The Indian oil sardine

The Indian oil sardine, Sardinella longiceps Val, supports a neritic pelagic fishery contributing 2 to 33 % of the annual marine fish production in India. Though distributed all along the Indian coast the species sustains a commercial fishery of high magnitude along the coasts of Kerala, Karnataka , Goa and southern part oJ Maharashtra. During the last fifty years the annual all India production oscillated between 14.000 t in 1952 to 3 lakh t during 1968. Presently the west coast indicates a declining trend compared to an ascending pattern along the east coasl. The production from east coast surpassed that of the west coast contributing 52% of the all India production of 2.03 lakh t in 1998. The fishery along the west coast is known for its fiuctuating nature. Further, the species indicates a cyclic pattern of abundance. A variety of traditional gears were engaged in exploiting the resource till the introduction of modern and sophisticated gear like the purse seines in the late seventies and the ring seines in the late eighties. In fact oil sardine is one among the few species that have ever remained a subject matter of intensive research. The focus of this compilation is to present a comprehensive picture of the Indian oil sardine, its fishery, biology, stock, future prospects of exploitation and management measures needed for yield optimisation

Age and growth of Malabar sole Cynoglossus macrostomus Norman off Kerala Coast

The age and growth of the Malabar sole, Cynogl- mocmtamcs Norman occurring along the coastal seas off Kerala were studied. The length frequency studies indicated that the fish attained 114.0 mm, 136.5 mm, 1525 mm and 159.5 mm at the end of 1 to 4 years. The growth rings on scales showed that the fish attained 118.7 mm, 134.8 mm and 150.3 mm when I to 111 rings are formed on scales. The time of formation of &he rinp on scales was found to be during October-December and February-April. The growth parameters were determined by the von Bertalanffy growth formula, Ford-Walford graph and by the Gulland and Holt plot The values obtained were Loo = 166 mm and K = 0.714lyear

Continuum description of profile scaling in nanostructure decay

The relaxation of axisymmetric crystal surfaces with a single facet below the roughening transition is studied via a continuum approach that accounts for step energy g_1 and step-step interaction energy g_3>0. For diffusion-limited kinetics, free-boundary and boundary-layer theories are used for self-similar shapes close to the growing facet. For long times and g_3/g_1 < 1, (a) a universal equation is derived for the shape profile, (b) the layer thickness varies as (g_3/g_1)^{1/3}, (c) distinct solutions are found for different g_3/_1, and (d) for conical shapes, the profile peak scales as (g_3/g_1)^{-1/6}. These results compare favorably with kinetic simulations.Comment: 4 pages including 3 figure

Seasonal landings of oil sardine, Sardinella longiceps at Rameswaram, Pamban and Mandapam areas

Unusual and unprecedented landings of oil sardine, Sardinella langiceps were noticed at Rameswaram and Pamban during January and February 1992. The estimated catch of oil sardine at Rameswaram for January- February 1992 was 4,561 t. The pair trawlers contributed 4,244 t and fish trawlers 317 t. The C/E varied from 1.5 to 8 t. At Pamban the pair trawling during the period realised 741 t

On the conservation and management of marine turtles

There are five species of marine turtles occurring in and around Mandapam - Rameswaram; both in the Gulf of Mannar and Palk Bay regions. They are incidentally caught live in trawl net, shore-seine, drift-gill net and bottom-set gill net operations in this area. They are in great demand in the rural sector. Though, the fishermen are aware that these endangered animals are protected, often the profit motive make them to sell these turtles. Whenever, any incidence is brought to the notice of the Regional Centre of the Institute, attempts have been made to rescue and release them back to the sea as a conservation measure

On the sei whale Balenoptera borealis Lesson stranded along Palk Bay coast near Pamban light house

A Sei whale got entangled in a gill net operated near Katchathievu on 27-l-'90 at a depth of 8.5 m at about 1900 hrs. Four boats joined together and brought the whale ashore near Pamban Light House on the 28th morning in live condition. Attempts were made to push the whale back into the sea but did not succeed. The medium sized female whale measured 11.4 m in total length and weighed about 7000 kg. The specimen was identified as Balaenoptera borealis Lesson (Fig. 1) and it had 47 throat grooves. The morphometric measurements are give

Observation of Pure Spin Transport in a Diamond Spin Wire

Spin transport electronics - spintronics - focuses on utilizing electron spin as a state variable for quantum and classical information processing and storage. Some insulating materials, such as diamond, offer defect centers whose associated spins are well-isolated from their environment giving them long coherence times; however, spin interactions are important for transport, entanglement, and read-out. Here, we report direct measurement of pure spin transport - free of any charge motion - within a nanoscale quasi 1D 'spin wire', and find a spin diffusion length ~ 700 nm. We exploit the statistical fluctuations of a small number of spins ($\sqrt{N}$ < 100 net spins) which are in thermal equilibrium and have no imposed polarization gradient. The spin transport proceeds by means of magnetic dipole interactions that induce flip-flop transitions, a mechanism that can enable highly efficient, even reversible, pure spin currents. To further study the dynamics within the spin wire, we implement a magnetic resonance protocol that improves spatial resolution and provides nanoscale spectroscopic information which confirms the observed spin transport. This spectroscopic tool opens a potential route for spatially encoding spin information in long-lived nuclear spin states. Our measurements probe intrinsic spin dynamics at the nanometre scale, providing detailed insight needed for practical devices which seek to control spin.Comment: 7 pages, 2 figures, under consideration at Nature Nanotechnolog

Status and scope of research on pelagic fisheries of India

Extensive and indiscriminate exploitation of marine natural resources, during the last three decades is leading to a situation where no more commercial fish stocks may be left in the sea by year 2050 unless ecosystems are protected and the biodiversity is revived, warns a new study cataloging the global collapse of marine ecosystems (Worm et al., 2006). The task of understanding the dynamics of large marine ecosystems to offer effective and relevant scientific advice to develop management interventions is a difficult, complex, expensive and lengthy process. This is especially true in the Indian context where the country has an EEZ of 2.02 million km2, which contributes nearly 40% of the total fish production from the Indian Ocean. Fishes have been mentioned in the ancient literature of India including the epics such as Ramayana and Mahabaratha. Excavations from Mohenjodaro and Harappa indicate that fishing with hooks and nets was common as back as 3000 B.C. and over the years fishing and fisheries in India have evolved at a rapid pace (Ayyappan et al., 2004). Marine fisheries is basically harnessing a natural resource and therefore its management must anchor on knowledge- based interventions generated through close monitoring of their distribution, abundance, exploitation, population dynamics and fluctuations of fish stocks in relation to natural factors and anthropogenic interventions. Against a scenario of an ever-increasing population and stagnant marine fish production in recent years, per capita seafood availability is a serious concern. The countr

Drift gill net fishery for large pelagics at Cochin - A case study on by-catch of pelagic sharks

In India, the elasmobranchs contributed on an average 60,8(X) t during 1986 to 1999 forming 2.7% of the total marine fish landings. The production varied from 50,000t in 1990 to a highest of 75,(X)0 t in 1998. The sharks dominated forming 62.4%, followed by rays (33.5%) and skates the rest. The west coast accounted for 55.5% and east coast 44.5%. The highest contribution of 30.2% was from Gujarat followed by Tamilnadu (26.2%). The drift gillnets, sharing 48.5% of the production, was the major gear, followed by trawls (31.5%) and hooks and line (6.1%). Since the drift gillnets (DGN), apart from the scombroids, exploit a variety of larger pelagics, a case study of the shark fishery by the gear at Kochi was made based on the data from 1979 to 1999 and the results are presented her