Herein, we report the response of indices based on phytoplankton and zooplankton and their combination to different nutrient concentrations in lakes. The study was carried out in ten lakes in northeastern Poland. Integrated samples were collected from the epilimnion during the summer of 2012-2013. Secchi disk visibility (SD), total phosphorus (TP), total nitrogen (TN), and chlorophyll a were us...

The Zerebar Lake is a shallow freshwater lake located in the northwestern Iran. The lake is surrounded by three human activities: agriculture, tourism and dam. The present study aimed to investigate (1) which human activity has the greatest impact on eutrophication of the Zerebar Lake (2) If phytoplankton communities, as the indicator, are correlated with the human activities. Water samples wer...

The Zerebar Lake is a shallow freshwater lake located in the northwestern Iran. The lake is surrounded by three human activities: agriculture, tourism and dam. The present study aimed to investigate (1) which human activity has the greatest impact on eutrophication of the Zerebar Lake (2) If phytoplankton communities, as the indicator, are correlated with the human activities. Water samples wer...

The Zerebar Lake is a shallow freshwater lake located in the northwestern Iran. The lake is surrounded by three human activities: agriculture, tourism and dam. The present study aimed to investigate (1) which human activity has the greatest impact on eutrophication of the Zerebar Lake (2) If phytoplankton communities, as the indicator, are correlated with the human activities. Water samples wer...

The impact of fish and oysters on components of the pelagic microbial food web (MFW) was studied in a 10 d mesocosm experiment using Mediterranean coastal waters. Two mesocosms contained natural water only (‘Controls’), 2 contained natural water with Crassostrea gigas (‘Oyster’), and 2 contained natural water with Atherina spp. (‘Fish’). Abundances and biomasses of microorganisms (viruses, bact...

There is a significant relationship between the intestine length (Y) and total body length (X) for 11 species of freshwater fish (Y = 0.08X1.42). Sufficient variation exists about this relationship to indicate important differences among the species' diets. The diets for each species, ranked on a Trophic Index scale determined from literature data, are negatively rank order correlated with the ...

Humans are increasingly subsidizing and altering natural food webs via changes to nutrient cycling and productivity. Where human trophic subsidies are concentrated and persistent within natural environments, their consumption could have complex consequences for wild animals through altering habitat preferences, phenotypes and fitness attributes that influence population dynamics. Human trophic ...

The Zerebar Lake is a shallow freshwater lake located in the northwestern Iran. The lake is surrounded by three human activities: agriculture, tourism and dam. The present study aimed to investigate (1) which human activity has the greatest impact on eutrophication of the Zerebar Lake (2) If phytoplankton communities, as the indicator, are correlated with the human activities. Water samples wer...

A food web customarily describes the qualitative feeding relationships in a community. Descriptors have been used to extract ecologically meaningful information from such data, e.g., the proportion of top species (the proportion of taxa without consumers) or vulnerability (the average number of consumers per taxon). Analyses of collections of food webs based on these properties have revealed re...

Species that have outstanding importance in the functioning of a community are called keystone species. Network indices are increasingly used to identify them, e.g. for conservation biological purposes. The problem is that the calculation of these indices is based on the particular network model of the studied food web, which can include network construction errors. For example, additional, unn...