Eutrophication (the overenrichment of aquatic ecosystems with nutrients leading to algal blooms and anoxic events) is a persistent condition of surface waters and a widespread environmental problem. Some lakes have recovered after sources of nutrients were reduced. In others, recycling of phosphorus from sediments enriched by years of high nutrient inputs causes lakes to remain eutrophic even a...

The carbon dioxide flux at the air/water interface in lakes was calculated after the determination of H2CO3* (free CO2) and atmospheric CO2 using flow injection analysis (FIA) coupled to a conductometric detector. The method is based on the diffusion of CO2 through a hydrophobic membrane into a flow of deionized water, generating a gradient of conductivity proportional to the concentration of C...

A paired whole-lake experiment was conducted on two remote, atmospherically driven lakes in the Experimental Lakes Area (ELA) to examine the stresses of trophic condition on air–water exchange and settling fluxes of polychlorinated biphenyls (PCBs). Lake 227 (L227) and Lake 110 (L110) are similar in volume, surface area, and watershed area but differ significantly in trophic status. The two lak...

BACKGROUND AND AIMS Convective gas flow in helophytes (emergent aquatic plants) is thought to be an important adaptation for the ability to colonize deep water. In this study, the maximum depths achieved by seven helophytes were compared in 17 lakes differing in nutrient enrichment, light attenuation, shoreline exposure and sediment characteristics to establish the importance of convective flow...

[1] Aquatic ecosystems are hotspots of decomposition and sources of carbon dioxide to the atmosphere that are globally significant. Carbon exported from land (allochthonous) also supplements the carbon fixed by photosynthesis in aquatic ecosystems (autochthonous), contributing to the organic matter (OM) that supports aquatic consumers. Although the presence of terrestrial compounds in aquatic O...

Abstract Metacommunity models describe species occupancy frequency distribution (hereinafter ‘SOFD’). Our goal is to present how the differences in eight macroinvertebrate orders dispersal ability affect SOFD patterns. A total of 293 from were observed 14 eutrophic lakes southern Finland. Species ranged 1 14. About 30% (89 out 293) found only one lake, yielding a surprisingly high number rare s...

Lake Võrtsjärv (270 km2, mean depth 2.8 m, Estonia) is an eutrophic and turbid lake (Secchi depth 0.5-1 m) with a high nutrient load (total nitrogen 1-2 mg N l(-1), total phosphorus approximately 50 microg P l(-1)) leading to a highly productive phytoplankton population (average chlorophyll a concentration 24 microg l(-1)). Seasonal dynamics of the main members of pelagic microbial loop - phyto...