Indicator value of lotic water mites (Acari: Hydrachnidia) and their use in macroinvertebrate-based indices for water quality assessment purposes

Abstract

Key-words: water mites, biotic indices, water qualityThe Water Framework Directive (WFD) of the European Union includes benthic macroinvertebrates for the ecological assessment of running waters. The invertebrate-based Star-ICMi index, adopted in 2010, does not include Hydrachnidia (water mites) in its complex formulation. However, Hydrachnidia are associated with many environmental variables and may be useful for stream ecological characterization. We have therefore assessed the bioindicator value of Hydrachnidia in streams of central Italy, and the ability of two mite-containing (the PTH and the newly formulated PTH fam indices) and four mite-excluding biotic indices (Star-ICMi, BMWP, ASPT, and IBE) to characterize 216 sites ranging from semipristine to impacted. Mite bioindicator value was high at family level. Index reliability was consistently low for the PTH and ASPT indices. Distribution of mite families across quality classes (QCs) was fully separated only for the PTH fam index. QC assignment remained reliable at high index values (i.e., at high ecological status) for the PTH fam and BMWP indices, while logarithmic correlations between the PTH fam and the other indices suggest that the latter may misrepresent sites in high, good, and moderate ecological status sensu WFD. Further studies on the PTH fam index are warranted in light of its simplicity, high reliability, and low sampling and taxonomic identification effort.

Responses of water mite assemblages (Acari) to environmental parameters at irrigated rice cultivation fields and native lakes

“…Several sensitive species are restricted to very clean water and immediately respond to the early contamination of their environment. Thus, water mites are excellent indicators of pure water conditions and provide a powerful early warning system (Zawal 1996, Miccoli et al 2013. Species of the genus Limnesia are very sensitive to altered sites ( Van der Hammen and Smit 1996) and, according to our study, Limnesia sp.…”

Application of macroinvertebrate multimetrics as a measure of the impact of anthropogenic modification of spring habitats

“…The response of the macroinvertebrate assemblages to hydromorphological deterioration was determined based on the six macroinvertebrate community metrics currently used in biomonitoring programmes in the European Union (Table ; an overview is given in Miccoli et al, ) and based on a new index – Spring_ICMi – proposed in this study (Table ). The new spring index is a modification of the STAR_ICMi, which is proposed to intercalibrate different assessment metrics in Europe (Buffagni et al, ).…”

“…This article explores how the standard macroinvertebrate metrics perform in sites with similar water quality but different types of hydromorphological modification. It was hypothesized that biotic metrics that include water mites (Miccoli, Lombardo, & Cicolani, ) and crenobiontic taxa (von Fumetti, Dmitrović, & Pešić, ) are more sensitive for assessing the response of spring assemblages to hydromorphological modification than indices that use Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa only. The aim of this study was to develop a new metric that can assess the response of spring macroinvertebrate assemblages to the hydromorphological modification of spring habitats.…”

Two water mite species (Acari: Hydrachnidia) from karst springs new for the fauna of Croatia with notes on distribution and environmental preferences

“…Since their freshwater invasion, water mites have developed a high diversity -around 6.000 species are described, with experts estimating these numbers to exceed 10.000 worldwide (Davids et al, 2007;Goldschmidt, 2016). Representatives of this group inhabit most types of freshwater ecosystems (Miccoli et al, 2013;Więcek et al, 2013), but are often neglected in environmental research due to perceived difficulties in identification (Proctor, 2007;Goldschmidt, 2016). In Europe today, around 1.000 species are described (Watermite.org, 2016), with the research on this group rapidly growing due to recently published comprehensive identification keys (Davids et al, 2007;Di Sabatino et al, 2010;Gerecke et al, 2016).…”