Effects of heavy metals on benthic macroinvertebrate communities in high mountain streams

Abstract

-We characterized the responses of benthic macroinvertebrates to heavy metals released from mines in high mountain streams of the Gangqu River in the Shangrila Gorge, China. Benthic macroinvertebrates were collected with a kick-net at 32 sampling sites. In addition, 25 environmental variables including heavy metal concentrations were measured at each sampling site. Although the concentrations of heavy metals were not seriously high, their effects were reflected in the changes of community composition of benthic macroinvertebrates. Total abundance and species richness decreased with increasing heavy metal concentrations. Species richness of Plecoptera and Trichoptera, Margalef richness index, and percentage of scrapers in functional feeding groups were negatively correlated with heavy metal concentrations. A high variation was observed in the response of different taxa to heavy metals. Heavy metals mainly affected the sensitive taxa of Plecoptera, Ephemeroptera, and Trichoptera. However, some tolerant taxa were observed in Trichoptera (such as Hydropsyche sp.) and Dugesia sp. Cluster analysis and a non-metric multidimensional scaling analysis were applied to characterize specific macroinvertebrate taxa composition. The analyses revealed the effects of different environmental factors such as geographical, hydromorphological, physical, and chemical factors including heavy metals on the distribution of benthic macroinvertebrates in high mountain streams. Although the effects were compounded with different factors such as altitude, temperature, stream width, turbidity, and heavy metals, the influence of heavy metals on benthic macroinvertebrate communities was clearly identified (decreased species richness, changes in species composition). Even though the contamination of heavy metals was low in the sampling area, the consequences were clear, indicating that longterm exposure to heavy metals could seriously impact aquatic communities in high mountain streams.

Aquatic Insect Biodiversity and Water Quality Parameters of Streams in Northern Thailand

“…Trichopterans are especially sensitive to decrease in water quality (Dohet 2002;Guilpart et al 2012). Ephemeroptera, Plecoptera and Trichoptera are often used as indicators of good water quality (Crisci-Bispo et al 2007;Qu et al 2010). One family in order Plecoptera was recorded in this study.…”

Water quality assessment using macroinvertebrates along the mining area of Brgy

“…Furthermore, characterization of the response of benthic macroinvertebrates to heavy metals released from the mines showed that although the concentration of heavy metals is not seriously high, their effects were reflected in the changes in species composition of macroinvertebrates particularly affecting the pollution sensitive EPT taxa and the decreased in total abundance and species richness as the concentration of heavy metals increases (Qu et al, 2010). Likewise, in this present study, although the concentration of mercury detected in the downstream portion of Bigaan River is low and still within the acceptable limit set by DAO-34, this concentration might still be detrimental to the aquatic macroinvertebrates especially for those species that are highly sensitive to pollutants like the EPT taxa.…”

The environmental requirements of Crunoecia irrorata (Curtis, 1834) (Trichoptera: Lepidostomatidae) and the potential of the species for use as an indicator: an example from the Vistulian glaciation area

“…However, the relationship between these pollutants and caddisfly representatives is rather complex. In general, the effects of heavy metals on the order Trichoptera (structure and abundance) in streams appear to be of minor importance, although slightly negative effects (Qu et al, 2010) as well as slightly positive effects (Hirst et al, 2002) (Qu et al, 2010). For the family Lepidostomatidae, evidence of significantly negative effects of lead and nickel as well as slightly negative effects of cadmium and zinc have been found for Lepidostoma sp.…”

“…For the family Lepidostomatidae, evidence of significantly negative effects of lead and nickel as well as slightly negative effects of cadmium and zinc have been found for Lepidostoma sp. in Chinese streams (Qu et al, 2010), suggesting that C. irrorata, as a representative of the same family, might show a similar sensitivity to these heavy metals. Surprisingly, high concentrations of neither these nor the other metals considered influenced the presence of C. irrorata in our study area in any way.…”

“…Many previous investigations have documented more or less strong relationships between various environmental components and the composition and/or diversity of crenic assemblages (Schindler, 2004;Barquín and Death, 2009;Ilmonen et al, 2012). However, considerably less information on the tolerance of individual species to particular water characteristics is currently available (Bonada et al, 2004;Qu et al, 2010), although the available information allows the determination of indicator species for specific pollutants in aquatic habitats and, additionally, for the assessment of water quality (Bonada et al, 2004). However, knowledge of the ecological requirements of individual species is an important tool in management and in strategies of biodiversity conservation, especially for predicting optimal conditions for rare species.…”