Search results for "macroinvertebrate"
showing 10 items of 42 documents
Fish introductions and light modulate food web fluxes in tropical streams : a whole-ecosystem experimental approach
2016
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (15N) stable isotope tracer to compare basal resource treatments (thinned canopy vs. con…
Proposed Environmental Risk Management Elements in a Carpathian Valley Basin, within the Roşia Montană European Historical Mining Area
2021
Non-ferrous metals mining activities have long accompanied people, and began in the study area of South East Europe over 2000 years ago. The environment quality is significantly affected by both historic mining activities and contemporary impacts. All these problems, inducing synergic negative effects on local organism communities, have created a chronic state of pollution. The Corna Valley has one of the oldest historical human impacts in Romania due to the influence of mining. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. The analysis of macroinvertebrate communities, correlated with the lack of fish and some biotope…
A comparison of the impacts of introduced signal crayfish and native noble crayfish in boreal lake ecosystems
2014
Assessment of possibilities of the biotic index application in the biological monitoring of the running water quality
2003
New applications of zoobenthos measurements for risk assessment of chemicals in aquatic ecosystems
2015
Artikkeliväitöskirja. Yhteenveto-osa ja viisi artikkelia. (Artikkelit eivät avoimesti saatavilla.) Article dissertation. An introduction and five articles (not available in this version). Benthic animals in aquatic ecosystems suffer from various anthropogenic pollutants. A challenge in risk assessment of chemicals in aquatic ecosystems (i.e. ecological risk assessment) has been to balance cost-efficiency and effectiveness in detecting early warning signals of chemicals. In this study, hyperspectral imaging and behavioural measurements were evaluated as novel applications for detecting chemical effects on benthic animals, and the reliability of the incidence of chironomid morphological defor…
Littoral-pelagic zone food web interactions in fishless, highly humic Lake Mekkojärvi
2007
Benthic foodweb structure in a large shallow lake studied by stable isotope analysis
2014
The benthic foodweb structure of Lake Võrtsjärv, a large (270 km2), shallow, and turbid Estonian lake, was evaluated based on C and N stable-isotope signatures (δ13C, δ15N). Variation in δ13C between sampling sites was not related to site proximity to the littoral zone or the more vegetated southern part of the lake, but rather appeared to be influenced by in-situ site peculiarities. δ13C was stable temporally and between functional feeding groups, a result implying that the whole benthic food web of the lake relies largely on the same C source admixture, essentially particulate organic matter (POM). Thus, the foodweb composition of Lake Võrtsjärv is remarkably homogeneous given the lake’s …
Fish introductions and light modulate food web fluxes in tropical streams: a whole-ecosystem experimental approach.
2016
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (15 N) stable isotope tracer to compare basal resource treatments (thinned canopy vs. co…
Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?
2016
Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana) on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recentl…