871 research outputs found
The cultural ecosystem services of winterbourne streams: what do these dynamic ecosystems mean to people?
No full textEstimating the contribution of in-stream cattle faeces deposits to nutrient loading in an English Chalk stream
No full textNumerous studies have shown that the addition of faecal matter from livestock to aquatic ecosystems can have a detrimental effect upon water quality. English Chalk streams, as groundwater-dominated rivers of high ecological importance, are particularly susceptible to nutrient loading from cattle faeces. Naturally low concentrations of nitrogen, phosphorus and potassium in such rivers increase their vulnerability to external perturbation from organic matter inputs. Despite this, the amount of faeces directly contributed by livestock such as cattle to a river system is rarely quantified.To provide an assessment of nutrient loading due to cattle, a study combining observational data of animal behaviour with faecal analysis was undertaken in an English Chalk stream. Results show that cattle faeces was 89.4% water, containing 0.79% nitrogen, 0.43% phosphorous and 0.43% potassium by wet mass. It was estimated that a herd of 33 cattle deposited over 8 tonnes of faeces into a 770 m river reach over a seven-month period in 2010. This loading is estimated to have increased in-stream nitrogen, phosphorus and potassium concentrations in the reach by 0.0036 mg l−1, 0.002 mg l−1 and 0.002 mg l−1 respectively; a small proportion of the overall nutrient content of the river. Moreover, it has been demonstrated that by combining behavioural data with faecal data it is possible to estimate the likely nutrient loading due solely to direct inputs from cattle faeces. With sufficient data, calculations such as those employed in this study can be used to provide accurate estimates of the nutrient loading due to livestock in watercourses
Economic evaluation of a stratified transport method for Atlantic halibut (Hippoglossus hippoglossus) juveniles
No full textThe objective of this study was to evaluate a convenient, low-cost modification to conventional transfer methods for Atlantic halibut juveniles. A series of wire mesh cages were stacked within transport tanks creating a stratified transport system (STS), increasing the surface area for settlement and facilitating a more homogeneous distribution of halibut throughout the tank compared with the conventional insulated box (Unstructured, UTS). A stochastic cost-benefit analysis determined investment into a STS to be cost-effective, generating a mean benefit-cost ratio of 1.31 (95% CI, 0.68–2.00) after 2 years and a mean 5-year net present value of 85,176(9546,906–$125,630). The implementation of a STS was found to be technically feasible and economically efficient method to improve Atlantic halibut transport.Peter J. Sykes, Carol A. McClure, Debbie J. Martin-Robichaud, Charles G. Caraguel, K. Larry Hammel
Claud Sykes
No full textClaud SykesProfessional actor, co-founder of the English Players, writer, and MI5 agent. Born in Ipswich, England, in 1912 Sykes married Annie "˜Daisy' Race (1885-1969), his co-star in Octavia Kenmore's and Leigh Lovel's London company. Sykes acted in two dozen productions of Ibsen between 1908 and 1914 before he and his wife relocated to Switzerland in 1915, ostensibly for Sykes's health. He and JJ first encountered one another in early 1917, and by the end of the year, Sykes was overseeing typescript production on the early episodes of Ulysses. With a mix of professional and amateur actors, JJ and Sykes formed the English Players, whose first performance was The Importance of Being Earnest in April 1918. Through late 1919, the Players produced nineteen plays in Zurich and toured Switzerland. Sykes returned to England in 1920. In 1927 Sykes read proofs and provided suggestions for the German translation of Ulysses, published that year. In the 1920s, he wrote adventure fiction in the mold of John Buchan before, in the 1930s, establishing himself as a translator and author of First World War aviation writing, often under the pseudonym "˜Vigilant'. His translation work from German proved an effective cover for counter-intelligence work and, by the mid-1930s, he was reporting to his MI5 handler using the code name 'M/S'. In 1939, he worked briefly as a double agent, feeding disinformation to a Gestapo agent in Berlin. His interests in the theatre continued: he produced plays for the Letchworth Citizens' Company in the 1920s and published the Rutland-theory inspired Alias William Shakespeare? (1947). He died in Malta in 1963. William Brockman and Ronan Crowley</p
Chalk stream restoration strategy 2021: Main report
No full textThis CaBA Chalk Stream Restoration Strategy represents the collective passion andambition of all sorts of people and organisations who care about chalk streams andwho wish to see them restored to full ecological health.In terms of our stewardship of the environment, chalk streams are a considerablechallenge, because they flow through the busiest part of the country; and a weightyresponsibility, because they are such rare and special rivers. Chalk-streamecological health is under pressure everywhere and failing in many places. ThisCaBA plan identifies what we need to do to relieve that pressure and address thosefailings. We will only succeed by working together and by acknowledging and livingup to our individual responsibilities and roles
The use of DNA fingerprinting to study the population dynamics of otters (<i>Lutra lutra</i>) in southern Britain: a feasibility study
No full textMany factors have the potential to limit the recovery of otter (Lutra lutra) populations.including road deaths, resource constraints such as prey, and habitat availability and quality. Current practical conservation measures are based on surveys assessing habitat potential, which is followed up by habitat improvements. There is very little investigation of the requirements of the animals themselves due to lack of suitable survey techniques. The use of DNA fingerprinting of spraint provides a much needed survey tool to address the acknowledged need for research into the conservation needs and population biology of this species. The Report presents the findings of a one-year feasibility study into the use of DNA fingerprinting to study the otter recovery in southern Britain. Four catchments were surveyed, one in Devon, two in Somerset and one in Hampshire. The long-term objective of this study is to characterise the population dynamics underlying the otter recovery in the UK over a period of four years, as a contribution to identifying the factors limiting population expansion, to facilitate a more focused, efficient and effective conservation effort. The objective of the feasibility study was to carry out a field test of the effectiveness of fingerprinting techniques in identifying individual otters and to develop a protocol for applying these techniques to large scale, repeatable projects. The report concludes that the DNA fingerprinting technique applied to otter spraint has great potential for investigation of otter biology but requires development before it can be applied to large-scale projects. Specific recommendations for further development work are made for consideration by the Agency’s Conservation Function and by the UK Biodiversity Action Plan Steering Group
Population genetics and PBDE analysis of English and Welsh otters. Integrated catchment science programme
No full textOtter populations declined drastically across many areas of England and Wales during the 1960s to 1980s. The main cause of this decline is thought to have been high concentrations of organic pollutants, in particular PCBs and dieldrin. This report investigates the health of present day otter populations in England and Wales and, in particular, populations in southwest England. The research focuses on otter numbers and the genetic diversity of populations. It also investigates a possible new threat from organic pollutants, polybrominated diphenyl ethers (PBDEs).In southwest England, research focused on two catchments, the River Camel in Cornwall and the River Itchen in Hampshire. A non-invasive, spraint genotyping study of the otter population inhabiting the Camel, revealed that a minimum of 16 otters used the river during the two consecutive seasons of study (October 2005 - May 2006 and October 2006 - June 2007). The research also provided insight into the ranges and genetic relationships of otters using the river. A genotyping study was also carried out on the otter population on the Itchen. This population declined drastically in the 1950s and 1960s, to just a few isolated individuals, before being supplemented with otters released as part of a captive breeding programme. Microsatellite genotyping of tissue samples showed the Itchen otter population to be relatively diverse, indicating a successful population recovery Additional analysis of genetic haplotypes indicated that captive bred otters have successfully interbred with wild otters, contributing to the genetic profile of the current Itchen population.In a second strand to the project, PBDEs were added to the existing list of organic pollutants detected in otter livers. The concentrations of PBDEs found in otters rival the high concentrations observed in many marine mammal species and are approaching the concentrations of PCBs and DDTs already reported in otters. The profile of PBDE congeners found in otters shows that BDE-47 is by far the most concentrated BDE congener, following the trend found in many aquatic environmental samples. Congeners BDE-99 and -100 are also found at significant concentrations. Otters contain relatively high concentrations of the congeners BDE-153 and BDE-209, a trend more typical of terrestrial top predators.In summary, the otter populations studied in southwest England appear to be recovering well. Genetic diversity of the populations appears to be recovering and levels of diversity observed in the Camel and in the Itchen, a river known to have received substantial input from captive bred animals, are similar. The extant otter population of the Itchen shows evidence of genetic input from releases of captive bred animals. High concentrations of PBDEs have been detected in a range of otter tissues; what effect these levels may be having upon the species is unknown
An Alternative Approach to the Mean
No full textThis article, created by Alan W. Sykes of Swansea University College, describes an alternate calculation of expected value, which illustrates continuous random variables. The author uses charts, graphs and text to help illustrate these mathematical concepts. The author provides external references for those interested in further study of this subject
Exploring the capability of natural flood management approaches in groundwater-dominated chalk streams
No full textThis study aims to address the gap in the Natural Flood Management (NFM) evidence base concerning its implementation potential in groundwater-dominated catchments. We generated a typology of 198 chalk catchments using redundancy analysis and hierarchical clustering. Three catchment typologies were identified: (1) large catchments, (2) headwater catchments with permeable soils, and (3) catchments with impermeable soils and surfaces (urban and suburban land uses). The literature suggests that natural flood management application is most effective for catchments <20 km2, reducing the likelihood of significant flood mitigation in large catchments. The relatively lower proportion of surface runoff and higher recharge in permeable catchments diminishes natural flood management’s likely efficacy. Impermeable catchments are most suited to natural flood management due to a wide variety of flow pathways, making the full suite of natural flood management interventions applicable. Detailed groundwater flood maps and hydrological models are required to identify catchments where NFM can be used in a targeted manner to de-synchronise sub-catchment flood waves or to intercept runoff generated via groundwater emergence. Whilst our analysis suggests that most chalk groundwater-dominated catchments in this sample are unlikely to benefit from significant flood reductions due to natural flood management, the positive impact on ecosystem services and biodiversity makes it an attractive propositio
- …
