50 resultados para language diversity
Resumo:
We determined the dis-tribution of multiple (n=68; 508−978 mm total length [TL]) striped bass (Morone saxatilis) along the estua-rine salinity gradient in the Mullica River−Great Bay in southern New Jersey over two years to determine the diversity of habitat use and the movements of striped bass. Ultrasoni-cally tagged fish were detected in this estuarine area by means of wireless hydrophones deployed at four gates inside the entrance of the study area and farther up to tidal freshwater (38 km). Numerous individuals frequently departed and returned to the estuary, primarily in the spring and late fall over periods of 15−731 days at liberty. The period of residency and degree of movement of individuals to and from the estuary varied extensively among seasons and years. The diversity of movements in and out of, as well as within, the estuary differed from the less-complex patterns reported in earlier studies, perhaps because of the comprehensive and synoptic nature of this study.
Resumo:
The paper describes the wide range of traditional fishing gear used by subsistence and professional fishers in the inland waters in Bangladesh as well as their impact on the fisheries and the environment. The negative impacts indicate the need for regulation of specific types of fishing gear at particular times of the year. An awareness/training program should be extended to the fishermen to create awareness of the long-term effects of their fishing practices and to impart knowledge of fishing laws.
Resumo:
China has a very rich genetic diversity in common carp (Cyprinus carpio) and the red common carp plays an important role in Chinese aquaculture and genetic studies. Selective breeding, particularly crossbreeding has been applied successfully to red common carps in China, and the products of these efforts have been in commercial use since the 1970s. However, knowledge of the quantitative and molecular genetics of these carps is limited. Studies were therefore undertaken to: (1) understand the genetic diversity and genetic relationship of red common carps in China; (2) understand the inheritance of color phenotype of Oujiang color carp; (3) select stable Oujiang color carp with fast growth rate and ornamental Oujiang color carp comparable with the Koi common carp from Japan; (4) study the culture performance and culture systems suitable for the Oujiang color carp in cages and paddies; (5) extend better quality fish and appropriate culture systems for small scale fish farmers in poor areas.
Resumo:
The giant freshwater prawn (Macrobrachium rosenbergii) is cultured widely around the world but little is known about the levels and patterns of genetic diversity in either wild or cultured stocks. Studies have suggested that genetic diversity may be relatively low in some cultured stocks due to the history of how they were founded and subsequent exposure to repeated population bottlenecks in hatcheries. In contrast, wild stocks have an extensive distribution that extends from Southern Asia across Southeast (SE) Asia to the Pacific region. Therefore, wild stocks could be an important resource for genetic improvement of culture stocks in the future. Understanding the extent and patterns of genetic diversity in wild giant freshwater prawn stocks will assist decisions about the direction future breeding programs may take. Wild stock genetic diversity was examined using a 472 base-pair segment of the 16S rRNA gene in 18 wild populations collected from across the natural range of the species. Two major clades ("eastern" and "western") were identifi ed either side of Huxley’s line, with a minimum divergence of 6.2 per cent, which implies separation since the Miocene period (5-10 MYA). While divergence estimates within major clades was small (maximum 0.9 per cent), evidence was also found for population structuring at a lower spatial scale. This will be examined more intensively with a faster evolving mtDNA gene in the future.
Resumo:
A discussion is presented on the topic of maintaining genetic diversity in aquatic ecosystems, considering the various threats caused by irreversible damage or loss to the environment. The current situation in aquaculture and future prospects regarding the conservation and protection of endangered species are outlined, describing the case of tilapias in Africa as one particular example of fish conservation.
Resumo:
This book is a research output on fishing gears used in the beels from Sunamgan Haor areas under the initiative of the Community Based Resource Management Project (CBRMP) of LGED and WorldFish. It presents a collection of gears recorded in the CBRMP project area during monitoring conducted by WorldFish from 2008 to 2012. The book contains a total of 63 gears found in Sunamganj haor area.
Resumo:
This book is a modest attempt at identifying Sunamganj haor fish species, especially in areas falling under the Sunamganj Community Based Resource Management Project (CBRMP). It contains a total of 126 fish species from 39 families found in the Sunamganj haor area. CBRMP has promoted community based fisheries management approaches that, along with their livelihoods focus, are helping to preserve and enhance natural fish stocks in the hoar basin. WorldFish support to LGED involves a number of areas including monitoring the impacts of CBRMP on fish catch, bio-diversity and livelihoods.
Resumo:
Temporal variation in the abundance of fish populations and diversity of assemblages in different sections of the Neyyar River in the Western Ghats were investigated during the year 1984. A decreasing trend in the abundance of fishes from the headwaters downwards has been noted. The fish community is represented by 33 species assignable to 15 families. The diversity indices of Shannon-Wiener and Margalef and Pielou's evenness have been calculated. The diversity indices are discussed in the light of species richness in different sectors.
Resumo:
A survey was conducted in 3000 fishermen households surrounding 54 wetlands (Beels) of Assam. The fish diversity of the wetlands has been decreasing during the last few years due to some extrinsic and intrinsic factors. The total number of fish species recorded so far during the present study is 67 belonging to 21 families. Cyprinidae is the most dominant family represented by major group species (8), intermediate group species (3) and minor group species (12) of high commercial value. Among these three groups, the diversity of fish species is higher in the minor group fish. The present paper deals with the economic condition of the fishermen who mainly fish in the wetlands. The economic condition of the fishermen community is found very poor. The income of fishermen varies from Rs. 4.478 to Rs.7,484 per annum. A regression analysis shows that the income of fishermen is not dependent alone on the fish production but it is exclusively dependent on the value of the fish catch. All the three groups (in terms of value) have significant influence at 10.00% confidence level. But analysis of β shows that the intermediate fish group exhibits the highest influence on the variation of the fishermen income followed by minor and major group respectively.
Resumo:
This monograph studies the progress achieved by conservation partners in South Africa on the implementation of the Convention on Biological Diversity (CBD) Programme Element Two components of governance, participation, equity and benefit sharing, from the perspective of small-scale fishing communities. It explores the strategies and mechanisms used by different authorities to create the conditions whereby local communities can benefit from marine protected areas (MPAs), of which South Africa has gazetted 24, highlighting examples of best practice. The monograph will be useful for researchers, scientists, fishworker organizations, environmentalists and anyone interested in the protection of marine biodiversity and the promotion of sustainable fisheries management.
Resumo:
Ichthyofauna was studied in the inshore waters around the Great Nicobar Island to assess the extent of biodiversity of fishery resources in the Great Nicobar waters by using various gears and crafts. During the present study, 258 species of fin fishes belonging to 141 genera, 84 families and 19 orders were recorded. Among these, Perciformes topped the list with 47 families, 84 genera and 169 species followed by Clupeiformes, Angulliformes, Tetrodoniformes, Cyprinodontiformes, Scorpaeniformes, Rajiformes, Elopiformes, Pleuronectiformes, Syluriformes, Laminiformes, Bercyformes, Aelopiformes, Syngathiformes and Gonorhychiformes which includes the medicinally important and ornamentally valuable species.