Exploratory data analysis of the interactions among physics, food web structure, and function in two Arctic polynyas

2008 ◽  
Vol 65 (6) ◽  
pp. 1036-1046 ◽  
Author(s):  
Olivier F. Berreville ◽  
Alain F. Vézina ◽  
Keith R. Thompson ◽  
Bert Klein

Polynyas are areas of open water in ice-covered seas, characterized by high biological productivity. The NEW (Northeast Water) and NOW (North Water) polynyas, located off the east and west coasts of Greenland, were extensively sampled in 1993 and 1998, respectively. We used principal component analysis to explore the seasonal covariations among physical, chemical, and ecological characteristics in these polynyas. In both polynyas, the most explanatory eigenvector revealed the expected seasonal development of the bloom (nutrient consumption and biomass increases) associated with declining ice cover, warming, and mixed-layer shallowing. This seasonal pattern, however, was much weaker in NEW than in NOW. No connections between the structure of the food web and recycling processes were apparent in either polynya. The analysis points to much stronger and richer interactions between the mesoplankton (i.e., diatoms–zooplankton) and microbial food webs in NOW than in NEW. The differences between the polynyas may be explained in part by differences in their longevity, with the longer-lived NOW polynya having more time to develop complex trophic interactions. The results also indicate that the connections between food web structure and ecosystem function (i.e., new production versus recycling), at least at the seasonal scale, are weaker than expected.

Oikos ◽  
2015 ◽  
Vol 125 (7) ◽  
pp. 1017-1026 ◽  
Author(s):  
Nicholas A. C. Marino ◽  
Diane S. Srivastava ◽  
Vinicius F. Farjalla

2021 ◽  
Vol 9 ◽  
Author(s):  
Stacey A. McCormack ◽  
Jessica Melbourne-Thomas ◽  
Rowan Trebilco ◽  
Gary Griffith ◽  
Simeon L. Hill ◽  
...  

Graphical AbstractGraphical summary of multiple aspects of Southern Ocean food web structure and function including alternative energy pathways through pelagic food webs, climate change and fisheries impacts and the importance of microbial networks and benthic systems.


2004 ◽  
Vol 37 ◽  
pp. 283-293 ◽  
Author(s):  
E Sintes ◽  
A Martínez-Taberner ◽  
G Moyà ◽  
G Ramon

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1241 ◽  
Author(s):  
Roberto Danovaro ◽  
Eugenio Rastelli ◽  
Cinzia Corinaldesi ◽  
Michael Tangherlini ◽  
Antonio Dell'Anno

Global change is altering oceanic temperature, salinity, pH, and oxygen concentration, directly and indirectly influencing marine microbial food web structure and function. As microbes represent >90% of the ocean’s biomass and are major drivers of biogeochemical cycles, understanding their responses to such changes is fundamental for predicting the consequences of global change on ecosystem functioning. Recent findings indicate that marine archaea and archaeal viruses are active and relevant components of marine microbial assemblages, far more abundant and diverse than was previously thought. Further research is urgently needed to better understand the impacts of global change on virus–archaea dynamics and how archaea and their viruses can interactively influence the ocean’s feedbacks on global change.


2019 ◽  
Vol 41 (2) ◽  
pp. 77-89 ◽  
Author(s):  
Beatrix E Beisner ◽  
Hans-Peter Grossart ◽  
Josep M Gasol

Abstract Growing attention to phytoplankton mixotrophy as a trophic strategy has led to significant revisions of traditional pelagic food web models and ecosystem functioning. Although some empirical estimates of mixotrophy do exist, a much broader set of in situ measurements are required to (i) identify which organisms are acting as mixotrophs in real time and to (ii) assess the contribution of their heterotrophy to biogeochemical cycling. Estimates are needed through time and across space to evaluate which environmental conditions or habitats favour mixotrophy: conditions still largely unknown. We review methodologies currently available to plankton ecologists to undertake estimates of plankton mixotrophy, in particular nanophytoplankton phago-mixotrophy. Methods are based largely on fluorescent or isotopic tracers, but also take advantage of genomics to identify phylotypes and function. We also suggest novel methods on the cusp of use for phago-mixotrophy assessment, including single-cell measurements improving our capacity to estimate mixotrophic activity and rates in wild plankton communities down to the single-cell level. Future methods will benefit from advances in nanotechnology, micromanipulation and microscopy combined with stable isotope and genomic methodologies. Improved estimates of mixotrophy will enable more reliable models to predict changes in food web structure and biogeochemical flows in a rapidly changing world.


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