نتایج جستجو برای: freshwater ecosystem

تعداد نتایج: 107604  

1998
Nicholas J. Barnes

Conventional techniques for assessing and monitoring water quality have been primarily based either on the use of living material as “bioindicators” or on the employment of analytical measurements to provide information about the physical and chemical status of aquatic ecosystems. The former have predominantly utilised the presence of selected species to indicate the quality of waters in which ...

2011
Jonathan W. Moore Nathan R. Franssen Keith B. Gido

Anthropogenic infl uences have disproportionally aff ected freshwater ecosystems, and a loss of biodiversity is forecasted to greatly reduce ecosystem function and services. Loss of species may destabilize communities by limiting the stabilizing forces of compensatory dynamics and/or statistical averaging, both of which are eff ects that can buff er variation in aggregate community properties. ...

2007
MARC J. RUSSELL PAUL A. MONTAGNA

Net ecosystem metabolism (NEM) is becoming a commonly used ecological indicator of estuarine ecosystem metabolic rates. Estuarine ecosystem processes are spatially and temporally variable, but the corresponding variability in NEM has not been properly assessed. Spatial and temporal variability in NEM was assessed in four western Gulf of Mexico shallow water estuaries. NEM was calculated from hi...

2008
Abhinav Singh Hao Wang Wendy Morrison Howard Weiss

Until recently, the only examples of inverted biomass pyramids have been in freshwater and marine planktonic communities. In 2002 and 2008 investigators documented inverted biomass pyramids for nearly pristine coral reef ecosystems within the NW Hawaiian islands and the Line Islands, where apex predator abundance comprises up to 85% of the fish biomass. We build a new refuge based predator-prey...

2004
ROBERTO F. NESPOLO FRANCISCO BOZINOVIC

Birds living in desert environments have been the preferred models for the study of physiological adaptations to water scarcity. Passerine birds living in marine coastal habitats face similar problems, yet physiological adaptations to water conservation in such species have been poorly documented. We measured total evaporative water loss (TEWL) and rates of oxygen consumption (VO2) in three spe...

2007
JOHN C. CALLAWAY THOMAS PARKER MICHAEL C. VASEY LISA M. SCHILE

There is currently a large regional effort to restore tidal marsh ecosystems in the San Francisco BayDelta Estuary involving the commitment of hundreds of millions of dollars and broad landscape-scale habitat manipulations. Although climate change has been on the horizon for many years, recent developments suggest that it must be taken seriously as a factor to be considered in future planning f...

2015
Caryn C. Vaughn Carla L. Atkinson Jason P. Julian

Extreme hydro-meteorological events such as droughts are becoming more frequent, intense, and persistent. This is particularly true in the south central USA, where rapidly growing urban areas are running out of water and human-engineered water storage and management are leading to broad-scale changes in flow regimes. The Kiamichi River in southeastern Oklahoma, USA, has high fish and freshwater...

Journal: :Applied and environmental microbiology 1990
J M González J Iriberri L Egea I Barcina

Differential decreases over time of two bacterial species, Escherichia coli and Enterococcus faecalis, in a freshwater and a marine ecosystem were observed and explained by a differential rate of digestion of these bacteria by phagotrophic flagellates and ciliates. For this purpose, fluorescence-labeled bacteria (FLB) were used and prepared from the two species cited above. The number of FLB wa...

Journal: :The Science of the total environment 2016
P Koundouri P Ker Rault V Pergamalis V Skianis I Souliotis

The development of the Water Framework Directive aimed to establish an integrated framework of water management at European level. This framework revolves around inland surface waters, transitional waters, coastal waters and ground waters. In the process of achieving the environment and ecological objectives set from the Directive, the role of economics is put in the core of the water managemen...

2010
Eric B. Taylor

Conservation of freshwater ecosystems for aesthetic, ethical, and utilitarian reasons is a top global conservation priority owing to the richness of freshwater biodiversity and the extent of threats against it (Dudgeon et al., 2006). For instance, on a per unit area basis, freshwaters contain the most diversity of fishes; some 10,000 species of freshwater fishes (c. 40% of Department of Zoology...

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