База резюме и ссылок по экологии бентоса

Дрифт в водотоках.

Дрифт – обзор.

Дрифт. Непал.

FRESHWATER BIOLOGY 1994, Vol 32, Iss 3, pp 573-583

Abstract:

1. Macroinvertebrate drift was investigated in seven small headwater streams along an altitudinal gradient (600-3350 m) in two adjacent river systems in east-central Nepal. Study streams in the Likhu Khola were at the lowest altitude and flowed through terraced agriculture. At higher altitudes, Langtang streams flowed through catchments of forest and alpine scrub. Samples were collected every 3 h over a 24 h period in each stream.

2. Terrestrial macroinvertebrate drift was greatest in streams with semi-natural catchments, but was scarce in streams where trees were absent.

3. At lower altitudes drift was dominated by Hydropsychidae and Baetidae, which were most abundant in night samples, and Hydracarina, which tended to be day active. Baetidae also dominated drift at high altitudes, but here drift was increasingly aperiodic or diurnal. The composition of the drift reflected a significant correlation between the percentage abundance of taxa in the drift and benthos.

4. As in other mountain regions of the world, drift was aperiodic in fishless streams (high altitude), but strongly nocturnal in streams where insectivorous fish were present (lower altitude). However, a wide array of potentially important variables along the altitudinal gradient, such as temperature, climate and community structure, might be important influences on these patterns.

Дрифт: определяющие факторы.

Authors: Kerby-BM Bunn-SE Hughes-JM

Факторы, влияющие на дрифт беспозвоночных в небольшой лесной речке в юго-восточном Квинсленде (Австралия).

Factors Influencing Invertebrate Drift in Small Forest Streams, South-Eastern Queensland

MARINE AND FRESHWATER RESEARCH

1995, Vol 46, Iss 8, pp 1101-1108

Abstract:

Aspects of invertebrate drift were investigated in four small rainforest streams in southeastern Queensland. Hourly sampling in two streams revealed low drift rates and no distinct diel patterns, This may have been a consequence of the low flows experienced during the study period, The drift was dominated by Simuliidae, Chironomidae and to a lesser extent Tasmanocoenis sp, (Caenidae) and Cheumatopsyche sp, 6 (Hydropsychidae). Additional studies were undertaken to examine why some individuals of particular taxa drift while others (of the same taxa) remain in or on the substratum, Analysis of the relative gut fullness of simuliid and chironomid larvae showed that a higher proportion of non-drifting individuals had full or nearly full guts compared with those in the drift. Hungrier individuals of these two taxa may enter the drift as a food searching mechanism, An analysis of limb loss of hexapod nymphs indicated that a disproportionate number of individuals in the drift had one or more limbs missing compared with those that remained in the benthos. These data support the hypothesis that invertebrates present in the drift are less fit than non-drifters.

Дрифт.

Influence of side-arms on aquatic macroinvertebrate drift in the main

channel of a large river.

Freshwater Biology 35(1). 1996. 149-164.

1. Drift from lotic and lentic side-arms to the main channel was studied

over 2 years in different sections of the Upper Rhone River (France). The

hypothesis of an influence of drift on the main channel was tested by

measuring drift in the main river at sites downstream and upstream from

the confluences with two side-arms, as well as in the two side-arms

themselves. 2. Side-arms were differentiated from the main channel by

having a typical composition of macrofauna with a high propensity to

drift, particularly in spring-summer and during spates. Drift densities in

side-arms averaged more than twice those measured in main channel sites,

but these inputs did not significantly affect taxon richness and total

drift density in the main channel. 3. Nevertheless, some taxa found in the

more lotic of the two side-arms were more abundant downstream of the

confluence than upstream, indicating that they had drifted into the main

channel; no such direct effect was found throughout the sampling period

for the more lentic side-arm. The densities of two competitive filter

feeders (Hydropsyche and Simuliidae) were significantly higher below the

confluences than above, suggesting that side-arms were also contributing

substantial amounts of seston to the main channel. 4. Therefore, side-arms

influence the community structure of drifting macroinvertebrates in the

Upper Rhone River, both directly through immigration-depending on the

degree of connectivity to the river-and indirectly via food supply.

Дрифт.

Title: Population and Community Patterns of Invertebrate Drift

in an Unregulated Coastal-Plain River

Source: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES

1991, Vol 48, Iss 5, pp 811-823

Language: English

Document type: Article

Addresses:

UNIV-ALABAMA, DEPT BIOL, AQUAT BIOL PROGRAM, TUSCALOOSA, AL

35487, USA

Keywords Plus:

MACROINVERTEBRATE DRIFT; MISSISSIPPI RIVER; BLACKWATER

RIVER; MOUNTAIN STREAM; LIFE-HISTORY; HABITAT; ZOOPLANKTON;

DYNAMICS; ALBERTA; INSECTS

Abstract:

Drifting invertebrates were sampled monthly during postdusk

hours for 2 yr in the Ogeechee River, a sixth-order river in the

southeastern United States. Drift quantities were among the

highest reported in the literature, with mean biomass varying

from 2.41 to 2.46 mg dry mass/m3 between years and mean density

from 20.4 to 22.8 individuals/m3. Major contributors to drift

biomass were Ephemeroptera (30.3%), Coleoptera (25.1%),

Plecoptera (16.6%), and Trichoptera (14.5%). Taxon-specific

seasonal patterns of drift biomass for several mayflies

(Ephemerellidae and Isonychia) and the dominant stonefly

(Perlesta placida) resulted in biomass peaks in winter - early

spring. Caddisflies (mostly Hydropsychidae and Chimarra) and

beetles (Elmidae and Gyrinidae) complemented the mayfly-stonefly

pattern with highest values in late spring - summer. These

seasonal patterns coincided with standing stock biomass patterns

on submerged wood (snags), their preferred habitat. Drift

values were about 5.7 times higher in the Ogeechee than in

another Coastal Plain river having only one fifth the amount of

snags, suggesting a relationship between habitat abundance and

drift. Percentages of snag-dwelling insects found in drift were

substantially higher (0.1 to > 1%) than is generally found for

smaller streams, indicating drift distances and times much

greater than previously shown.

Дрифт: определяющие факторы.

Authors: Kerby-BM Bunn-SE Hughes-JM

Факторы, влияющие на дрифт беспозвоночных в небольшой лесной речке в юго-восточном Квинсленде (Австралия).

Factors Influencing Invertebrate Drift in Small Forest Streams, South-Eastern Queensland

MARINE AND FRESHWATER RESEARCH

1995, Vol 46, Iss 8, pp 1101-1108

Abstract:

Aspects of invertebrate drift were investigated in four small rainforest streams in southeastern Queensland. Hourly sampling in two streams revealed low drift rates and no distinct diel patterns, This may have been a consequence of the low flows experienced during the study period, The drift was dominated by Simuliidae, Chironomidae and to a lesser extent Tasmanocoenis sp, (Caenidae) and Cheumatopsyche sp, 6 (Hydropsychidae). Additional studies were undertaken to examine why some individuals of particular taxa drift while others (of the same taxa) remain in or on the substratum, Analysis of the relative gut fullness of simuliid and chironomid larvae showed that a higher proportion of non-drifting individuals had full or nearly full guts compared with those in the drift. Hungrier individuals of these two taxa may enter the drift as a food searching mechanism, An analysis of limb loss of hexapod nymphs indicated that a disproportionate number of individuals in the drift had one or more limbs missing compared with those that remained in the benthos. These data support the hypothesis that invertebrates present in the drift are less fit than non-drifters.

Дрифт.

Authors: Lancaster-J Hildrew-AG Gjerlov-C

Дрифт беспозвоночных и продольные транспортные процессы в речках.

Invertebrate Drift and Longitudinal Transport Processes in Streams

Source: CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES 1996, Vol 53, Iss 3, pp 572-582

Abstract:

Benthic macroinvertebrates were disturbed from stream

substrata and caught in drift nets at various distances

downstream. Four experiments were carried out at several

discharges in each of four streams with contrasting hydraulic

transport characteristics. The numbers of all invertebrates and

of Plecoptera in the water column at each distance were fit to a

negative exponential function. The channel with the highest mean

velocity had the lowest return rate (beta). In any one channel,

beta decreased with increasing velocity; this relationship

approximated a power function, with stream-specific slope

corresponding to channel hydraulics. The stream with a high

fraction of dead zones had high beta values that varied little

with velocity; streams with fewer dead zones had lower beta

values that decreased with increased velocity. At any particular

velocity, channel-specific depth and turbulence may account for

different beta values in streams with similar dead zones. The

return rates of two stonefly families varied relative to one

another, possibly owing to species-specific behavioural changes

in response to current. In a low-velocity stream, Leuctridae had

higher beta values than Nemouridae; the rates were similar in a

higher velocity stream. Our results are consistent with the view

that the physical habitat influences the distance drifted by

dislodged invertebrates.

Дрифт, влияние жесткости.

Authors: Koetsier-P Minshall-GW Robinson-CT

Дрифт макробентоса в 6 водотоках различной жесткости.

Benthos and Macroinvertebrate Drift in 6 Streams Differing in Alkalinity

HYDROBIOLOGIA 1996, Vol 317, Iss 1, pp 41-49

Abstract:

The productive capacity of aquatic systems often is equated

with the 'chemical richness' of the water. A primary objective

of the present study was to relate macroinvertebrate benthos and

drift to a streams' productive capacity as indicated by absolute

levels of alkalinity. We tested this relationship in six 2nd-3rd

order tributaries of the Salmon River, Idaho that ranged in

alkalinity from 50 to 360 mg 1(-1). Benthic density and biomass,

drift biomass, and benthic organic matter increased with

increasing levels of alkalinity, although not all relationships

were significant. The proportion of drift biomass to benthic

biomass was similar among study streams suggesting that drift

was primarily passive during the study period. The data suggest

that spatial variations in landscape-scale geology may

indirectly affect spatial patterns of macroinvertebrate benthic

and drift standing crops among streams within a single river

basin by mediating lotic chemical richness as found among

tributaries of the Salmon River basin.

Дрифт

Authors: Kreutzweiser-DP Sibley-PK

Title: Invertebrate Drift in a Headwater Stream Treated with Permethrin

Source: ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY

1991, Vol 20, Iss 3, pp 330-336

Language: English

Document type: Article

Addresses:

FORESTRY-CANADA, INST FOREST PEST MANAGEMENT, POB 490,

SAULT-ST-MARIE P6A-5M7, ONTARIO, CANADA

UNIV-WATERLOO, DEPT BIOL, WATERLOO N2L-3G1, ONTARIO, CANADA

Keywords Plus:

IMPACT

Abstract:

An injection of the insecticide permethrin in a stream

(peak concentration 8.64-mu-g/L in water) resulted in

catastropic but transient increases in the drift density of

macroinvertebrates. Peak drift increases ranged from 100- to

5600-fold. Drift declined sharply over a 2-h period after the

first detection of the insecticide in streamwater, and returned

to pre-treatment or control levels within 36 h. Drift densities

were strongly correlated with permethrin residues at some sites,

but overall, permethrin concentration was a poor predictor of

drift response. The results indicated that the initial

concentration of permethrin was more important than exposure

duration in eliciting a drift response. Significant reductions

in benthos occurred at sites with drift densities of 4,000 and

5,600 times pre-treatment levels, but not at sites with 100- or

300-fold drift increases. An order of sensitivity to permethrin

was determined for several species, based on drift density

relative to benthos abundance and insecticide concentrations.

Дрифт. Дунай в Австрии.

Authors: Anderwald-PH Konar-M Humpesch-UH

Title: Continuous Drift Samples of Macroinvertebrates in a

Large River, the Danube in Austria

Source: FRESHWATER BIOLOGY

1991, Vol 25, Iss 3, pp 461-476

Language: English

Document type: Article

Addresses:

UNIV-VIENNA, INST ZOOL, DEPT LIMNOL, A-1010 VIENNA, AUSTRIA

AUSTRIAN-ACAD-SCI, INST LIMNOL, MONDSEE, AUSTRIA

Keywords Plus:

LOWER MISSISSIPPI RIVER; LAKE DISTRICT STREAM; INVERTEBRATE

DRIFT; UPSTREAM MOVEMENTS; COLONIZATION; ALBERTA; INSECTS;

LOUISIANA

Abstract:

1. A new method is described for sampling the drift in

large rivers continuously and automatically, using equipment

based on the marine, continuous plankton sampler of Hardy

(1936).

2. Between April and November 1989, about 790h were

sampled continuously, equivalent to a water volume of 2937 m3

and the total catch was 527 drifting macroinvertebrates, in

forty-nine taxa. Twenty-five of these taxa are recorded in the

drift for the first time and twenty-eight of the drifting taxa

were present in benthos samples from the Danube.

3. Total drift density varied between 12 and 31 animals

per 100 m3 of water sampled throughout the year, with a maximum

of 31 animals in May. The composition of major faunal groups

showed a significant seasonal pattern, with Oligochaeta and

Diptera predominant in spring, Crustacea and Insecta in summer

and only Crustacea in autumn. The overall density of the

macrozoobenthos from October 1986 to December 1987 was about 19

360 animals m-2 and the proportion of total benthos animals,

drifting at any instant in time, ranged from 0.0026 to 0.0064%.

4. The relationship between drift density day-1 and mean

daily discharge was described by a power-function. Total mean

drift rate of macroinvertebrates in the Danube was estimated to

be 13 600 000 animals per 24h and the mean drift distance was

estimated to vary between about 4 and 31 m, dependent on the

animal group and the water velocity.

5. No obvious consistent diel pattern could be established

from the continuous samples, and no marked diel rhythm could be

detected for Oligochaeta, Diptera larvae and Crustacea.

Дрифт, Австрия

02.02-04А2.83. Пространственное распределение дрифта и его экологическое значение. Spatial drift distributions and their ecological importance : Докл._[27 Congress of the International Association of Theoretical and Applied Limnology, Dublin, 1998_] / Wagner Franz H. // Verh. / Int. Ver. theor. und angew. Limnol. - 2001. - 27, № 3. - С. 1631_ѕ1634. - Англ.

Исследование проводили на р. Оберер Зеебах на участках с расходом воды 4300 и 460 л/с. Плотность дрифта колебалась от 2 до 52 экз/м{3} для Baetis alpinus, B. muticus и B. rhodani от 7 до 39 экз/м{3} для личинок хирономид, при этом конц-ия тонкого взвешенного органического вещества составляла 0,01_ѕ0,17 г/м{3} в сухом весе. Отмечено сходное пространственное распределение дрифта личинок хирономид и бетид и тонкого взвешенного органического вещества. При низком расходе воды плотность дрифта ниже в середине русла, чем у отмелей. При высоком расходе воды значимой разницы не выявлено. Пространственное распределение дрифта рассматривается с точки зрения активного движения организмов или пассивного их переноса. Скорость дрифта всех организмов возрастает с увеличением скорости тока воды, но для Baetis эти различия статистически незначимы. Плотность дрифта падает с глубиной и скоростью водотока. Австрия, Biological Station, A-3293 Lunz/See. Ил. 4. Табл. 1. Библ. 14.

Дрифт

Freshwater Biology Volume 47 Issue 9 Page 1674 - September 2002

Temporal variation in the drift of plant litter and propagules in a small boreal river

E. Andersson* and C. Nilsson

SUMMARY1.Rivers are linear ecosystems across landscapes with an effective

transport of organisms, sediment and organic matter. Dispersal is studied mostly

during single events and for single species, and there is little knowledge on how the

drift of plant litter and propagules varies within and between years for entire

communities.

2.We used floating traps for collecting waterborne plant litter and propagules in a

small boreal river over 2years. We installed the traps at four different locations

along the river, and emptied them at least once a week during the ice-free season.

We analysed propagule content by sorting and identifying species and through

germination tests on bare soil.

3.In total, we recorded at least 54 taxa in the samples, and the highest density

recorded in one sample was 5000 propagules per 100 g litter (dry weight). Large

temporal variations in litter and propagule transport were revealed, both within and

between years.

4.The longitudinal pattern was consistent between years, with an increasing mass of

litter and number of propagule taxa downstream. The results highlight the

importance of the temporal and longitudinal dimensions in river management.

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