نتایج جستجو برای: trophic state index
تعداد نتایج: 1243378 فیلتر نتایج به سال:
Trophic assessments of 10 publicly-owned northeastern Ohio lakes including Aquilla, Baldwin, Findley, Hinckley, Hodgson (Muddy), Spencer, Lower Shaker, Upper Shaker, Virginia Kendall, and Wallace indicated that all were highly eutrophic. Criteria for these assessments were based on a Trophic State Index developed by the U.S. Environmental Protection Agency that incorporated epilimnetic levels o...
In a field study conducted in Georgia, cucurbit plants with high (Cucurbita andreana) and low (Cucurbita maxima) concentrations of cucurbitacins were used in combination with two types of fertilizers to investigate their effects on the community of soil nematodes. Ecological measures of soil nematode community structure such as total nematode abundance, number of genera, trophic diversity, trop...
The abundance and the distribution of trophic resources available for consumers influence the productivity and the diversity of natural communities. Nevertheless, assessment of the actual abundance of food items available for individual trophic groups has been constrained by differences in methods and metrics used by various authors. Here we develop an index of food abundance, the framework of ...
The worldwide depletion of major fish stocks through intensive industrial fishing is thought to have profoundly altered the trophic structure of marine ecosystems. Here we assess changes in the trophic structure of the English Channel marine ecosystem using a 90-year time-series (1920-2010) of commercial fishery landings. Our analysis was based on estimates of the mean trophic level (mTL) of an...
Competition between marine mammals and fisheries for marine resources-whether real or perceived-has become a major issue for several countries and in international fora. We examined trophic interactions between marine mammals and fisheries based on a resource overlap index, using seven Ecopath models including marine mammal groups. On a global scale, most food consumed by marine mammals consist...
Response of Trophic Groups of Macrobenthic Fauna to Environmental Disturbance Caused by Fish Farming
Sediment dynamics and the hydrodynamics of the environment cause the complexity and variability in animal-sediment relationship, both in spatial and temporal. This study is focused on the response of macrobenthic fauna to environmental disturbance caused by fish farming using their trophic structure. Their changes in trophic structure can be used as an indicator of disturbance. Eight control si...
23 24 Understanding how marine ecosystems are structured and how they function is a 25 scientific challenge. Nowadays, to learn about ecosystem trophic dynamics ecologists use 26 two complementary methodological approximations, mass-balance ecosystem models and 27 isotopic tools. However, despite the wide applications of these methodologies, the 28 comparison and combination of both are still s...
To determine the composition and abundance of zooplankton assemblages in Eğirdir Lake-Turkey, monthly surveys were conducted from January to December 2010 at four stations. A total of 65 major zooplankton species were identified. Rotifera was the most abundant taxon dominated mainly by the species Polyarthra dolichoptera and Keratella cochlearis. Rotifers were recorded at the maximum abundance ...
Abstract This study aims to analyse the spatio-temporal trends in water quality, trophic state, and organic contamination of an alpine lake Darjeeling Himalaya through field investigations portray a comprehensive picture using multivariate analysis. Analysed parameters have shown notable seasonal variations were within acceptable range for inland surface water. Water quality index (WQI) polluti...
To determine the composition and abundance of zooplankton assemblages in Eğirdir Lake-Turkey, monthly surveys were conducted from January to December 2010 at four stations. A total of 65 major zooplankton species were identified. Rotifera was the most abundant taxon dominated mainly by the species Polyarthra dolichoptera and Keratella cochlearis. Rotifers were recorded at the maximum abundance ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید