scholarly journals The response of the rotifer community in Loch Leven, UK, to changes associated with a 60% reduction in phosphorus inputs from the catchment

2014 ◽  
Vol 99 (1-2) ◽  
pp. 65-71 ◽  
Author(s):  
Linda May ◽  
Bryan M. Spears ◽  
Bernard J. Dudley ◽  
Iain D. M. Gunn
Keyword(s):  
Loch Leven ◽  
Rotifer Community

scholarly journals Primary Productivity of Phytoplankton in Loch Leven, Kinross

1974 ◽  
Vol 74 ◽  
pp. 157-181 ◽  
Author(s):  
Margaret E. Bindloss
Keyword(s):  
Photosynthetic Capacity ◽  
Photochemical Oxidation ◽  
Light Extinction ◽  
Poor Correlation ◽  
Dark Bottle ◽  
Gross Photosynthesis ◽  
Ph Values ◽  
Photosynthetic Productivity ◽  
Loch Leven ◽  
Crop Density

SynopsisPhotosynthetic productivity of phytoplankton in Loch Leven was studied over a 4-year period (1968–71), using the oxygen light and dark bottle technique. Marked seasonal changes in hourly and daily rates of gross photosynthetic productivity are described within the range 0·02 to 1·59 g O2/m2.h and 0·4 to 21·0 g O2/m2.day respectively. Hourly rates are shown to be relatively insensitive to variations in surface light intensity, whereas daily rates are influenced to a considerable extent by the duration of incident radiation (daylength).The phytoplankton itself exerts a dominant influence on underwater light penetration, accounting for ca 75 per cent of light extinction at highest crop densities. This self-shading effect contributes to the poor correlation observed between crop density and areal gross productivity. The chlorophyll a content per unit area in the euphotic zone often approached its estimated theoretical limit of 430 mg/m2.In general, increase in photosynthetic capacity (per unit content of chlorophyll a) accompanied increase in water temperature. During certain periods an inverse relationship between photosynthetic capacity and population density was evident. Reduction in photosynthetic capacity is attributed, in part, to the high pH values (> 9·5) with concomitant CO2-depIetion associated with dense phytoplankton crops.Estimates of net photosynthetic productivity were frequently zero or negative, even over periods when algal populations were increasing and dissolved oxygen and pH values were above their respective air-equilibrium values. Underestimation of gross photosynthesis due to photochemical oxidation, photorespiration or the use of stationary bottles could not account for this apparent anomaly. The most probable sources of error in the estimates of net photosynthetic productivity are discussed.

scholarly journals Seasonal quantitative dynamics and ecology of pelagic rotifers in an acidified boreal lake

2017 ◽  
Vol 77 (1) ◽  
Author(s):  
Svein Birger Wærvågen ◽  
Tom Andersen
Keyword(s):  
Community Structure ◽  
Environmental Gradients ◽  
Seasonal Succession ◽  
Biotic Interactions ◽  
Resource Limitation ◽  
Local Environment ◽  
Food Competition ◽  
Variance Partitioning ◽  
Boreal Lake ◽  
Rotifer Community

Lake Gjerstadvann is a dimictic, oligotrophic, slightly acidified boreal lake in southern Norway (northwest Europe). The planktonic rotifer community of this lake was studied quantitatively during one year in order to investigate the impacts of the local environment and biotic interactions on seasonal succession and habitat selection. Pure suspension feeders (mainly Keratella spp., Conochilus spp., and Kellicottia longispina) together with raptorial graspers or specialised feeders (mainly Polyarthra spp. and Collotheca spp.) dominated the rotifer community over prolonged periods, whereas carnivorous/omnivorous species (mainly Asplanchna priodonta) were extremely uncommon. Low bicarbonate buffering capacity resulted in a distinctive seasonal oscillating pH between 5.0 and 5.6, defining a special acid-transition lake category. The pH values were highest in the productive period during summer, and lowest during ice break-up coinciding with the peak reactive aluminium concentrations of 250-300 mg L-1. As in typical Norwegian boreal perch lakes, the most abundant cladoceran was Bosmina longispina due to perch predation on the genus Daphnia. Rotifer community structure was significantly related to temperature and oxygen (P=0.001 and P=0.022), illustrating the important effects of the seasonal cycle and vertical density stratification. The most significant competition indicator species were B. longispina and Eudiaptomus gracilis (both with P=0.001). A variance partitioning indicated that 14% of the total community composition variance could only be explained by biotic interactions, while 19% of the variance could be attributed to environmental gradients. Of the variance, 23% could not be resolved between biotic interactions and environmental gradients, while a residual of 44% was not explainable by any of the variables. Acid conditions alone cannot account for all the observed changes in the rotifer community of this lake with low humic content, since resource limitation and food competition are also important factors shaping rotifer population dynamics and the community structure.

scholarly journals The effect of seasonality on the structure of rotifers in a black-water shallow lake in Central Amazonia

2014 ◽  
Vol 86 (3) ◽  
pp. 1359-1372 ◽  
Author(s):  
CLARICE C. NOVA ◽  
VANESSA G. LOPES ◽  
LEONARDO COIMBRA E SOUZA ◽  
BETINA KOZLOWSKY-SUZUKI ◽  
TALITA A.A. PEREIRA ◽  
...  
Keyword(s):  
Species Composition ◽  
Driving Force ◽  
Community Dynamics ◽  
Flood Pulse ◽  
Small Lakes ◽  
Black Water ◽  
Negro River ◽  
Rotifer Community ◽  
Central Amazonia ◽  
Physical And Chemical

Rotifers have often been used as indicators of sudden changes in physical and chemical features of the aquatic environment. Such features vary greatly during flood pulse events in small lakes connected to major floodplains. However, few are the studies that investigate the consequences of the flood pulse in rotifer species composition, abundance, richness and diversity, especially in Amazonian lakes. We analyzed samples from a small blackwater lake of an “igarapé” connected permanently to the Negro river, in Central Amazonia. Samples were taken twice a year for two years, comprising flooding and receding periods of the flood pulse. Rotifer abundance increased significantly after draught events, and electrical conductivity and turbidity were intrinsically related to such variation. Species composition also changed from flooding to receding periods. Some taxa, such as Brachionus zahniseri reductus and Lecane remanei were restricted to receding periods, while Brachionus zahniseri, Brachionus gillardi and Lecane proiecta were only present during flooding. A shift in the composition of rotifer families was observed from one period to another, showing the effect of renewing waters of the flood pulse. These results suggest that the flood pulse acts as a driving force and stressing condition, considerably altering rotifer community dynamics, either changing species composition or decreasing abundance.

scholarly journals Limnological characteristics and rotifer community composition of Northern Mexico Chihuahuan Desert Springs

2019 ◽  
Vol 160 ◽  
pp. 32-41 ◽  
Author(s):  
Judith V. Ríos-Arana ◽  
Luz del Carmen Agüero-Reyes ◽  
Robert L. Wallace ◽  
Elizabeth J. Walsh
Keyword(s):  
Community Composition ◽  
Chihuahuan Desert ◽  
Northern Mexico ◽  
Rotifer Community ◽  
Desert Springs

scholarly journals The Loch Leven Water-Power Works

Nature ◽  
1911 ◽  
Vol 88 (2195) ◽  
pp. 129-130 ◽  
Keyword(s):  
Water Power ◽  
Loch Leven
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