Microbial diversity from the continental shelf regions of the Eastern Arabian Sea: A metagenomic approach

The marine microbiome is a complex and least-understood habitat, which play a significant role in global biogeochemical cycles. The present study reported the culture-independent assessment of microbial diversity from the Arabian Sea (AS) sediments (from Gujarat to Malabar; at 30 m depth) by using metagenome sequence analysis. Our results elucidated that bacterial communities in the Malabar coastal region are highly diverse than the Gujarat coast. Moreover, Statistical analysis (Spearman rank correlation) showed a significant correlation co-efficient value (r = P < 0.001) between microbial communities and physicochemical parameters (salinity and dissolved oxygen) in the water column. A total of 39 bacterial phyla were recorded from the eastern side of AS, of which six phyla Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Firmicutes, and Planctomycetes were found to be the most dominant group. The most dominant genus from Valapad region (Malabar Coast) was found to be Halomonas sp., while other regions were dominated with Psychrobacter pulmonis. The subsequent Principal Coordinate Analysis (PCoA) showed 99.53% variance, which suggests that, highly distinct microbial communities at Valapad (Malabar Coast) sampling location than other sites. Moreover, the microbial metabolic activity analysis revealed the important functions of microbial communities in the AS are hydrocarbon degradation, polymer degradation, nutrient oxidation and sulphate reduction (biodegradation process). Further extended studies are needed to be carried out for better understanding the functional diversity of microbial communities from the marine sediments.     

持久性有机污染物（POPs）对鸟类的影响

持久性有机污染物(POPs)是高残留物质,进入生物体后会长期存留并产生危害。近年来,有关生物体中POPs的研究已成为环境化学、生态毒理学研究的热点之一。本文概述了持久性有机污染物(POPs)的主要类型、生态特征、来源和污染效应。介绍了POPs在鸟类体内富集的特点及其对鸟类的危害;分析了以鸟类作为环境监测指示生物时应注意的问题;对POPs的防治以及利用鹭类等水鸟监测环境污染的方法提出了建议。     

Water quality index,Labeo rohita,and Eichhornia crassipes: Suitable bio-indicators of river water pollution

The present study investigated the water quality index (WQI) of the Kshipra river at Dewas, Madhya Pradesh, India, using native fish Labeo rohita, and plant Eichhornia crassipes. The temperature, pH, dissolved oxygen, alkalinity, turbidity, and dissolved solids were found to be within the prescribed limits. However, heavy metals concentration exceeded the limit except for Cu and Zn. Their occurrence in river water was as follows: Ni > Fe > Cd > Cr > Mn > Zn > Cu. Among these heavy metals, Cd was found to be highly bioavailable, whereas Zn was the least bioavailable metal. Based on WQI, the water was found to be unfit for drinking, and the high WQI value was due to the presence of Cr and Cd. In fish tissues (muscle, liver, gut, gills, and kidney), the highest and lowest metal pollution index was found in gills (45.03) and kidneys (12.21), respectively. Bioaccumulation of these metals resulted in significant depletion of energy reserves (protein, glucose, and glycogen) and also altered hematological parameters. Moreover, liver function tests showed hepatic damage in the exposed fish. In-plant, both the bioaccumulation and mobility factor exceeded 1 for all these metals. On the other hand, the translocation factor was found to be beyond 1 for Fe, Ni, and Zn. These high values make this plant fit for phytoextraction of Mn, Fe, Cu, Zn, and Cd and phytostabilization of Cr in water. Moreover, consumption of L. rohita from the Kshipra River does not pose a non-cancer risk as the target hazard quotient was below 1, but it may pose cancer risk because of the presence of Cr in the range of 1.402 × 10^?3 to 1.599 × 10^?3.     

土壤原生动物对环境污染的生物指示作用

土壤原生动物具有丰富的种类和巨大的生物量,在土壤生态系统中具有十分重要的地位．作为指示生物,土壤原生动物具有与其他土壤动物相比更独特的优势．研究它们的群落结构、数量及多样性动态变化,可以很好地评价和监测自然环境变化及人类活动带来的环境污染．本文根据国内外相关文献,简要概述了土壤原生动物在生态系统中的作用．对原生动物的生物指示物优势、土壤原生动物对环境因子响应和污染指示作用及对大气CO2浓度变化的响应等进行了论述,并对土壤原生动物在生态毒理诊断中的应用前景进行了展望．     

三种重金属元素在鹭卵中富集特征的初步研究

2004年4～6月,采集了合肥地区大蜀山、肥西圆通山、肥东太子山集群繁殖的夜鹭、小白鹭、池鹭和牛背鹭鸟卵及组织样品,用原子吸收法测定了卵壳、内容物及组织中Cd、Pb、Cr的残留量.结果表明,4种鹭卵壳、内容物及组织的绝大多数样品中均检出相当高水平的Cd、Pb和Cr残留量,且卵壳和骨骼是重金属富集的主要场所,表明通过卵壳可以排出体内部分重金属污染物.卵壳中重金属显著高于卵内容物,卵壳中重金属残留量为Cr>Pb>Cd,4种鹭卵壳中重金属残留量的种间差异都极其显著,Cr残留水平的种间波动幅度最大,池鹭卵壳中的最高,牛背鹭的最低;Pb的种间波动幅度相对较小,Cd的种间波动幅度最小;而卵内容物中3种重金属残留量的种间差异都不显著,Cr残留量种间波动幅度最大,池鹭卵内容物中,Cr含量最高,牛背鹭卵内容物中没有检出;Pb的种间波动幅度相对较小,Cd的种间波动幅度最小.由于鹭的卵壳取样容易,可用作重金属污染物的指示物,监测和评价湿地生态系统中重金属的污染状况.     

Seasonal and spatial shifts in copepod diets within tropical estuaries measured by fatty acid profiles

Fatty acids are the main components of lipids and are necessary for the production and permeability of cell membranes, playing an essential role in the physiological responses of organisms. The biochemical composition of zooplankton might be used as bio-indicators of the trophic status of aquatic ecosystems. Aiming to fill the gap of knowledge in tropical estuaries, the main aim of this study was to test if the fatty acid profiles can reveal spatial and temporal shifts in the diet of copepods and therefore can be used as indicators of the trophic status of estuarine systems. We investigated the fatty acids composition of copepod species and their possible food sources along the salinity gradient of two tropical estuaries (Paraíba do Norte and Mamanguape estuaries, northeastern Brazil), during the rainy and dry seasons. We found clear seasonal differences regarding fatty acids composition and concentration in copepods, with maximal concentrations and diversity of total fatty acids during the rainy season. The copepods species were mainly carnivorous in the dry season and omnivorous in the rainy season and, in both estuaries, the diet of most copepods was dependent on food availability. The fatty acid profiles suggest that, in general, feeding patterns of zooplankton change spatially and temporally, reflecting the shifts in their food sources abundance (i.e., dominance among diatoms and flagellates, terrestrial detritus and small animals). We observed a residual proportion of terrestrial detritus and green algae in the diets and these items were only present in the dry season. Furthermore, the food sources in the Paraiba do Norte estuary, a system with high levels of anthropogenic disturbance, showed lower feeding quality, with lower essential fatty acids concentrations. Our study showed that fatty acid profiles can be used as ecological indicator to assess seasonal and spatial shifts in the trophic ecology of copepods in tropical estuaries and to distinguish systems with different levels of human impact in a fast and accurate way.     

Environment determines nitrogen content and stable isotope composition in the sporophyte of <Emphasis Type="Italic">Undaria pinnatifida</Emphasis> (Harvey) Suringar

Nitrogen content and δ¹⁵N (nitrogen stable isotope ratio) were measured in different parts of the sporophyte of Undaria pinnatifida (Harvey) Suringar from two bays in the northeastern Japan. There were clear differences between the thalli collected in winter and in summer: high nitrogen content and low average δ¹⁵N were observed for the thalli collected in winter, while the opposite pattern was found for the thalli from summer. In addition, the pattern of internal δ¹⁵N distribution in the thallus changed with season. It is possible that the cause for these seasonal differences in the algae was the seasonal change in environmental conditions, because in winter water is normally rich in nitrogen, while in summer it is poor. U. pinnatifida sporophyte may be useful as an indicator of nitrogen sources in coastal waters, but consideration must be given to the effect of isotope fractionation on δ¹⁵N of the plant, especially in winter. Potential may exist for the use of different parts of the thallus to indicate nitrogen sources at different periods, but more investigation is necessary to accomplish this.     

Developing a regional diatom index for assessment and monitoring of freshwater streams in sub-tropical Australia

The use of borrowed indices to assess stream health has limitations and research suggests a need to develop more reliable regionally based indices that are sensitive to the relationship between taxa and environmental conditions. Implementing this is challenging in the Southern Hemisphere given the scarcity of diatom indices, specifically in sub-tropical areas. The purpose of this study was to develop a regionally based diatom index to assess freshwater lotic systems in sub-tropical eastern Australia and compare the results with borrowed indices to derive meaningful inferences on river health. A total of 119 epilithic diatom and water samples were collected during 2014–2015 from the Richmond River Catchment in Northern NSW Australia. Statistical analysis indicated that total phosphorus (TP) and total nitrogen (TN) were strong variables influencing the data set and subsequently TP was chosen as a nutrient proxy for the index. Analysis of diatoms resulted in TP sensitivity values (1–5) being assigned to 105 species with relative abundance of >1% in the data set. These species were used to calculate the Richmond River Diatom Index (RRDI) for 45 sites within the Catchment. The index effectively scored sites along the environmental gradient with sites in the upper catchment generally scoring lower (healthier) than the mid and lower catchment sites. The index compared positively with both the Diatom Species Index for Australian Rivers (DSIAR) (r = 0.76) and the Trophic Diatom Index (TDI) (r = 0.65). Further research is suggested to test the RRDI on independent sites in neighbouring catchments and develop class boundaries from the RRDI so that the index can be readily used by water managers to assess and monitor freshwater systems in sub-tropical Australia.     

下辽河平原不同土地利用方式下土壤微节肢动物群落结构研究

2000年10月～2001年10月对下辽河平原地区撂荒、林地、旱田、水田4种不同土地利用方式的土壤微节肢动物进行了调查。应用个体数密度、类群丰富度、多样性指数和均匀度4个群落参数,研究了土壤微节肢动物的群落结构和季节变化。结果表明,撂荒中土壤微节肢动物的4个群落参数均为最高,旱田均为最低,季节变化影响土壤微节肢动物的群落结构,但土地利用方式不影响群落结构的季节变化型,下辽河平原地区不同土地利用方式共鉴定出土壤微节肢动物12个类群,撂荒、林地、旱田中弹尾目(Collembola)和蜱螨目(Acarina)为优势类群,双翅目(Diptera)、鞘翅目(Coleoptera)和膜翅目(Hymenoptera)为常见类群,水田中弹尾目、蜱螨目和双翅目为优势类群,鞘翅目为常见类群,各土地利用方式、各季节均在表层土壤出现的类群最多、密度最高,中层次之,底层最少。     

Species diversity of longicorn beetles in humid warm-temperate forests: the impact of forest management practices on old-growth forest species in southwestern Japan

In the humid warm-temperate zone of southwestern Japan, old-growthforests have been seriously fragmented to small remnants due to traditionalagriculture and coppicing as well as recent rapid plantation with conifers.Assemblages of longicorn beetles (Coleoptera: Disteniidae and Cerambycidae) werecompared among old-growth forests, second-growth forests and conifer plantationsusing collision traps baited with chemical attractants. Species richness oflongicorn beetles was poorer in second-growth forests and conifer plantationsthan in old-growth forests. It was proved by multidimensional scaling(MDS) that the beetle assemblages of old-growth forests were distinct from thoseof conifer plantations, while those of second-growth forests were intermediatebetween them. Further analysis showed that a number of species, including manyPidonia spp., were specific to or closely associated withold-growth forests, and the results were largely supported by the indicatorvalue (IndVal) approach. It is likely that many of such old-growth forestspecies in the larval and pupal stages require large broad-leaved trees standingor fallen with thick bark. At the same time, the flower-visiting adults wouldplay an important role in pollinating various herbaceous and woody plants.Regional forest management for the conservation of insect biodiversity is alsodiscussed.