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

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.

2010 ◽  
Vol 3 ◽  
pp. 79-99 ◽  
Author(s):  
Hayal Desta Yimer ◽  
Seyoum Mengistou

The wetlands located at the periphery of Jimma town, southwestern Ethiopia, have critical roles in providing a range of ecological and socio-economic benefits, yet they are subject to increasing anthropogenic disturbances, notably through agriculture, settlement, intensive grazing and brick-making. This study assessed the ecological status of these wetlands, and examined the scale of the human disturbances that local communities might impose on them. Macroinvertebrate communities, water quality parameters, and human disturbance scores were assessed. Except for electrical conductivity and water temperature, no significant difference (P < 0.05) was found in physico-chemical parameters between the sampled sites. Nitrate was the only parameter that correlated with significant influence on species richness of the sampled macroinvertebrates. A total of 10 metrics were used to generate the index of biotic integrity (IBI). This IBI was then tested based on macroinvertebrate data collected. Ways of assessing and evaluating the existing ecological status of the wetlands are discussed in the context of physico-chemical parameters, IBI based on macroinvertebrates and human disturbance scales. Key Words: Catchments land use; Water quality; Macroinvertebrate; Index of Biotic Integrity; Wetland DOI: 10.3126/jowe.v3i0.2265 Journal of Wetlands Ecology, (2009) Vol. 3, pp 77-93


2021 ◽  
Vol 151 ◽  
Author(s):  
Jan Breine ◽  
Ericia Van den Bergh ◽  
Gerlinde Van Thuyne ◽  
Claude Belpaire

This Corrigendum corrects an error in Table 2 that was published in Breine et al. (2021) on the pages 114–115: the line concerning the weatherfish Misgurnus fossilis (Linnaeus, 1758) on the page break was erroneously removed during publication and is added here.


2021 ◽  
Vol 4 ◽  
Author(s):  
Victor Hugo Salinas Camarillo ◽  
Javier Carmona-Jiménez ◽  
Nelida Abarca ◽  
Jonas Zimmermann ◽  
Demetrio Mora

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.


2015 ◽  
Vol 16 (2) ◽  
pp. 419 ◽  
Author(s):  
L. PIAZZI ◽  
P. GENNARO ◽  
E. CECCHI ◽  
F. SERENA

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.


2020 ◽  
Vol 12 (18) ◽  
pp. 7716
Author(s):  
Pengwen Gao ◽  
Alimujiang Kasimu ◽  
Yongyu Zhao ◽  
Bing Lin ◽  
Jinpeng Chai ◽  
...  

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.


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