scholarly journals Evaluating the ecological status of mountain streams from a megacity (Mexico City) with diatoms: development and implementation of morphological and eDNA-based methods

2021 ◽  
Vol 4 ◽  
Author(s):  
Victor Hugo Salinas Camarillo ◽  
Javier Carmona-Jiménez ◽  
Nelida Abarca ◽  
Jonas Zimmermann ◽  
Demetrio Mora
Keyword(s):  
Community Structure ◽  
Ecological Status ◽  
Fish Farming ◽  
Organic Pollution ◽  
Mountain Streams ◽  
Rrna Gene ◽  
Ecological Quality ◽  
Basin Of Mexico ◽  
Diatom Communities

In central Mexico, streams flow from mountain protected areas at high elevations, i.e. abive 2,400 m a.s.l., being exposed to different human activities along their course. The main human threats of these aquatic ecosystems include the presence of hydraulic infrastructure (e.g. canals and dams), the construction of bridges or roads, fish farming, agriculture, livestock, unregulated tourism or irregular human settlements, resulting in nutrient enrichment, organic pollution and low hydromorphological quality. Diatoms, widely recognized as valuable indicators of environmental conditions, offer a unique opportunity to assess the ecological quality of the streams in and around this megacity, as they respond directly and sensitively to specific physical, chemical and biological changes. To conduct ecological assessment, the composition of diatom communities has traditionally been characterized by morphological methods and most recently by environmental DNA (eDNA) metabarcoding. However, the diatom communities of only a few of these streams in the Basin of Mexico have been characterized morphologically at low resolution light microscopy (LM), and no eDNA-based studies have been conducted yet. In this context, our aims are to 1) implement morphological and eDNA metabarcoding methods for the identification and quantification of epilithic diatoms and to assess their seasonal and spatial response in three peri-urban mountain streams from the Basin of Mexico, and 2) develop a metric to assess and monitor the ecological quality in these streams. For this purpose, we characterized a) the physical, environmental and hydro-morphological conditions related to ecosystem quality, and b) the diatom diversity and community structure of nine sites per stream (27 sites). The sites include headwaters, as well as middle and lower reaches with different land-use and anthropologic pressures, and were investigated over three hydrological periods, i.e. post-rainy, dry-cold and dry-warm. Species identification was first conducted under LM and scanning electron microscopy (SEM), and is currently been done by eDNA metabarcoding of the V4 region of the 18S rRNA gene and a fragment of the chloroplast marker rbcL. Our study has resulted in 520 infrageneric taxa identified by LM and SEM, the largest diversity ever found for freshwater diatoms of Mexico. From this data, we found a clear environmental gradient from almost pristine conditions towards heavily polluted states as the streams enter the city. These changes are well reflected by variations in the diatom community structure, as revealed by the Diatom Ecological Quality Index (DEQI), newly developed to evaluate the ecological quality of the streams in and around this megacity.

scholarly journals 16S and 18S rRNA Gene Metabarcoding Provide Congruent Information on the Responses of Sediment Communities to Eutrophication

2021 ◽  
Vol 8 ◽  
Author(s):  
Jesse P. Harrison ◽  
Panagiota-Myrsini Chronopoulou ◽  
Iines S. Salonen ◽  
Tom Jilbert ◽  
Karoliina A. Koho
Keyword(s):  
Community Structure ◽  
Bottom Water ◽  
18S Rrna ◽  
Ecological Status ◽  
18S Rrna Gene ◽  
Ecological Impacts ◽  
Nutrient Concentrations ◽  
Rrna Gene ◽  
Sediment Depth ◽  
Using Data

Metabarcoding analyses of bacterial and eukaryotic communities have been proposed as efficient tools for environmental impact assessment. It has been unclear, however, to which extent these analyses can provide similar or differing information on the ecological status of the environment. Here, we used 16S and 18S rRNA gene metabarcoding to compare eutrophication-induced shifts in sediment bacterial and eukaryotic community structure in relation to a range of porewater, sediment and bottom-water geochemical variables, using data obtained from six stations near a former rainbow trout farm in the Archipelago Sea (Baltic Sea). Shifts in the structure of both community types were correlated with a shared set of variables, including porewater ammonium concentrations and the sediment depth-integrated oxygen consumption rate. Distance-based redundancy analyses showed that variables typically employed in impact assessments, such as bottom water nutrient concentrations, explained less of the variance in community structure than alternative variables (e.g., porewater NH4+ inventories and sediment depth-integrated O2 consumption rates) selected due to their low collinearity (up to 40 vs. 58% of the variance explained, respectively). In monitoring surveys where analyses of both bacterial and eukaryotic communities may be impossible, either 16S or 18S rRNA gene metabarcoding can serve as reliable indicators of wider ecological impacts of eutrophication.

scholarly journals Improvement of the esca index for the evaluation of ecological quality of coralligenous habitat under the european framework directives

2015 ◽  
Vol 16 (2) ◽  
pp. 419 ◽  
Author(s):  
L. PIAZZI ◽  
P. GENNARO ◽  
E. CECCHI ◽  
F. SERENA
Keyword(s):  
Spatial Variability ◽  
Ecological Status ◽  
Sampling Effort ◽  
Photographic Method ◽  
Ecological Quality ◽  
Anthropogenic Pressures ◽  
Small Scales ◽  
High Good ◽  
Different Sources

The ESCA (Ecological Status of Coralligenous Assemblages) index was recently developed to evaluate the ecological quality of coralligenous habitat. The study aims to improve the first index proposal through testing response to different sources of anthropogenic pressures and optimizing the sampling effort. ESCA was calculated on 14 sites and tested against a gradient of human pressures. Moreover, the main scales of spatial variability of assemblages were evaluated and values of index obtained with different sampling designs were compared. Results showed that studied sites resulted in high, good or moderate ecological status, according to an increasing gradient of the anthropization level. Values of ESCA index obtained with different methods have been compared and photographic method provides EQR values lower than destructive method. Spatial variability of assemblages was higher at large and small scales than at intermediate ones. Two locations for each study site and 20 replicated samples for each location may be consider the best sampling combination providing reliable values of ESCA index for the evaluation of ecological quality of coralligenous assemblages.

scholarly journals Evaluation of the Temporal and Spatial Changes of Ecological Quality in the Hami Oasis Based on RSEI

2020 ◽  
Vol 12 (18) ◽  
pp. 7716
Author(s):  
Pengwen Gao ◽  
Alimujiang Kasimu ◽  
Yongyu Zhao ◽  
Bing Lin ◽  
Jinpeng Chai ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Explanatory Power ◽  
Ecological Status ◽  
Quality Level ◽  
Ecological Quality ◽  
P Values ◽  
Ecological Index ◽  
Poor Grade ◽  
Window Method

Given the restrictions on special geographic locations in development processes, the measurement and analysis of the ecological quality of the Hami Oasis are of great significance for the protection of this fragile oasis. In this study, the ecological quality of the Hami Oasis was monitored by constructing a remote sensing ecological index (RSEI) for arid areas. Using the standard deviation ellipse and moving window method, the ecological status and space–time changes were explored for both their external and internal factors in the Hami Oasis. Finally, a geo-detector was employed to determine the driving factors of the ecological quality of the Hami Oasis. The results revealed that: (1) In the remote sensing ecological index constructed in the Hami Oasis, the main influencing factors were dryness and wetness. The average value of the ecological quality of the oasis was less than 0.5, and the ecological quality level was relatively poor. Among the five grades of ecological quality in the Hami Oasis, the poor grade and the good grade showed the largest changes, decreasing by 200 and increasing by 300, respectively, which were mainly concentrated in the periphery of the oasis. (2) The improved ecological quality of the Hami Oasis was mainly manifested in the expansion of the artificial oasis, while the deteriorated area was manifested as an increase in the built-up area. Moreover, the ecological quality of the Hami Oasis presented a ringlike nesting distribution pattern from the internal built-up area to the artificial oasis periphery. (3) The external expansion direction of the ecological quality of the Hami Oasis featured southeast–northwest expansion, which was consistent with the direction of the rivers and traffic roads. The transformation between different ecological qualities in the oasis and the expansion of the built-up area were the reasons for the fragmentation of the Hami Oasis’ landscape. (4) Compared to a single factor, the dual-factor for the ecological quality of the Hami Oasis had stronger explanatory power. Moreover, changes in land use types caused changes in the ecological quality of the Hami Oasis. During the study period, we found that human activities had a more significant impact than natural factors on the development of the Hami Oasis. (5) The Moran’s I Index increased from 0.835268 in 2000 to 0.923976 in 2018, and the p values in the study area all reached a 0.05 significant level. At the same time, the areas with p values above the 0.01 and 0.001 significant levels have also increased significantly in the past 18 years.

scholarly journals Integración de el índice ESCA por medio de los macro-invertebrados sésiles

2017 ◽  
Vol 81 (2) ◽  
pp. 283 ◽  
Author(s):  
Luigi Piazzi ◽  
Paola Gennaro ◽  
Enrico Cecchi ◽  
Fabrizio Serena ◽  
Carlo Nike Bianchi ◽  
...  
Keyword(s):  
Marine Protected Areas ◽  
Ecological Status ◽  
Biological Indicator ◽  
Ecological Quality ◽  
Environmental Condition ◽  
Human Pressure ◽  
Sensitivity Level ◽  
Nw Mediterranean ◽  
Nw Mediterranean Sea

The ESCA (Ecological Status of Coralligenous Assemblages) index was developed to assess the ecological quality of coralligenous habitat using macroalgae as a biological indicator. The aim of this study was to evaluate the response to human-induced pressures of macroalgae and sessile macro-invertebrates shaping the coralligenous habitat and to integrate their sensitivity into the ESCA index. Coralligenous assemblages were sampled at 15 locations of the NW Mediterranean Sea classified into three groups: i) marine protected areas; ii) low urbanized locations; and iii) highly urbanized locations. A sensitivity level value was assigned to each taxon/group on the basis of its abundance in each environmental condition, the data available in the literature and the results of an expert judgement survey. The index that includes the totality of the assemblages (named ESCA-TA), calculated using both macroalgae and sessile macro-invertebrates, detected the levels of human pressure more precisely than the index calculated with only macroalgae or with only invertebrates. The potential for assessing the ecological quality of marine coastal areas was thus increased with the ESCA-TA index thanks to the use of a higher variety of descriptors.

scholarly journals A new fish-based index of biotic integrity for lowland rivers in Flanders (Belgium)

2021 ◽  
Vol 151 ◽  
Author(s):  
Jan Breine ◽  
Ericia Van den Bergh ◽  
Gerlinde Van Thyune ◽  
Claude Belpaire
Keyword(s):  
Ecological Status ◽  
Independent Set ◽  
Index Of Biotic Integrity ◽  
Biotic Integrity ◽  
Reference List ◽  
Ecological Quality ◽  
Lowland Rivers ◽  
Pressure Indicators ◽  
Using Data

The first fish-based index to assess the ecological quality of lowland rivers in Flanders (Belgium) is based on data obtained from different fishing techniques without considering the gear specificity. As a consequence, this index could not be intercalibrated with other European indices which concentrate on one gear type only. In order to comply with the European Water Framework Directive, we developed a new fish-based index using data obtained from surveys in rivers with electric gear only. All 293 selected rivers belonged to the bream or barbel zone. An updated reference list of fish species was compiled based on previous work and recent data. Abiotic data were collected according to standard methods and habitat quality of all surveyed sites was pre-classified using pressure indicators. To develop the new index candidate metrics were selected from the literature and metric values were calculated. Linear mixed regression models selected metrics based on their response to the pre-classified habitat status. Correlation tests were performed to avoid redundancy among responsive metrics. Boundaries for metric scores were defined based on the calculated metric values. The new index of biotic integrity (IBI) was calculated by summation of the metric scores, and transformed to an ecological quality ratio (EQR), ranging between 0 and 1. Five integrity classes, ranging from bad to maximal ecological potential, were attributed and compared to the pre-classified habitat status of the site. In addition, the new index was also validated with an independent set of data. The new IBI proved to successfully assess the ecological status of the rivers.

scholarly journals From paper to practice: an initial approach to implementation of the environmental monitoring plan for fish farming proposed by JACUMAR

2018 ◽  
Vol 82 (1) ◽  
pp. 27 ◽  
Author(s):  
Elena Martinez-Garcia ◽  
Victoria Fernandez-Gonzalez ◽  
Felipe Aguado-Giménez ◽  
José Luis Sánchez-Lizaso ◽  
Pablo Sanchez-Jerez
Keyword(s):  
Multivariate Analysis ◽  
Environmental Monitoring ◽  
Spatial Heterogeneity ◽  
Statistical Power ◽  
Univariate Analysis ◽  
Ecological Status ◽  
Fish Farming ◽  
Accurate Information ◽  
Ecological Data

The Spanish National Advisory Board of Mariculture (JACUMAR) developed an initiative to unify methodologies between the regions of Spain, in which they proposed the implementation of site-specific “Environmental Monitoring Plans” (EMPs). In this study, we tested the feasibility of an EMP on a fish farm in the Mediterranean Sea. The methods and tools proposed in the EMP are highly useful for environmental monitoring of aquaculture. However, spatial heterogeneity figured prominently in a univariate analysis with environmental variables and a multivariate analysis of polychaete assemblages. This variability may be due to habitat patchiness, and may therefore be solved by an improved experimental design, e.g. by adding replications for increasing statistical power. Multivariate analysis of polychaete assemblages provided accurate information about the quality of the sediment. This information could also be improved using ecological data about key polychaete families in order to avoid misleading results. Thus, the JACUMAR EMP has proved useful in providing precise information about the ecological status of marine benthic habitats, meeting the requirements of current European Directives. However, we suggest that some modifications may be required in order to account for possible misleading thresholds for environmental quality standards, spatial heterogeneity and increasing power analyses.

scholarly journals Harmonization of the assessment method for classifying the ecological quality status of very large Greek rivers

2018 ◽  
pp. 50 ◽  
Author(s):  
Maria Lazaridou ◽  
Chrysoula Ntislidou ◽  
Ioannis Karaouzas ◽  
Nikolaos Skoulikidis ◽  
Sebastian Birk
Keyword(s):  
Ecological Status ◽  
Organic Pollution ◽  
Assessment Method ◽  
Environmental Data ◽  
Biological Assessment ◽  
Ecological Quality Status ◽  
Status Assessment ◽  
High Good ◽  
Good Ecological Status

The intercalibration exercise is required by the European Water Framework Directive (WFD) to harmonize the national ecological class boundaries across Member States. It is applied to individual types of water bodies, comparing WFD-compliant biological assessment methods using specific quality elements. This study addresses the harmonization of the STAR_ICMi index for the ecological status assessment of very large Greek rivers in compliance with the completed intercalibration exercise for European very large rivers. River sites were sampled biannually for benthic invertebrates (as biological quality element) and environmental data during different surveys. The water quality of the samples ranged from high to bad. STAR_ICMi was significantly correlated to the Combined Abiotic Pressure index (CAPi) and its component pressures channelization, riparian vegetation alteration, and to a lesser extent to organic pollution. During the intercalibration approach benchmark standardization was applied to the component metrics of the intercalibration index prior to boundary comparison to minimize typological differences. The Greek class boundaries of high/good and good/moderate ecological status were compared and harmonized with the “Global Mean View” defined in the completed European intercalibration exercise. Similarity percentage analysis of biological community variation was performed for sites in high, good, and less than good ecological status according to the intercalibrated Greek classification.

scholarly journals Seafloor integrity down the harbor waterfront: the coralligenous shoals off Vado Ligure (NW Mediterranean)

2012 ◽  
Vol 3 (1) ◽  
pp. 51 ◽  
Author(s):  
Giulia Gatti ◽  
Monica Montefalcone ◽  
Alessio Rovere ◽  
Valeriano Parravicini ◽  
Carla Morri ◽  
...  
Keyword(s):  
Ecological Status ◽  
Visual Assessment ◽  
Ecological Quality ◽  
Landscape Indicators ◽  
European Directives ◽  
Marine Habitats ◽  
Deep Waters ◽  
Nw Mediterranean ◽  
Direct Inspection

In the last ten years, European Directives stressed the necessity to assess the ecological status of marine habitats by means of ecosystem or landscape indicators, rather than just species or chemical ones. In this paper, the seascape approach to characterise and assess the ecological quality of coralligenous rocky shoals of Vado Ligure (Savona, Italy) is introduced. This approach integrates biological, mesological and geomorphological information collected with a Rapid Visual Assessment technique (RVA). The RVA also optimised underwater operations in deep waters where coralligenous reefs usually develop and provided a sufficient amount of data collected by direct inspection. The seascape approach results are appropriate for the characterisation of the coralligenous shoals studied and for the assessment of their ecological quality. The quality of the assemblages was in general low, mainly due to high sedimentary stress; however, some exceptions showing a high ecological quality indicate that, with proper manage- ment tools, they would still have good potentialities of recovery.

Typical errors and violations of biotechnics of artificial breeding of pacific salmon

2020 ◽  
pp. 13-23
Author(s):  
Ekaterina Grinberg
Keyword(s):  
Production Process ◽  
Preventive Measures ◽  
Pacific Salmon ◽  
Fish Farming ◽  
Important Condition ◽  
The Third ◽  
Fish Breeding ◽  
Artificial Breeding ◽  
Strict Compliance

In two parts of the article, more than 70 errors and violations of the Biotechnics of artificial breeding of Pacific salmon in salmon hatcheries are collected and summarized, which lead to an immediate or delayed deterioration of the quality of reared fry and a decrease in their survival rate. Deviations from the biological basis of fish farming are shown and possible consequences of such errors or violations are predicted. In the first part of the article (#7,2020) there were General errors (throughout the entire fish-breeding process), as well as violations of Biotechnics during the work with producers, collecting eggs and preparing them for incubation, in the second part-violations of Biotechnics during the incubation of eggs, holding pre-larvae, rearing and release of young. Their correction, prevention or minimization of consequences will significantly improve the quality of sexual products and offspring from producers, increase the linear and weight gain of juveniles during rearing, improve the coefficient of feed payment, reduce the time of rearing, improve the epizootic situation by developing immunity in fry and mobilizing other protective reactions of their body, significantly reduce waste at all stages of the production process, increasing survival by 10–15%. In conclusion, it is noted that the first and most important condition for an efficient salmon hatchery is the creation of optimal environmental conditions at each stage of the production process. The second condition is strict compliance with the Biotechnics of artificial salmon breeding and the complex of veterinary and sanitary, fish-breeding and meliorative and therapeutic and preventive measures. The third is the availability of competent specialists who regularly improve their skills in accredited Universities to implement, control and manage the first two conditions.

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