966 resultados para FISH ASSEMBLAGES
Resumo:
Egypt’s aquaculture production (921,585 tonnes in 2010) is by far the largest of any African country. The aquaculture sector, dominated by semi-intensive pond production of tilapia, makes a significant contribution to income, employment creation and food and nutrition security in the country, all of which are national priority areas given low per capita income levels, rising population, worsening food and nutrition security indicators, and official unemployment levels which have remained at around 10% for the last ten years. The Improving Employment and Income through Development of Egypt’s Aquaculture Sector (IEIDEAS) project funded by the Swiss Agency for Development and Cooperation (SDC) is a three-year project which commenced in December 2011, and which aims to support the development of the aquaculture sector in Egypt so as to increase productivity, profitability, and employment in the sector, and the nutritional status of poor consumers. This report represents the output of a short two-week study to better understand the market for Egyptian farmed fish. The intention of the study was to provide an output which would cut-across, and potentially benefit, all five of the project outcomes.
Resumo:
Government development programmes and policies in fisheries are focused on the problems and needs of men though women are known to dominate the post-harvest sector in artisanal fisheries and are involved, to varying degrees, in pre-harvest and harvest activities. A lack of women’s participation in decision-making bodies within communities, fisheries organizations and government has resulted in a general neglect of their interests. This has led to a constant demand by women’s-rights activists and organizations to address market-related issues of women vendors. This study, “Women Fish Vendors in Mumbai”, aims to provide insights into the challenges faced by women fish vendors in the city of Mumbai (formerly Bombay).
Resumo:
Protogynous sequential hermaphroditism is very common in marine fish. Despite a large number of studies on various aspects of sequential hermaphroditism in fish, the relationship between body shape and colour during growth in dichromatic species has not been assessed. Using geometric morphometrics, the present study explores the relationship between growth, body shape and colouration in Coris julis (L. 1758), a small protogynous labrid species with distinct colour phases. Results show that body shape change during growth is independent of change in colour phase, a result which can be explained by the biology of the species and by the social control of sex change. Also, during growth the body grows deeper and the head has a steeper profile. It is hypothesized that a deeper body and a steeper profile might have a function in agonistic interactions between terminal phase males and that the marked chromatic difference between colour phases allows the lack of strict interdependence of body shape and colour during growth.
Resumo:
The possible differences between sexes in patterns of morphological variation in geographical space have been explored only in gonochorist freshwater species. We explored patterns of body shape variation in geographical space in a marine sequential hermaphrodite species, Coris julis (L. 1758), analyzing variation both within and between colour phases, through the use of geometric morphometrics and spatially-explicit statistical analyses. We also tested for the association of body shape with two environmental variables: temperature and chlorophyll a concentration, as obtained from time-series of satellite-derived data. Both colour phases showed a significant morphological variation in geographical space and patterns of variation divergent between phases. Although the morphological variation was qualitatively similar, individuals in the initial colour phase showed a more marked variation than individuals in the terminal phase. Body shape showed a weak but significant correlation with environmental variables, which was more pronounced in primary specimens.
Resumo:
Invasive species generate significant environmental and economic costs, with maintenance management constituting a major expenditure. Such costs are generated by invasive Indo-Pacific lionfish (Pterois spp.) that further threaten already stressed coral reefs in the western Atlantic Ocean and Caribbean Sea. This brief review documents rapid range expansion and potential impacts of lionfish. In addition, preliminary experimental data from targeted removals contribute to debates about maintenance management. Removals at sites off Little Cayman Island shifted the size frequency distribution of remaining lionfish toward smaller individuals whose stomachs contained less prey and fewer fish. Fewer lionfish and decreased predation on threatened grouper, herbivores and other economically and ecologically important fishes represent key steps toward protecting reefs. However, complete evaluation of success requires long-term data detailing immigration and recruitment by lionfish, compensatory growth and reproduction of lionfish, reduced direct effects on prey assemblages, and reduced indirect effects mediated by competition for food. Preventing introductions is the best way to avoid impacts from invasive species and early detection linked to rapid response ranks second. Nevertheless, results from this case study suggest that targeted removals represent a viable option for shifting direct impacts of invasive lionfish away from highly vulnerable components of ecosystems.
Potentialities for increased utilization of scrap fish and fish waste in the Gulf and Caribbean area