1,183 research outputs found
Fishing and the impact of marine reserves in a variable environment
We use discrete-time models to investigate the impact of marine reserve establishment on fishery catch and biomass levels in open-access and quota-regulated fisheries under conditions of recruitment variability and natural mortality events. We find that under the conditions of variability tested, reserves can increase the probability of achieving target levels of biomass (60%, 35%, and 5% of carrying capacity) and can reduce catch variability in neighbouring fisheries, making future planning in the fishery more efficient. The size of the reserve required to meet each objective will depend on the initial condition of the stock and the exploitation rate in the fishery. Reserve coverage of between 20% and 40% prevent stock collapse in most cases. In heavily exploited fisheries, reserves are also likely to enhance mean catches, particularly in highly variable systems. If the stock has previously been heavily exploited, large reserves (greater than or equal to60%) may be required to significantly increase the probability of achieving target biomass levels. However, once stocks have recovered, reserve coverage may be reduced without a reduction in this probability of success
Pesticides and occupational safety and health in Zimbabwe
A research paper on pesticides danger to occupational health in the Zimbabwe industrial employment sector.In Zimbabwe, the Department of Occupational Safety, Health and Workersā Compensation in the Ministry of Labour collates, analyses and develops information systems out of reported accidents or cases of poisoning occurring throughout industry. The accidents/poisoning cases also include those due to pesticides. Reporting systems of accidents/poisonings are poor and deteriorating due to poor control strategies. This is because there is lack ol safety guidelines, enforcement machinery, low level of functional literacy among workers and users and lack of social security or health insurance schemes. It is therefore important to improve the accident/poisoning reporting system so as to get reliable representative statistics about occupational safety and health especially in association with pesticide poisonings
The importance of habitat quality for marine reserve fishery linkages
We model marine reserve - fishery linkages to evaluate the potential contribution of habitat-quality improvements inside a marine reserve to fish productivity and fishery catches. Data from Mombasa Marine National Park, Kenya, and the adjacent fishery are used. Marine reserves increase total fish biomass directly by providing refuge from exploitation and indirectly by improving fish habitat in the reserve. As natural mortality of the fish stock decreases in response to habitat enhancement in the reserve, catches increase by up to 2.6 tonnes (t).km(-2).year(-1) and total fish biomass by up to 36 t.km(-2). However, if habitat-quality improvement reduces the propensity of fish to move out of the reserve, catches may fall by up to 0.9 t.km(-2).year(-1). Our results indicate that habitat protection in reserves can underpin fish productivity and, depending on its effects on fish movements, augment catches
Control of InGaAs facets using metal modulation epitaxy (MME)
Control of faceting during epitaxy is critical for nanoscale devices. This
work identifies the origins of gaps and different facets during regrowth of
InGaAs adjacent to patterned features. Molecular beam epitaxy (MBE) near SiO2
or SiNx led to gaps, roughness, or polycrystalline growth, but metal modulated
epitaxy (MME) produced smooth and gap-free "rising tide" (001) growth filling
up to the mask. The resulting self-aligned FETs were dominated by FET channel
resistance rather than source-drain access resistance. Higher As fluxes led
first to conformal growth, then pronounced {111} facets sloping up away from
the mask.Comment: 18 pages, 7 figure
Tuberculosis from Mycobacterium bovis in Binational Communities, United States
The incidence in San Diego is increasing and is concentrated mostly in persons of Mexican origin
Evaluating the success of a marine protected area: A systematic review approach.
Marine Protected Areas (MPAs), marine areas in which human activities are restricted, are implemented worldwide to protect the marine environment. However, with a large proportion of these MPAs being no more than paper parks, it is important to be able to evaluate MPA success, determined by improvements to biophysical, socio-economic and governance conditions. In this study a systematic literature review was conducted to determine the most frequently used indicators of MPA success. These were then applied to a case study to demonstrate how success can be evaluated. The fifteen most frequently used indicators included species abundance, level of stakeholder participation and the existence of a decision-making and management body. Using the indicator framework with a traffic light system, we demonstrate how an MPA can be evaluated in terms of how well it performs against the indicators using secondary data from the literature. The framework can be used flexibly. For example, where no MPA data currently exist, the framework can be populated by qualitative data provided by local stakeholder knowledge. This system provides a cost-effective and straightforward method for managers and decision-makers to determine the level of success of any MPA and identify areas of weakness. However, given the variety of motivations for MPA establishment, this success needs to be determined in the context of the original management objectives of the MPA with greater weighting being placed on those objectives where appropriate
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