bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Linguatula serrata Infestation in Stray Dogs of Shahrekord, Iran
Authors: Meshgi B. , Asgarian O.
Published: November 2003

The present study was undertaken to determine the prevalence of pentastomid parasites in stray dogs between 16 November 2002 and 16 April 2003 in Sahrekord from Chaharmahalobakhtiari province, Iran. A total of 143 stray dogs were shot and the heads were longitudinally sectioned to expose the nasal cavity, and worms, if any, were carefully removed. Adult Linguatula serrata were found in the nasal cavities of 89 (62.2%) dogs. The infestation rate was 67.4 and 53.7% in males and females, respectively. The examined dogs were divided into three age groups: 1–2, 3–4 and up to 5 years old. There was a significant relationship between age and infestation rate with L. serrata (P < 0.01). The highest rate of infestation was in the second group. The number of parasites in each dog varied from one to 29 and totally 382 adult parasites were collected of which 219 were female (57.3%) and 163 were male (42.7%). Adult L. serrata were registered for the first time from dogs in Iran. This study indicates that infestation with L. serrata occurs commonly in stray dogs of this region in Iran.
Tetracycline Resistance in Staphylococci from Free‐living Rodents and Insectivores
Authors: Hauschild T. , Kehrenberg C. , Schwarz S.
Published: November 2003

One hundred and fifty‐eight staphylococcal strains isolated from wild rodents and insectivores were analysed for plasmid‐borne resistance to tetracycline (Tc). Only 10 isolates, sixStaphylococcus saprophyticusisolates and single isolates ofS. xylosus, S. equorum, S. warneriandS. cohniisubsp.cohniicarried a Tc resistance plasmid of approximately 4.4 kb as confirmed by protoplast transformation. All 10 plasmids harboured a Tc resistance gene of hybridization class K [tet(K)] as confirmed by polymerase chain reaction (PCR). The plasmid was assigned to the pT181 family as it revealed a high degree of restriction map homology to pT181 and other members of this family. Macrorestriction analysis with the enzymeSmaI showed that three of the six isolates identified asS. saprophyticusshared the same pulsed‐field gel electrophoresis (PFGE) pattern.
Services for pre‐school children with behaviour problems in a Midlands city
Authors: Coe C. , Spencer N. , Barlow J. , Vostanis P. , Lainé L.
Published: November 2003

Objectives  To study the services for pre‐school children with behaviour problems in a Midlands city and the level of co‐ordination and co‐operation between providers.

Setting  A socially and ethnically diverse Midlands city in the UK.

Methods  Survey methods were employed with city health visitors in order to determine their role and identify service providers. Service providers from different agencies were interviewed and data collected related to service offered, materials used, theoretical basis of interventions, referrals to and from the service, inclusion and exclusion criteria and co‐ordination and co‐operation with other providers. Themes were identified related to the content and process of the services using qualitative data analysis methods. Frequencies of themes were estimated for different provider groups.

Results  Health visitors and nursery nurses working in the primary care services were the primary point of contact for children with pre‐school behaviour problems. Nursery nurses were one of the major sources of referral for children with pre‐school behaviour problems and a significant majority of these providers had not received any specific training for this role. The majority of the providers used evidence‐based programmes but few adhered strictly to a particular programme and instead used a mixture of materials drawn from different programmes. Many health service providers in particular offered interventions to parents on a one‐to‐one basis only. Most providers used behaviour modification approaches. While many providers claimed to have knowledge of other local providers and have good links, there was little evidence of co‐ordination within and between agencies.

Conclusions  While there appears to be high levels of activity by providers from both statutory and voluntary sectors in providing services for pre‐school children with behaviour problems, there is evidence to suggest that some of the main providers of services are not being adequately prepared and supported in the role. There is a lack of co‐ordination within and between services, and indication that evidence‐based programmes are being modified and used in an ad hoc manner. It is concluded that surveys of this nature may be an important preliminary step in establishing co‐ordinated services for the primary and secondary prevention of pre‐school behaviour problems.
Patterns of smoking, quit attempts and services for a cohort of 15‐ to 19‐year‐olds
Authors: Grimshaw G. , Stanton A. , Blackburn C. , Andrews K. , Grimshaw C. , Vinogradova Y. , Robertson W.
Published: November 2003

Objectives  To establish patterns of smoking among 15‐to 19‐year‐olds within mixed urban and suburban area and explore preference for the nature of services to assist quitting.

Design  Postal survey and depth interviews with focus group validation.

Setting  People registered with health services in the Borough of Solihull, UK. The borough has a diverse population with areas of high deprivation to the north and a range of prosperity elsewhere.

Participants  Questionnaires were sent to 50% of those registered and 20 people interviewed aged from 15 to 19 years.

Main outcome measures  The survey contained demographic questions relating to educational attainment and family, smoking status, history and quit attempts, use of facilities for quit attempts. Qualitative themes explored attitudes and experience of quitting, utilization of cessation services, barriers to access and nicotine replacement therapy.

Results  Total survey response rate was 32.6%. Three in five reported smoking a cigarette sometime, 17.2% current regular smokers, 7.2% current occasional smokers. Median age of starting smoking was significantly lower (P = 0.004) for current regular smokers, distinguishable in two groups; weekend smokers and all week smokers. More quit attempts had been made or planned by current regular smokers but were often short lived. Weekend smokers had a slightly longer duration of quitting (P = 0.03). Eight‐two per cent were optimistic about quitting in the future although the majority (80%) had already made one quit attempt. Knowledge and use of existing services was poor, with concerns about privacy and confidentiality. Models based on autonomy were identified as potentially useful.

Conclusion  Teenage smoking is characterized by optimism about quitting despite the failure of many quit attempts, lack of regard for existing services and barriers to uptake.
Overnight deep body temperature and urinary cortisol excretion in infants from economically deprived areas
Authors: Wailoo M. P. , Westaway J. A. , Joseph D. , Petersen S. A. , Davies T. , Thompson J. R.
Published: November 2003

Objectives  To assess the pattern of postnatal physiological maturation in economically deprived infants by measuring the age‐related changes in deep body temperature during night‐time sleep.

Setting  Inner city Leicester, UK.

Participants  Forty‐eight infants aged 6–21 weeks from economically deprived areas and 87 control infants from more affluent areas.

Outcome measures  Average deep body temperature between 2 and 4 h after bedtime, overnight and early morning urinary cortisol excretion.

Results  Both groups showed a decline in overnight deep body temperature with age that averaged 0.030°C per week (SE = 0.003). Over the age range studied, the average age‐adjusted overnight temperature in the infants from deprived homes was 0.090°C (SE = 0.028) higher than that for the affluent group (P = 0.001). Deprived infants had on average 51% higher overnight urinary cortisol and 80% higher morning cortisol. The differences remained when the effects of room temperature, clothing, smoking, birthweight and gestational age were taken into account.

Conclusion  These indicators of postnatal physiological maturation suggest that infants from economically deprived homes mature less quickly. This might increase their vulnerability to illness.
Parental views about services for children attending schools for the emotionally and behaviourally disturbed (EBD): a qualitative analysis
Authors: Crawford T. , Simonoff E.
Published: November 2003

Aim  This study examines the views of parents of children attending schools for the emotionally and behaviourally disturbed (EBD). The study aims to gain an understanding of the journey through the educational system taken by these children and to explore their families’ experience of services along the way.

Methods  Thirty parents of 25 children attending primary and secondary EBD schools in three South London boroughs took part in focus group discussions. Parents were asked about their experiences of services, including educational, health and social services, as well as how they thought services should be improved.

Results  Qualitative analysis identified a complex web of individual, professional and organizational factors which contributed to social exclusion of children with EBD problems and their families. These factors included children receiving inadequate education because of long periods of exclusion or inappropriate placements whilst waiting for a statement of special educational needs. Parents also felt personally socially excluded because of lack of childcare provision out of school hours. Many parents felt that their children did not fit into services and were constantly being passed on to other professionals. The analysis identified aspects of services that promote social inclusion and provide support to families, including acceptance of children into EBD schools, help from voluntary organizations and support from other parents with children with EBD problems. Parents particularly stressed the value of working in collaboration with professionals to achieve shared goals.

Conclusion  EBD schools provide a valuable resource for parents. However parents often lack emotional and practical support in coping with their children's complex needs. Agencies need to improve communication and joint working to provide effective services for these families.
Negotiating deaf–hearing friendships: coping strategies of deaf boys and girls in mainstream schools
Authors: Martin D. , Bat‐Chava Y.
Published: November 2003

Background  Increasingly, deaf students are educated in mainstream school environments. This poses a question of how deaf children negotiate the demands of forming friendships with their hearing peers. The present study was designed to examine coping strategies of 35 deaf children attending full or partial mainstream school settings.

Method  Using a qualitative analysis design, a range of coping strategies used by the children was described based on parents’ reports. The relative success of these coping strategies in establishing relationships with hearing peers was assessed by examining strategies that increased the social success of deaf girls and boys.

Results  The results showed differences by gender in the effectiveness of coping strategies used by the participants. Deaf girls who were confident and frequently asked for clarifications or who were comfortable playing alone tended to achieve good relationships with hearing peers. In contrast, deaf boys’ relationships with hearing peers benefited mostly from the boys’ ability to perform well in sports.

Conclusions  These findings are discussed in light of existing research on coping and current debates on the benefits of mainstreaming for deaf children.
A focus group investigation into young children's understanding of mental health and their views on appropriate services for their age group
Authors: Roose G. A. , John A. M.
Published: November 2003

Background  Children's views about mental health and concurrent service provision are under researched areas. Yet there is concern regarding appropriate service development to meet the increasing mental health needs of children and young people. Recent government policy underlines the need for collaborative work with consumers in service development.

Method  This was a qualitative study designed to explore 10‐ and 11‐year‐old children's understanding of the concept of mental health and their opinions regarding an appropriate service for their age group. Two focus groups were conducted with 10‐ and 11‐year‐old children and the data was analysed using Interpretative Phenomenological Analysis.

Results  The participants showed a sophisticated understanding of mental health. The participants thought that school‐based services would not be appropriate for their age group.

Conclusion  The participants demonstrated that their level of understanding and interest qualifies them for a place in discussions about services for their age group. Collaborative work with children and young people in line with government policy in this area is necessary for appropriate service development.
Responses of natural enemies to experimentally increased populations of the forest tent caterpillar, Malacosoma disstria
Authors: PARRY DYLAN , SPENCE JOHN , VOLNEY W.
Published: November 2003

1. The responses of predators and parasitoids to increased forest tent caterpillar populations were studied by introducing eggs to two trembling aspen, Populus tremuloides Michx., forests where natural populations were at very low density.

2. Of five parasitoid species recovered, only the braconid Aleiodes malacosomatos (Mason) and the tachinid Patelloa pachypyga (Aldrich & Webber) exhibited spatially density‐dependent responses, in dry upland forest and mesic lowland forest, respectively. Forest type restrictions on the abundance of these species and the weak density‐dependent response by A. malacosomatos suggests that parasitoids may not be capable of regulating low‐density tent caterpillar populations.

3. Predation of final‐instar larvae and pupae by birds, in particular the northern oriole, Icterus galbula (L.), virtually eliminated the experimental populations. Avian predation was widespread and dominated mortality at all densities.

4. Implications for the initiation of outbreaks of cyclic defoliators are discussed.
Contact with the host plant enhances aphid survival at low temperatures
Authors: BUTTS R.A. , HOWLING G.G. , BONE W. , BALE J.S. , HARRINGTON R.
Published: November 2003

1. The hypothesis, suggested by previous studies, that host plant contact reduces the cold tolerance of anholocyclic aphids was tested under laboratory conditions. Adult and first‐instar Rhopalosiphum padi (L.) were exposed to temperatures of 0, –5 and –10 °C on intact plants, excised leaves and in the absence of contact with plant material.

2. Median lethal time (LT50) values at all three temperatures indicate that aphids exposed in association with plant material survive longer than aphids that have no contact with their host plant. The difference in survival was most pronounced at –10 °C. Therefore, the above hypothesis is rejected for aphids on cereals because host plant contact apparently enhances cold tolerance.

3. Exposure on excised leaves also enhanced aphid survival at low temperature but was less effective than the intact plant. This suggests that plant quality as well as the presence or absence of plants is important in the cold tolerance of aphids on cereals.
Survival and habitat preferences of adult Bolitophagus reticulatus
Authors: TORBJÖRN NILSSON
Published: November 2003

1. Data from a 4‐year mark–recapture study of the fungivorous tenebrionid beetle Bolitophagus reticulatus at a locality in central Sweden and a trapping study of the species elsewhere in the same region are used to describe the survival and habitat preferences of the species.

2. The adult beetle was found to survive for up to three winters. A minimum estimate of the yearly survival rate was 0.20.

3. The beetle was found to occur preferentially on tree trunks that were either standing or lying but only touching the ground along a minor part of their length; that were relatively thick; and that carried many Fomes fomentarius sporocarps. In contrast to previous information for this species, the beetle was found to use living sporocarps to a large extent, and not only dead ones.

4. An experiment with beetles given a choice between living and dead fungus tissue indicated that pairs of one male and one female beetle preferred living fungus while single beetles preferred dead fungus.
Influence of the hyperparasitoid Dendrocerus carpenteri on the reproduction of the grain aphid Sitobion avenae
Authors: BOENISCH ANKE , PETERSEN GERT , WYSS URS
Published: November 2003

1.Alate S. avenae (F.) reproduced earlier and produced more offspring in the vicinity of Dendrocerus carpenteri (Curtis) females than control aphids without neighbouring hyperparasitoids.

2. This effect was evident only during the first 6 days of the aphid’s reproduction period and did not affect the physiological condition of the aphids or their offspring.

3. Virgin hyperparasitoid females had a stronger influence on the reproduction rate of the aphids than did mated females, probably due to an unidentified emitted volatile sex pheromone.
Coincidence between consumer and host occurrence: macrolepidoptera in Britain
Authors: QUINN RACHEL , GASTON KEVIN , ROY DAVID
Published: November 2003

1. The interspecific relationship between the distributions of consumers and resources is examined, using data for macrolepidoptera (moths) in Britain.

2. Monophagous moth species feeding on host plants with small geographical ranges also have small ranges, whilst those feeding on host plants with large ranges may have small or large ranges themselves. Likewise, there is an approximately triangular relationship between the proportion of the range of its host that a monophagous moth occupies and the size of the host range.

3. Most monophagous moths occupy a small proportion of the range of their host, and only feed on hosts that have relatively large geographical ranges.

4. Factors determining both the range size of a monophage and the proportion of the host plant’s range that it occupies are independent of taxonomy.

5. Monophages tend to have smaller geographical ranges than congeneric polyphages, but do not occupy a smaller proportion of the ranges of the plants that they consume.
Genetic variation in resistance and tolerance to insect herbivory in Salix cordata
Authors: SHEN CYNTHIA , BACH CATHERINE
Published: November 2003

1. This study investigated whether sand‐dune willow Salix cordata, exhibits genetic variation in resistance and tolerance to herbivory.

2. A field experiment using cuttings from nine willow clones demonstrated genetic variation in resistance to the specialist herbivore Altica subplicata, as measured by beetle densities. Willow clones differed significantly in both total biomass and leaf trichome densities, and herbivore densities were marginally correlated with both of these parameters.

3. Tolerance to herbivory was measured in a greenhouse experiment by comparing growth response of plants experiencing 50% artificial defoliation and plants experiencing no defoliation. Clones showed significant differences in tolerance to herbivory for some growth measures (changes in height and number of leaves), but not for other growth measures (stem diameter growth and final biomass).

4. Despite the significant genetic variation in both resistance and tolerance, no trade‐off was found between resistance and tolerance to herbivory.
HLA‐B44 ALLELE FREQUENCIES AND HAPLOTYPIC ASSOCIATIONS IN THREE EUROPEAN POPULATIONS
Authors: VIDAN‐JERAS B. , BREUR‐VRIESENDORP B. , BOHINJEC M. , JEANNET M. , ROOSNEK E. , TIERCY J.‐M.
Published: November 2003

HLA‐B44 is among the most frequent class I antigens in many populations studied so far. It has been subdivided into seven allelic forms that can only be discriminated by DNA typing. Using a simple PCR/sequence‐specific oligonucleotide hybridization procedure, we have analysed the frequency distribution of B44 subtypes in three European populations from Slovenia, the Netherlands, and Switzerland. B*4402 and B*4403 were by far the predominant alleles, B*4404 and 4405 were rare, while B*4406 and B*4407 were not observed. Interestingly, B*4402 and 4403 occurred with different frequencies in the three populations, with B*4402 being most frequent in the Swiss (65% vs. 57% in the Dutch, and 46.5% in the Slovenes). Of the 139 individuals studied, 60 HLA‐B44 ABDR haplotypes could be determined by family studies. In the respective populations, the linkage disequilibria between B44 and other HLA antigens occurred with different frequencies. A2‐B*4402 haplotypes were very frequent in the Swiss sample, mostly associated with DRB1*0101, 0401 and 1301. B*4402 was more often linked with non‐A2 antigens in the Slovenes (predominantly A24, A28) than in the Swiss and the Dutch. The predominant association of B*4403 was with DR7: this haplotype was very frequent in the Swiss (82% of the B*4403 haplotypes), while lower frequencies were found in the Dutch (72%) and Slovenian (59%) populations. In the Swiss population, more than half of the B44‐DR7 haplotypes were A23‐B*4403‐DR7 (53% of all B*4403 haplotypes). This haplotype was significantly less frequent in the Slovenian (6%) and in the Dutch (14%) populations. The second most frequent B*4403 haplotype in both the Swiss and Slovenes is the A29‐B*4403‐Cw*1601‐DR7 haplotype (17.6 and 29.4%, respectively). Concomitant with the increased frequency of B*4403 in the Slovenes, a higher diversity of non‐DR7 B44 haplotypes was observed in this population (41% of all B*4403 haplotypes).

HLA‐B44 oligotyping analysis allowed us to detect B44‐subtype incompatibilities in several AB‐sero, DRB1/B3/B5‐oligo matched unrelated bone marrow donor/patient combinations. The different frequency distributions of HLA‐B44 haplotypes in the three populations analysed in this study argue in favour of local volunteer bone marrow donor recruitment. This might significantly improve the chance of finding a highly matched donor for patients with less frequent A‐B‐DRB1 haplotypes.
Estimating critical state soil mechanics parameters from constant cell volume triaxial tests
Authors: Kirby J. M. , O'sullivan M. F. , Wood J. T.
Published: November 2003

Compaction, tillage, stresses around growing roots and other soil deformation events may be predicted by the critical state model of soil mechanics, but estimating the parameters is time consuming and expensive. We develop a back analysis of the constant cell volume triaxial test, in which the critical state parameters are derived from the results of a single test. This both saves much labour and provides more information than traditional analyses, which require several triaxial compression tests and an isotropic compression test to yield the same information. The method finds, using a minimization algorithm and a quasi‐analytical solution to the stress–strain equations, the simulated soil deformation (and hence the properties used in that simulation) that best fits the test data. The minimization is a form of regression analysis.

For normally consolidated samples the method provides stable estimates of the slope of the critical state line (M), the slope of the virgin compression line (λ) and elastic modulus (E). The standard errors of the estimates are small in relation to the means of these parameters. The estimates appear to be more reliable than those of more commonly used estimation procedures. The slope of the rebound line (κ) is estimated, but a measure of the accuracy of the estimate cannot be calculated.
Fishing strategies, fishery development and socioeconomics in traditionally managed Fijian fishing grounds
Authors: JENNINGS S. , POLUNIN N.V.C.
Published: November 2003

Increasing urban drift of the Fijian population coupled with an increasing proportion of Fijians in full time employment has led to escalating demands for fish and an associated rise in fish prices. Traditionally‐managed reef fisheries are now exploited to meet existing subsistence needs and to supply large urban markets. The fishing strategies employed by three fishing communities were compared at different stages of their development from primitive to market economies. It was suggested that the fishing‐rights owners have expanded their fisheries for economic gain, but that such expansion has, to date, had minimal impact on favoured fishing tactics and management regimes. However, the socioeconomic impact of the transition to a market economy is profound, with increasing reliance upon income from the fishery.
The use of alizarin complexone for immersion marking of the otoliths of embryos and larvae of the turbot, Scophthalmus maximus (L.): dosage and treatment time
Authors: IGLESIAS J. , RODRÍGUEZ‐OJEA G.
Published: November 2003

The purpose of this work was to determine the efficacy of marking turbot, Scophthalmus maximus (L.), eggs and larvae with alizarin complexone (ALC) for use in enhancement programmes and in studies of the ecology and behaviour of the species. The main aim was to determine the optimum dosage and treatment time for large batches of larvae destined for release into the sea.Eggs and larvae were immersed in a range of ALC concentrations (0–60 mg L–1) for various times (3–24 h). On day 8 after hatching, eggs marked with the different ALC dosages had 99% marking success and had mainly good‐quality or very‐good‐quality marks, whereas larvae achieved 100% success and had mainly very‐good‐quality marks. The best results were obtained after marking larvae with ALC at 60 mg L–1 for 6–24 h.During the first months after marking, the fluorescent rings formed in the otoliths were easily detected when directly examined with a UV microscope, no prior preparation of the otoliths was necessary, but after 7 months the marks become faint as the otoliths get thicker, so it is necessary to cut or polish the otoliths before examination.
Changes in water quality within anglers’ keepnets during the confinement of fish
Authors: POTTINGER T.G.
Published: November 2003

The influence of mesh size and loading density on conditions within keepnets during the confinement of fish was examined. The performance of a mixed‐mesh net was also evaluated. Confinement of fish within nets of a standard diameter and length and of three different mesh sizes for 5 h resulted in no deleterious changes in levels of dissolved oxygen, un‐ionized ammonia, carbon dioxide, or pH at any of three sample points within each net. Transfer of fish to similar nets at a similar, and a higher, loading for 5 h resulted in a depletion of oxygen, and accumulation of ammonia, in the high‐load nets. No changes in carbon dioxide levels or pH were observed in nets containing either moderate or high loads. Confinement of fish in mixed‐mesh nets for 5 h resulted in a depletion of dissolved oxygen in the lower section of the net and an accumulation of un‐ionized ammonia. There were no changes in carbon dioxide or pH. These results are discussed with reference to the water quality requirements of freshwater fish. It is concluded that changes in water quality within anglers’ keepnets during the confinement of fish are not of sufficient magnitude to adversely affect the confined fish.
Effects on growth and survival of retention of rod‐caught cyprinids in large keepnets
Authors: RAAT A.J.P. , KLEIN BRETELER J.G.P. , JANSEN S.A.W.
Published: November 2003

The long‐term (about 2 months) mortality and the growth of five species of cyprinids retained and not retained in large keepnets (490 L, 2.5 mm mesh, knotless netting) were determined in drainable ponds. All experiments were carried out at least in duplicate. No statistically significant difference was found in mortality and growth between fish that were kept in the keepnets and fish that did not undergo this treatment. Differences in growth and mortality were related to fish species and season. No effect of retention time in the keepnet on mortality and growth was observed. No statistically significant difference in mortality and growth was found between bream, Abramis brama (L.), captured by anglers and the controls. Also, no differences were found in mortality and growth of rod‐caught bream retained in keepnets and rod‐caught bream that did not undergo this treatment. No statistically significant effect of lifting of the keepnets could be determined.

Based on the available evidence, it was concluded that the holding of rod‐captured cyprinids in a small keepnet may cause temporary adaptations to the behaviour and physiology of the fish. Depending on the type and size of the keepnet, the material and the mesh of the netting, loss of scales and secretion of mucus may take place. The data from experiments with large keepnets do not show irreversible changes, leading to decreased fitness and ultimately to death of the cyprinids.
Stomach contents of trout, Salmo trutta L., caught by angling on Loch Dee, an acid water in south‐west Scotland PH16 5LB.
Authors: MORRISON B.R.S.
Published: November 2003

The stomach contents of 459 rod‐caught brown trout, Salmo trutta L., collected over a period of 7 years from Loch Dee, an acid water in south west Scotland, were identified. The relative importance of each item was assessed volumetrically. The range of taxa available to the fish was limited because of the loch’s acidity (annual pH means 5.1–5.6) but up to 25 taxa were recorded in the stomachs. Ephemeroptera nymphs, Trichoptera pupae and terrestrial insects formed the greatest bulk, but chironomid larvae and pupae were found in almost half the stomachs. Among the zooplankton, Bythotrephes longimanus was the most abundant species in the samples despite its scarcity (less than 1% of animals in net samples). Despite the adverse conditions of water chemistry and limited range of food, the loch is able to support a regular trout fishery.
Winter distribution and habitat use by fish in a regulated lowland river system of south‐east England
Authors: PILCHER M.W. , COPP G.H.
Published: November 2003

The macrohabitat preferences of 1+ fish (10 cm FL) and the microhabitat use of 0+ juvenile fishes in the River Lee catchment (UK) were examined from data collected over a 3‐year period between late autumn and early spring using depletion sampling and point abundance sampling, respectively. Canonical correspondence analysis and habitat profiles revealed preferences in the more rheophilous fish species (e.g. brown trout, Salmo trutta L., barbel, Barbus barbus (L.)) for features characteristic of upstream natural channels and meander sections of the by‐passed old river, with the more ubiquitous (e.g. perch, Perca fluviatilis L.) and limnophilous fishes [e.g. pike, Esox lucius L., tench, Tinca tinca (L.)] preferring habitats mainly in downstream channelised stretches. The microhabitat of 0+ juvenile fishes in the River Lee was similar to that reported elsewhere for the same species, influenced mainly by channel width, depth, and distance from the bank, though microhabitat overlap in 0+ roach, Rutilus rutilus (L.), and gudgeon, Gobio gobio (L.), was greater in the Lee than observed in larger, more open river systems.
Comparative behaviour and dietary effects in early life phases of American sturgeons
Authors: ROSS R.M. , BENNETT R.M.
Published: November 2003

Experiments were conducted with the larvae and early juveniles of three species of sturgeon to determine effects of diet and development on swimming and foraging behaviour as well as depth distribution in 100‐L aquaria. About 500 hatchlings were placed in each tank with two or three replicates of three or six diet treatments, including live and dry feeds. Eight types of swimming or foraging activity were recorded with a lap‐top event recorder and with fish counts in three depths of water. Analysis of variance showed live diets resulted in greater foraging activity in upper water horizons than most dry diets for Atlantic sturgeon, Acipenseroxyrhynchus Mitchill. Scouring, a foraging activity, differed among diet types in early juvenile lake sturgeon, A. fulvescens Rafinesque. Developmental effects included early peaks in the performance of swim‐up for all species and swim near surface for two of three species. Postlarvae (post‐yolk‐sac larvae) of shovelnose, Scaphirhynchusplatorhynchus (Rafinesque), and Atlantic sturgeon swam inverted, an apparent foraging tactic associated with elevated or air‐water surfaces. Postlarvae maintained (lake sturgeon) or shifted to (other species) bottom swimming with increased scouring activity. Shovelnose early postlarvae occupied higher average water‐column heights than lake or Atlantic sturgeon. Shovelnose (only species tested) postlarvae showed greater activity in upper water horizons at night. These results suggest a fundamental shift to benthic foraging during the postlarval phase, with shovelnose sturgeon continuing to forage in suprabenthic zones to a greater degree than the other two species.
A test of crayfish predatory and nonpredatory fish species as bait in crayfish traps
Authors: TAUGBØL T. , SKURDAL J. , BURBA A. , MUNOZ C. , SÁEZ‐ROYUELA M.
Published: November 2003

The effectiveness of different crayfish: predatory (pike, Esox lucius L., perch, Perca fluviatilis L.) and nonpredatory [roach, Rutilus rutilus (L.), and bream, Abramis brama (L.)] fish species as bait for noble crayfish, Astacus astacus L., was tested. Trapping was conducted in two lakes in Norway and Lithuania. Nonpredatory bream and roach were superior as noble crayfish bait compared with predatory perch and pike. In the Norwegian lake bream was also superior to roach. Pike‐ and perch‐baited traps tended to catch larger crayfish than bream‐ and roach‐baited traps. An alarm or avoidance response to different live or dead fish predators (e.g. pike or perch) might exist and could be more pronounced in smaller crayfish, thus explaining that pike and perch as bait catch fewer and larger crayfish. Another explanation could be that the odour of pike and perch flesh is simply less attractive or diffuses more slowly through the water. Selecting the most efficient bait will increase the catch per unit effort (CPUE); in this study there was a four‐fold variation in CPUE between the best and worst bait type. In test‐fishing/monitoring surveys it is important to standardize the bait type used.
A retrospective assessment of the flow regulation of the West Salmon River, Newfoundland, Canada
Authors: SCRUTON D. A. , LEDREW L. J.
Published: November 2003

The Upper Salmon Hydroelectric Project in central Newfoundland, Canada, constructed in the early 1980s, affected the hydrology of the West Salmon River, a major spawning and juvenile rearing river for landlocked Atlantic salmon, Salmo salar L., and brook trout, Salvelinus fontinalis (Mitchill). A controlled flow release strategy, based on Tennant’s Montana method, was developed to protect this habitat and prescribed a release of 40% of the mean annual flow (MAF) (2.6 m3 s–1) between 1 June and 30 November and 20% of the MAF (1.3 m3 s–1) from 1 December to 31 May. Studies were conducted to assess the impact of river regulation including: (1) a post‐impoundment evaluation of the anticipated geomorphic and sedimentary characteristics; (2) monitoring of juvenile fish populations under regulation; and (3) a retrospective IFIM (instream flow incremental methodology) assessment. Studies provided evidence of the initial stages of river aggradation. Biological monitoring found no apparent effects of sediment deposition on spawning and egg incubation. However, densities of older age classes (parr, 1+ and greater) declined under regulation, possibly related to poor overwintering conditions under the lower winter flow. IFIM study results supported these observations and indicated that the prescribed flow regimen provided habitat conditions that would benefit salmon fry more than older age classes. This retrospective assessment suggested that future proposals for flow regulation in Newfoundland should consider the need for more dynamic flow management as well as to provide overwintering habitat for resident fish. Habitat–hydraulic models are preferred to standard setting approaches owing to more detailed analysis of habitat trade‐offs as related to flow regulation.
Preliminary study on the fishery resources of the River Niger in the Upper Niger National Park, Guinea
Authors: CRESPI V.
Published: November 2003

A survey of fishing activity, main fishing methods and fish species composition in the upper River Niger enabled current fishing effort, seasonal yield and its economic value to be assessed. Fishing is a traditional activity, supporting part of the regional economy, and an important animal protein source for local people. The catches, 63 fish species included in 20 different families, confirmed the high biological diversity present in the River Niger. Sixteen main fish species were identified as the most important by weight in the commercial captures. Fishing methods used are very selective. The catch is mainly large fishes, and only a low percentage of juvenile specimens is present in the catch, suggesting there is no overfishing of the exploited fish stocks.
Identification of juvenile hilsa in Bangladesh by genetic methods
Authors: RAHMAN M. , NÆVDAL G.
Published: November 2003

Knowledge of the biology and ecology of anadromous populations of the hilsa [or hilsa shad], Tenualosa ilisha (Hamilton), indicates that the juveniles are the same fish that is known locally in Bangladesh as ‘jatka’. However, this view is not always accepted by fishermen and management authorities. To confirm the status of jatka, samples were taken from inland waters, mostly from its known nursery grounds, and the genotypes and genotype distributions were compared with previous analyses of adult hilsa. With one exception, all jatka samples displayed the same patterns as adult hilsa, and the distributions of genotypes of the polymorphic systems PGM, AAT, EST (two loci) and UMP were in fairly good accordance between adult and juveniles from the same areas.
Interannual–interdecadal variations in zooplankton biomass, chlorophyll concentration and physical environment in the subarctic Pacific and Bering Sea
Authors: SUGIMOTO TAKASHIGE , TADOKORO KAZUAKI
Published: November 2003

Interannual, decadal and interdecadal variations in summer plankton biomass during 1954–1994 in the whole subarctic Pacific and Bering Sea were compared among regions as well as with climatic and oceanographic conditions. The zooplankton biomass and chlorophyll concentration during the mid 1960s to early 1970s in the central and western subarctic Pacific were a few times higher than those in the preceding and following decades. The values in the eastern Bering Sea and eastern subarctic Pacific also increased in the mid 1960s, but remained at an elevated level until the end of the 1980s. These decades of higher and mid plankton biomass levels during the mid 1960s to early 1970s and mid 1970s to late 1980s correspond to the period of positive and negative values of the Northern Hemisphere zonal index (NHZI), respectively. In the decadal scale, one can see a significant positive correlation between the summer plankton biomass and the wind speed during winters in the eastern Bering Sea. The effect of grazing by biennially fluctuating Asian pink salmon on zooplankton biomass and its effect on chlorophyll concentration in the central subarctic Pacific is also significant.
Variability in timing and magnitude of spring bloom in the Oyashio region, the western subarctic Pacific off Hokkaido, Japan
Authors: KASAI HIROMI , SAITO HIROAKI , YOSHIMORI AKIRA , TAGUCHI SATORU
Published: November 2003

The spring bloom of phytoplankton is a well‐established, regular, seasonal event in the western subarctic Pacific and is considered one of the most important conditions of massive production of pelagic fishes. A series of 12 cruises was conducted from 1990 to 1992 to examine the timing and magnitude of the spring phytoplankton bloom in the Oyashio region, the western subarctic Pacific off Hokkaido, Japan. An interannual variability in the bloom events was also analysed. On the basis of hydrographical characteristics, the study area was divided into three water masses: the Oyashio Water Mass, the Mixed Water Mass, and the Coastal Water Mass. Spring blooms were observed first in April in the Oyashio and the Coastal Water Masses, and continued to May in 1991 and 1992. However, no bloom was recorded in the Mixed Water Mass. High nutrient supply into the surface mixed layer during winter is likely to be one of the factors supporting an intense spring bloom in the Oyashio Water Mass. A significant positive relationship between log‐transformed surface chlorophyll a concentration and maximum density gradient (MDG) within the euphotic layer was obtained in April, indicating the importance of vertical stability of the water column in the initiation of spring blooms in the Oyashio and the Coastal Water Masses. The spring blooms in 1991 were much more extensive and lasted longer than in 1990. It is suggested that meteorological conditions and abundance of grazers were responsible for this interannual difference.
A numerical model of the dispersion of blue whiting larvae, Micromesistiuspoutassou (Risso), in the eastern North Atlantic
Authors: BARTSCH J. , COOMBS S.
Published: November 2003

A numerical circulation and transport model system was used to simulate the dispersion of larvae of blue whiting, Micromesistius poutassou (Risso) in the eastern North Atlantic. The area of the model extends from the northern Bay of Biscay to the Norwegian Sea and covers the shelf‐edge and adjacent waters at a horizontal resolution of around 20 km in 16 vertical layers. Larval input data were based on the long‐term mean distribution, abundance and seasonal occurrence of larvae, derived from historical information. The circulation model was run using tidal forcing and climatological density fields as well as both climatological meteorological forcing and actual six‐hourly wind stress fields for 1994 and 1995. Transport from the main spawning areas to the west of the British Isles and north of Porcupine Bank was associated with currents along the shelf‐edge and in the Rockall Trough. Tracers were either dispersed to the north and north‐east along the shelf‐edge, extending into the northern North Sea and Norwegian Sea, or were retained in the Rockall Gyre and over Porcupine Bank. A less intense southerly flow from Porcupine Bank was observed both under climatological conditions and in the 1995 simulation, when winds were more variable than in 1994. The results based on the 1995 meteorological conditions showed the most extreme retention of tracers in the Rockall Trough/shelf‐edge area west of Scotland and a low penetration of tracers onto the shelf. These results are discussed in relation to the observed distribution of 0‐group juveniles and to indices of year‐class strength – in particular, in relation to the 1995 year class, which is the highest year‐class estimate of blue whiting on record.
Variability in the spawning habitat of Pacific sardine (Sardinops sagax) off southern and central California
Authors: Lynn Ronald J.
Published: November 2003

The spatial pattern of sardine spawning as revealed by the presence of sardine eggs is examined in relation to sea surface temperature (SST) and mean volume backscatter strength (MVBS) measured by a 150 kHz acoustic Doppler current profiler (ADCP) during four spring surveys off central and southern California in 1996–99. Studies in other regions have shown that MVBS provides an excellent measure of zooplankton distribution and density. Zooplankton biomass as measured by survey net tows correlates well with concurrently measured MVBS. The high along‐track resolution of egg counts provided by the Continuous Underway Fish Egg Sampler (CUFES) is a good match to the ADCP‐based data. Large interannual differences in the pattern and density of sardine eggs are clearly related to the concurrently observed patterns of surface temperature and MVBS. The strong spatial relationship between sardine eggs and MVBS is particularly evident because of the large contrast in zooplankton biomass between the 1998 El Niño and 1999 La Niña. The inshore distribution of sardine spawning appears to be limited by the low temperatures of freshly upwelled waters, although the value of the limiting temperature varies between years. Often there is an abrupt offshore decrease in MVBS that is coincident with the offshore boundary of sardine eggs. Possible reasons for this association of sardine eggs and high zooplankton biomass include an evolved strategy that promotes improved opportunity of an adequate food supply for subsequent larval development, and/or adult nutrient requirements for serial spawning. Hence, the distribution of these parameters can be used as an aid for delineating the boundaries of sardine spawning habitat.
Absence or masking of metabolic fractionations of 13C in a freshwater benthic food web
Authors: FRANCE R. L.
Published: November 2003

1. Although marine research has indicated that metabolic fractionations of 13C due to differences in organismal trophic position and proximal composition can complicate the isotopic interpretation of energy flow pathways, such potentially confounding problems have never been examined in freshwater benthic food webs.

2. The δ13C values of animals comprising a littoral benthic food web composited from four Canadian Shield lakes showed no relationship with either individual trophic position (δ15N) or lipid content (C/N ratios).

3. Differences in the relative incorporation of autochthonous and allochthonous energy sources by freshwater benthic organisms will alter their δ13C and δ15N values, thereby masking any possibility of observing 13C trophic enrichment.

4. Removal of the possibly confounding influences of lipids through either empirical correction or by analytical extraction may be unnecessary in studies of freshwater benthic food webs. Likewise, a priori adjustments in δ13C for freshwater benthic organisms in order to accommodate trophic fractionations which are presumed to occur, based on data from marine offshore food webs, may also be inappropriate.
Retention time as a primary determinant of colour and light attenuation in two tropical Australian reservoirs
Authors: TOWNSEND SIMON , LUONG‐VAN JIM , BOLAND KEVIN
Published: November 2003

1. The light climates of Darwin River Reservoir (DRR) and Manton River Reservoir (MRR), in northern Australia, are compared for an 8‐year period. The reservoirs are subject to the same wet/dry tropical climate and have similar catchment characteristics, but differ in their basin morphology, retention time and trophic status.

2. Median euphotic depths in DRR and MRR were 9.7 and 4.4 m, respectively. Seasonal variation in each reservoir’s euphotic depth was best explained by colour, based on a stepwise linear regression. Turbidity was excluded from the two regressions, while chlorophyll a concentration was significant only for the MRR regression.

3. Both reservoirs showed the same seasonal pattern for colour. Wet season inflow increased reservoir colour, and was followed by a reduction in colour due to photodegradation and microbial decomposition of humic material, reaching a minimum before the next wet seasons inflow.

4. Although the colour of catchment run‐off into both reservoirs was similar, MRR colour was two to three times greater than that measured in DRR. The higher colour and greater light attenuation of MRR is attributed primarily to its shorter retention time, and therefore shorter time for colour removal. Annual retention time accounted for 97% of the variability of average annual colour (measured as absorption at 440 nm), based on a linear regression of log10 transformed data for both reservoirs.

5. Long retention times favour reduced colour, increasing water transparency, particularly in water bodies of low trophic state and inorganic turbidity.