scholarly journals Accumulation and fluxes of mercury in terrestrial and aquatic food chains with special reference to Finland

2013 ◽  
Vol 2 (2) ◽  
pp. 77-83
Author(s):  
Martin Lodenius
Keyword(s):  
Special Reference ◽  
Food Chains ◽  
Aquatic Food

Bioaccumulation and trophodynamics of the antidepressants sertraline and fluoxetine in laboratory-constructed, 3-level aquatic food chains

2016 ◽  
Vol 36 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
Marja L. Boström ◽  
Gustaf Ugge ◽  
Jan Åke Jönsson ◽  
Olof Berglund
Keyword(s):  
Food Chains ◽  
Aquatic Food

On means and variances in aquatic food chains and recruitment to the fisheries

1987 ◽  
Vol 17 (2) ◽  
pp. 381-386 ◽  
Author(s):  
GRAHAM P. HARRIS ◽  
F. BRIAN GRIFFITHS
Keyword(s):  
Food Chains ◽  
Aquatic Food

scholarly journals The need to account for cell biology in characterizing predatory mixotrophs in aquatic environments

2019 ◽  
Vol 374 (1786) ◽  
pp. 20190090 ◽  
Author(s):  
Susanne Wilken ◽  
Charmaine C. M. Yung ◽  
Maria Hamilton ◽  
Kenneth Hoadley ◽  
Juliana Nzongo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Single Cell ◽  
Gold Standard ◽  
Cell Biology ◽  
Aquatic Ecosystems ◽  
Eukaryotic Cells ◽  
Food Chains ◽  
Aquatic Environments ◽  
Unicellular Eukaryotes ◽  
Aquatic Food

Photosynthesis in eukaryotes first arose through phagocytotic processes wherein an engulfed cyanobacterium was not digested, but instead became a permanent organelle. Other photosynthetic lineages then arose when eukaryotic cells engulfed other already photosynthetic eukaryotic cells. Some of the resulting lineages subsequently lost their ability for phagocytosis, while many others maintained the ability to do both processes. These mixotrophic taxa have more complicated ecological roles, in that they are both primary producers and consumers that can shift more towards producing the organic matter that forms the base of aquatic food chains, or towards respiring and releasing CO 2 . We still have much to learn about which taxa are predatory mixotrophs as well as about the physiological consequences of this lifestyle, in part, because much of the diversity of unicellular eukaryotes in aquatic ecosystems remains uncultured. Here, we discuss existing methods for studying predatory mixotrophs, their individual biases, and how single-cell approaches can enhance knowledge of these important taxa. The question remains what the gold standard should be for assigning a mixotrophic status to ill-characterized or uncultured taxa—a status that dictates how organisms are incorporated into carbon cycle models and how their ecosystem roles may shift in future lakes and oceans. This article is part of a discussion meeting issue ‘Single cell ecology’.

Low-Level Experimental Selenite Additions Decrease Mercury in Aquatic Food Chains and Fish Muscle but Increase Selenium in Fish Gonads

2013 ◽  
Vol 66 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Mariah Mailman ◽  
R. A. Bodaly ◽  
Michael J. Paterson ◽  
Shirley Thompson ◽  
Robert J. Flett
Keyword(s):  
Fish Muscle ◽  
Food Chains ◽  
Low Level ◽  
Aquatic Food ◽  
Fish Gonads

Acidification increases mercury uptake by a freshwater alga, Chlamydomonas reinhardtii

2011 ◽  
Vol 8 (6) ◽  
pp. 612 ◽  
Author(s):  
Séverine Le Faucheur ◽  
Yvan Tremblay ◽  
Claude Fortin ◽  
Peter G. C. Campbell
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Natural Waters ◽  
Aquatic Organisms ◽  
Hydrolysis Rate ◽  
Food Chains ◽  
Unexpected Result ◽  
Surface Binding ◽  
Mercury Uptake ◽  
Aquatic Food ◽  
Influence Of Ph

Environmental contextMercury is classified as a priority pollutant owing to the biomagnification of its methylated species along food chains and the consequent effects on top consumers. The pH of natural waters affects many of the biogeochemical processes that control mercury accumulation in aquatic organisms. Here, evidence is presented that pH affects mercury uptake by unicellular algae, primary producers in aquatic food chains, thereby providing a new example of the pervasive influence of pH on the mercury biogeochemical cycle. AbstractWe have examined the influence of pH on HgII uptake (mainly in the form of the lipophilic complex HgCl2) by a green, unicellular alga, Chlamydomonas reinhardtii. Uptake of the dichloro complex increased by a factor of 1.6 to 2 when the pH was lowered from 6.5 to 5.5, an unexpected result given that the intracellular hydrolysis rate of fluorescein diacetate (FDA), used as a probe for the passive diffusion of lipophilic solutes through algal membranes, decreased in the studied alga under similar conditions. Several mechanisms were explored to explain the enhanced uptake at pH 5.5, including pH-induced changes in cell surface binding of Hg or in Hg loss rates from cells, but none of them gave completely satisfactory explanations. The present findings imply that inorganic HgII in aqueous solution behaves, in terms of uptake, neither as a lipophilic complex (the uptake of which would be expected to decrease with acidification because of algal membrane packing), nor as a cationic metal (the transport of which by facilitated transport would be expected to diminish with increasing proton concentration because of metal–proton competition at the transporter binding sites). Mercury uptake by algae seems rather to be stimulated by proton addition.

scholarly journals Biokinetic food chain modeling of waterborne selenium pulses into aquatic food chains: Implications for water quality criteria

2015 ◽  
Vol 12 (2) ◽  
pp. 230-246 ◽  
Author(s):  
David K DeForest ◽  
Suzanne Pargee ◽  
Carrie Claytor ◽  
Steven P Canton ◽  
Kevin V Brix
Keyword(s):  
Water Quality ◽  
Food Chain ◽  
Quality Criteria ◽  
Food Chains ◽  
Water Quality Criteria ◽  
Aquatic Food

scholarly journals Dynamics of Plankton Community in Banahao-Palhi River in Leyte, Philippines

2016 ◽  
pp. 130-152
Author(s):  
Marita Galinato ◽  
Julissah Evangelio
Keyword(s):  
Fish Larvae ◽  
Zooplankton Community ◽  
Dry Season ◽  
Ecosystem Change ◽  
Food Chains ◽  
Wet Season ◽  
Principal Role ◽  
Aquatic Food ◽  
Common Genus ◽  
Pelagic Algae

Plankton consists of microscopic plants “phytoplankton” and animals “zooplankton“. They play a principal role in aquatic food web and zooplankton indicators of ecosystem change. Phytoplankton are the food source for zooplankton, and together, form the base of ocean and river food chains. In Leyte, few researches have been conducted in plankton specifically in river systems. The study was conducted to understand phytoplankton dynamics by first studying their occurrence, composition, and abundance. Three sampling sites were established along Banahao-Palhi river during dry and wet seasons. A total of 162 plankter samples were analyzed in the laboratory. Dry season sampling showed 99 pelagic algae belonging to 58 genera across sites. In all sites, the commonly occurring diatoms were Biddulphia, Meridion, and Synedra . For the green algae (Chlorophyceae) group, Groenbladia was the most common genus, while in the blue-greens (Cyanophyceae), Nostoc. In wet season, 165 pelagics in 68 genera were observed. Bacillariophyceae got the most number of pelagic algae in all sites for both seasons. For true zooplankton, eight families were recorded during the dry season with four, belonging to Rotifera, two under Copepoda and one, from Cladocera. Similar groups were found during wet season. Larvae of insects and benthics were found part of the zooplankton community. Insect groups include Orders Coleoptera, Diptera, Ephemeroptera, Megaloptera, Plecoptera and Trichoptera. Non-insect groups include Arachnida, Amphipoda, Gastropoda and fish larvae. The Rotifera is the commonly occurring holoplankton with six genera identified. However, the copepods were the most abundant in Brgy. Palhi while protozoans, in Brgy. Banahao.

Sign in / Sign up

Export Citation Format

Share Document