Marine fisheries in India-Winter School on Towards Ecosystem Based Management of Marine Fisheries – Building Mass Balance Trophic and Simulation Models

Endowed with a long coastline of 8129 km, 2.02 million sq.km.of EEZ, and 0.5 million sq.km. of continental shelf and with an annual marine fishery potential of 3.93 million t, India occupies a unique position among the countries bordering the Indian Ocean. India is one of the leading nations in the world in marine fishery exports. From the traditional subsistence level, the Indian marine fisheries grew to an industrial status over a period of half a century since independence. The subsistence fisheries during the early 50's produced about 0.5 million tonnes annually. Currently, the total annual production is of the order of about 2.6 million tonnes. This increase is the result of improvements in the harvesting methods, increase in the fishing effort and extension of fishing into relatively deeper regions

Micro-analytical models – virtual population analysis, Thompson & Bell- Winter School on Towards Ecosystem Based Management of Marine Fisheries – Building Mass Balance Trophic and Simulation Models

The most methods currently used in temperate fisheries stock assessments rely on catch-at-age data an among them virtual population analysis (VPA) or cohort analysis is the most common method that calculates stock size based on catches with no underlying statistical assumptions. Virtual population analysis (VPA) calculates past stock abundances based on past catches. Once stock sizes are calculated, fishing size-selectivity as well as changes in vulnerability over time can be determined. The stock size estimates, which include recruitment estimates for each year, can be used for stock and recruitment analysis. VPA, also known as cohort analysis, is one of the most powerful techniques available for the analysis of fisheries data and forms the heart of many current assessment methods where catch-at-age data are available. Virtual population analysis or VPA is basically an analysis of the catches of commercial fisheries

Fish stock assessment – an overview- Winter School on Towards Ecosystem Based Management of Marine Fisheries – Building Mass Balance Trophic and Simulation Models

During the last five decades there has been a tremendous increase in fish production, concomitant with the improved technologies in the harvest and post harvest operations, and the extension of fishing areas beyond the conventional grounds. In most of the countries, however, the production trends in respect of the commercially important fishery resources have been showing gradual decline. The situation is no different in India. The phenomenal increase in production triggered by market growth was achieved through adoption of modern methods for exploitation and extension of fishing from the traditional near shore waters to deeper regions. This has also brought in its wake regional and sectoral imbalances in the exploitation of the common resources. The artisanal sector is increasingly marginalized by the growth in mechanized and motorized sector. Many of the resources in different regions of our EEZ are reportedly over-fished

Concepts of growth & mortality of fish stocks- Winter School on Towards Ecosystem Based Management of Marine Fisheries – Building Mass Balance Trophic and Simulation Models

Knowledge of growth and mortality is essential for a meaningful assessment of the exploited stock. The parameters of growth and mortality are components of majority of the yield models used to explain the dynamics of the exploited stocks and the effect of fishing on them

An Improved Approach for Contrast Enhancement of Spinal Cord Images based on Multiscale Retinex Algorithm

This paper presents a new approach for contrast enhancement of spinal cord medical images based on multirate scheme incorporated into multiscale retinex algorithm. The proposed work here uses HSV color space, since HSV color space separates color details from intensity. The enhancement of medical image is achieved by down sampling the original image into five versions, namely, tiny, small, medium, fine, and normal scale. This is due to the fact that the each versions of the image when independently enhanced and reconstructed results in enormous improvement in the visual quality. Further, the contrast stretching and MultiScale Retinex (MSR) techniques are exploited in order to enhance each of the scaled version of the image. Finally, the enhanced image is obtained by combining each of these scales in an efficient way to obtain the composite enhanced image. The efficiency of the proposed algorithm is validated by using a wavelet energy metric in the wavelet domain. Reconstructed image using proposed method highlights the details (edges and tissues), reduces image noise (Gaussian and Speckle) and improves the overall contrast. The proposed algorithm also enhances sharp edges of the tissue surrounding the spinal cord regions which is useful for diagnosis of spinal cord lesions. Elaborated experiments are conducted on several medical images and results presented show that the enhanced medical pictures are of good quality and is found to be better compared with other researcher methods.Comment: 13 pages, 6 figures, International Journal of Imaging and Robotics. arXiv admin note: text overlap with arXiv:1406.571

Marine fish landing in India during January – June 2003

The marine fish landings of India has been provisionally estimated as 10.96 lakh tones during half of year 2003. There was an increase of 3.06% compared to the corresponding half year of 2002

Bootstrap evaluation of the sampling scheme to estimate the marine fish landings - A case study

Usefulness of the Bootstrap methodology in complex surveys has been demonstrated with the help of an application to the sampling scheme to estimate the marine fish landings. The methodological approach and evaluation of the sampling design with reference to the coefficient of variation of the estimate has been indicated. The optimum sample size (number of days) for a desired level of precision has also been estimated

Fishery forecasting - present status and future prospects

A review of the approaches. procedures and models for fishery forecasting has been presented. The relative performance of some of the predictive models has been indicated. Applicability of some of the methods is demonstrated with help of a real life data. The future directions of the methodological approaches have also been outlined

Stock assessment models and methods

Fish stocks have an important role in providing cheap protein food, income and employment to millions of people in the world. Judicious management and exploitation of the renewable fish resources is important for sustained production over years. Over fishing leads to disappearance of the renewable fish stocks. Assessment of fish stocks is the first step to determine the level of exploitation necessary for arriving at maximum sustainable yields from the fish resources. Assessment of stocks and study of impact of present level of exploitation on exploited stocks are necessary for maintenance of stocks at maximum sustainable level. Many mathematical and statistical models have been developed and used for fish stock assessment studies. The unique features of fish stocks are, they do not come under visual horizon for direct evaluation of stock sizes, their distribution over space, time and species varies at higher dimension and fish stocks are affected by fishery dependent factors such as effort exerted, size at first capture and fishery independent factors like salinity, temperature, water current etc. The models to study fish stocks should consider the three aspects namely, size of the stock, level of exploitation and effect of fishery independent factors. Multi species and multi gear situation adds to the problem of assessing the fish stock. Stock assessment models satisfying some of these requirements have been developed and successfully used for management of the fishery

Demersal fish assemblages of the Southwest Coast of India

Demersal surveys from the southwest coast of India were analyzed to determine the general pattern of distribution of demersal species assemblages in the area. Seasonality is pronounced, indicating three major periods, pre-monsoon, monsoon and post-monsoon. Each of the periods is characterized by different oceanographic circulation patterns that mainly determine the pattern of distribution of species assemblages. Spatial analysis confirmed that the Wadge Bank has the highest potential for producing good quality fish. Region-wise analysis of data indicated that maximum effort and highest landings are from the known grounds along the southwest coast, although certain northern areas were also found to be fairly productive.Fishery resources, Demersal fisheries, Fishery surveys, Biomass, Population density, Shrimp fisheries, Catch/effort, Trawling, Population characteristics, ISW, India, Southwest,