Water temperature studies on the R. North Tyne after impoundment by Kielder dam. 3. Preliminary examination of water temperature data

The report describes the results of preliminary analyses of data obtained from a series of water temperature loggers sited at various distances (0.8 to 21.8 km) downstream of Kielder dam on the River North Tyne and in two natural tributaries. The report deals with three aspects of the water temperature records: An analysis of an operational aspect of the data sets for selected stations, a simple examination of the effects of impoundment upon water temperature at or close to the point of release, relative to natural river temperatures, and an examination of rate of change of monthly means of daily mean, maximum, minimum and range (maximum - minimum) with distance downstream of the point of release during 1983.

Turbidity and the suspended sediment load of the regulated River Tees

The physical effects of river regulation in the U.K. by impoundments have attracted most attention from hydrologists and engineers concerned with predicting and maintaining discharge regimes for water supply. Grimshaw & Lewin (1980) suggested two basic methods to investigate the effects of regulation on suspended sediment discharge: (i) Compare the river load before and after reservoir construction, and (ii) adopt a paired catchment approach. The former method assumes stationarity of process in the natural system. The latter method, involving selecting two adjacent catchments of similar physical attributes, one regulated and one unregulated, assumes constancy of process spatially. In this report both approaches are adopted to examine the turbidity and suspended sediment concentration regime of the regulated River Tees. Neither approach was entirely satisfactory in the present case. This report examines the discharge and turbidity record consisting of approximately 4000 paired data points, representative of an 11-year post-impoundment period, that has been examined for the River Tees at Broken Scar, Darlington. A small amount of suspended sediment concentration data was also processed: these data are representative of both the pre-impoundment and post-impoundment sediment regime.

Ecology and management of water plants in lowland streams

A review article which discusses the ecology and management of common water plants in lowland streams, with an introduction containing a review of previous studies on the subject. The article covers the significance of seasonal growth, the significance of stand structure (particularly in relation to hydraulic resistence), an assessment of current river management, improvements to plant management techniques (in relation to cutting), and alternatives to the traditional techniques of river plant management. There are a number of accompanying figures.

The communities of running water in Cumbria

For conservations of nature to be effective. there must be an understanding of what is present to be conserved. Thus in order to conserve the communites of the Cumbrian rivers, there must first be surveys to determine the spp present and their relative numbers. This has been carried out for many years, by a number of workers. It has been shown that the communities present are influenced by the substratum, the flow, the chemicals present, water temp and predation. Findings of the work on the River Lune were given at a seminar on the rivers of north-west Europe, held at Amiens in November, 1975. The proceedings of the seminar are to appear in special numbers of Bulletin francais de Pisciculure.

Physiological aspects of the life cycle of the river lamprey, Lampetra fluviatilis L

The life cycle of the river lamprey, L. fluviatilis, is reviewed. The larval lamprey, or ammocoete, is a blind, filter-feeding animal, which normally lies concealed in the silt deposits of streams and rivers. After a period of 3-5 years in fresh water the ammocoete undergoes a metamorphosis in the summer months into a sexually immature, non-feeding stage known as the macrophthalia, which is active. This stage migrates downstream in late winter. It adopts a parasitic existence, in intertidal areas. After 18 months it returns to spawn in fresh water, after a final freshwater stage lasting up to 9 months. The river lamprey dies within a few days after the spawning period of 3-4 weeks, and none survive to spawn the following year.

The impact of Cow Green Reservoir on invertebrate populations in the River Tees

Cow Green is a new reservoir situated in Pennine moorland. It has an area of 312 ha, a capacity of 40 . 9 x 10 SUP-6 m SUP-3 and a maximum depth of 22 . 8 m. The function of the reservoir is to regulate flow in the River Tees to provide industrial Teesside with sufficient water during the dry spells. Invertebrate studies were carried out in the Tees to monitor changes resulting from the construction of the reservoir both in the flooded basin and below the dam. The overall effect of the reservoir on the Tees has been to increase the numbers and biomass of certain taxa, but generally not at the expense of previous fauna. Some of the positive effects, ie. increase in number and biomass, and maintenance of faunal diversity, may in part be attributable to the presence of the rapids and waterfall. Turbulence resulting from this rapid flow over heterogeneous bottom is sufficient to prevent clogging of interstitial spaces by silt and to maintain the variety of ecological niches necessary for a diverse fauna.

Description of sampling stations, methods of benthic sampling and biological water quality assessment; with some consideration of the influence of sample variation on the assessment values obtained

The first bilateral study of methods of biological sampling and biological methods of water quality assessment took place during June 1977 on selected sampling sites in the catchment of the River Trent (UK). The study was arranged in accordance with the protocol established by the joint working group responsible for the Anglo-Soviet Environmental Agreement. The main purpose of the bilateral study in Nottingham was for some of the methods of sampling and biological assessment used by UK biologists to be demonstrated to their Soviet counterparts and for the Soviet biologists to have the opportunity to test these methods at first hand in order to judge the potential of any of these methods for use within the Soviet Union. This paper is concerned with the nine river stations in the Trent catchment.

Joint Anglo-Soviet biological surveillance exercise on River Dnieper

As one part of an on-going programme concerned with environmental protection as provided for under the terms of a UK/USSR Joint Environmental Protection Agreement signed in London, 21 May 1974, a seminar — ”The elaboration of the scientific basis for monitoring the quality of surface water by hydrobiological indices” was held at Valdai in Russia 12—14 July, 1976. As a continuation of this theme it was agreed that delegations of hydrobiologists from each side should carry out reciprocal visits to carry out comparative field tests on selected systems of biological surveillance in use in the respective countries. In May 1978 a team of British hydrobiologists visited the USSR, under the auspices of the Department of Environment, to carry out joint exercises on the River Dnieper and some tributaries. This paper reports the results of selected methods used by the British side when applied to the conditions found in the River Dnieper.

Ecological indicators of water quality in small rivers

At the present time hydrobiological indicators are widely used for the control of surface water quality. Results of the applying of methods suggested at the 1st Soviet-American seminar (1975), development of improved methods and estimation of their usefulness for various conditions are presented in this report. Among the criteria permitting an estimation of the degree and character of changes in water quality and their connection with the functioning of river ecosystems in general, the biological tests of natural waters appears to be the most universal one and is being carried out in two main directions — ecological and physiological. This study summarises approaches in both directions.

Investigations on phytoplankton with special reference to water usage

Experiments and observations on the phytoplankton of certain lakes in the English Lake District were made from early 1973 to the end of March, 1974. They included laboratory and lake bioassays and observations on the quantity and quality of the phytoplankton in six lakes. The introductory sections of the report are about algae, the ecology of phytoplankton and the scope of the contracted work. Laboratory bioassays on water from one lake, Blelham Tarn, showed that phosphorus, silicon (for diatoms) and organic substances forming complexes with iron were the major substances limiting the growth of the algae tested. The growth of the test algae was limited to different degrees by those substances and, to some extent, to a greater or lesser degree at different times of year. It is suggested that a relatively simple form of bioassay could give valuable information to water undertakings. Lake bioassays and other experiments were carried out by using large in situ tubular plastic enclosures. Two such investigations are described. The effects of a change in sewerage in two drainage basins on the phytoplankton of three lakes is described and some data given about changes since 1945 in three other lakes in the same overall drainage basin. These latter lakes have been affected too by changes in sewerage and by increasing inputs of domestic and agricultural wastes. Throughout, the relevance of the work done to practical problems of water usage is kept in mind and discussed. In the last section special reference is made to the largely unpredictable results of water transfers. The report ends with a note on river phytoplankton.

Eutrophication in the River Meuse

The severe problems caused by large phytoplankton populations in the River Meuse date back to the beginning of the 1980s. However, no clear relationship can be established between an increase of algal growth and dissolved nutrient concentrations, at least in the Belgian part of the river. Most probably, plankton algae start developing in France, utilizing large inputs of phosphorus from some of the tributaries: this point will be investigated further, as well as the effect of a reduction in the releases of phosphorus. A mathematical model helps to understand the main factors which control algal growth: underwater light, temperature, discharge and grazing by zooplankton. The last is a major loss process in summer and, as shown by recent observations, may trigger a seasonal succession leading to dominance by large phytoplankton taxa. With regard to water quality, eutrophication is a major problem in drinking-water treatment (filter clogging, etc.) and large numbers of decomposing algae may adversely affect the oxygen budget of the river. On the other hand, algal photosynthesis is the most important oxygen source at periods of low discharge, and reduced algal production may result in dramatic oxygen decreases in heavily polluted stretches of the river.

Water temperature studies on the R. North Tyne after impoundment by Kielder dam. 1. General introduction and background data

This report describes the general background to the project, defines the stations from which data sets have been obtained and lists the available data. The project had the following aims: To develop a more accurate and less labour-intensive system for the collection and processing of water temperature data from a number of stations within a stream/river system, and to use the River North Tyne downstream of the Kielder impoundment as a test bed for the system. This should yield useful information on the effects of impoundment upon downstream water temperatures.

Marine biology of the Sierra Leone River Estuary. 1. The physical environment

The Sierra Leone River Estuary is a relatively young drowned river valley, it is shallow except for a deep channel which passes close to the Freetown shoreline. The upper reaches merge into a network of creeks and channels fringed by large areas of mangrove swamps. It is a tidal estuary of the semi-mixed type with the saline oceanic water entering it on a diurnal cycle. The climate of Sierra Leone is marked by a very distinct change between a very wet rainy season and a dry season. The tidal range of the Estuary (spring 3.03m; neap 2.28m) does not impede normal use of the harbour. The tidal variations can be felt as far as 42 miles inland along the water courses of the Sierra Leone River and its tributaries. The volume of fresh water entering the Estuary is large during the rainy season and greatly reduced during the dry season. Consequently there is a marked fall in salinity during the rainy season and higher salinities due to the marine influence prevailing during the dry season. The nature of the shores and bottom, the hydrography and chemistry of the estuarine system have been outlined in relation to the prevailing climatic conditions.

Juvenile salmon investigations River Wenning catchment 1981-86

As part of the River Lune juvenile salmonid investigation, a number of sites on the River Wenning catchment were electrofished annually from 1981 - 1985. Particularly low Salmon parr populations were evident for much of the Wenning catchment which has caused some concern. All the Wenning catchment electrofishing results are reported in this paper and comparisons are made with designated groups of sites on the remainder of the Lune catchment. These groups of sites are: River Lune and tributaries, upstream Tebay, Upper Middle Lune, Lower Middle Lune, Lower Lune, Birk & Borrow Becks, Chapel & Crosdale Becks, Rawthey system, Barbon & Leek Becks and the Greta system. The general scarcity of Salmonids in large sections of the main river Wenning probably reflects the apparent limited natural spawning areas on the catchment. Details of Salmon fry and ova planting on the Wenning catchment since 1981 have been collated and whilst survival through the 0+ stage appears to be quite good, recruitment to the 1++ stage appears to be poor. Water quality does not appear to be responsible for the very low salmonid densities at some main river sites but is possibly a factor in apparently preventing any Salmon run in Keasden Beck. Recommendations for future Fisheries and Biological work are given.

A summary report on juvenile salmonid populations of the River Lune catchment, 1981 to 1991

This report summarises the fisheries electrofishing survey work undertaken on the River Lune, England, in the period 1981-85 and 1991. As part of a long term monitoring programme by the National Rivers Authority, juvenile surveys, with the emphasis on salmonids, have been carried out on the River Lune on a number of occasions since 1981. The latest survey in 1991 now gives the opportunity to assess what, if any, changes have occurred in the juvenile populations across the last 11 years and how future fisheries management may impact on the River Lune as a fishery. The areas of trout and salmon, fry and parr production will be considered in detail, as will adult trout populations. Water quality issues will be mentioned briefly as will habitat issues, where they are deemed to be important in affecting fish densities.