Summary Lake methane (CH 4 ) emissions are largely controlled by aerobic methane‐oxidizing bacteria (MOB) which mostly belong to the classes Alpha‐ and Gammaproteobacteria (Alpha‐ and Gamma‐MOB). Despite the known metabolic and ecological differences between the two MOB groups, their main environmental drivers and their relative contribution to CH 4 oxidation rates across lakes remain unknown. Here, we quantified the two MOB g...

Small‐scale vertical structure in the distribution of phytoplankton could be fundamentally important for zooplankton foraging, trophic coupling, and carbon cycling in planktonic ecosystems. Here, we identify regions of structure in phytoplankton communities that would be undetected by fluorometers by comparing the vertical distribution of chlorophyll fluorescence to the concentration of fluorescent particles over submeter scal...

We performed a series of gas exchange measurements in 12 diverse aquatic systems to develop the direct relationship between near‐surface turbulence and gas transfer velocity. The relationship was log‐linear, explained 78% of the variation in instantaneous gas transfer velocities, and was valid over a range of turbulent energy dissipation rates spanning about two orders of magnitude. Unlike wind‐based relationships, our model i...

We explore the role of lakes in carbon cycling and global climate, examine the mechanisms influencing carbon pools and transformations in lakes, and discuss how the metabolism of carbon in the inland waters is likely to change in response to climate. Furthermore, we project changes as global climate change in the abundance and spatial distribution of lakes in the biosphere, and we revise the estimate for the global extent of c...

Dissolved organic carbon (DOC) is a key parameter in lakes that can affect numerous features, including microbial metabolism, light climate, acidity, and primary production. In an attempt to understand the factors that regulate DOC in lakes, we assembled a large database (7,514 lakes from 6 continents) of DOC concentrations and other parameters that characterize the conditions in the lakes, the catchment, the soil, and the cli...

On the basis of data collected in Quebec lakes, del Giorgio and Peters (1994) and Carignan et al. (2000) have come to opposite conclusions regarding the metabolic balance between heterotrophy and autotrophy in lakes in general. In the present study, epilimnetic oxygen and carbon dioxide saturation was measured in 33 lakes from the St. Lawrence Lowlands region of Quebec to examine the extent of epilimnetic net heterotrophy (i.e...