Ring seine fishery of Kerala: An overview

Among the various fishing gears employed for pelagic schooling fishes along the Kerala coast, seines are the most efficient. Contribution of ring seine to total marine fish landings of Kerala has steadily increased since its introduction during the early eighties. It was 21.4 % in the nineties rising to 36.7 % during the period 2000-2004 and contributing more than 50 % since then. In recent years, about 90 % of the oil sardine and about 60 % of the mackerel landed in Kerala were caught in ring seines. Ring seines were introduced during the early eighties by traditional fishers of Alappuzha District which became highly successful

Novel Plasmonic Nanocavities for Optical Trapping-Assisted Biosensing Applications

Plasmonic nanocavities have proved to confine electromagnetic fields into deep subwavelength volumes, implying their potentials for enhanced optical trapping and sensing of nanoparticles. In this review, the fundamentals and performances of various plasmonic nanocavity geometries are explored with specific emphasis on trapping and detection of small molecules and single nanoparticles. These applications capitalize on the local field intensity, which in turn depends on the size of plasmonic nanocavities. Indeed, properly designed structures provide significant local field intensity and deep trapping potential, leading to manipulation of nano-objects with low laser power. The relationship between optical trapping-induced resonance shift and potential energy of plasmonic nanocavity can be analytically expressed in terms of the intercavity field intensity. Within this framework, recent experimental works on trapping and sensing of single nanoparticles and small molecules with plasmonic nanotweezers are discussed. Furthermore, significant consideration is given to conjugation of optical tweezers with Raman spectroscopy, with the aim of developing innovative biosensors. These devices, which take the advantages of plasmonic nanocavities, will be capable of trapping and detecting nanoparticles at the single molecule level

Fishery and estimation of potential yield of Bombayduck Harpadon nehereus (Hamilton, 1822) along Gujarat coast, India

Bombayduck Harpadon nehereus (Hamilton, 1822) is one of the key fishery resources landed along the Indian coast with uniqueness in distribution and exploitation. The resource is known for discontinuous distribution, majorly along the north-west and north-east coasts of India. Gujarat is the lead state to contribute nearly 64.72% (72,949 t) to the total national landings of the resource (11,2705 t) in 2018. Dolnet gear contributes nearly 95% of the total landings of the resource in the region. The landings and the corresponding catch per unit effort (CPUE) showed a fluctuating trend over the study period of 1994-2014. The catches fluctuated between 35,235 t (2016) and 92,188 t (2004), whereas the CPUE oscillated in the range of 15 to 20 kg h-1 (1998) and 30.76 kg h-1 (2003). The period of 1994-2000 was the most productive period with an average catch of 72,133 t, whereas the succeeding decade was the leanest phase with an average annual catch of 50,035 t. The estimated potential yield (= maximum sustainable yield, MSY) was estimated at 73,700 t and 70,108 t using the Bayesian surplus production model (CMSY & BSM) and basic Schaefer surplus production model respectively. The present catch and exploitation levels were found to be close to the optimum level and a further increase in effort for the resource is not recommended

Fishery, biology and stock structure of skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) exploited from Indian waters

Global catches of skipjack tuna have been steadily increasing since 1951, reaching a peak in 2009 at 25, 99,681 t (Fig.1). Most of the catches were reported from the fishing areas 71, 51, 61 and 34 (FA0, 2011). Globally skipjack tuna is caught at the surface, mostly with purse seines and pole and lines and to a small extent by gillnets, troll lines and longlines. Gears like purse-seine and very long gillnets enabled few nations to augment their production, whereas traditional pole and line nations suffered heavily

Potential Yield Estimates for marine fisheries of Gujarat

Seagrass meadows worldwide are declining fast, taking with them many species which depend on these underwater prairies as their habitat and feeding as well as breeding grounds. Our results obtained on the biomass and density of seagrass vegetation in the reef and lagoons of Agatti, Chetlat, Kavaratti and Kiltan Islands of U.T. Lakshadweep, indicated gradual but steady shrinking of seagrass meadows. The percentage reduction in density of seagrass meadows since December 2011 to November 2015 was estimated at 88.5% in Agatti, 88.7% in Chetlat, 78.4% in Kavaratti and 81.3% in Kiltan. Wet biomass of parts below the sediment were always higher than the epigeal parts comprising leaves, stem and bracts. The possible reason behind this decline in seagrass biomass might be grazing, deterioration of water quality due to increased anthropogenic activities and climate change. This situation calls for urgent steps to monitor the ecology and physico-chemical parameters of water and sediment in the existing meadows and to undertake immediate habitat restoration programmes

Role of Anti Thymocyte Globulin (ATG) Prior to Unrelated Donor Stem Cell Transplantation (URD SCT) in Patients with Hematologic Malignancies: A Single Center Experience

15 juillet 19461946/07/15 (N16)

Cetacean bycatch in Indian Ocean tuna gillnet fisheries

Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combined published results from 10 bycatch sampling programmes (1981−2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100 000 ind. yr−1 during 2004−2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, or of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean

Cetacean bycatch in Indian Ocean tuna gillnet fisheries

Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combined published results from 10 bycatch sampling programmes (1981−2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100 000 ind. yr−1 during 2004−2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, or of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean