57 research outputs found
Biological indices applied to benthic macroinvertebrates at reference conditions of mountain streams in two ecoregions (Poland, the Slovak Republic)
The study was carried out from 2007 to
2010 in two ecoregions: the Carpathians and the
Central Highlands. The objectives of our survey were
to test the existing biological index metric based on
benthic macroinvertebrates at reference conditions in
the high- and mid-altitude mountain streams of two
ecoregions according to the requirements of the EU
WFD and to determine which environmental factors
influence the distribution of benthic macroinvertebrates.
Our results revealed statistically significant
differences in the values of the physical and chemical
parameters of water as well as the mean values of
metrics between the types of streams at the sampling
sites. RDA analysis showed that the temperature of the
water, pH, conductivity, the stream gradient, values of
the HQA index, and altitude were the parameters most
associated with the distribution of benthic macroinvertebrate
taxa and the values of the metrics. The
values of biological indices should be considered
according to the stream typology including altitude
and geology. At the reference conditions, the suggested
border values of biological indices are very
harsh. The values of the biological indices of most
sampling sites did not correspond to the requirements
of the high status in rivers. The streams at altitudes
above 1,200 m a.s.l. should be treated as another river
type and new reference values should be established
Macrophyte and macroinvertebrate patterns in unimpacted mountain rivers of two European ecoregions
The aim of the study was to compare the
patterns of development of macrophytes and macroinvertebrates
in different types of reference mountain
rivers. The study is based on reference river sites
surveyed throughout the mountains in Poland and
Slovakia in two European ecoregions (9—Central
Highlands, 10—The Carpathians). A wide range of
environmental variables were estimated, including
water chemistry, hydromorphology, geology, and the
spatial factor. Based on the Jaccard index, macrophyte
and macroinvertebrate variation was confirmed
between four mountain and upland river types. It
was found that the biological diversification is mainly
influenced by geological and associated chemical
factors. In the case of macroinvertebrates, additionally,
the importance of the spatial factor was revealed
(difference between ecoregions). Finally, the habitat
preferences of various taxa were identified. It was
found that extreme mountain conditions can sometimes
distort bioindicative response, as was detected in
the case of macroinvertebrates in the highest mountain
sites. We concluded that consideration of two groups
of organisms enables more comprehensive and reliable
monitoring than assessment based on a single
group, especially when standard bioindicative methods
can be distorted by extreme local conditions
Long-term trends in aquatic ecosystem bioassessment metrics are not influenced by sampling method: empirical evidence from the Niobrara River
Choosing an aquatic invertebrate sampling method for biomonitoring depends upon study goals, resources, and ecosystem conditions. In this study, we compared two methods that are widely used in stream ecology, but have not been directly compared: Hester–Dendy (HD) and Hess sampling. Hester–Dendy sampling uses artificial substrate that invertebrates colonize over a specific period of time. In contrast, Hess samplers surround a fixed area of natural substrate with a net. To compare approaches, we combined 5 years of simultaneous HD and Hess data collection (2010–2014) from the Niobrara River with a 14-year (1996–2009) historical HD data set for the same study sites. We used this full 19-year data set to assess how ecosystem health has changed in the Niobrara River over time, while also testing the influence of HD versus Hess data (2010–2014) on historical trends (1996–2009). Our results showed that HD samples are more taxonomically variable and bias bioassessment metrics because they collect more sensitive taxa versus Hess sampling. However, when combined with the 1996–2009 HD data set, both recent HD and Hess data sets recovered the same trend of declining ecosystem health in the Niobrara River. These results provide empirical evidence that even when historical HD data are combined with recent Hess data, long-term bioassessment trends remain unchanged despite more accurate perspectives of invertebrate assemblages being collected
Pollution of Flooded Arable Soils with Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs)
Biological indices applied to benthic macroinvertebrates at reference conditions of mountain streams in two ecoregions (Poland, the Slovak Republic)
The potential of the Phytotoxkit microbiotest for hazard evaluation of sediments in eutrophic freshwater ecosystems
Assessment of heavy metals mobility and toxicity in contaminated sediments by sequential extraction and a battery of bioassays
Fitotoxicidade e citogenotoxicidade da água e sedimento de córrego urbano em bioensaio com Lactuca sativa
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