Niche Preference of Escherichia coli in a Peri-Urban Pond Ecosystem

Escherichia coli comprises diverse strains with a large accessory genome, indicating functional diversity and the ability to adapt to a range of niches. Specific strains would display greatest fitness in niches matching their combination of phenotypic traits. Given this hypothesis, we sought to determine whether E. coli in a peri-urban pond and associated cattle pasture display niche preference. Samples were collected from water, sediment, aquatic plants, water snails associated with the pond, as well as bovine feces from cattle in an adjacent pasture. Isolates (120) were obtained after plating on Membrane Lactose Glucuronide Agar (MLGA). We used the uidA and mutS sequences for all isolates to determine phylogeny by maximum likelihood, and population structure through gene flow analysis. PCR was used to allocate isolates to phylogroups and to determine the presence of pathogenicity/virulence genes (stxI, stxII, eaeA, hlyA, ST, and LT). Antimicrobial resistance was determined using a disk diffusion assay for Tetracycline, Gentamicin, Ciprofloxacin, Meropenem, Ceftriaxone, and Azithromycin. Our results showed that isolates from water, sediment, and water plants were similar by phylogroup distribution, virulence gene distribution, and antibiotic resistance while both snail and feces populations were significantly different. Few of the feces isolates were significantly similar to aquatic ones, and most of the snail isolates were also different. Population structure analysis indicated three genetic backgrounds associated with bovine, snail, and aquatic environments. Collectively these data support niche preference of E. coli isolates occurring in this ecosystem.

A Positive Response to Urban Ecological Aspects Around an Urban Pond Through Urban Design Guidelines

Cities are growing at a phenomenal pace and the speed has created a huge gap between the urban dwellers and nature. Though development of cities are driven by many economic factors and ecological driving factors are acknowledged in recent times, water resources still lack importance. The significance of urban water bodies are mainly in two ways: one is to help the survival of the water dependent ecosystem and landscape and the other is to recharge the water beneath the ground. Since ancient times water had a great role in human culture in many ways through rituals and lifestyle, especially in India. Creating huge man made reservoirs, for agriculture and day to day uses. Unfortunately, in recent times anthropogenic activities have created the worst phase of degradation of natural resources and mainly water. So as an urban designer there is a great social responsibility and commitment for building up a better and healthy city have a key role in integrating such natural resources positively with the newly heading urbanized world.In this study an attempt to make a qualitative analysis of the current scenario of urban ponds in Trivandrum has been made.

Ecological engineering approaches to restoring the aquatic biological community of an urban pond ecosystem and its effects on water quality ‑ a case study of the urban Xixi National Wetland Park in China

There is a global increase in urbanization, which contributes to the loss and fragmentation of urban wetland and pond habitats. Urban ponds have an important role in the ecology of urban areas, as they provide essential habitats for aquatic species. The objective of this study is to demonstrate ecological engineering approaches to restoring aquatic biological communities in an urban pond ecosystem, which can be used to achieve water purification of such ecosystems globally. The general approach of first cleaning out the ponds and then systematically applying different treatments of plants and fish was designed and implemented in the field. We used three replicated ponds per engineering treatment to determine which of the treatments was the best option based on an assessment of water quality and biological indicators. The main findings of this study were as follows: a combination of aquatic animals and aquatic plants can provide the best water purification performance; furthermore, macrobenthos, such as Bellamya purificata, can be used as biological indicator species for monitoring dominant species and water quality in a local urban pond ecosystem. In conclusion, maintaining biological species diversity over different trophic levels can provide the best water purification performance in urban pond ecosystems.

Komunitas makroinvertebrata bentik di perairan Situ Cibuntu, Jawa Barat

Situ Cibuntu, is one of urban ponds located in Bogor Regency, West Java. With a maximum surface area of 11 ha and maximum depth of 1,20 m, the pond serves as irrigation for nearby agricultural fields and recreational fishing. Located in relatively high urban pressure, the pond is highly affected by domestic, agricultural and industrial inflow which can influence the biotic community such as benthic macroinvertebrate. We studied benthic invertebrate community structure in Situ Cibuntu from October to November 2018 to determine the role of environmental factors on benthic macroinvertebrates. Samples were collected biweekly from five sampling points using an Ekman sediment grab with three replicates. Our study revealed 16 species of benthic macroinvertebrates belonging to four classes including Gastropoda, Bivalvia, Clitellata, and Insecta. Melanoides tuberculata species was found to have the highest abundance with an average abundance of 858 individuals/m2. Shanon-Wiener Diversity Index shows a relatively low diversity ranged from 0.61 to 1.26, while evenness index ranged from 0.36 to 0,66. Simpson Dominance Index ranged from 0.24 to 0.93.Keywords:DominanceCommunityAbundanceDiversityBenthic MacroinvertebratePond CibuntuABSTRAKSitu Cibuntu merupakan salah satu situ urban (urban pond) yang terletak di Kabupaten Bogor, Provinsi Jawa Barat. Situ Cibuntu yang memiliki luas permukaan 2,11 ha dengan kedalaman maksimum 1,20 m dimanfaatkan sebagai sumber irigasi pertanian dan sarana pemancingan ikan. Situ di kawasan perkotaan dapat mengalami tekanan karena pengaruh limbah domestik, pertanian, dan industri yang dapat mempengaruhi komunitas biotik seperti makroinvertebrata bentik. Penelitian ini bertujuan untuk mengetahui komunitas makroinvertebrata bentik di perairan Situ Cibuntu. Penelitian dilakukan pada bulan Oktober hingga November 2018 di lima stasiun pengamatan. Pengambilan sampel dilakukan sebanyak tiga kali dengan interval waktu dua minggu. Sampel makroinvertebrata bentik diambil dari sedimen pada setiap stasiun dengan menggunakan Ekman grab sebanyak tiga kali ulangan. Secara keseluruhan ditemukan 16 spesies makroinvertebrata bentik yang tergolong ke dalam empat kelas meliputi Gastropoda, Bivalvia, Clitellata, dan Insekta. Spesies Melanoides tuberculata memiliki kelimpahan tertinggi dengan nilai rata-rata sebesar 858 individu/m2. Keanekaragaman makroinvertebrata bentik tergolong rendah hingga sedang dengan nilai indeks Shanon Wiener (H’) berkisar 0,61-1,26. Nilai indeks kemerataan Pielou (E) berkisar 0,36-0,66, sedangkan indeks dominansi Simpson (D) berkisar 0,24-0,93.Katakunci:DominansiKomunitasKelimpahanKeanekaragamanMakroinvertebrata bentikSitu Cibuntu

Gomphonema alavariense sp. nov. (Cymbellales, Gomphonemataceae) from an urban pond

Gomphonema alavariense sp. nov. is a new freshwater diatom described in Portugal from phytobenthos samples in an urban pond located in Aveiro (Portugal). This new diatom is illustrated and discussed based on different samples collected in July–August 2017 from Santo António Park pond in the city centre. This taxon was compared with other Gomphonema taxa and the morphological features are documented through light and scanning electron micrographs. Gomphonema alavariense sp. nov. is characterized by showing solitary cells, rhombic-lanceolate to lanceolate valves with rounded apices, a narrow, linear axial area, and slightly asymmetrical central area. This taxon may be confused with G. affine var. rhombicum in terms of length, striae density and outline. Gomphonema alavariense sp. nov. was present in freshwater with low dissolved oxygen concentrations, high conductivity, neutral to slightly alkaline pH and high nitrate concentrations.

Periphyton colonization and changes in the diatom assemblages of an artificial urban pond

Artificial ecosystems are sometimes the only opportunity for citizens to experience nature. Maintaining their quality is essential for continuing to enjoy the ecosystem services. We studied an urban pond in the Northwest Iberian Peninsula (Aveiro, Portugal) as a model for testing the suitability of diatom assemblages and indices of water quality in these particular ecosystems. Weekly sampling of three replicas was performed over 28 days on stones and ceramic tiles in a shaded site (Site-SH) and in a sunnier one (Site-SU). The best model of the distance-based analysis included temperature and NH4+as the variables that best explained the diatom assemblages (R 2= 0.43). Chlorophyll-α taken as a proxy for algae biomass, and ash-free dry mass increased until the third week, when a turbid runoff entered the system. After this disturbance, chlorophyll-α increased only at Site-SH (from 14.4 mg m –2 to 62.4 mg m–2); ash-free dry mass increased at Site-SU (from 7.2 mg m–2 to 42.3 mg m–2). The Specific Polluosensitivity Index of the diatoms showed low values below 16 that further decreased with the incubation time. Shannon diversity did not vary between sites, while ANOSIM (analysis of similarity) enabled the identification of differences in the species composition among sites and over time. Cyclotella meneghiniana and Sellaphora nigri were abundant at both sites, but other species showed a prevalence to one of the sites: Nitzschia amphibia and Gomphonema parvulum dominated at site-SH, whereas Amphora pediculus and Grunowia solgensis were abundant at site-SU. This study provides evidence that the use of benthic diatoms is a useful tool for evaluating the ecological potential of artificial ecosystems. Moreover, such systems in the close vicinity of urban areas need better management and monitoring to reduce the risk of deterioration.