Bycatch in the gillnet and beach-seine fisheries in the Western Cape, South Africa, with implications for management

Interview questionnaires and access point surveys were conducted in order to describe and quantify the catch composition of the inshore net-fisheries in the Western Cape, South Africa. A total of 138 562 fish, representing 29 species from 20 families, was recorded in 141 monitored commercial gillnet fishing operations between February 1998 and October 1999. Numerically, the legal target species, harders Liza richardsonii, dominated the catches, contributing 94.87% of the total gillnet catch. Elf, Pomatomus saltatrix, horse mackerel Trachurus trachurus capensis, gurnard Chelidonichthys capensis and barbel Galeichthys feliceps were the most common bycatch species, and contributed 4.2% to the total catch numerically and occurred in 12–47% of the marine 44–64-mm gillnet catches that were monitored. Five species most frequently targeted by shore-anglers on the West Coast: galjoen Dichistius capensis, white stumpnose Rhabdosargus globiceps, hottentot Pachymetopon blochii, silver kob Argyrosomus inodorus and white steenbras Lithognathus lithognathus, also occurred in gillnet catches. Most of the bycatch consisting of immature, undersized fish that were often injured during entanglement and were not released alive. L. richardsonii also numerically dominated the beach-seine hauls that were monitored (>99%) with only four bycatch species being recorded in low numbers. Beach-seine questionnaire respondents, however, reported sporadic catches of at least 17 bycatch species, including occasional appreciable catches of the important linefish species L. lithognathus and A. inodorus.Keywords: beach-seine, bycatch, catch composition, gillnets, fishery management, inshore netfishingAfrican Journal of Marine Science 2002, 24: 227–24

Catch-and-effort estimates for the gillnet and beach-seine fisheries in the Western Cape, South Africa

Total catch and effort for the inshore net-fisheries in the Western Cape, South Africa, were estimated by means of face-to-face questionnaire, telephone and access point surveys, analysis of factory records and compulsory catch returns. In most areas, gillnet fishing effort was confined to summer, with highest average catch per unit effort during months of low effort. Records of monofilament gillnet sales show that approximately 180 illegal nets are sold annually (20% of all sales). During the period 1994–1999, only 26 illegal mesh size nets were confiscated annually (14% of those sold) on average, indicating that few illegal fishers are apprehended. Beach-seine fishers appeared to operate opportunistically throughout the year along the West Coast, whereas South-West Coast permitholders concentrate their activity during summer. Sources of survey error in effort and catch-rate estimation are discussed. Approximately 25 000 gillnet days and 3 200 beach-seine hauls made annually land around 6 000 tons of fish, substantially more than the mean annual reported catch of 1 369 tons. Comparison of observed or documented catches with compulsory catch returns confirmed that as little as 21% of the actual effort and only 8% of the fish caught are reported. Despite the fact that catches are much greater than those reported, the lower catch rates, smaller average size of fish caught and historical and anecdotal evidence suggest that the harder Liza richardsonii stock is regionally overexploited in areas with high fishing effort. It is concluded that the inshore net fishery in the Western Cape is oversubscribed in most regions and a reduction in latent and “recreational” effort is therefore recommended. A suitable reduction in total effort may allow the L. richardsonii stock to recover, reduce the ecosystem effects of the fishery by reducing the amount of bycatch and improve catch rates for bona fide commercial fishers. It would also facilitate improved monitoring and policing of the fishery and hopefully improve compliance with regulations. Keywords: beach-seine, catch-and-effort estimates, catch returns, gillnets, Liza richardsoniiAfrican Journal of Marine Science 2002, 24: 205–22

Are Payment Card Contracts Unfair?

Fraud victims are often refused a refund by their bank on the grounds that they failed to comply with their bank’s terms and conditions about PIN safety. We, therefore, conducted a survey of how many PINs people have, and how they manage them. We found that while only a third of PINs are ever changed, almost half of bank customers write at least one PIN down. We also found bank conditions that are too vague to test, or even contradictory on whether PINs could be shared across cards. Yet, some rather hazardous practices are not forbidden at all by many banks: of the 22.9% who re-use PINs across devices, half also use their bank PINs on their mobile phones. We conclude that many bank contracts fail a simple test of reasonableness, and that ‘strong authentication’, as required by PSD II, should include usability testing

The effect of sea temperature and food availability on the spawning success of Cape Anchovy engraulis capensis in the Southern Benguela

Data on the thermal structure, copepod biomass and production, and total number of eggs of the Cape anchovy Engraulis capensis were obtained from monthly surveys during the periods August 1993 – March1994 and September 1994 – March 1995 on the western Agulhas Bank and off the South-Western Cape, South Africa. Previous work suggested that anchovy spawn on the western Agulhas Bank in temperaturesbetween 16 and 19°C, where they feed predominantly on copepods. This study shows that the western Bank is a more suitable spawning area for anchovy, having greater thermal stability, a larger area of 16–19°Cwater and a more consistent food environment than off the South-Western Cape. Also, copepod production on the western Bank was highest in 16–19°C water. To identify factors controlling the area of this watermass, a cluster analysis was used on a suite of hydrographic variables. Three periods were identified: winter (August-September), spring (October-December) and summer (January-March), reflecting changes in theextent of the 16–19°C water and anchovy spawning, both of which peaked during spring. Spring was further characterized by infrequent surface upwelling. During summer, upwelling frequently reached the surface andthe upwelling front migrated offshore, constricting the area of 16–19°C water. It is hypothesized that spawning success in anchovy is dependent upon the extent of suitable spawning habitat, both spatially (16–19°Cwater) and temporally (spring). To put this concept into a predictive framework, the number of anchovy eggs was regressed against the area of 16–19°C water; a significant, positive relationship (p < 0.001, r2 = 0.56, n = 17) was found. An implication of the hypothesis is that the duration of spawning may be important to recruitment

Health economics and quality of life in a feasibility RCT of paediatric acute appendicitis: a protocol study

Background: Acute appendicitis is one of the most common acute surgical emergencies in children and accounts for an annual cost of approximately £50 million to the National Health Service. Investigating alternative treatment options offers the best prospect of enhancing the quality of care for patients and potential opportunities for cost savings through better allocative efficiency. A feasibility randomised controlled trial (RCT) comparing a non-operative treatment pathway with appendicectomy for children with acute uncomplicated appendicitis is underway (CONTRACT feasibility RCT). Aims: The prime objective of this economic substudy conducted alongside the CONTRACT feasibility RCT is to better understand and assess: (1) cost data collection tools and cost drivers by identifying patients’ pathways and (2) patient quality of life by assessing alternative paediatric health-related quality of life (HRQoL) instruments. Outcomes from this study will inform a future efficacy RCT assessing the effectiveness and cost-effectiveness of nonoperative treatment pathway for the treatment of acute uncomplicated appendicitis in children. Methods: The economic substudy will use individuallevel data and will be conducted from the health system perspective over the study’s 6-month follow-up period. Microcosting will include health resource and service use, while potential benefits acquired will be measured using the HRQoL measures, Child Health Utility 9D (CHU9D) and Euroqol-5 dimensions and 5 levels (EQ-5D-5L). We will assess the appropriateness of using the cost per quality-adjusted life year framework in the future RCT, as well as testing and identifying the most suitable HRQoL instrument. Conclusions: The outcomes of the investigational economic substudy will be used to inform the design of our future definitive RCT. However, the result from this economic study will also provide a detailed description and account of the issues inherent in paediatric Economic Evaluations Alongside Clinical Trials with an emphasis on costing methods of interventions taking place in secondary care settings. Trial registration number: ISRCTN1583043

Occupational cancer in Britain: Exposure assessment methodology

To estimate the current occupational cancer burden due to past exposures in Britain, estimates of the number of exposed workers at different levels are required, as well as risk estimates of cancer due to the exposures. This paper describes the methods and results for estimating the historical exposures. All occupational carcinogens or exposure circumstances classified by the International Agency for Research on Cancer as definite or probable human carcinogens and potentially to be found in British workplaces over the past 20–40 years were included in this study. Estimates of the number of people exposed by industrial sector were based predominantly on two sources of data, the CARcinogen EXposure (CAREX) database and the UK Labour Force Survey. Where possible, multiple and overlapping exposures were taken into account. Dose–response risk estimates were generally not available in the epidemiological literature for the cancer–exposure pairs in this study, and none of the sources available for obtaining the numbers exposed provided data by different levels of exposure. Industrial sectors were therefore assigned using expert judgement to ‘higher'- and ‘lower'-exposure groups based on the similarity of exposure to the population in the key epidemiological studies from which risk estimates had been selected. Estimates of historical exposure prevalence were obtained for 41 carcinogens or occupational circumstances. These include exposures to chemicals and metals, combustion products, other mixtures or groups of chemicals, mineral and biological dusts, physical agents and work patterns, as well as occupations and industries that have been associated with increased risk of cancer, but for which the causative agents are unknown. There were more than half a million workers exposed to each of six carcinogens (radon, solar radiation, crystalline silica, mineral oils, non-arsenical insecticides and 2,3,7,8-tetrachlorodibenzo-p-dioxin); other agents to which a large number of workers are exposed included benzene, diesel engine exhaust and environmental tobacco smoke. The study has highlighted several industrial sectors with large proportions of workers potentially exposed to multiple carcinogens. The relevant available data have been used to generate estimates of the prevalence of past exposure to occupational carcinogens to enable the occupational cancer burden in Britain to be estimated. These data are considered adequate for the present purpose, but new data on the prevalence and intensity of current occupational exposure to carcinogens should be collected to ensure that future policy decisions be based on reliable evidence

Occupational cancer in Britain: Statistical methodology

An approach using the attributable fraction (AF) has been developed to estimate the current burden of occupational cancer in Britain. The AF combines the relative risk (RR) associated with exposure with the proportion exposed. For each cancer–exposure pairing, the RR is selected from key epidemiological literature such as an industry, or population-based study, meta-analysis or review. The CARcinogen EXposure (CAREX) database provides point estimates for the number of workers exposed to a range of carcinogens; alternative sources are national surveys such as the Labour Force Survey and Census of Employment. The number of workers exposed are split between high and low exposure levels matched to appropriate RRs from the literature. The relevant period for cancer development during which exposure occurred is defined as the risk exposure period (REP). Estimation of the numbers ever exposed over the REP takes into account the changes in the number of people employed in primary and manufacturing industry and service sectors in Britain where appropriate, and adjustment is made for staff turnover over the period and for life expectancy. National estimates of the population ever of working age during the REP are used for the proportion denominator. Strategies have been developed to combine exposure AFs correctly while avoiding double counting and minimising bias. The AFs are applied to national cancer deaths and registrations to obtain occupation-attributable cancer numbers. The methods are adaptable for other diseases and other geographies, and are also adaptable to more sophisticated modelling if better exposure and dose–response data are available

Identification of single-site gold catalysis in acetylene hydrochlorination

There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species

A telephone survey of cancer awareness among frontline staff: informing training needs

Background: Studies have shown limited awareness about cancer risk factors among hospital-based staff. Less is known about general cancer awareness among community frontline National Health Service and social care staff. Methods: A cross-sectional computer-assisted telephone survey of 4664 frontline community-based health and social care staff in North West England. Results: A total of 671 out of 4664 (14.4%) potentially eligible subjects agreed to take part. Over 92% of staff recognised most warning signs, except an unexplained pain (88.8%, n=596), cough or hoarseness (86.9%, n=583) and a sore that does not heal (77.3%, n=519). The bowel cancer-screening programme was recognised by 61.8% (n=415) of staff. Most staff agreed that smoking and passive smoking ‘increased the chance of getting cancer.’ Fewer agreed about getting sunburnt more than once as a child (78.0%, n=523), being overweight (73.5%, n=493), drinking more than one unit of alcohol per day (50.2%, n=337) or doing less than 30 min of moderate physical exercise five times a week (41.1%, n=276). Conclusion: Cancer awareness is generally good among frontline staff, but important gaps exist, which might be improved by targeted education and training and through developing clearer messages about cancer risk factors