the parameters used to determine the trophic state of a water body are: total phosphorus (tp),transparency (secchi disk depth) and chlorophyll a. however, these parameters show strong seasonalfluctuations which may hinder the estimation of trophic state. some authors have proposed that sediments be used as an additional tool to evaluate the trophic state of a water body. the aim of this study w...

1. While fish-based Indices of Biotic Integrity have been developed for a wide array of lotic systems, equivalent tools have seldom been adapted to the monitoring and assessment of lakes. Major difficulties arise in such work: (i) collecting data that allow statistically robust analyses, (ii) choosing the relevant variables to describe the biotic, environmental and anthropogenic data sets and (...

An index model for quality evaluation based on the formula of similarity membership functions in the fuzzy c-means (FCM) clustering algorithm is proposed. Summing up the weighted similarity degrees between an observation and designed specific quality-ordered levels develops an alternative overall index. Stretching the values of the controlling parameters in the formula of the similarity members...

The main scientific goal of COSTAS project is to bring useful knowledge to the understanding of the conditions, which favor the accumulation and transfer of organic and metallic contaminants at the primary trophic levels (autotrophes and hetetrophes), and then within the food web of small pelagic fish (anchovy and sardine) in the Gulf of Lion, Western Mediterranean.

The current study deals with the physicochemical characterization, temporal variability and trophic state evaluation of a post glacial mountain lake in eastern Himalaya during the period of 2014-2016. Notable seasonal variations are recorded for physicochemical parameters of lake water. The values for electrical conductivity, total suspended solids, total dissolved solids, total alkalinity and ...

Citation: Djurhuus A, Port J, Closek CJ, Yamahara KM, Romero-Maraccini O, Walz KR, Goldsmith DB, Michisaki R, Breitbart M, Boehm AB and Chavez FP (2017) Evaluation of Filtration and DNA Extraction Methods for Environmental DNA Biodiversity Assessments across Multiple Trophic Levels. Front. Mar. Sci. 4:314. doi: 10.3389/fmars.2017.00314 Evaluation of Filtration and DNA Extraction Methods for Env...

Eutrophication phenomenon is one of the most common water quality problems in reservoirs in many regions. Determining the trophic status of the reservoirs is not a precise process and contains vagueness. Fuzzy set and entropy theories are concepts which can model uncertainty and imprecision in the data and the analysis. In this study, an Entropy-based Fuzzy Eutrophication Index model has been d...

Quantification of key pathways sustaining ecosystem function is critical for underpinning informed decisions on development approvals, zoning and offsets, ecosystem restoration and for meaningful environmental assessments and monitoring. To develop a more quantitative understanding of the importance and variation in food webs and nutrient flows in tropical estuaries, we investigated the spatio-...

Many human and natural events can impact aquatic populations and communities, leaving strong imprints as altered food web dynamics. Stable C and N isotopes in fish can record these altered trophic dynamics in an integrated way, and a new simple methodology is presented to extract measures of food web change from isotope measurements of fish species. Measured C and N isotope data are re-scaled a...