River Esk Research Articles

Wing polymorphism in females of Zwicknia bifrons (Newman, 1838) (Plecoptera: Capniidae)

Wing polymorphism is reported for the first time in female specimens of Zwicknia bifrons from the River Esk, Cumbria. Identification of specimens is confirmed by morphological features and DNA sequencing.

The effect of riparian pool‐riffles on the hydrochemistry of hyporheic habitats: The River Esk, Yorkshire, UK

AbstractEuropean Union Water Framework Directive (WFD) (2000/60/EC) waterbody statuses are often derived from the assemblage of mixed‐taxon organisms found within bed sediments. Yet no routine water chemistry samples are taken from riverbed substrate, despite many interstitial species being dependant on specific physicochemical conditions. This paper examines water and nutrient exchanges between stream and substrate, the hyporheic zone, and the consequent alteration to the chemistry of interstitial and in‐stream waters, which in turn leads to small‐scale but significant changes in habitat. Bed topography, principally a pool‐riffle sequence, was surveyed and hydraulically sampled to examine the hyporheic flow pathways generated between the stream, substrate, and groundwater—creating an ecotone. Hyporheic zone, in‐stream and groundwater hydrochemistry, and hydraulic measures were assessed at a braided woodland river reach using a dense monitoring approach. The findings demonstrate that through a 23‐m pool‐riffle sequence, where water infiltrates at the riffle‐head and subsequently exfiltrates at the riffle‐tail, there is a 5% reduction in mean in‐stream nitrate‐N and a 73% reduction in hyporheic zone concentration. When calcium‐enriched riffle‐tail exfiltrate meets riffle‐runoff water that is turbulently oxygenated from riffle‐flow, an interstitial redoxcline is created. Dissolved oxygen nocturnally drops, with photosynthetic rate reduction, which causes hyporheic nitrate‐N to double its daytime concentration. The results are related to the Yorkshire River Esk freshwater pearl mussels, Margaritifera margaritifera Linnaeus (1758), a declining endangered species. At present, scant monitoring of interstitial hydrochemistry and diurnal change across stream and substrate occurs.

Assessing the Potential of Phytolith Analysis to Investigate Local Environment and Prehistoric Plant Resource Use in Temperate Regions: A Case Study from Williamson’s Moss, Cumbria, Britain

ABSTRACT The archaeological site of Williamson’s Moss, located in north-west England, was excavated in the 1980s as part of an investigation of the Mesolithic, Neolithic, and Bronze Age populations living around the estuary of the River Esk in Cumbria. Recovery of plant remains was generally low, but bulk sediment samples were collected from different contexts as part of a project archive for future analysis. This paper presents the results of new analyses conducted on these archived samples, carried out to assess whether phytolith analysis could offer additional insights into the local environment and plant use at the site. Whilst the results indicate the presence of a diverse range of phytolith types from both monocotyledon and dicotyledon plants (along with sponge spicules, diatoms and microcharcoal), interpretation of the data is problematic. Comparison with existing palynological and excavation data indicate methodological limitations in using bulk archived samples. Nevertheless, the recovery of abundant microfossil material is encouraging for the emerging field of phytolith studies in temperate environments such as Britain, and suggestions are made regarding future sampling strategies and taphonomic considerations that will reduce problems for future analyses.

Glencartholm revisited: describing for the first time Stan Wood's discovery and excavation of Mumbie Quarry, adjacent to the important Palaeozoic fossil site of Glencartholm

ABSTRACTGlencartholm in Dumfries and Galloway, Southern Scotland, is one of the most important Palaeozoic fossil fish sites in the world, with a fauna containing more than 30 species. Originally discovered in the bank of the River Esk in 1879, further collecting in the 1930s removed all the accessible fossiliferous strata. These strata were not known to occur elsewhere and despite the site's international importance, details of the section including the fossil bearing beds have not been described. An excavation of a new exposure at Mumbie, 50 metres east of the original site, was undertaken by Stan Wood in the 1990s. Sediments were logged over an 18-metre section. Three separate fish beds were identified and more than 200 specimens of ray-finned fish collected, including one possible new species. Differences in scale colour enables fishes from the different horizons to be distinguished. This should allow material collected previously to be more accurately assigned and assist palaeoecological analysis of the site. In addition to ray-finned fish, cartilaginous fishes were collected together with plants, bivalves, crustaceans, scorpions and horseshoe crabs which have not previously been reported from Glencartholm.

Dissolved Iron Behavior in the Ravenglass Estuary Waters, An Implication on the Early Diagenesis

Estuaries are suitable places for both clay mineral accumulation and iron trapping. Flocculated and deposited Fe compounds in the estuaries can lead to neo-formed minerals which they have a basic role in reservoir quality estimation. The aqueous geochemistry of the Ravenglass estuary and its feeding rivers has been studied to assess if, where and when aqueous iron is lost from the river water and accumulates as part of the sediment in the estuary. Ravenglass estuary waters are conservative mixtures between river water and seawater in terms of chloride, sodium, potassium and magnesium. Alkalinity (bicarbonate), calcium and sulphate are locally non-conservative and are affected by biological and mineral processes. The River Irt contains twice as much dissolved iron as the River Esk but all iron concentrations are much lower in the estuary samples than in the feeding rivers. Aqueous iron undergoes large-scale accumulation in the Ravenglass estuary. Iron concentrations are lowest at high tide at all sampling sites on the Ravenglass estuary. Iron concentrations are highest at low tide for the Irt arm of the estuary but are highest on the falling tide between high and low tide. Iron concentrations in estuary samples decrease rapidly as salinity increases with low iron concentrations in all estuary samples once salinity exceeds 5,000 mg/lit. Iron concentrations also decrease as pH increases. The loss of iron is presumably due to flocculation of colloidal iron oxides, hydroxides and iron-organic complexes. Fluvial aqueous iron does not behave conservatively on mixing with seawater; most iron is lost from the water column at an early stage of river water mixing with estuary water. The site of primary iron-loss from the water occurs towards the heads of estuaries but this site will move as a function of time within the tide cycle. Given that the Esk has highest iron concentrations between high and low tide, it is likely that iron is swept from the iron-rich Irt arm of the estuary into the iron-poor Esk arm soon after high tide.

Making sense of policy implementation: The construction and uses of expertise and evidence in managing freshwater environments

This paper explores how environmental policy is implemented and enacted through the management of technical and institutional knowledge at the local level. We use the conservation of the freshwater pearl mussel in the River Esk, North Yorkshire, UK, as an empirical case study to examine the interaction that takes place between professionals from different institutional and disciplinary backgrounds as they come together to work on a common problem. We focus on two aspects: the way in which an institutional context was created; and the interaction between the professionals involved. Our analysis demonstrates that the strategic intermediary role of professionals is vital to policy implementation. The intermediary uses their strategic vision and undertakes political manoeuvring following the presentation and interaction of different knowledges and evidence to ensure a certain course of action. This is different from a knowledge broker. The role of the professional is to draw on expertise, both formal and tacit, to interpret and judge data in relation to decision making. Those individuals participating in decision making of this nature have multiple histories, roles and motivations which enables innovation in the creation of meaning within environmental management. The quality of the evidence can be assumed adequate once subject to diverse professional scrutiny. These findings are important since innovative behaviour that creates new structures and practices is becoming central to delivering good management of land, water and biodiversity.

The launching of the River Esk bridge, UK

The River Esk bridge carries the southbound carriageway of the M6 motorway over the River Esk estuary and forms part of the recently constructed M6 Carlisle to Guards Mill motorway extension, which provides the missing link in the motorway network between England and Scotland. The bridge is a 180 m long four-span steel composite viaduct. Due to site constraints the most economical and practical method of construction was to launch the steelwork into position rather than to lift the steelwork in by crane. The bridge steelwork, weighing over 800 t, was assembled on the northern approach to the bridge and launched southwards over the River Esk estuary. This paper demonstrates that the design and construction of a launched bridge can be significantly more complicated than the design of a comparable bridge that is constructed using conventional methods and that there are many more load cases and construction details to consider. This paper covers the approach for carrying out the analysis, design, detailing and construction of the structure and focuses specifically on the key issues relating to launching steelwork.

A protocol for stocking hatchery reared freshwater pearl mussel Margaritifera margaritifera

Abstract Freshwater pearl mussel (Margaritifera margaritifera L.) populations are under serious threat of extinction throughout their geographical range and only a few remnant populations are recruiting to adulthood. Consequently, M. margaritifera is classified as endangered on the International Union for Conservation of Nature Red List. Several institutions across many countries have set up Ark sites at hatcheries to culture and rear young M. margaritifera from population remnants, with the intention of stocking these juveniles into rivers. The release location must fulfill the habitat requirements for the full life‐cycle of the species, so they can contribute to the next generation and thus the long‐term recovery of the species. However, little research or advice exists about how to decide if river environments are suitable for stocking. A protocol is presented for determining whether a M. margaritifera population will benefit from stocking hatchery reared juveniles and how to identify suitable areas. Stocking locations are considered from catchment scale to microscale using water quality (reach), macrohabitat (site) and microhabitat, including physicochemical properties of the substratum (spots). A case study of the River Esk in north‐east England, is incorporated to exemplify the myriad of considerations surrounding attempts to conserve M. margaritifera, and describes how implementation of the protocol can structure and assist stocking programmes. Copyright © 2010 John Wiley & Sons, Ltd.

The West March on the Anglo-Scottish Border in the Twelfth Century, and the Origins of the Western Debatable Land

'The West March on the Anglo-Scottish Border in the twelfth century and the origins of the Western Debatable Land'. Although there was a frontier zone between medieval England and Scotland where March Law applied, within that zone there was, at any rate in time of peace between the Crowns, an ascertainable frontier line. Two conflicting views on the location of this line west of the Cheviot are reviewed and a third proposal advanced. From William II's conquest of Cumberland in 1092 up to 1552, the line lay along the River Esk and Liddel Water, except when the Scots possessed Cumberland and Westmorland in 1136–1157 and 1216–1217. After 1136, David I granted to the lords of the English barony of Liddel additional land comprising the parishes of Kirkandrews-on-Esk and Canonbie, north of the Esk. From 1157, the barony remained a cross-Border holding until the Scots dispossessed the English lords of Kirkandrews and Canonbie between 1300 and 1318. The English lords continued to claim that land, however, and their claim was assigned to the English Crown after 1349. At that point, what had been a claim to private rights started to become confused with national sovereignty. In 1552, arbitrators partitioned what had become known as the Western Debatable Land, a no-man's-land, and the Border then assumed its present line.

Fishing in the River Esk

Fishing in the River Esk

Estimating spatial patterns of effluent exposure concentrations in direct toxicity assessment studies.

Hydrodynamic models of differing scale and complexity were used to estimate spatial patterns of effluent concentration in discharge plumes in the River Esk and the Lower Tees Estuary. The output from the Tees model was used, in conjunction with measurements of toxicity determined in short-term oyster embryo tests, to predict contours/zones of toxicity in the estuary associated with effluent discharges from four chemical processing sites. One of the discharges also combined the input from a municipal sewage treatment works. The models appeared to be effective in predicting patterns of dilution and dispersion of the effluent discharges in the respective receiving environments. Confirmation of the predictive capabilities of the Tees model was achieved by comparing predicted and measured toxicity in different regions of the plumes associated with the four discharges. Differences between predicted and measured toxicity for two of the four discharges were explicable in terms of failure to take account of the effects of real-time wind conditions when test samples were collected or overlap of adjacent discharge plumes. Suggested refinements to the models and measurement of effluent toxicity would further enhance the utility of this approach for determining the extent and significance of the effects of effluent discharges in receiving environments.

Risk characterisation in direct toxicity assessment of the River Esk and the Tees Estuary.

This paper illustrates the use of deterministic and probabilistic approaches to the ecotoxicological risk assessment of effluents through two simple examples taken from the UK Direct Toxicity Assessment Demonstration Programme. In this study, the direct protection objective for the River Esk in Scotland was the prevention of short-term lethal toxicity to invertebrates from exposure to effluent containing insecticides. Both a deterministic and a probabilistic risk characterisation show that such toxicity is very unlikely to occur. The protection objectives for the Lower Tees Estuary were more complex, due to a variety of discharges and potentially sensitive species. A deterministic risk assessment using the most sensitive species suggests that toxicity will be high at all times. In contrast, a probabilistic risk assessment suggests that, although acute toxicity is considerable, it is not likely to occur at all times or affect all species, and discharge scenarios do exist in which acute toxicity could be relatively low. These two case studies illustrate the use of probabilistic risk assessment in achieving more realistic assessments of effluent toxicity through use of all available data.

Toxicity reduction evaluation, toxicity identification evaluation and toxicity tracking in direct toxicity assessment.

Toxicity reduction evaluations (TREs) in the River Esk and Lower Tees Estuary were based on the approach described by USEPA, but adapted to tackle the specific problems of the two sites. A combination of toxicity tracking and toxicity identification evaluation (TIE) was used at both locations to enhance the understanding of source and type of toxicants present. The assessment of toxicity at Langholm focussed on pesticides present in the sewerage network. The TIE programme indicated that the most likely toxic agents within the effluent were the organophosphate pesticides diazinon and to lesser extent propetamphos, although these did not account for all of the observed toxicity. The exact source of these toxicants was not clear although toxicity tracking identified two potential candidates. The TRE undertaken on the discharge to the lower Tees utilised high-throughput methods with standard test organisms to generate toxicity information throughout a complex sewerage network. The toxicity tracking information was used in conjunction with TIEs to identify a number of key sources of toxicity. Substantial toxicity was associated with a currently untreated industrial effluent. Chemical analysis and TIE highlighted cyanide as the likely toxicant in this effluent and its possible significance in the final discharge.

The use of direct toxicity assessment in the assessment and control of complex effluents in the UK: a demonstration programme.

This paper outlines the background, objectives, methodology, findings, outputs and recommendations from the Direct Toxicity Assessment (DTA) Demonstration Programme. This was a trial of a suite of bioassay methods and a seven-step protocol designed to deliver water quality improvements in catchments with well-defined water quality problems, where ecotoxicity from effluents was a contributing factor. The trial was run as a collaborative venture between the environmental regulators and water and manufacturing industries in the UK and was conducted at three project sites: -a reach of the river Aire near the city of Bradford in Yorkshire; -a reach of the River Esk near the town of Langholm on the border between Scotland and England; and -the lower Tees estuary on the north-east coast of England. The outcomes of each project are summarised in this paper. The learning points delivered by the programme were used to make recommendations to the regulators on how best to use bioassays for the assessment and control of complex effluents in the UK. Guidance was provided on how to carry out the bioassays and on how to use the data generated for regulatory decision-making. The programme also demonstrated how the regulators and the regulated can successfully work together to tackle environmental issues and deliver effective and workable solutions.

Plutonium solubility in sediment pore waters

Using in situ porous cup samplers, dissolved Pu concentrations have been measured over a year in the pore waters from two contrasting sites in the valley of the River Esk, North West England. In saltmarsh sediments, dissolved Pu represents approximately 1 part in 10 6 of the total inventory. The Pu concentration in solution is in the range 1.1–3.5 mBq l −1, varying by a factor of 3 in the course of the year. Most of the changes in dissolved Pu coincide with changes in dissolved Fe and Mn concentrations, with Pu being low in the summer months when Fe and Mn are high. Nevertheless, there are a number of factors which make it unclear as to whether these patterns might be related to seasonal redox changes in the saltmarsh. At the highly organic, reducing reedbed site, the proportion of Pu in solution is typically around 1 part in 10 3, proportionately much higher than in the saltmarsh, giving concentrations ranging between 9.0 and 28.5 mBq l −1, and are apparently maintained by complexation to dissolved organic matter. There is no obvious seasonal pattern at the reedbed site nor is there any relation to any of the dissolved species measured (Fe, Mn, Na, DOC).

A Roman Signal Station at Whitby

SUMMARYThe possible existence of a Roman signal station at Whitby has a significant impact upon the study of the Roman defensive system of the North Yorkshire coast and our understanding of the Anglo-Saxon ecclesiastical topography of the area. Whitby lies at the mouth of the River Esk and its associated harbour on the North Yorkshire coast, amidst an intervisible chain of five known signal stations, but is perhaps best known for its Anglo-Saxon monastery founded by the Northumbrian king Oswy in A.D. 657. No absolute archaeological evidence of a signal station at Whitby exists, but the toponym suggests that the site had an association with a signal station or watchtower. It is clear that the existing stations were designed to function as a cohesive system, given their similar form and contemporary dates: communication and intervisibility were therefore essential aspects of this defensive network. Despite this, the stations to the north and south of Whitby—those at Goldsborough and Ravenscar respectively—are not intervisible. A station positioned at Whitby would effectively close this gap in the system.Attempting to reconcile the near complete absence of archaeological remains with the place-name and geographical evidence, this paper uses geologically determined erosion rates to examine the possibility that such a station existed on the more than three hundred metres of coastal land that has eroded since the Roman period. In doing so it addresses the extent to which archaeologists can reconstruct and work with an ancient coastline on a local scale. Having established the probability of a ‘lost’ station, the paper discusses the results of a GIS viewshed application which address the feasibility of such a station's intervisibility from its neighbouring station to the south. The concluding sections investigate the stations' possible form.

The effect of liming agricultural land on the chemistry and biology of the River Esk, north-west England

A land-use study indicated that a reduction in agricultural liming may have been a major factor in the development of acid episodes and consequent fish kills in the River Esk and River Duddon. A field study was carried out to determine whether the reintroduction of catchment liming in the Esk valley could ameliorate acid episodes and thus prevent fish kills. Lime was applied to areas which had been limed in the past, comprising 10% of the Esk catchment. Flow, pH, calcium, aluminium, total humic substances, conductivity and invertebrates were monitored before and after liming. The River Duddon was monitored as a reference. There was a general reduction of the acidity of both the River Esk and the River Duddon during the study period. This appeared to be controlled by rainwater chemistry. There was little evidence for a major effect of liming on water chemistry which suggests that the mortalities of salmonids in the early 1980s were not due to a reduction in agricultural liming.

Studies of a fatal pollutant-induced hyperbilirubinaemia in spawning Atlantic salmon

Freshly run adult Atlantic salmon ( Salmo salar) returning to the River Don (Aberdeenshire, Scotland) show, periodic epidemics of a fatal disease of the blood and liver, characterised by hyperbilirubinaemia, haemolytic anaemia and structural damage to the liver. Since previous studies have ruled out agents of infectious aetiology, attention has focused on the possible causative role of xenobiotics present in the River Don. In this study the activities of inducible biotransformation and detoxication systems, plasma and tissue components were investigated in farmed salmon, in wild salmon from the River Don and from the non-polluted River Esk, and in Esk salmon held in tanks containing water from a paper mill effluent, an effluent from an industrial drain or a mixture of the two. The results indicated that the diseased and many of the apparently healthy River Don salmon had induced mixed function oxygenase activities and metallothionein levels indicative of both organic and heavy metal pollutant impact. In fish exposed experimentally to paper mill effluents hepatic MT levels were not induced but effluents from industrial drains in the lower river induced MFO activities up to 35-fold. Bilirubinaemia was inducible by sequential exposure to the industrial drain effluent and effluent from the paper pulp mill, indicating that some aspects of the disease are due to synergistic pollutant effects.

The impact of feral mink Mustela vison on water voles Arvicola terrestris in the North Yorkshire Moors National Park

This study explores mink-water vole interactions on five of the principal rivers in the North Yorkshire Moors National Park, in an area where mink are still spreading. It uses a variety of techniques—tracking (field signs), trapping and radio-tracking—at a range of 38 sites that differed in average water vole and mink abundances over two years, in conjunction with a longer term four-year study at one site on the river Esk under active colonisation by mink. The overall conclusion is unavoidable. Mink pose a serious threat to the long-term survival of water vole populations, at least in the North Yorkshire Moors study area.

Laboratory studies of the chemical behaviour of plutonium associated with contaminated estuarine sediments

Laboratory experiments, with contaminated Esk Estuary sediment and uncontaminated River Esk and North Sea waters, have provided detailed information on Pu remobilisation behaviour. Of the 977 mBq g −1 Pu (III, IV) associated with the sediment, 2·6% is subject to a rapid reversible exchange reaction. Well-defined distribution coefficients (K d) have been determined with respect to this labile fraction (e.g. 5 × 10 3 litres kg −1 for remobilisation into river water). A low level of Pu (III, IV) remobilisation can be maintained following complete removal of the labile fraction, probably through a rate-limited reaction involving a more strongly bound form of Pu. Plutonium (V, VI) remobilisation occurs both through rapid exchange of a comparable labile component and through a mechanism involving photo-oxidation of Pu (III, IV). A dominant proportion of the remobilised Pu (III, IV) in solution is anionic with a molecular weight1000 daltons, probably in the form of an organic complex. Remobilised Pu (V, VI) is mainly in true solution in variously charged forms. Addition of natural colloidal organic carbon (COC) to river water increased the level of labile Pu (III, IV) remobilisation. The effect can be described by two competing equilibria in which labile Pu (III, IV) (a) is complexed by COC, and (b) is adsorbed by the sediment. The same additions of COC reduced the level of Pu (V, VI) remobilisation, either through its action as a reducing agent or through the indirect effect of associated pH changes. Increasing the carbonate alkalinity (NaHCO 3) in river water decreases the remobilisation of both Pu (III, IV) and Pu (V, VI).