A decade of monitoring and management of freshwater algae, in particular Cyanobacteria, in England and Wales

Although the toxicity of cyanobacteria has been known for many years, cyanobacteria-related problems in the UK were generally limited in frequency. However, this all changed and became of national concern following the exceptional environmental conditions in the autumn of 1989, when widespread cyanobacterial blooms and scums developed in fresh waters. This paper summarises the Environment Agency's monitoring programme for freshwater algae since 1991 and describes the actions the Environment Agency has taken as a result of the monitoring data

Diel surface temperature range scales with lake size

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at Diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of Diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface Diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer Diel ranges in their near-surface temperatures of between 4 and 7°C. Large Diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored

Diel surface temperature range scales with lake size

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored

An investigation into nutrient fluxes in a lowland, pumped-storage reservoir during ferric sulphate dosing

This study (between August 1992-May 1994) of the impact of ferric sulphate dosing, examined phosphorous and nitrogen inputs and outputs, nutrient fluxes within the water column, and phosphorus sediment-water interactions in Rutland Water. Rutland Water, a lowland, eutrophic pumped-storage reservoir in the UK experienced severe cyanobacterial blooms and scums during the late summer of 1989 which received national media attention. In response to this, from June 1990, ferric sulphate was added to the reservoir with the pumped input from the rivers Nene and Welland to attempt to precipitate phosphorus to the sediments to limit phytoplankton abundance.;The seasonality of phosphorus and nitrogen loadings influenced in-lake nutrient concentrations and subsequent phytoplankton biomass. The pumped input was the dominant source; the natural inflows were insignificant. Ferric sulphate did not influence nutrient temporal and spatial patterns, although the decline in in-lake phosphorus concentrations between 1990 and 1991 was related primarily to the decline in the annual phosphorus loading during drought conditions and also to the large quantities dosed.;Wind-generated mixing, together with the effect of the jetted input were sufficient to prevent the development of full stratification, although at the deepest site slight dissolved oxygen stratification developed during summer. Nutrient depth variation was attributed to sedimentation and subsequent decomposition of organic matter in the bottom waters. Ferric sulphate increased phosphorus sedimentation, which was the dominant downward flux.;Ferric sulphate floc increased the sediment redox potential, lowered pH and increased the phosphorus-binding capacity of the sediments, although the high ratio of total iron:total phosphorus already present was inferred as governing the strong phosphorus-binding capacity. Although no sediment phosphorus release was detected under the redox-driven mechanism, any potentially released phosphorus influenced by microbiological actions was reprecipitated to the sediments due to the maintenance of relatively aerobic conditions in the water column

Chrysochromulina associated with fish mortalities in a Scottish freshwater loch

Volume: 25Start Page: 43End Page: 4

Ollicola vangoorii (Chrysophyceae, Chromulinales): an unfamiliar loricate protist newly documented in UK freshwaters from a southern upland loch, Scotland

Volume: 26Start Page: 110End Page: 11

The fusiform green alga Desmatractum spryii (Chlorophyta, Chlorococcales): a noteworthy discovery made in a peninsula loch, SW Scotland

Volume: 26Start Page: 111End Page: 11

Some uncommon desmids (Chlorophyta, Zygnemophyceae) encountered in the phytoplankton of Scottish lochs

Volume: 26Start Page: 119End Page: 12