We used a longline tethering method to examine the relationship between prey refugia, prey body morphology and the location and magnitude of predation mortality within an individual lake and among three lakes that differed in coarse woody habitat (CWH) and aquatic macrophyte abundances. Predation events were lowest in the macrophyte and/or CWH refuges, peaked at or just beyond the refuge edge a...

Wetlands, and especially their littoral zones, are considered to be CH4 emissions hotspots. The recent creation of reservoirs has caused a rapid increase in the area of the world's littoral zones. To investigate the effects of water depth and water level fluctuation on CH4 fluxes, and how these are coupled with vegetation and nutrients, we used static closed chamber and gas chromatography techn...

Structurally complex environments strongly affect the behaviours and foraging efficiencies of predators and prey. I studied temporal variation in the habitat distribution of perch (Perca fluviatilis) and pike (Esox lucius) in relation to habitat complexity and prey abundance in a lake. The study involved quantitative estimates of different habitat types, estimates of macroinvertebrate prey avai...

Ecological speciation occurs when reproductive isolation evolves ultimately as a result of divergent natural selection between populations inhabiting different environments or exploiting alternative resources. I tested a prediction of the ecological model concerning the fitness of hybrids between two young, sympatric species of threespine sticklebacks (Benthics and Limnetics). The two species a...

Diel and seasonal variations in denitrification were determined in a littoral lake sediment colonized by the perennial macrophyte Littorella uniflora (L.) Aschers. In the winter, the activity was low (5 mumol of N m h) and was restricted to the uppermost debris layer at a depth of 0 to 1 cm. By midsummer, the activity increased to 50 mumol of N m h and was found throughout the root zone to a de...

The littoral zone varies in size among lakes from ∼3% to 100% of lake surface area. In this paper, we derive a simple theoretical scaling relationship that explains variation, and test theory using bathymetric data across the spectra freshwater (surface area = 0.01–82,103 km2, maximum depth 2–1,741 m). Littoral primarily reflects ratio photosynthesis depth. However, are similar these characteri...