Changes In Macroinvertebrate Communities Research Articles

A preliminary assessment of the impact of forest conversion from natural to pine plantation on macroinvertebrate communities in two mountain streams in Zimbabwe

This study presents preliminary data on the influence of forest conversion from natural to pine plantation on benthic macroinvertebrates in streams in the Chimanimani Mountains in the Eastern Highlands of Zimbabwe, a region that has received little attention with respect to human impacts on stream ecology. Benthic macroinvertebrate assemblages from the Haruni River, draining native deciduous forest, were compared with those of the Nyahode River draining commercial pine plantations. Functional feeding groups composition was not significantly different between the two rivers. Only small differences in macroinvertebrate assemblages were detected, with Shannon-Weiner diversity = 3.80 and Evenness = 0.89 in both cases and Sørensen similarity index = 0.79. Cluster analysis and multidimensional scaling ordination also demonstrated little spatial variation in the community composition of the two streams. In contrast, the clearfelling index indicated that taxonomic richness and Ephemeroptera/Plecoptera/Trichoptera (EPT) taxa richness were negatively affected by forest conversion. Taxonomic richness and EPT richness were negatively correlated with embeddedness, the single tangible evidence of forestry impact. Development of a multimetric index may enhance detection of subtle changes in macroinvertebrate communities resulting from modest alteration of the riparian vegetation.

Composition and temporal changes in macroinvertebrate communities of intermittent streams in Hawke's Bay, New Zealand

Macroinvertebrate communities in three stony‐bottomed intermittent headwater streams in central Hawke's Bay, New Zealand, were sampled once per month (on average) for 11 months from autumn 2005 to summer 2006, and compared with communities in three perennial streams and three intermittent streams with perennial headwaters. Among the intermittent headwater sites, 95 taxa were found, with Oligochaeta, Copepoda, Chironomidae, and Ostracoda occurring in greatest abundance. Eight mayfly, 6 stonefly and 16 caddisfly species were found. Macroinvertebrate abundance at intermittent headwater sites was equal to nearby perennial sites, but taxon richness per sample was lower. Community composition changed progressively during the autumn‐to‐spring flow period (March‐November 2005) at one intermittent headwater site, but at the other two sites a directional change was not evident, probably because stream flow stopped briefly several times during the flow period. Most of the taxa collected in riffles during the flow period were also in disconnected pools after flow stopped in summer (January 2006), but some taxa were absent and the disconnected pools contained several additional species. The disconnected pools in January had higher macroinvertebrate density and richness than connected pools during the flow period. At intermittent sites with perennial headwaters, taxon richness and EFT (Ephemeroptera, Plecoptera, and Trichoptera) richness were intermediate between intermittent headwater sites and perennial streams. Two weeks after flow began, the intermittent sites with perennial headwaters showed much higher EPT abundance and richness than the intermittent headwater sites, but after 8 weeks the proportional difference was less.

Long‐term changes in macroinvertebrate communities of a heavy metal polluted stream: the river Nent (Cumbria, UK) after 28 years

AbstractThe macroinvertebrate fauna of the river Nent, a heavy metal polluted upland stream in northern England, first surveyed in 1976, was re‐examined in 2004 to assess long‐term changes in relation to activities in the catchment which have included, a river restoration project, works associated with the development of a mine heritage site and the removal of a chicken farm and more effective organic pollution control measures. The degree of change between years in total abundance, numbers of taxa and community composition varied considerably between sites. Two tributary sites showed marked changes between years due to a reduction in acidity in one and changed substratum in the other but in the main river no significant difference in total taxa and total abundance was observed between years, although seasonal differences were significant. Multivariate community analyses grouped 1976 samples with those taken in 2004 but revealed a clear separation between upper and lower Nent sites. This observed difference may be related to increased algal cover in the lower sites in conjunction with geomorphological features of the lower Nent. Environmental assessment methodology River Invertebrate Prediction and Classification System (RIVPACS) identified ‘sensitive’ faunal groups and indicated that the extensive impact of zinc pollution in the main river has remained practically the same between 1976 and 2004. This persistence of community structure despite the heavily disturbed nature of the river is attributed to relative constancy in instream habitat conditions. The recent activities in the catchment have had little effect on the overall controllers of faunal communities in this system, zinc concentrations and geomorphological characteristics of the stream. However, further disturbances involving movement of spoil heaps and channel alterations in the upper catchment may increase both sediment and heavy metal loadings to the river. Copyright © 2007 John Wiley & Sons, Ltd.

Resistance and resilience of macroinvertebrates to irrigation water withdrawals

Summary1. Water withdrawal for irrigated agriculture is one of the leading uses of freshwater resources in the world; however, effects of low flow disturbances on lotic ecosystems are poorly understood. We studied an intensively managed agricultural catchment to determine: (i) how macroinvertebrate assemblages and environmental variables respond to water withdrawals of varying magnitude and duration; (ii) what environmental variables are associated with macroinvertebrate responses and (iii) the resiliency of macroinvertebrate communities to irrigation water withdrawals.2. We sampled above and below four irrigation diversions that create a gradient of increasing water withdrawal from upstream to downstream (i.e. 0%, 22%, 87%, 90% and 97% water withdrawn) along a 36 km river section. Three reaches were sampled above and below each point of diversion from June to September 2004 and 2005, which represented average and drought water conditions respectively.3. Irrigation water withdrawals were associated with both direct and indirect changes to the physicochemical environment. Direct effects (e.g. decreased velocity, depth and wetted habitat) were approximately proportional to the amount of water withdrawn, while indirect effects (e.g. increased conductivity and temperature) occurred when water withdrawals exceeded 85% of ambient levels.4. Changes in macroinvertebrate communities were more strongly related to indirect than direct effects of irrigation water withdrawals. In an average water year, community changes were associated with interacting thresholds of reduced discharge and increased conductivity. During a drought year, community changes were related to the interacting thresholds of reduced discharge and increased temperature.5. Between years, macroinvertebrate responses differed with the magnitude and duration of low flow conditions. In 2004, high‐intensity, relatively short‐duration water withdrawals (<2 months) and alterations to the physicochemical environment changed the relative abundance of macroinvertebrate communities, while macroinvertebrate indices and proportional abundances of functional feeding groups remained unchanged. In contrast, discharge reductions exceeding 90% of ambient levels and temperatures above 30 °C from July to September 2005 were associated with shifts in community composition from a dominance of collector‐gatherer and filterer Ephemeroptera, Plecoptera and Trichoptera taxa to predatory insects, non‐insect taxa and scraping elmid beetles.6. On an annual basis macroinvertebrate communities appeared resilient to the impacts of water withdrawals following winter high flows. In contrast, recovery was not observed after discharge and physicochemical variables returned to predisturbance conditions for only one month.7. Irrigation water withdrawals appear to impact macroinvertebrates through indirect effects that intensify with the magnitude and duration of water withdrawals and annual water availability. Preserving environmental conditions within natural ranges of variability, especially during low water years, appears critical to mitigating adverse biological responses to water withdrawals.

Macroinvertebrate communities in willow (Salix spp.) and reed beds (Phragmites australis) in central Victorian streams in Australia

Exotic willows (Salix spp.) are widespread riparian tree species of rivers in temperate Australia and New Zealand. Despite being considered as a weed of national significance, little is known about the habitat value of willows and the impact on aquatic biota of vegetation change following willow management programmes. Macroinvertebrate fauna in root habitats of willows and Phragmites australis habitats were examined in three central Victorian rivers to understand the effect of such littoral habitat changes on macroinvertebrates. Data were analysed using Partially Nested Factorial ANOVA with season, river and habitat as main effects. Habitat structure had a significant effect (P < 0.05) on macroinvertebrate community assemblage. However, effect of habitat was not consistent among seasons. The greatest community differences among habitats were observed during winter and least separation during autumn. Taxa responsible for community differences among habitats were also identified. Species richness and abundance did not show consistent variation among habitats over different rivers or seasons. This study provided some indication of the macroinvertebrate community changes that would take place in situations where riparian vegetation changes takes place from willows to P. australis.

Response of stream macroinvertebrates to changes in salinity and the development of a salinity index

Many streams and wetlands have been affected by increasing salinity, leading to significant changes in flora and fauna. The study investigates relationships between macroinvertebrate taxa and conductivity levels (µS cm−1) in Queensland stream systems. The analysed dataset contained occurrence patterns of frequently found macroinvertebrate taxa from edge (2580 samples) and riffle (1367 samples) habitats collected in spring and autumn over 8 years. Sensitivity analysis with predictive artificial neural network models and the taxon-specific mean conductivity values were used to assign a salinity sensitivity score (SSS) to each taxon (1—very tolerant, 5—tolerant, 10—sensitive). Salinity index (SI) based on the cumulative SSS was proposed as a measurement of change in macroinvertebrate communities caused by salinity increase. Changes in macroinvertebrate communities were observed at relatively low salinities, with SI rapidly decreasing to ~800–1000 µS cm−1 and decreasing further at a slower rate. Natural variability and water quality factors were ruled out as potential primary causes of the observed changes by using partial canonical correspondence analysis and subsets of the data with only good water quality.

Heavy metal bioaccumulation and macroinvertebrate community changes in a Mediterranean stream affected by acid mine drainage and an accidental spill (Guadiamar River, SW Spain)

In the 1998 Aznalcóllar mining accident, 5 million cubic meters of toxic waste were spilled into the Guadiamar River (SW Spain). This paper describes the likely effects of metal pollution on the macroinvertebrate community in the first 15 km of the river adjacent to the mine, 2 years after the spill. The contents of Zn, Cu, Pb, As, Cd, Tl, and Sb in water, sediment, and in the caddisfly Hydropsyche were analysed, together with some physico-chemical parameters. From the results of physico-chemical and community parameters, the studied area was divided into three sections: the first section contained upstream control stations, not affected by current mining activities, and with a diverse macroinvertebrate community structure (mean number of families=19); the second section, close to the mine, was severely polluted, with more than 50 mg l −1 of Zn or 1.6 mg l −1 of Cu in water, a pH of nearly 4, and a very diminished macroinvertebrate community (three families); in the last section, 6–15 km downstream from the mine, the water quality improved, metal concentrations decreased, pH reached neutrality and the macroinvertebrate community comprised eight families. We also determined metal concentrations in the larvae of Hydropsyche and found increases of 3- to 35-fold (for Cu and Cd, respectively) compared to control sites. As far as we are aware, these values are the highest concentrations so far detected in this caddisfly anywhere in the world. Different patterns of metal and pH tolerance were identified in macroinvertebrates. Most of the species were intolerant to present pollution levels and were only present in control sites. Others were tolerant to metal pollution but not to low pH and were present in the main river downstream of the mine, while a very few species managed to live in the most polluted section, with very low pH and high metal concentrations.

Changes in water quality and macroinvertebrate communities resulting from urban stormflows in the Provo River, Utah, U.S.A.

Short-term changes in water quality from 7 summer stormflows and long-term changes in substrates and macroinvertebrate communities resulting from urban runoff from the city of Provo, Utah, were examined from 1999–2002 in the lower Provo River. Stormflows resulted in increased total suspended solids and concentrations of dissolved copper, lead and zinc, and decreased conductivity and dissolved oxygen. The degree of change was generally in proportion to the magnitude of the storm. However, changes were temporary with water quality parameters returning to pre-storm levels within 12 hours. River substrates showed a trend of increased compaction and decreased debris dam area downstream through the urban corridor. Macroinvertebrate communities showed trends of decreased abundance and total species diversity with increasing urbanization. Compared to non-urban reaches, communities in urban reaches had few `sensitive' species and were dominated by tolerant species, particularly snails and leeches. Comparisons with previous studies show that changes in macroinvertebrate community composition in the urban reaches reflected shifts in land use during the past 15–25 years and corresponded to expected threshold levels of impact for amount of impervious surface cover.

Macroinvertebrate response to logging in coastal headwater streams of Washington, U.S.A.

We examined the effects of logging on macroinvertebrate assemblages in first-order streams of four coniferous watersheds in Washington's Coastal Mountain ranges. Each watershed contained three to four first-order streams that were placed into one of three treatment types: clear-cut logging, operational buffer-strip (2.5–21 m) logging, or uncut reference streams. Prelogging baseline data on macroinvertebrate assemblages, channel morphology, sediment composition, sediment accretion rates, and water temperatures were collected from each stream in summer 1998. Logging operations were conducted the next winter and spring. Streams were resampled in summer 1999, within 1 year of logging, and summer 2000, 1+ years after logging. Preexisting treatment differences did not exist in 1998, indicating that postharvest treatment differences could be attributed to logging operations. In 1999, densities of macroinvertebrate collectors, densities and biomass of macroinvertebrate shredders, and accretion rates of organic sediments were greater in clear-cut and buffered streams than uncut references. These differences diminished by 2000. An increase in collecting and shredding macroinvertebrate is not a typical response to logging and may reflect the fact that logged streams became buried under slash, increasing detrital food supplies for these organisms. The narrow buffers used for this study did not prevent macroinvertebrate community changes associated with logging.

Macroinvertebrate community changes at coarse sediment recruitment points along two gravel bed rivers

Field data from two gravel bed rivers are used to investigate the response of mainstream macroinvertebrate communities to changes in bed sediment character at sites of significant coarse sediment recruitment. There is clear evidence that these points, where downstream fining trends are punctuated, are associated with significant changes in community composition. Community differences are greater between pairs of riffles that straddle recruitment points than between similarly spaced riffles that do not. Taxa that prefer coarse substrate and energetic flows tend to be more abundant below recruitment points where there is also a tendency for taxa diversity to increase. Classification procedures discriminate faunal assemblages at those sites which occur immediately downstream of recruitment points from assemblages at other sites. Although most of the lateral sediment sources examined are tributaries, a number of arguments suggest that, at least in this case, faunal changes are primarily due to abrupt changes in bed sediment character and are not due to concomitant changes in water quality or quantity. Our results suggest that at moderate spatial scales, patterns of coarse sediment recruitment are partly responsible for the spatial organization of macroinvertebrate communities in gravel bed rivers.

Bank profile and structure as determinants of macroinvertebrate assemblages—seasonal changes and management

AbstractManagement and restoration procedures in rivers frequently have a major influence on the bank and marginal zone, depending on the timing of disturbance and the eventual structure of the bank. This study examines changes in macroinvertebrate communities in four different bank types at 3‐weekly intervals throughout a year. The banks differed in their profile and in their structure: shallow sloping and vegetated, stepped shallow profile, steep profile (eroded soil bank), and iron revetments. Velocity patterns over the year showed much variability, both between and within bank types ranging from standing water in the summer to velocities in excess of 0.9 m s−1 in the winter. The shallow‐sloping vegetated site supported a total of 115 taxa, in contrast to the artificial iron revetment, on which only 32 taxa were recorded. Total abundances were five to six times greater in the shallow vegetated sites compared with the steeply sloped and artificial banks. Highest abundances were recorded in the late spring (May/June) and most taxa were found in August and September. Fluctuations in both abundance and number of taxa were least on the reveted bank. Ordination of the fauna/site matrix revealed a seasonal separation with specific winter and summer communities. The results suggest that the bankside is a dynamic environment where communities change in relation to growth of bankside vegetation and its concomitant effect on flow. The implications of these findings to management activities and restoration procedures are discussed. Copyright © 2001 John Wiley & Sons, Ltd.

Correlation of vegetation and benthic macroinvertebrate community changes in Florida pondcypress swamps following clearcutting

Correlation of vegetation and benthic macroinvertebrate community changes in Florida pondcypress swamps following clearcutting

Influence of taxonomic determination level on several community indices

The aim of the present study was to test the possible influence of different taxonomic determination levels on several commonly used indices. Ephemeroptera, Plecoptera and Trichoptera communities of five acidified and three reference headwater streams were sampled 11 times during one year, providing quantitative faunistic lists. Richness, four diversity indices and two similarity indices were compared when calculated from species, genus and family determination levels. The results showed that high taxonomic level determinations lead to underestimation of all indices excepted for Jaccard which was overestimated. Underestimation was generally higher for communities of reference streams than for impacted streams. Consequently, determinations to family level make the interpretation of metric values very hazardous, especially when indices are used to assess both water quality and macroinvertebrate community changes.

Impact of hypolimnetic oxygenation on profundal macroinvertebrates in a eutrophic lake in central Alberta. I. Changes in macroinvertebrate abundance and diversity

Hypolimnetic oxygenation from 1988 to 1991 in the north basin of Amisk Lake increased mean summer (June-August) dissolved oxygen (DO) concentrations in the deep hypolimnion (25 m) from <0.4 mg ·L-1 during pretreatment years (1980-1987) to 2.7 mg ·L-1 during treatment. Mean summer hypolimnetic temperatures at 25 m also increased from 6.3 (pretreatment) to 8.1°C (treatment). Profundal (15-25 m) Chironomus spp. abundance in the treated basin increased from <100 to >2000 ·m-2 from 1988 to 1991 whereas Chaoborus spp., Tubificidae, and other taxa remained uncommon at similar depths. Shannon-Weaver indices of diversity decreased as oxygenation progressed, in contrast with previous studies. Similar patterns in densities and diversity were observed in the south basin of Amisk Lake, although the increase in DO concentrations was smaller relative to the north basin. The impact of increased water temperature on macroinvertebrates appeared minor relative to the effects of increased DO concentrations. No changes in macroinvertebrate communities were noted in a nearby reference lake during the study period. Responses to hypolimnetic oxygenation in Amisk Lake differed markedly from those reported for smaller, single-basined water bodies.

Analysing benthic macroinvertebrate community changes along a pollution gradient: A framework for the development of biotic indices

The present study used a new model to analyse macroinvertebrate community changes along an organic pollution gradient in the River Trent system, U.K. The model divides community changes into four types, three of which are further differentiated into two sub-types. These type and sub-type variations are of different ecological significance. The results showed that as water quality deteriorated, species loss, the average abundance of sample-specific species and the average maximum ratio of in-common species abundance increased substantially, while the numbers of persisting species were reduced rapidly. However, polluted sites were also found to gain some tolerant species, particularly at slightly polluted sites. The abilities of several commonly used biotic indices to summarise these changes were compared. The design of the Chandler score system appeared to be more effective than the other systems examined. The Chandler-ASPT was modified by multiplying by log S (species richness/the number of key taxa) to improve its sensitivity over the lower range of water quality while retaining its effectiveness over the upper range of water quality. The modified index was tested using a published data set.

Longitudinal changes of macroinvertebrate communities along an Appalachian stream continuum

On a determine la richesse ainsi que l'abondance et la biomasse annuelle moyenne des taxons benthiques dans des habitats prevalants le long d'un continuum fluviatile d'ordre une a sept dans le secteur sud des Appalaches (E.-U.). La richesse etait maximale dans les passages d'ordre moyen, tandis que les habitats a cailloux, suivis des aires constituees du substratum rocheux, de galets-gravier, et les aires sedimentaires presentaient la densite benthique la plus elevee. Des valeurs estimatives, basees sur l'abondance, de la composition des groupes d'alimentation fonctionnels indiquaient qu'il y avait surtout des organismes collecteurs et que la composition ne changeait guere d'un habitat a l'autre. Par contraste, les valeurs estimatives basees sur la biomasse variaient considerablement d'un habitat a l'autre; les collecteurs-filtreurs dominaient generalement dans les aires recouvertes de cailloux et celles constituees du substratum rocheux, tandis que ce sont les collecteurs et les dechiqueteurs et collecteurs qui dominaient dans les aires de galets-gravier et les habitats sedimentaires, respectivement. Lorsque les valeurs estimatives de la biomasse des groupes fonctionnels etaient ponderees pour tenir compte de la disponibilite relative des habitats le long du continuum, la composition de la communaute benthique correspondait generalement aux previsions du concept du continuum fluviatile (RCC), meme si des changements localises dans la geomorphologie du cours d'eau influaient egalement sur la structure de la communaute. Les valeurs estimatives ponderees pour tenir compte de l'habitat n'ont pas indique des tendances semblables. Comme les previsions du concept du continuum fluviatile (RCC) sont fondees sur la biomasse benthique, il faut faire preuve de prudence et nuancer les conclusions lorsqu'on utilise des donnees d'abondance pour verifier les previsions RCC.

Longitudinal changes of macroinvertebrate communities along an Appalachian stream continuum

Longitudinal changes of macroinvertebrate communities along an Appalachian stream continuum

Long‐term changes of macroinvertebrate communities in relation to flow variations: The river Glen, Lincolnshire, England

AbstractTaxa and community relationships with flow were investigated using National Rivers Authority macroinvertebrate sampling records from a total of 45 sites in the River Glen catchment and daily flow records, taken over the period 1976–1994. Four sites (two upstream and two downstream of an interbasin transfer outflow) were studied in detail. Community analyses of summer samples (41 records from 1977 to 1994) showed April mean flow and low flows in the same summer as sampling to be the best predictors of macroinvertebrate community type. Comparison of the frequency of individual taxa in summers when flows were above or below the flow sustained by the inter‐basin transfer (0.107 m3 s−1) showed a relatively high number of taxa, including Sailidae, Molannidae, Planorbis spp. and Haliplidae, to be more frequent in low‐flow summers, whereas other taxa, including Rhyacophilidae and Leptophlebidae, were more frequent in high‐flow summers, differences apparently related to position in the catchment and variability in the development of marginal macrophytes. The implications of altering flow regime on habitat and macroinvertebrate communities are discussed, and the suitability of National Rivers Authority biological records for developing long‐term flow‐preference relationships for individual taxa are considered.

Multispecies toxicity tests using indigenous organisms: Predicting the effects of complex effluents in streams

A study was conducted to determine if contaminant-induced changes in macroinvertebrate communities in laboratory stream microcosms could be used to predict responses of these organisms in a natural stream receiving the same contaminant. Test organisms were transferred to the artificial streams in rock-filled containers previously colonized for 30 days upstream of the effluent outfall. The microcosms were exposed for 20 days to concentrations of the effluent that reflected those at field sites where macroinvertebrates were collected.