Ischnura Graellsii(Insecta: Odonata) A Water Pollution Biovulnerability Indicator—Probability Mapping Using Spatial Uncertainty

Abstract

Monitoring changes of anthropogenic impacts from a broad scope of species in biodiversity research require practical, easy-to-use and efficient assessment as well as monitoring methods. Odonates (Insecta: Odonata) are a valuable tool for assessing freshwater systems' quality and have been used as bioindicators of environmental variety.The Águeda watershed, located in the central west of the Iberian Peninsula, shows an exponential increase in the last 60 years of natural resource exploitation coupled with alterations in consumer habits, causing significant environmental changes and deferred direct effects on the natural habitats.Fourteen river sites, selected a priori, were sampled. Adult odonates were collected using standardized methods. Selected environmental variables and water quality parameters were evaluated in situ. Precipitation and altitude were the most important physical, environmental variables in explaining the assemblage structure. Meaningful abiotic-biotic as well as biotic-biotic relationships were set up. Furthermore, situations in the urbanized watershed area showed to be highly impacted and closely related with damselfly Ischnura graellsii, which should be targeted as a possible vulnerability indicator for polluted fresh waters.A probability map for Ischnura graellsii distribution was performed using indicator kriging with external drift and spatial uncertainty obtain through the calculation of two categorical maps (binary), corresponding to the mean (0.485) and the trimmed mean by discharging the 10% lower distribution tail (0.533). The subsequent overlapping of both categorical maps (binary) allowed the definition of the higher spatial uncertainty map for surface water contamination. Figure 6. (a) Categorical map (binary) of the Ig probability being higher (1) or lower (0) than the μ = 0.485; (b) categorical map (binary) of the Ig probability being higher (1) or lower (0) than the trimmed μ = 0.533; (c) spatial uncertainty visualization ISCHNURA GRAELLSII-A WATER POLLUTION BIOVULNERABILITY INDICATOR

Ecological correlates of odonate assemblages of a Mediterranean stream, Wadi Cherf, northeastern Algeria: implications for conservation

“…Equally important, our results indicated congruence between both P. subdilatata and I. graellsii and polluted sites. Some odonates, like Ischnura spp., are well known for their capacity to withstand pollution (Campos et al, 2014;Ferreras-Romero, Márquez-Rodríguez, & Ruiz-García, 2009;Solimini, Tarallo & Carchini, 1997;Yalles-Satha & Samraoui, 2017). This finding provides support to the reliability of our pollution index at detecting water quality deterioration.…”

Environmental factors influencing odonata communities of three mediterranean rivers : Kebir-East, Seybouse, and Rhumel Wadis, northeastern Algeria

“…Our results for Wadi Seybouse concur with these findings. The presence of two species of Ischnura: I. graellsii and I. pumilio is unsurprising as species of Ischnura have been shown to be quite tolerant of water pollution (Ferreras-Romero et al, 2009;Campos et al, 2014).…”