bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conservation of freshwater fish in the British Isles: The current status and biology of threatened species
Authors: Maitland Peter S. , Lyle Alex A. 
Published: February 2007

Abstract1. The objective of this paper is to review the status of all freshwater fishes in the British Isles and to identify theatened species, races and communities which are in need of conservation.2. Using objective criteria to assess the degree of threat, two of the 55 freshwater species known in the British Isles are thought to be extinct here and eight are believed to be under significant threat.3. The biology of these ten species is reviewed. They are: Sturgeon Acipenser sturio, Allis Shad Alosa alosa, Twaite Shad Alosa fallax, Arctic Charr Salvelinus alpinus, Houting Coregonus oxyrinchus (extinct), Powan Coregonus lavaretus, Pollan Coregonus autumnalis, Vendace Coregonus albula, Smelt Osmerus eperlanus and Burbot Lota lota (extinct).4. In addition, there are several races of commoner species which are believed to be worthy of special conservation measures. These fish include the purely freshwater race of River Lamprey Lampetra fluviatilis in Loch Lomond, dwarf Brook Lampreys Lampetra planeri in the Inner Hebrides, spineless Three‐spined Sticklebacks Gasterosteus aculeatus in the Outer Hebrides and a number of important races of Brown Trout Salmo trutta in various waters in Ireland and Scotland.5. There is also a range of fish communities in individual rivers and lakes which merit conservation attention. These are important for a variety of reasons, including high (and very low) diversity, unique assemblages, pristine stocks and highly characteristic communities.6. The major threats to these species and communities include industrial and domestic pollution, acidification, land use changes, river barriers, drainage, fish farming, fishery management and the introduction of new species.7. The identification of these threatened fishes and important freshwater sites provides a foundation for a review of existing protection in the British Isles and a major fish conservation management programme. These will be described in subsequent papers.
European estuaries and lagoons: A personal overview of problems and possibilities for conservation and management
Authors: Barnes R. S. K. 
Published: February 2007

Abstract1. European estuaries and lagoons fall into three categories in respect of their conservation status and potential for ecological management. (i) Small lagoons, although greatly reduced by natural and man‐made changes to the coastal environment, are relatively easily recreated behind longshore shingle barriers, but natural colonization of such habitats may have ceased and successful artificial introduction of species or whole assemblages is hampered by lack of knowledge of the processes structuring natural lagoonal communities. (ii) Small estuaries require very little conservation management, only control of further human exploitation especially in respect of the siting of marinas and other recreational usage. (iii) Large estuaries are in many cases already altered beyond recognition, and such is their economic importance that it is unlikely that the pressures for further reclamation, impoundment, and development will be resisted. Nevertheless, it is may be possible to protect areas within each such estuarine system that could serve as staging posts for migratory birds.2. Integrated action is needed to assess the status and importance of the remaining European estuarine and lagoonal habitats, and to conserve and manage them in the future, if they are to continue to provide any significant habitats for organisms into the 21st Century and beyond.
Distribution of freshwater crayfish in the British Isles, with particular reference to crayfish plague, alien introductions and water quality
Authors: Holdich David M. , Reeve Ian D. 
Published: February 2007

Abstract1. The distribution of native and alien crayfish in the British Isles, based on records from 1970–1991, is figured at the 10 km square level and that for Britain is tabulated regionally.2. Since 1981 crayfish plague has been recorded from six catchments in Britain and one in Ireland, and suspected from an additional four catchments in Britain; 56.2% of native crayfish sites in Britain occur in catchments from which plague has been confirmed.3. Since the mid‐1970s approximately 300 signal crayfish implants have been made in Britain. Only 117 “successful” implants of signals are known to the authors; 39 crayfish farmers were registered in 1986 and 68 by 1990. In 1989 declared production was approximately 7 tonnes.4. Some mixed populations of natives and disease‐free signals exist. Evidence for exclusion of natives is being monitored.5. Signal crayfish are found in the flowing waters of seven catchments; 58.1% of native crayfish sites are located in catchments which support farmed and wild populations of signals. Some rapidly‐expanding Turkish crayfish populations are known, particularly in the Thames catchment.6. At least 87% of native crayfish records are from good quality waters.7. Native populations from 88.6% of sites recorded in Britain since 1970 have either been eliminated, or are directly threatened, by crayfish plague infection, and/or habitat invasion by signals, and/or pollution.8. The native crayfish was added to the list of species protected under the Wildlife and Countryside Act in 1986.9. Recommendations to assist in the conservation of the native crayfish include a ban on future imports of alien crayfish, a reassessment of records, the setting up of “no‐go” areas, the protection of isolated sites, and a restocking programme.10. There are many restrictedt, healthy populations of native crayfish in areas which could be protected by designating them as Sites of Special Scientific Interest (SSSIs).
A life table for powan, Coregonus lavaretus (L.) in Loch Lomond, Scotland: A basis for conservation strategy
Authors: Brown E. A. R. , Finnigan N. , Scott D. B. C. 
Published: February 2007

Abstract1. A static life table for Loch Lomond powan, Coregonus lavaretus (L.) has been constructed from data obtained during 1980–1988, as a basis for monitoring any changes in the population which may ensue from exploitation of the Loch.2. Mortality was 99.95% during the first year of life, and adult mortality highest at 5–6 years.3. Average fecundity was 20.7 ova mm−1 fork length.4. Mortality and fecundity have not changed in 25 years.5. It is not yet possible to assess the effect of the recent introduction of ruffe, Gymnocephalus cernuus (L.) into Loch Lomond, but their effect on recruitment into the vulnerable 0–1 year‐class may be critical.
Biotic score and prediction to assess the effects of water abstractions on river macroinvertebrates for conservation purposes
Authors: Armitage P. D. , Petts G. E. 
Published: February 2007

Abstract1. The possible impacts of abstraction of water from streams and rivers in the UK have generated concern in conservation bodies.2. This paper examines the feasibility of using biotic scores and predictions from the computer‐based RIVPACS system to assess the effects of abstractions on benthic fauna.3. Control and ‘impacted’ sites on 22 rivers which experienced abstractions for hydroelectric power generation, supply of drinking water (either directly or through groundwater abstraction), spray irrigation and fish farming, were examined.4. The ratios of observed to predicted biotic scores and comparison of observed fauna with that predicted by RIVPACS were used to assess the biological quality of the sites.5. Only 11 of the 51 sites on the 22 rivers showed signs of reduced environmental quality. These included eight sites on a small lowland stream which receives run‐off from fertilized agricultural land and is subject to spray irrigation; two sites on upland streams which had experienced severe spates prior to our survey and a small chalk stream, the Pang.6. Discharge, baseflow, substrate and altitude were factors which explained most of the variation in faunal parameters such as biotic score, numbers of species, numbers of families and total abundance.7. The main conclusions of the study are that upland streams did not appear to suffer adverse effects as a result of abstraction whereas lowland streams appeared to be more degraded, but with the exception of the Pang this could not necessarily be attributed to abstraction.8. Biotic scores with RIVPACS cannot be used to set ‘minimum ecological flows’ but can be used either directly, to assess site‐quality and to identify areas of concern which may or may not be related to abstraction; or indirectly, by reference to the RIVPACS data‐base to assess the conservation interest of invertebrate assemblages.
On the ecology of brackish water lagoons in Great Britain
Authors: Bamber R. N. , Batten S. D. , Sheader M. , Bridgwater N. D. 
Published: February 2007

Abstract1. Recent data on habitat characteristics and the animal and plant communities from 166 brackish lagoons in Great Britain have been analysed to interpret their community stucture and the environmental features important to maintaining the diversity of specialist lagoonal species.2. Lagoons supporting a diverse community of specialist species of restricted distribution are considered to be the most valuable in conservation terms.3. Lagoons are concentrated in the south and east of the country, are predominantly shallow with fine sand and mud sediments and cover a range of sea‐inlet types, areas and salinities (from zero to hyperhaline).4. The environmental characteristics of lagoons show more variability than those of ambient sea‐or estuarine water.5. Six suites of species are identified: freshwater species, stenohaline marine lagoonal specialists, euryhaline lagoonal specialists, estuarine species tolerant of lagoons, estuarine species incidental in lagoons and underrecorded species.6. The lagoons are categorized as freshwater sites and groups of saline sites of a range of conservation value in terms of their community, from high value sites dominated by stenohaline specialist species to sites supporting no specialist lagoonal community.7. The higher value sites are bar‐built or sluiced lagoons with a channel inlet, with salinities close to 35%0, a heterogeneous sediment, predominantly shallow and with larger area if narrow. Spatial density of lagoons may be important in recruitment of stenohaline specialist species, and frequent exchange of a proportion of the lagoon water with adjacent estuary or sea‐water may be important in maintaining requisite salinity.8. Aspects worthy of further study are identified.
Small scale sediment removal from beaches in Northern Ireland: environmental impact, community perception and conservation management
Authors: Carter R. W. G. , Eastwood David A. , Bradshaw Philip 
Published: February 2007

Abstract1. Small scale sand removal (loads of 0.5 to 10 tonnes) is a persistent environmental problem on beaches within Areas of Outstanding Natural Beauty in Northern Ireland.2. This study provides the first objective assessment of the problem in the British Isles, examining both the physical and biological impacts on the beach and the cultural background. These approaches are combined to indicate possible management strategies.3. About 5000 to 6000 tonnes of sediment (sand and gravel) was ‘drawn’ from the eleven beaches in the study area during 1990. The rate and magnitude of sediment removal varied between and within sites, by day of the week and by season.4. There are two direct impacts to the shoreline environment. First, over a long period, the amount of sediment removed is enough to cause serious erosion on some smaller beaches. Up to 80% of shoreline recession can be explained by sand lost through extraction. Second, extraction appears to lead to an impoverished beach fauna. More indirect impacts include the loss of aesthetic quality (important in an area reliant on tourism), disturbance of wildlife, damage to and possible reduction of access provision, and impairing the ability of the shoreline to develop foredunes.5. The views of the coastal community are quite polarized. One group (about 55%) wish to see sand removal cease, while the remainder (45%) do not. Interviews with people actually taking sand suggest that they do not see their actions as damaging the environment.6. Several options for future management are discussed. It would appear that a management prescription for each site, backed by legislation, might relieve the problem.
Seasonal and size‐related changes in the diet of perch, Perca fluviatilis L., in the shallows of an Australian river, and their implications for the conservation of indigenous teleosts
Authors: Pen L. J. , Potter I. C. 
Published: February 2007

Abstract1. Perca fluviatilis was sampled monthly over 2 years from the shallow waters (<2 m deep) of the Collie River in south‐western Australia to determine the diet of this introduced species and the extent to which it comprised indigenous fish species.2. As P. fluviatilis increased in size, its diet shifted from predominantly planktonic crustaceans to benthic invertebrates, with decapod crustaceans constituting between 55% and 88% of the volume of the food ingested by larger fish (> 120 mm long) in spring, summer and autumn.3. All size groups of P. fluviatilis fed on the small indigenous teleosts Edelia vittata and Bostockia porosa.4. The prevalence with which the different size groups of P. fluviatilis ingested indigenous fish species in the main channel of the river was as high as 14% in fish < 50 mm long in summer, 25% in fish 50–120 mm long in spring and 17% of fish > 120 mm long in autumn.5. Despite appreciable predation and a relatively high prevalence of P. fluviatilis, indigenous fish species have coexisted with perch in the Collie River since the early 1900s. Such coexistence has apparently been facilitated by a high density of invertebrate prey (as a result of eutrophication) and limited interspecific dietary overlap.6. The absence of E. vittata in those parts of a nearby river system now occupied by P. fluviatilis and the extremely high prevalence of fish that is sometimes found in P. fluviatilis stomachs, suggest that under certain extreme conditions, such as when a marked depletion in alternative food sources occurs, the presence of perch could pose a threat to the conservation of indigenous fish species in certain river systems in south‐western Australia.
The effects of riparian management and physicochemistry on macroinvertebrate feeding guilds and community structure in upland British streams
Authors: Rundle S. D. , Clare Lloyd E. , Ormerod S. J. 
Published: February 2007

Abstract1. Patterns in the community structure and feeding guild composition among macroinvertebrates in the margins and riffles of 66 streams in upland Wales and Scotland were appraised and related to site chemistry, physiography and riparian management. We aimed to assess the effectiveness of riparian strips of broadleaves and moorland/grassland in protecting stream communities and their trophic function during commercial forestry.2. The composition of macroinvertebrate communities in margins and riffles most strongly reflected stream pH and aluminium concentrations; acidic riffles contained fewest species of all major macroinvertebrate groups. However, the character of marginal habitats had some influence on communities in stream margins through the presence of broadleaf trees or moorland/grassland vegetation in the riparian zone. Even at low pH, streams with moorland riparian zones had different macroinvertebrates from those with pure conifer.3. Stream chemistry was important in explaining patterns among feeding guilds. Species richness and abundances of grazers and filterers were reduced at acidic sites with high aluminium concentrations. The number of shredder species was significantly lower in riffles at low pH than at high pH.4. In contrast, marginal habitat structure was of overriding importance in explaining patterns among collectors and predators. These functional groups were most abundant at sites with riparian zones of moorland and grassland, but scarce in streams where the bankside vegetation consisted of coniferous or broadleaved trees. Total grazer abundances were lowest at sites with riparian zones of pure conifer.5. We conclude that riparian management can modify effects of forestry on the trophic dynamics and structure of the macroinvertebrate communities of upland streams, but the effect operates within a strong gradient due to acidity. Thus, the array of macroinvertebrates which may benefit from riparian management in forest streams is liable to be restricted by low pH.6. We discuss the wider ramifications of riparian management for the conservation of streams during commercial forestry. In particular we assess if management proposals set out by the forestry industry are supported. We also discuss the problem of scale when considering measures implemented for stream conservation, emphasizing that the control of problems such as acidification may only be possible at a regional level.
Conservation of Hector's dolphins: The case and process which led to establishment of the Banks Peninsula Marine Mammal Sanctuary
Authors: Dawson S. M. , Slooten E. 
Published: February 2007

Abstract

Entanglement in gillnets constitutes the greatest known threat to populations of small cetaceans. In 1988, in response to data on the distribution and abundance, incidental catch, reproduction and population biology of Hector's dolphins, and after an extended period of public consultation, New Zealand's Department of Conservation created a 1170 km2 Marine Mammal Sanctuary. Within this area, gillnetting on a commercial scale is illegal and amateur fishers may only set gillnets in specific times and places.
This paper summarizes the salient points of research that led to the creation of the sanctuary, briefly describes the process by which the sanctuary was established, and offers some comments on the information required for conservation management of small cetaceans.
Effects of river regulation and diversion on marine fish and invertebrates
Authors: Drinkwater Kenneth F. , Frank Kenneth T. 
Published: February 2007

AbstractThe effects of freshwater regulation and diversion on the adult and larval stages of fish and invertebrates in coastal marine waters are reviewed.Potential impacts of river modification are highlighted based on our present understanding of the role of fresh water on the physical, chemical and biological processes on the marine environment. These include effects on migration patterns, spawning habitat, species diversity, water quality and distribution and production of lower trophic levels. The effect of dams on anadromous and catadromous fish are also presented.We discuss in detail the marine response to specific river regulation projects on the Nile, Indus and rivers flowing into the Black Sea, San Francisco Bay and James Bay in Canada. A decline in some coastal fisheries with an overall negative impact on the biota is generally associated with reductions in freshwater flow.Extensive ecological considerations are needed during the planning stage of large‐scale freshwater modification projects to minimize potential impacts.
Classification of river corridors: Issues to be addressed in developing an operational methodology
Authors: Gurnell A. M. , Angold P. , Gregory K. J. 
Published: February 2007

AbstractThe classification of river corridors may simply aim to describe what is there in a concise form or it may form a tool to support the assessment of conservation or enhancement potential and management decision‐making.An analysis of 140 international publications on river corridor classification illustrates temporal trends towards (i) multidisciplinary bases for classification related to (ii) increasingly small spatial units and spatially hierarchical structures, with (iii) the majority of the schemes being developed in North America and most of the remainder generated within Europe.An operational classification scheme that is robust and widely applicable will be based on a wide range of information types with a hierarchical structure incorporating different types and resolutions of information suitable to support classifications for different applications.In developing an operational scheme, spatial units for data handling must be defined which present a compromise between the natural boundaries representative of the character of the river corridor, and the environmentally arbitrary boundaries which often define the spatial units against which environmental data sets have been collected.A variety of data sources may support classification, including routine field surveys and laboratory determinations, thematic maps and remotely sensed information. Different sources present different problems of spatial resolution, generalization, age and changing data standards.Problems arise when data from different sources are integrated to derive a classification. GIS provides a flexible technology for such integration but the results may be misleading if GIS functions are not used intelligently. Data handling should (i) maintain separation between raw data and their derivatives, (ii) apply spatial aggregation or smoothing of data to a consistent spatial resolution prior to integration, and (iii) the spatial resolution selected should be appropriate for the hierarchical level to which it applies.
Imminent extinction of the Nore freshwater pearl musselMargaritifera durrovensisPhillips: A species unique to Ireland
Authors: Moorkens Evelyn A. , Costello Mark J. 
Published: February 2007

AbstractThe last population of the Nore freshwater pearl musselMargaritifera durrovensiswas surveyed each year from 1990 to 1994 in the River Nore, southern Ireland.The population has fallen from a ‘flourishing colony’ in the 1920s to an estimated 2000 in 1990 and 420 in 1994. No juvenile mussels were observed in any of the surveys.If life history data forMargaritifera margaritiferaare applicable toM. durrovensis, the population would need to be 20 times greater for successful recruitment.Although given special mention in the Bern Convention,M. durrovensiswas omitted from the European Union Habitats Directive, perhaps due to uncertainty regarding its taxonomic status as it shares characteristics with bothM. margaritiferaandM. auricularia.Immediate measures are required to prevent the extinction ofM. durrovensisincluding, (a) a captive breeding programme, (b) habitat restoration, and (c) formal recognition of its priority status within the Habitats Directive.