نتایج جستجو برای: abundance of tolerant taxa eg chironomidae

تعداد نتایج: 21174288  

2003
Godtfred A. Halvorsen Einar Heegaard Arne Fjellheim

Chemical recovery of acidified waters due to reductions in emissions has been reported from Europe and North America (1). The western Norwegian river Nausta is an example of a river where chemical recovery was observed during 1989–1998. Continuous monitoring of the zoobenthos using acidification indices indicated that biological recovery has followed chemical recovery (2). The Nausta was, there...

2014
Gert Everaert Jan De Neve Pieter Boets Luis Dominguez-Granda Seid Tiku Mereta Argaw Ambelu Thu Huong Hoang Peter L. M. Goethals Olivier Thas Syuhei Ban

We assessed and compared abiotic preferences of aquatic macroinvertebrates in three river basins located in Ecuador, Ethiopia and Vietnam. Upon using logistic regression models we analyzed the relationship between the probability of occurrence of five macroinvertebrate families, ranging from pollution tolerant to pollution sensitive, (Chironomidae, Baetidae, Hydroptilidae, Libellulidae and Lept...

Journal: :Environmental DNA 2023

Tundra arthropods are of considerable ecological importance as a seasonal food source for many arctic-breeding birds. Dietary composition and preferences rarely known, complicating assessments interactions in changing environment. In our field study, we investigated the nestling diet snow buntings (Plectrophenax nivalis (L., 1758)) breeding Svalbard. We collected fecal samples from 8-day-old ne...

2017
Peter C Jacobson Gretchen J A Hansen Bethany J Bethke Timothy K Cross

Eutrophication and climate warming are profoundly affecting fish in many freshwater lakes. Understanding the specific effects of these stressors is critical for development of effective adaptation and remediation strategies for conserving fish populations in a changing environment. Ecological niche models that incorporated the individual effects of nutrient concentration and climate were develo...

Ehsan Abedi, Eiman Arebi, Hamid Rezai, Mahshid Jalili, Vahid Sepahvand,

The zooplankton community and environmental conditions were monitored during Dec. 2012 PG-GOOS (Persian Gulf and Gulf of Oman Oceanographic Study) oceanographic cruise on board N/V Ja Nayband throughout the northwestern part of the Persian Gulf. Data of temperature, salinity, depth and pH as well as zooplankton community composition and abundance were collected from 17 stations. The zoopla...

Journal: :Revista brasileira de biologia 1999
M M Marques F A Barbosa M Callisto

Patterns of abundance and distribution of chironomid midges (Diptera, Chironomidae) in the middle Rio Doce basin were analysed. Human activities (mining, steel processing, and Eucalyptus spp. forestry) contribute to environmental degradation and low water quality in this watershed. Physical and chemical water traits (dissolved oxygen, pH, total alkalinity, electric conductivity, phosphorus and ...

Journal: :international journal of environmental research 0
l.i. kiteresi kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya e.o. okuku kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya, 2 soil and water management division, faculty of bioscience engineering, katholike universiteit s.n. mwangi kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya, university of nairobi, p.o. box 30197, g.p.o, nairobi, kenya b. ohowa kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya v.o. wanjeri kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya s. okumu kenya marine and fisheries research institute, p.o. box 81651, mombasa, kenya m. mkono

phytoplankton communities play a significant role in the oceanic biological pump by forming the base of the trophic structure. increase in nutrients loading affects spatial and temporal distribution of phytoplankton. this study examined the phytoplankton community structure and ecological indices in relation to nutrients dynamics in both estuarine and oceanic areas of ramisi-vanga systems along...

2007
Katharine I. Predick Monica G. Turner M. G. Turner

1. Invasive species are present worldwide, yet predicting which invasive species will become problematic in which ecosystems remains an important ecological challenge. Floodplains are at particular risk for invasion, especially when subjected to anthropogenic disturbance. 2. We examined how components of flood regime, habitat quality and habitat configuration influenced the presence and abundan...

2010
Haibo Wan Christopher J. Chizinski Christine L. Dolph Bruce Vondracek Bruce N. Wilson

The index of biotic integrity (IBI) is a commonly used bioassessment tool that integrates abundance and richness measures to assess water quality. In developing IBIs that are both responsive to human disturbance and resistant to natural variability and sampling error, water managers must decide how to weigh information about rare and abundant taxa, which in turn requires an understanding of the...

2003
C. N. Coimbra

Macroinvertebrate communities and environmental variables were assessed seasonally for 1 year in a temporary river in South Portugal receiving an effluent with high conductivity, pH, sulphates, nitrates and low oxygen content. The usefulness of the ordination method canonical correspondence analysis (CCA) and the classification method cluster analysis (UPGMA) were examined to evaluate the pertu...

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