scholarly journals Effects of Non‐native Fish on Lacustrine Food Web Structure and Mercury Biomagnification along a Dissolved Organic Carbon Gradient

2020 ◽  
Vol 39 (11) ◽  
pp. 2196-2207
Author(s):  
Benjamin D. Barst ◽  
Karista Hudelson ◽  
Gretchen L. Lescord ◽  
Andrea Santa‐Rios ◽  
Niladri Basu ◽  
...  
2000 ◽  
Vol 57 (2) ◽  
pp. 487-496 ◽  
Author(s):  
Michael L Pace ◽  
Jonathan J Cole

We assessed planktonic respiration in whole-lake manipulations of nutrient loading and food web structure in three manipulated and one unmanipulated lake over 7 years. The manipulations created strong contrasts in zooplankton body size across a series of nutrient loads. Large-bodied zooplankton were suppressed by planktivorous fish in one lake, while in the other two manipulated lakes, large-bodied zooplankton dominated community biomass. Nutrients were added as inorganic N and P. Nutrient loads ranged from background to conditions resembling eutrophic lakes. Planktonic respiration was measured weekly in each lake by dark bottle oxygen consumption. Respiration was low when lakes were not fertilized (average 8.5 µmol O2·L-1·day-1) and was correlated with differences in dissolved organic carbon among the lakes. Respiration increased with nutrient addition to a mean range of 12-25 µmol O2·L-1·day-1; however, respiration differed among lakes at the same nutrient loading. Further, respiration was independent of dissolved organic carbon in the fertilized lakes. Differences in the intensity of zooplankton grazing as determined by food web structure strongly regulated primary and bacterial production across the range of nutrient loads. Consequently, respiration was positively related to primary production, phytoplankton biomass, and bacterial production and inversely related to the average size of crustacean zooplankton.


2020 ◽  
Vol 10 (10) ◽  
pp. 3601
Author(s):  
Sae-Hee Kim ◽  
Jin Ho Kim ◽  
Seung Ho Baek ◽  
Joo-Hwan Kim ◽  
Penelope A. Ajani ◽  
...  

The green alga Tetraselmis striata is regarded as a suitable candidate microalga for bio-diesel production. Recently, T. striata was cultured near Yeonghueung Island, Korea, in a “marine culturing field”; however, its environmental impacts are not yet studied. We estimated the amount of dissolved organic carbon (DOC) released from T. striata cultivation in the marine culturing field, and we investigated the changes in bacterial composition. Then, we designed and installed a mesocosm for further understanding. From the mesocosm results, the DOC released from the cultivation of T. striata led to changes in bacterial communities, disturbance of the microbial food web structure, rapid depletion of nutrients, and a decrease in dissolved oxygen (DO) and pH. Our novel work demonstrates that large amounts of DOC secreted by large-scale microalgal cultures such as that of T. striata can potentially have a significant impact on the structure and function of the surrounding microbial ecosystem.


2017 ◽  
Vol 27 (4) ◽  
pp. 1190-1198 ◽  
Author(s):  
Joshua J. Thoresen ◽  
David Towns ◽  
Sebastian Leuzinger ◽  
Mel Durrett ◽  
Christa P. H. Mulder ◽  
...  

2020 ◽  
Vol 106 (2) ◽  
pp. 69-85
Author(s):  
Matthew J. Young ◽  
Frederick Feyrer ◽  
Paul R. Stumpner ◽  
Veronica Larwood ◽  
Oliver Patton ◽  
...  

2009 ◽  
Vol 364 (1524) ◽  
pp. 1789-1801 ◽  
Author(s):  
Kevin Shear McCann ◽  
Neil Rooney

Here, we synthesize a number of recent empirical and theoretical papers to argue that food-web dynamics are characterized by high amounts of spatial and temporal variability and that organisms respond predictably, via behaviour, to these changing conditions. Such behavioural responses on the landscape drive a highly adaptive food-web structure in space and time. Empirical evidence suggests that underlying attributes of food webs are potentially scale-invariant such that food webs are characterized by hump-shaped trophic structures with fast and slow pathways that repeat at different resolutions within the food web. We place these empirical patterns within the context of recent food-web theory to show that adaptable food-web structure confers stability to an assemblage of interacting organisms in a variable world. Finally, we show that recent food-web analyses agree with two of the major predictions of this theory. We argue that the next major frontier in food-web theory and applied food-web ecology must consider the influence of variability on food-web structure.


Nature ◽  
10.1038/47023 ◽  
1999 ◽  
Vol 402 (6757) ◽  
pp. 69-72 ◽  
Author(s):  
Owen L. Petchey ◽  
P. Timon McPhearson ◽  
Timothy M. Casey ◽  
Peter J. Morin

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