Spatio-temporal analysis and impact assessment of trawl bycatch of Karnataka to suggest operation based fishery management options

Trawling is one of the most efficient methods of catching fish world over and is also the most important human intervention causing physical disturbance to the world’s continental shelves, and consequently, the physical destruction of ecosystems (Jennings and Kaiser, 1998). Trawling is targeted at specific groups of organisms, and trawl net being a non-selective gear, catches everything available in its towing path

Bycatch from Trawlers with special reference to Its Impact on Commercial Fishery, off Mangalore

Trawling, though one of the most efficient methods of fish capture, is also found to be the most important human caused physical disturbance on the world's continental shelves and hence the physical destruction of ecosystems (Jennings and Kaiser, 1998), Trawl fishery is generally a mixed fishery targeting a number of species and sizes simultaneously. Discarding is the practice of returning an unwanted section of the catch back to the sea during fishing operations (Alverson, 1994; Van Beek, 1998; Hall,2000

SYNTHESIS OF MESOPOROUS SILICA NANOPARTICLES AND DRUG LOADING FOR GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

Objective: To synthesize mesoporous silica nanoparticles using the sol-gel method and to determine the antibacterial activity of mesoporous silica nanoparticles and tetracycline loaded mesoporous silica nanoparticles.Methods: In the synthetic procedure, the surfactant Cetyl Trimethyl Ammonium Bromide (CTAB) is initially dissolved in basic aqueous solution, and the mixture is vigorously stirred. Tetra Ethyl Ortho Silicate (TEOS) is added, and the solution is kept stirring for 6 h. After the reaction is complete, the as-synthesized product is filtered and washed with deionized water. The antibacterial was tested using disc diffusion method and minimum bactericidal concentration (MBC).Results: The synthesized mesoporous silica nanoparticles were characterized by using Scanning Electron Microscope (SEM) micrographs showed spherical particles with an average size of 350 nm. The powder X-Ray Diffraction (XRD) analysis of the material further confirmed the crystallinity of the mesopores as evidenced by the diffraction pattern of an intense peak at θ=24º. Fourier Transform Infra Red Spectroscopy (FTIR) indicated the involvement of carboxyl, amine and hydroxyl groups in the synthetic process. The result shows the inhibitory growth zone of 20 mm and 18 mm for tetracycline loaded mesoporous silica nanoparticles against Escherichia coli and Staphylococcus aureus respectively.Conclusion: To summarize, it has been experimentally demonstrated that mesoporous silica nanoparticle and tetracycline loaded mesoporous silica nanoparticles show very good antimicrobial behavior against the gram-positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria.Keywords: Mesoporous silica nanoparticles, Sol-gel method, Drug loading, Antibacterial activit

Preliminary experiments on application of participatory GIS in trawl fisheries of Karnataka and its prospects in marine fisheries resource conservation and management

Geographic Information System (GIS) has become a part of our day today life in empowering institutions to formulate acceptable solutions in societal issues. More recently, public participatory GIS (PPGIS) and participatory GIS (PGIS) were viewed as more efficient tools in solving social and resource conservation issues, which empower communities those who are often ignored in traditional GIS practices. In fisheries, PGIS concept was first reported from Canada and on these lines pioneering efforts of involving concept of PGIS in fisheries is being attempted in Karnataka, where the geospatial data on fishing, catch and samples of fish caught by commercial fishing vessels were shared with the research organization and the data and samples thus shared were processed by fishery and GIS experts to come out with various tools for fishery management and resource conservation of the region. The study showed that the trawlers from Mangalore carried out trawling operations from sea off Calicut in the south (75 oE, 11 oN) to off Ratnagiri in the north (73.5 oE, 17 oN). Their depth of operation was between 5 m and 167 m, which signify the importance of revalidation of state–wise policies in introduction of mechanized vessels based on the landing in the respective states. The study showed that during the period, 237 species / groups of marine fauna were discarded of which many were juveniles of commercial species and rest were of adult size fishes of low or no market value. Spatio-temportal distribution and abundance of commercially lesser known species, which was not reported earlier from the coast,which have high trophic importance like small crabs, Charybdis hoplites and shrimp species like Metapenaeus andamanensis were brought out as the results of the study. Study also provided information on a unique ecosystem off Karnataka coast and with reef species and there is an immediate need for conserving this ecosystem. Based on the results of distribution and abundance of marine resources, spatial and seasonal restrictions on fishing efforts can be advocated in areas and seasons during which high incidence of bycatch of juveniles and non-commercial biota is being caught. This will help in sustaining marine fisheries from Malabar and Konkan coasts

A Case Study of Clustering Algorithms for Categorical Data sets

The data clustering, an unsupervised pattern recognition process is the task of assigning a set of objects into groups called clusters so that the objects in the same cluster are more similar to each other than to those in other clusters. Most traditional clustering algorithms are limited to handling numerical data. However, these cannot be directly applied for clustering of nominal data, where domain values are discrete and have no ordering. In this paper various categorical data clustering algorithms are going to be addressed in detail. A detailed survey on existing algorithms will be made and the scalability of some of the existing algorithms will be examined

Bivalve resources of Moorad Estuary, north Kerala

A bivalve resource survey of Moorad estuary in Badagara District of north Kerala was carried out during February 2004 to assess the bivalve species, their distribution and potential stock. Sampling sites were fixed within five main zones of the Moorad estuary based on the clam fishery activities and local enquiries. The bivalve distribution in a unit area was taken by demarking the area of clam bed with a quadrant. Observations on the area of clam bed, water clarity, depth and temperature were recorded at each site. Surface and bottom water samples were collected and hydrographic parameters like salinity, temperature, pH and dissolved oxygen content, productivity, nitrate, phosphate and silicate were recorded. Sediment samples were collected to analyse the grain size and organic content of the clam beds. All samples were analysed within 24 h except sediment samples. Average density of bivalve per square metre area was analysed and the potential stock was estimated for each bivalve species in the estuary

Fishery and biology of Meretrix casta (Chemnitz) in the Moorad estuary, Kerala

Meretrix casta forms an important fishery in the Moorad estuary. The average annual landing for the period 2000-2004 was 426t, the average catch per effort was 573 kg and total effort was 3182. Clams ranging from 28 to 32 mm size contributed to the fishery. M casta is a continuous breeder with two peaks in March-April and August-September. The precentage edibility ranged between 8 and 16. The standing stock biomass in the Moorad estuary was estimated at 2073 t with an average density of 1096 numbers per sq. m. The present status and management options for this important fishery are discussed

ग्रानडे द्दीप, गोवा के आसपास के प्रावाल खंडों पर जैवविविधता अध्ययन

कृपया पूरा लेखा पढ

Coral fish diversity in Netrani waters off Murudeshwar Karnataka, south India

Fish diversity associated with coral reef patches around Netrani Island, in Karnataka (south India) was investigated by visual census method. Sampling was done in four sites around the Island. A total of 69 species belonging to 39 genera, 19 families and 3 orders were recorded in the transect in four sites. When comparing the abundance, the fishes of Balistidae family dominated in all the four sites (22 %) followed by Pomacentridae (12.5 %), Caesionidae (9.7 %), Labridae (7.8 %), Acanthuridae (7.3 %), Haemulidae (6.7 %) and Scaridae (6.1 %). In line with the abundance and number, Shannon diversity indices (H’) were 2.8 in site 1; 2.6 in site 3; 2.3 in site 4 and 2.2 in site 1. The evenness (J’) of species distribution was more in site 2 (0.9), followed by site 3 (0.8); site 4 (0.7) and site 1 (0.7). The Bray-Curtis similarity was in the range of 69.98 to 79.50. The dendrogram plotted showed that site 2 and 3 form a group with similarity of 79.50, to which site 1 and site 4 got linked. There was no significant difference in the hydrographic parameters of the surface and bottom waters in four sites and also between different sites. The study revealed high coral fish density in the area indicating the need for adopting conservation measures.invertebrates, cnidarians and worms, zooplankton dominated by copepods and nekton dominated by Acetes spp. and clupeid juveniles were the major food items of A. monoceros. The von Bertalanffy growth equation was Lt = 63.53 [1 – e - 0.22 (t + 0.077)]. Natural mortality, fishing mortality and exploitation ratio were 0.53, 0.58 and 0.52 respectivel