This study evaluated the differences in composition, abundance and morphology of testate amoebae among different habitats of the same aquatic environment (plankton, aquatic macrophyte and sediment) in the Upper Paraná River floodplain. Triplicate samplings were undertaken monthly at each habitat from April 2007 to March 2008. The structure of the community of testate amoebae was different among...

1. In this paper we examine the potential of a cichlid fish species (Sarotherodon galilaeus) to both maintain positive growth rates through filter-feeding on phytoplankton and improve water quality in Lake Kinneret through suppression of dinoflagellate (Peridinium gatunense) blooms. 2. Seasonal plankton consumption by S. galilaeus from Lake Kinneret was examined experimentally by monitoring cha...

There are four main sources of aquatic pollution: industrial wastes, municipal wastes, agricultural run-off, and accidental spillage. Non-point sources, such as automobile exhausts, add appreciable amounts of pollutants to air that may enter aquatic systems in rainfall or dry fall-out. These sources add pesticides, heavy metals, oil, petroleum products, and a large number of organic and inorgan...

This work was aimed at assessing the effect of crude oil spill on the diversity and abundance of plankton communities of the Njaba River area of the spill. Sampling was carried out in 1999 in nine clusters of stations, three each from upstream, spill-point and downstream transects. Each cluster was made up of three perpendicular sampling points across the river. Standard methods were used in co...

Background: The Present study was carried out to track and calculate Biomagnification Factor (BMF) of total mercury (T-Hg) between two different trophic levels (i.e., plankton and a planktivorous fish) in a fresh water grazing food chain. Methods: Experimental organisms were planktonic biomass and silver carp (Hypophthalmichthys molitrix) as a planktivorous fish. Silver carp samples were obt...

To the marine ecosystem, plankton are vitally significant for they produce more than half of the primary productivity on earth and play an irreplaceable role in the global carbon cycle. However, most of traditional plankton population measuring and monitoring methods become gradually impractical for they are time consuming and cannot scale to the granularity required in large-scale studies. Thu...

Mixotrophic plankton, which combine the uptake of inorganic resources and the ingestion of living prey, are ubiquitous in marine ecosystems, but their integrated biogeochemical impacts remain unclear. We address this issue by removing the strict distinction between phytoplankton and zooplankton from a global model of the marine plankton food web. This simplification allows the emergence of a re...

We examined the contents of the alimentary tract of juvenile Atlantic menhaden, an obligate filter-feeding fish, with epifluoresence microscopy. All plankton taxa and detrital material observed in plankton samples from the sampling area could also be found in the esophagus of the fish. The corresponding plankton taxa were absent from the pre-feces sampled in the hindgut with the exception of cy...

[1] In an idealized situation of a baroclinically unstable single eddy, we study the impact of eddy-induced mixing on the soft-tissue carbon pump. The new element here is the coupling of a three-dimensional nonhydrostatic ocean model with a physiological plankton model that is able to represent a variable plankton C:N ratio. During the development and breakup of the eddy, a complicated vertical...

Climate change scenarios predict that lake water temperatures will increase up to 4°C and rainfall events will become more intense and frequent by the end of this century. Concurrently, supply of humic substances from terrestrial runoff is expected to increase, resulting in darker watercolor ("brownification") of aquatic ecosystems. Using a multi-seasonal, low trophic state mesocosm experiment,...