Tracing possible drivers of synchronously fluctuating species catches in individual logbook data

Abstract Recreational fisheries statistics can provide valuable information on the dynamics of fish stocks and their exploitation. For some reservoirs in the Czech Republic, there are conspicuous synchronous fluctuations in catches of different species that might be caused by fishing skills and strategies. This study describes a method that could detect signatures of such phenomena in individual logbooks. It classifies anglers by species reported during 1 year and compares the resulting angler groups by group size, fishing effort, catch per unit effort (CPUE) and annual catch. The method is illustrated by data from one reservoir, showing that the number of generalist anglers who caught several species was higher than expected. Generalists also had higher catches and effort but lower CPUE than specialists who caught only one of the species. The results indicate that generalist anglers with a low degree of specialisation and high effort could contribute to long‐term correlations in species catches.     

The occurrence and distribution of potato cyst nematodes in Croatia

Potato cyst nematodes (PCN) Globodera rostochiensis (Wollenweber, 1923) Behrens, 1975 and Globodera pallida (Stone, 1973) Behrens, 1975 are the most troublesome pests of potatoes worldwide. Since 1968 there have been no investigations of the presence of PCN in ware potato lands in Croatia although these pests were recognised as an A1 plant-health quarantine species. After the first discovery of G. rostochiensis in the locality of Belica (Medjimurska County) in 2001, intensive monitoring of the distribution of PCN in Croatia started. In 2001 G. rostochiensis was detected in 55% of soil samples taken in ware potato lands. In 2002 G. rostochiensis was detected in 4.1% of soil samples and in 0.08% of soil samples in mixed populations with G. pallida. The pathotype Ro1 was found in all tested populations and Ro1 and Pa 2/3 were detected in populations from localities Vidovec, Ivanovec and Sivice. In 2003 G. rostochiensis was detected in 1.03% of soil samples, and also in 12.8% of soil samples collected in 2004. In 2003 cysts of G. rostochiensis were detected in several seed potato fields. These results indicate the urgent need for the application of further control measures to determine the presence and distribution of PCN in ware and seed potato lands in Croatia, in order to prevent the spread of PCN to non-infested areas. Integrated management strategies, neglected until 2001, have now been implemented and will prevent the build-up of infestation and replace the previous practices of monoculture, the use of short rotations and growing susceptible cultivars.     

Development of alder carr after the abandonment of wet grasslands during the last 70 years

? The secondary succession of wet grasslands to communities of alder carr dominated by Alnus glutinosa was recorded in different parts of Europe during the 20th century. However, knowledge of such development of alder carr remains insufficient.

? The development of alder carr was reconstructed at five sites in the Czech Republic, using historical aerial photographs and methods of dendrochronology. The aims were to investigate the succession from wet grasslands to alder carr at sites previously intensively managed for agriculture and to find out the role of fluctuations in the groundwater table, caused by artificial drainage channels, in the observed stand dynamics and tree growth.

? The spread of forest (i.e., an increase in forest cover) predominated until the 1970s at all sites. This trend was disrupted by a large-scale dieback of forest stands in four of the five sites after the 1970s, followed by an increase in patch heterogeneity, as indicated by landscape metrics. The radial growth increment in Alnus glutinosa has been affected predominately by local environmental factors, probably including the changing degree of waterlogging. Forest dieback was presumably connected with a lesser extent of drainage channels.

? Our results indicate that observed successional pathways at sites of alder carr were probably caused by local changes in the groundwater table.

     

Multi Criteria Assessment of Zero Residue Apple Production

During the 2008–2010 growing seasons, an alternative ‘zero residue apple production system’ was compared with integrated apple production with cvs ‘Idared’, ‘Golden Delicious’, ‘Jonagold’ and ‘Gala’ in commercial orchards at several locations throughout Slovenia, using data envelopment analysis (DEA), and multi criteria assessment by an analytical hierarchical process (AHP). The principle of the ‘zero residue apple production’ is a combination of integrated (IP) and organic apple production. During the first 3 months of the growing season (1 April–30 June), pesticides used in IP with rapid degradation (8–10 applications) were used to control pests and diseases. During the second part of the season from 1 July to harvest, organic products (6–12 applications) were employed compared with 19–25 applications overall in IP. The goal of the alternative system was to reduce the amount of applied conventional pesticides by 40 % and to minimize pesticide residues in fruits to below the limit of 0.5 % of the legal maximum residue level (MRL) or below the residue concentrations of 0.005–0.01 mg/kg and to retain the high long-term level of yield, fruit quality, and net income per hectare. The number of pesticide residues was reduced from 4.2–5.5 in IP to 1.8–3.4 in zero residue cultivation, while 3 year average yields (class 1 fruit) were 4–9 % lower than in IP. The break even prices ranged from € 0.31 for Idared in IP, € 0.34 for ‘Elstar’ of both production systems to € 0.35/kg for zero residue cultivated ‘Golden Delicious’. Overall, a price increase of just € 0.02/kg for residue free apples would make this new ‘zero residue apple production’ profitable then representing a realistic alternative to the standard integrated apple production system.     

Direct evidence of Hymenoscyphus fraxineus infection pathway through the petiole‐shoot junction

The symptoms of ash dieback caused by the fungus Hymenoscyphus fraxineus include wilting of the foliage followed by dieback of shoots, twigs and branches. Necroses in shoots are assumed to develop after infection through leaf petioles; however, clear evidence of this infection pathway has not yet been provided. Considering the multiple pathogen genotypes in dead ash petioles, we aimed to obtain a spatial overview of all H. fraxineus genotypes colonizing individual shoots and their corresponding petioles before leaf shedding to acquire precise information about the infection biology of H. fraxineus and its ability to cross the petiole‐shoot junction. Individual genotypes of H. fraxineus were characterized by the analysis of microsatellites using DNA extracted directly from petiole segments or cultures isolated from the segments. We detected 150 different multilocus genotypes in 10 analysed shoots and their respective petioles; the highest number of genotypes was eight for a single petiole and three for a single shoot. The genotypes of most shoot lesions were identical to particular genotypes from the proximal segments of petioles, implicating the main pathway of shoot infections. To test whether the amount of colonized substrate or intraspecific competition have an effect on successful infection, genotypes that reached the most proximal end of the petioles were scored for the number of invaded petiole segments and for the number of other H. fraxineus genotypes co‐occurring in the segments. However, the extent of colonization of the scored genotypes and intraspecific competition with other H. fraxineus strains did not influence pathogen success in entering the shoot. This study confirms that the majority of ash shoot infections are caused by genotypes of H. fraxineus originating from petioles. Compared to petioles, the frequency of shoot colonization as well as number of H. fraxineus genotypes in shoots was much lower.     

Prevalence,Characterization and Antibiotic Resistance of Salmonella Isolates in Large Corvid Species of Europe and North America Between 2010 and 2013

It is well understood that Salmonella is carried by animals and in majority of cases as asymptomatic hosts. Surveillance efforts have focused on the role of agriculture and contamination points along the food chain as the main source of human infection; however, very little attention has been paid to the contribution of wildlife in the dissemination of Salmonella and what effect anthropogenic sources have on the circulation of antibiotic resistant Salmonella serovars in wildlife species. A purposive survey was taken of large corvids roosting yearly between November and March in Europe and North America. Two thousand and seven hundred and seventy‐eight corvid faecal specimens from 11 countries were submitted for Salmonella spp. culture testing. Presumptive positive isolates were further serotyped, susceptibility tested and analysed for antibiotic resistance genes. Overall, 1.40% (39/2778) (CI = 1.01, 1.90) of samples were positive for Salmonella spp. Salmonella Enteritidis was the most prevalent serovar followed by S. Infantis, S. Montevideo and S. Typhimurium. No significant difference (P > 0.05) was found in the proportion of Salmonella recovered in Europe versus North America. The most variability of serovars within a site was in Kansas, USA with five different serovars recovered. European sites were significantly more likely to yield Salmonella resistant to more than one antibiotic (OR 71.5, P < 0.001, CI = 3.77, 1358) than North American sites, where no resistance was found. Resistance to nalidixic acid, a quinolone, was recovered in nine isolates from four serovars in four different sites across Europe. Large corvids contribute to the transmission and dissemination of Salmonella and resistance genes between human and animal populations and across great distances. This information adds to the knowledge base of zoonotic pathogen prevalence and antibiotic resistance ecology in wild birds.     

The peculiarities of new textile hand evaluation method

The paper presents information concerning metrological and technical characteristics of KTU-Griff-Tester device, the optimization of its parameters and the cases of its application. It was defined that the behaviour of textile material during its extraction through a rounded hole depends upon its structure. Variations of geometrical shape of woven and knitted specimens can be described by mathematical expressions of shortened epicycloids and Cassini ovals. It is shown that waving process of disc shaped specimen can be predicted on the basis of the law of sine curve. The examples of textiles treatment with different types of commercial softeners are presented, herewith showing the suitability (sensitiveness) of the new device to detect the changes of textile hand. Meantime it is shown that the level of materials anisotropy can be decided on the basis of transformations of specimen’s geometrical shape.     

Contribution to the toxic action of S-methyl fenitrothion

The toxicity of the S-methyl isomer of fenitrothion was found to be higher than that of both fenitrothion and technical fenitrothion. Repeated administration of the compound showed a rapid decrease in toxicity with decreasing doses.Excretion of p-nitro-m-cresol into the urine of rats was more rapid and the excreted amounts were larger from a single dose of the isomer than from fenitrothion.Single doses of the isomer increased the pentobarbitone sleeping time in mice at both 24 and 48 hr, but showed no change after 4 days. Administration of the isomer and purified fenitrothion to mice for 1 week had no effect on the pentobarbitone sleeping time, nor did a single dose of fenitrothion change the effectiveness of pentobarbitone.Dominant lethal tests in rats revealed a possible mutagenic effect from this compound.The anticholinesterase activity of the fenitrothion S-methyl isomer in vitro was found to be two to three times higher than that of fenitrothion.     

Verwendung vonLymantria dispar-Pheromon zur Kontrolle des Vorkommens und der Flugdauer vonLymantria monacha L. undLymantria dispar L.

Zusammenfassung Synthetisches Pheromon cis-7,8-epoxy-2-methyloctadecan — Disparlure — hat sich als wirksames Attraktant bei der Kontrolle des Vorkommens und der Flugdauer des SchwammspinnersLymantria dispar L. und der NonneLymantlria monacha L. bewährt.Die durch Disparlure-Lockfallen kontrollïerte Flugdauer beider Arten dauerte in den Beständen mehr als 6–7 Wochen, bei der Nonne in Böhmen bis Ende der ersten Septemberdekade, d. h. länger als früher angenommen wurde.Es wird der Gedanke geäußert, daß die Menge der Männchen jeder der beiden Arten, die unter 100 pro Lockfalle während der Flugdauer bleibt, der Latenz- periode des Schädlings entspricht.Der Gebrauch des synthetischen Pheromones bietet in der Forstpraxis die möglichkeit festzustellen, welche Abundanzwerte den verschiedenen Phasen des Massenwechsels dieser Schädlinge zukommen und ermöglicht auch die Beantwortung bisher unvollständig gelöster ökologischer Fragen besonders hinsichtlich der Latenzperiode der Schädlinge.

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Summary The synthetic pheromone cis-7,8-epoxy-2-methyloctadecan (Disparlure) has proved to be an effective attractant for examination of the occurrence and time of flight ofLymantria monacha L. andLymantria dispar L. The time of flight of both species, observed by means of traps with Disparlure, takes 6–7 weeks in central Europe. With Lymantria monacha in Bohemia it lasts almost till the middle of September, i. e. by 3–4 weeks longer than it has been stated so far. The number of 1–100 males captured in one trap (450 cm²) throughout the period of flight indicates the pest's abundance in the period of latency. The use of the synthetic pheromone enables to ascertain abundance in individual phases of the pest's buildup, also making it possible to explain some ecological problems, from the period of latency of the pest.