with typical lentic lakes previously studied in Central Italy. We selected metrics, such as macrophyte belt extent and taxa richness, invertebrate species richness and Shannon diversity, ETOM (Ephemeropta + Trichoptera + Odonata + Mollusca), ETOC (Ephemeropta + Trichoptera + Odonata + Coleoptera) and LCrM (Large Crustacea + Mollusca). The comparison indicated a good ecological status of the vegetation zone of Lake Fibreno mainly due to the continuous washout effects (dilution and fast water removal) which reduce the nutrient content available for phytoplankton and maintain the high transparency and good oxygenation of the lake waters.

Development of Bioassessment Tools for Ecological Status Using Macrozoobenthic Community in Upstream Area (Case Study: Citarum River, West Java, Indonesia)

This research aims to develop an assessment tool of ecological status in the upstream area using macrozoobenthic community and its relationship to the physicochemical parameters of water and sediment, in Citarum River. The number of species and abundance of macrozoobenthos in the dry season was higher compared to rainy season. The predominant family (Pachychilidae, Hydropsychidae, Glossiphonidae, and Chironomidae) obtained in both season was significantly correlated with the physicochemical parameter. Based on the Shannon-Wiener index, diversity in upstream area of Citarum River during the dry season (1.68) was similar with the rainy season (1.80) and it showed that the diversity of macrozoobenthic community was moderately diverse in both seasons. The physicochemical parameters that strongly related with the presence and abundance of predominant macrozoobenthic taxa were turbidity, total suspended solid (TSS), total nitrogen, total phosphate, gravel particle, and organic carbon. By considering biological and physicochemical parameters obtained from this study, we developed a modified scoring system to assess the ecological status of upstream area in Citarum River. Based on the scoring system, the ecological status was quite polluted in dry season (2.19) and moderately polluted in rainy season (4.94).

A Comparison of Two Macroinvertebrate Multi-Plate Sampling Methods to Inform Great Lakes Monitoring and Remediation Efforts

Hester-Dendy (HD) multi-plate samplers have been widely used by state and federal government agencies for bioassessment of water quality through use of macroinvertebrate community data. To help guide remediation and restoration efforts at the Niagara River Great Lakes Area of Concern site, a multi-agency study was conducted in 2014 to assess the contribution of seven major urban tributaries on the US side of the river toward the impairment of the Niagara River. As part of this study, macroinvertebrate communities were sampled using two co-located versions of HD samplers: one version used by the New York State Department of Environmental Conservation (NYSDEC) and another by the US Environmental Protection Agency Office of Research and Development. Samplers were deployed in tributaries in highly developed watersheds with high percent impervious surface. The two sampling methods varied in terms of number and size of plates, between-plate spacing, and deployment method. Comparison of the similarity/grouping of communities with multivariate ordination techniques, Nonmetric Multidimensional Scaling and Multi-Response Permutation Procedure, showed that both methods were able to detect differences in communities at stations, despite some grouping by month and method. The indices and metrics derived from the two HD methods were found to give comparable but not identical assessments of water quality. Despite their differences, the methods were robust with respect to water quality categories derived from indices used nationally (HBI) and by NY state (BAP). For the common richness metrics, total taxa and EPT richness, there was no statistical difference between means from 3 samplings. Some metrics, especially percent tolerant collector-gatherer individuals, did show significant differences at certain stations. Indicator Species Analysis showed some taxa associated with each method. The observed community differences were thought mostly due to the difference in sampler deployment position. .

Colonization features of marine biofilm-dwelling protozoa in Chinese coastal waters of the Yellow Sea

Colonization features of biofilm-dwelling protozoa,especially ciliates,are routinely used as a useful tool for marine bioassessment.In this review,we summarize some of these features to develop an optimal sampling strategy for using biofilmdwelling protozoa as bioindicators of marine water quality.We focus on the utility of:(1)diversity in dices to analyze the colonizahon features of biofilm-dwelling protozoa for monitoring marine water quality;(2)MacArthur-Wilson and logistic equation models to determine spatio-temporal variations in colonization dynamics;and(3)homogeneity in taxonomic breadth of biofilm-dwelling protozoa during the process of colonization.The main findings are that:(1)the colonization dynamics of biofilm-dwelling protozoa are similar at depths of 1-5 m in spring and autumn;(2)temporal variability was well fitted to the MacArthur-Wilson and logistic models(P<0.05);and(3)species composition reached an equilibrium after a colonization period of 10-14 days in spring and autumn,but this took less time in the summer and more time in the winter.Ellipse-plotting tests demonstrated spatial variability in homogeneity in taxonomic structure of the ciiiate communities at different depths in the water column,with high levels at 1 m and 2 m and lower levels at 3.5 m and 5 m.Thus,the findings of this review suggest that the colonization dynamics of biofilin-dwelling protozoa may be influenced by different depths and seasons in coastal waters and 1-2 m in spring and autumn may be optimal sampling strategy for bioassessment on large spatial/temporal scales in marine ecosystems.