Effects of artificial freshets on substratum composition, benthic invertebrate fauna and invertebrate drift in two impounded rivers in mid-Wales

Hydrobiologia ◽  
1983 ◽  
Vol 107 (3) ◽  
pp. 261-269 ◽  
Author(s):  
J. Scullion ◽  
A. Sinton
Keyword(s):  
Benthic Invertebrate ◽  
Invertebrate Drift ◽  
Invertebrate Fauna ◽  
Artificial Freshets ◽  
Impounded Rivers

scholarly journals The effects of riparian forestry on invertebrate drift and brown trout in upland streams of contrasting acidity

2004 ◽  
Vol 8 (3) ◽  
pp. 578-588 ◽  
Author(s):  
S. J. Ormerod ◽  
M. E. Jones ◽  
M. C. Jones ◽  
D. R. Phillips
Keyword(s):  
Land Use ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Benthic Invertebrate ◽  
Acid Sites ◽  
Invertebrate Drift ◽  
Conifer Forest ◽  
Terrestrial Invertebrates ◽  
Invertebrate Abundance ◽  
Drift Density

Abstract. Variations in macroinvertebrate drift and benthic invertebrate abundance were assessed in 30 upland Welsh streams of varying acidity (pH < 5.7 or pH.> 6.0) and riparian land-use (conifer, moorland or native broadleaf). The consequences for the diet and condition of wild brown trout Salmo trutta were also assessed. As expected from previous studies, there were significant reductions in benthic invertebrate abundance, aquatic drift density (by >60%), aquatic drift biomass (by >35%), total drift density (by >35%) and total drift biomass (by >20%) at acid sites by comparison with circumneutral sites due largely to the scarcity of mayflies. Absolute drift from terrestrial sources was unrelated to stream pH but formed a significantly greater proportion of total drift at acid sites (30-65% of density) than at circumneutral sites (20-40%) as aquatic contributions declined. Most of this apparent land use effect reflected significantly increased terrestrial drift under broadleaves. There was no significant reduction in terrestrial or aquatic drift at conifer forest sites per se after accounting for low pH. Trout diet varied substantially between locations partly reflecting variations in drift: significantly fewer mayflies and stoneflies were eaten at acid sites, and significantly more terrestrial prey were eaten under broadleaves. However, acidity did not reduce trout condition or gut-fullness. Unexpectedly, trout condition was significantly enhanced at conifer sites, irrespective of their pH. Hence, acidity has greater effects on the benthic abundance and drift density of invertebrates in upland streams than does riparian land use. However, trout forage flexibly enough to offset any possible food deficit, for example by switching to chironomids and terrestrial invertebrates. Enhanced terrestrial contributions to invertebrate drift from riparian broadleaf trees may be important in supplementing foraging opportunities for trout where aquatic prey are scarce. These data illustrate the value of native tree species in riparian locations in upland Britain and the energy subsidy they provide might well be disproportionately important for otherwise impoverished acid streams Keywords: brown trout, land-use, acidification, drift, forestry, streams

Habitat use by Harlequin Ducks breeding in Hebron Fiord, Labrador

1998 ◽  
Vol 76 (5) ◽  
pp. 897-901 ◽  
Author(s):  
Michael S Rodway
Keyword(s):  
Vegetation Cover ◽  
Benthic Invertebrate ◽  
Breeding Habitat ◽  
Habitat Characteristics ◽  
Habitat Requirements ◽  
North American Population ◽  
American Population ◽  
Invertebrate Fauna ◽  
Chironomid Larvae ◽  
Harlequin Ducks

Understanding of breeding habitat requirements is vital to recovery plans for the endangered eastern North American population of Harlequin Ducks (Histrionicus histrionicus). I compared habitat characteristics and benthic invertebrate fauna between streams in Hebron Fiord, Labrador, used and unused by Harlequin Ducks in 1996. Used streams were narrower, had higher pH and temperature, a larger substrate, steeper shorelines, and greater vegetation cover on islands and shorelines than unused streams. Greater numbers of invertebrates were recovered from kick samples, simuliid larvae and plecopteran nymphs were more frequent, and chironomid larvae and emphemeropteran nymphs were less frequent in used than in unused streams. Results from this study will help focus future survey and conservation efforts.

scholarly journals Aquatic Oligochaeta (Annelida) of Dam Lakes Çatören and Kunduzlar (Turkey) 

Zoosymposia ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. 70-76
Author(s):  
NAIME ARSLAN ◽  
DENIZ KARA ◽  
CANSEV AKKAN KÖKÇÜ ◽  
MELIH RÜZGAR
Keyword(s):  
Pearson Correlation ◽  
Environmental Parameters ◽  
Wiener Index ◽  
Benthic Invertebrate ◽  
Quality Parameters ◽  
Correlation Index ◽  
Invertebrate Fauna ◽  
Chironomidae Larvae ◽  
Central Turkey ◽  
Point Source Discharges

Çatören and Kunduzlar Dam Lakes, located on Seydi River, represent the main irrigation water resources of the Seyitgazi District (Eskişehir Province), in west-central Turkey. The river and the reservoirs are both under the threat of pollution primarily originating from several domestic point source discharges and land-based runoff. The numerical and proportional distributions of oligochaetes in Çatören and Kunduzlar Dam Lakes were surveyed seasonally in 2010 and 2011 at two stations on each lake. According to the results of this study, the benthic invertebrate fauna of Çatören Dam Lake consisted of Oligochaeta (40.2 %), Chironomidae larvae (32.2 %) and the varia (27.6 %); the benthic invertebrate fauna of Kunduzlar Dam Lake consisted of Oligochaeta (56.7 %), Chironomidae larvae (18.2 %) and the varia (25.1%). By evaluating the data via a Shannon-Wiener index it was found that the Çatören Dam Lake had an index of 2.32; while Kunduzlar Dam Lake had an index of 3.27. Several physicochemical water quality parameters were also analyzed during this study. The relationships between the dynamics of organisms and environmental parameters were supported by Pearson correlation index. It was determined that Çatören and Kunduzlar Dam Lakes waters were polluted and slightly polluted, respectively. The dominance and abundance of oligochaete species and low species richness showed that similar studies should be carried out periodically in Çatören and Kunduzlar Dam Lakes for the future monitoring of the dam lakes.

Review of Benthic Invertebrate Fauna in Extremely Acidic Environments (pH ≤ 3)

2001 ◽  
Vol 20 (3) ◽  
pp. 114-121 ◽  
Author(s):  
Gilberto Gonçalves Rodrigues ◽  
Burkhard W. Scharf
Keyword(s):  
Benthic Invertebrate ◽  
Invertebrate Fauna ◽  
Acidic Environments

Benthic Invertebrate Fauna and Feeding Relationships of Brown Trout, Salmo trutta Linnaeus, and River Blackfish, Gadopsis marmoratus Richardson, in the Aberfeldy River, Victoria

1978 ◽  
Vol 29 (6) ◽  
pp. 725 ◽  
Author(s):  
PD Jackson
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Benthic Invertebrate ◽  
Invertebrate Fauna ◽  
Kendall Rank Correlation ◽  
Brown Trout Salmo Trutta

The benthic invertebrate fauna and the stomachs of brown trout and river blackfish in a section of the Aberfeldy River, Victoria, were sampled regularly from October 1971 to November 1972. The ranges of food organisms utilized by the two species were very similar as were the proportions of the different food categories. Kendall rank correlation coefficients indicated that the diets of the two fishes were similar on all but the July sampling date. Due to apparent differences in habitat prefer- ences this similarity in diets may be regarded as giving rise to indirect competition.

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