نتایج جستجو برای: macroinvertebrate

تعداد نتایج: 1654  

2008
M. C. Thoms M. A. Reid

Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Abstract Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Abstract Spatial variation in hydraulic conditions in streams often results in distinct water surface patterns, or surface flow types. Visual assessments of the distribution of surface flow types have been used t...

2014
Argaw Ambelu Seblework Mekonen Magaly Koch Taffere Addis Pieter Boets Gert Everaert Peter Goethals

Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of pres...

2013
Stefan Grab

Currently, there is little understanding of the controls that instream thermal limits and hydraulic biotype diversity have on macroinvertebrate assemblages, particularly in association with changing altitude within given southern African mountain drainage systems. Thus, the aim of this research was to examine aquatic macroinvertebrate assemblage changes in response to spatial and temporal geo-h...

2014
Ryan A. McManamay Donald J. Orth Charles A. Dolloff

Sediment transport, one of the key processes of river systems, is altered or stopped by dams, leaving lower river reaches barren of sand and gravel, both of which are essential habitat for fish and macroinvertebrates. One way to compensate for losses in sediment is to supplement gravel to river reaches below impoundments. Because gravel addition has become a widespread practice, it is essential...

2014
K. E. Fabricius G. De'ath S. Noonan S. Uthicke

The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classe...

Journal: :Revista de biologia tropical 2014
Ramsa Chaves-Ulloa Gerardo Umaña-Villalobos Monika Springer

Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinver...

2008
CHRISTOPHER M. LORION BRIAN P. KENNEDY

1. Few studies have evaluated the effectiveness of riparian buffers in the tropics, despite their potential to reduce the impacts of deforestation on stream communities. We examined macroinvertebrate assemblages and stream habitat characteristics in small lowland streams in southeastern Costa Rica to assess the impacts of deforestation on benthic communities and the influence of riparian forest...

2004
Robert F. Swarthout

Benthic macroinvertebrate communities of Lake Tanganyika tributaries in pristine, forested, and impacted, deforested, watersheds were examined. Samples were collected using a Surber-sampler, and identified under a dissecting microscope. Family biotic indices (FBI), percent of Ephemeroptera/Plecoptera/Trichoptera (%EPT), relative Chironomid abundance (RCA), and taxa richness of five impacted str...

2001
Song S. Qian Ryan King Curtis J. Richardson

A nonparametric method and a Bayesian hierarchical modelling method are proposed in this paper for the detection of environmental thresholds. The nonparametric method is based on the reduction of deviance, while the Bayesian method is based on the change in the response variable distribution parameters. Both methods are tested using macroinvertebrate composition data from a mesocosm experiment ...

2008
Carissa Ganong Gregory Carson

In this study meiobenthic communities were sampled from several acid mine drainage (AMD) impacted sites along the Tioga River in North Central Pennsylvania. Concentrations of several chemical indicators of aquatic health (Fe/Fe, Mn, and SO4) were measured along with the pH. Meiobenthic communities were present at all AMD impacted locations but diversity and abundance varied. The diversity and a...

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