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Freshwater Macroinvertebrates (freshwater + macroinvertebrate)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Effects of long-chain hydrocarbon-polluted sediment on freshwater macroinvertebrates

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2005
Vincent Pettigrove
Abstract High-molecular weight (>C16) hydrocarbons (HMWHs) are common pollutants in sediments of freshwater systems, particularly urban water bodies. No sediment quality guidelines exist for total hydrocarbons; more emphasis is placed on polyaromatic hydrocarbons, the most toxic component of hydrocarbons. A field-based microcosm experiment was conducted to determine whether unpolluted sediments spiked with synthetic motor oil impair freshwater macroinvertebrate assemblages. Total petroleum hydrocarbon (TPH) concentrations of 860 mg/kg dry weight significantly increased the abundance of Polypedilum vespertinus and Cricotopus albitarsis and decreased the abundance of Paratanytarsus grimmii adults (all Chironomidae), whereas TPH concentrations ranging from 1,858 to 14,266 mg/kg produced a significant reduction in the total numbers of taxa and abundance, with significant declines in the abundance of nine chironomid taxa. About 28% of water bodies surveyed in urban Melbourne, Australia, had TPH concentrations in sediments likely to cause ecological impairment, and about 14% of the water bodies surveyed are likely to have reduced species richness and abundance. Therefore, HMWHs can be a significant pollutant in urban water bodies. Freshwater sediment quality guidelines should be developed for this ubiquitous urban pollutant. [source]

Life-history strategies in freshwater macroinvertebrates

FRESHWATER BIOLOGY, Issue 9 2008
WILCO C. E. P. VERBERK
Summary 1Explaining spatial and temporal differences in species assemblages is a central aim of ecology. It requires a sound understanding of the causal mechanisms underlying the relationship of species with their environment. A species trait is widely acknowledged to be the key that links pattern and process, although the enormous variety of traits hampers generalization about which combination of traits are adaptive in a particular environment. 2In three steps, we used species traits to match species and environment, and chose lentic freshwater ecosystems to illustrate our approach. We first identified key environmental factors and selected the species traits that enable the organism to deal with them. Secondly, we investigated how investments in these traits are related (e.g. through trade-offs). Thirdly, we outlined 13 life-history strategies, based on biological species traits, their interrelations known from life-history theory and their functional implications. 3Species traits and environmental conditions are connected through life-history strategies, with different strategies representing different solutions to particular ecological problems. In addition, strategies may present an integrated response to the environment as they are based on many different traits and their interrelationships. The presence and abundance of (species exhibiting) different life-history strategies in a location may therefore give direct information about how a particular environment is experienced by the species present. 4Life-history strategies can be used to (i) explain differences in species assemblages either between locations or in different periods; (ii) compare waterbodies separated by large geographical distances, which may comprise different regional species pools or span species distribution areas and (iii) reduce often very complex, biodiverse assemblages into a few meaningful, easily interpretable relationships. [source]

Biological and ecological traits of benthic freshwater macroinvertebrates: relationships and definition of groups with similar traits

FRESHWATER BIOLOGY, Issue 2 2000
Philippe Usseglio-Polatera
Summary 1Relating species traits to habitat characteristics can provide important insights into the structure and functioning of stream communities. However, trade-offs among species traits make it difficult to predict accurately the functional diversity of freshwater communities. Many authors have pointed to the value of working with groups of organisms as similar as possible in terms of relationships among traits and have called for definition of groups of organisms with similar suites of attributes. 2We used multivariate analyses to examine separately the relationships among 11 biological traits and among 11 ecological traits of 472 benthic macroinvertebrate taxa (mainly genera). The main objective was to demonstrate (1) potential trade-offs among traits; (2) the importance of the different traits to separate systematic units or functional groupings; and (3) uniform functional groups of taxa that should allow a more effective use of macroinvertebrate biological and ecological traits. 3We defined eight groups and 15 subgroups according to a biological trait ordination which highlighted size (large to small), reproductive traits (K to r strategists), food (animal to plant material) and feeding habits (predator to scraper and/or deposit feeder) as ,significant' factors determining the ordination of taxa. This ordination partly preserved phylogenetic relationships among groups. 4Seven ecological groups and 13 ecological subgroups included organisms with combinations of traits which should be successively more adequate in habitats from the main channel to temporary waters, and from the crenon to the potamic sections of rivers, and to systems situated outside the river floodplain. These gradients corresponded to a gradual shift from (1) rheophilic organisms that lived in the main channel of cold oligotrophic mountain streams to (2) animals that preferred eutrophic habitats of still or temporary waters in lowlands. The groups with similar ecological traits had a more diverse systematic structure than those with similar biological traits. 5Monitoring and assessment tools for the management of water resources are generally more effective if they are based on a clear understanding of the mechanisms that lead to the presence or absence of species groups in the environment. We believe that groups with similar relationships among their species traits may be useful in developing tools that measure the functional diversity of communities. [source]

Stream mosses as chemically-defended refugia for freshwater macroinvertebrates

OIKOS, Issue 2 2007
John D. Parker
Marine and terrestrial studies show that small, sedentary herbivores that utilize plants as both food and habitat can gain enemy-free space by living on hosts that are chemically defended from larger, generalist consumers. Although large herbivores are increasingly recognized as important consumers of macrophytes in freshwater communities, the potential indirect effects of herbivory on plant-associated macroinvertebrates have rarely been studied. Here, we show that the large, generalist consumers in a riverine system, Canada geese, Branta canadensis, and crayfish, Procambarus spiculifer, both selectively consumed riverweed, Podostemum ceratophyllum, over an aquatic moss, Fontinalis novae-angliae, even though moss comprised 89% of the total plant biomass on riverine rocky shoals. Moss supported twice as many plant-associated macroinvertebrates as riverweed, suggesting that it might provide a spatial refuge from consumption by these larger consumers. Bioassay-guided fractionation of moss extracts led to the isolation of a C18 acetylenic acid, octadeca-9,12-dien-6-ynoic acid, that deterred crayfish feeding. In contrast to results with Canada geese and crayfish, both the amphipod Crangonyx gracilis and the isopod Asellus aquaticus consumed significant amounts of moss but rejected riverweed in laboratory feeding assays. Moreover, neither amphipod nor isopod feeding was deterred by the crude organic extract of Fontinalis, suggesting that these mesograzers tolerate or circumvent the chemical defenses that deterred larger consumers. Thus, herbivory by large, generalist herbivores may drive freshwater plant community structure towards chemically defended plants and favor the ecological specialization of smaller, less mobile herbivores on unpalatable hosts that represent enemy-free space. [source]

Effects of nitrate nitrogen pollution on Central European unionid bivalves revealed by distributional data and acute toxicity testing

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2010
Karel Douda
Abstract 1.Studies from Central Europe have shown a relationship between the impaired population status of threatened freshwater mussel species and elevated nitrate nitrogen (N,NO) concentrations in running waters. 2.Causal mechanisms, however, remain unknown, and no experimental data or comprehensive studies involving more species are available, which causes uncertainty in prioritizing conservation actions. 3.This study uses both descriptive and experimental approaches to identify the effects of nitrates on freshwater mussels and demonstrates the need for integrating different research methods for development of conservation strategies for threatened species. 4.Spatial co-occurrence of five native freshwater mussel species (Anodonta anatina, Pseudanodonta complanata, Unio pictorum, Unio tumidus, Unio crassus) and N,NO concentrations were examined in a 7th-order river catchment (Lu,nice River, Czech Republic) with anthropogenically-induced increasing N,NO levels and declining populations of these species during the 20th century. 5.Acute toxicity of N,NO was then estimated for artificially reared juveniles of A. anatina and U. crassus using both lethal and sublethal test endpoints. 6.Results showed that the probability of occurrence of all species was significantly reduced in reaches with elevated N,NO levels. 7.In contrast, the results of toxicity testing revealed that the juvenile stages of the two tested species were less sensitive to N,NO than most previously tested freshwater macroinvertebrates. The detected 96-h median lethal N,NO concentrations were two orders of magnitude higher than the limits derived from distributional data. 8.Despite the probable absence of a direct negative effect of N,NO on freshwater mussel populations, N,NO has potential to be used as an effective indicator of biotope conditions. Identification of causal mechanisms responsible for the observed relationship between unionids and N,NO will require further research. Copyright © 2009 John Wiley & Sons, Ltd. [source]