Shrimp culture - its ecological imperatives and eco ethical solutions

The number of shrimp farming countries grown from 33 in 1984 to 62 in 2001. In 1997, 27% of the shrimp consumed came from aquaculture and percentage in increasing as shrimp catches from the seas world over declines (Primevera, 1977). The total shrimp production in the world stands at approximately 3 million tonnes per annum of which farmed shrimp formed 700,000 tonnes in 1999. Now it stands at 1.1 14 million metric tonnes, a five-fold increase from 2,13,640 tonnes in 1985. Almost half the international . trade is cornered by shrimp and shrimp products produced through aquaculture, with the top five producers being Thailand, Ecuador, Indonesia, China and India. The United States is the single largest importer of shrimp, though India markets a substantial portion of its produce to Japan, Singapore and the European Union Countries

Histopathological changes in the hepatopancreas of the penaeid shrimp Metapenaeus dobsoni exposed to petroleum hydrocarbons

Petroleum hydrocarbons are toxic to marine invertebrates when present above a threshold level in the marine ecosystem. The major detoxification organ in shrimps is the hepatopancreas, which has been used as an indicator organ for toxicity assessment. The effects of Bombay High Crude on the morphology of hepatopancreatic tubules of Metapenaeus dobsoni when examined under the light and electron microscopes reveal a series of changes indicating that the cellular compensatory mechanism is activated by low or sub lethal doses of hydrocarbons. At the high sub lethal dose of 8 ppm the cellular detoxification mechanisms fail resulting in severe structural damage. The changes indicate that they are dose and time related histopathological responses. Changes such as an increased presence of B - cells towards the distal end of the tubule, substantial increase in the number of F/B cells, extensive cytrorrhexis, reduction in the number of E- cells. vacuolation of E-, R- and F- cells are changes which can be detected under light microscope along with the presence of pyknotic nuclei, storage of large lipid droplet in combination with cells voided of other subcellular components, proliferation and distortion of Golgi apparatus and mitochondria which were detected in the ultrastructure study can be used as biomarkers of stress caused by petroleum hydrocarbon pollution

Shoreseine (Yendi) operations during the monsoons at Karwar, Uttar Kannada District of Karnataka

After the introduction of trawlers in the 1970s and purseseiners in 1980s, the rampan shoreseine, which was a gear of primary importance along the Uttar Kannada coast, was phased out or replaced and has gradually disappeared. Legislation was promulgated on fishing by mechanised boats in coastal areas in the interest of traditional fishers who fish within 10 m depth

New way to achieve chaotic synchronization in spatially extended systems

We study the spatio-temporal behavior of simple coupled map lattices with periodic boundary conditions. The local dynamics is governed by two maps, namely, the sine circle map and the logistic map respectively. It is found that even though the spatial behavior is irregular for the regularly coupled (nearest neighbor coupling) system, the spatially synchronized (chaotic synchronization) as well as periodic solution may be obtained by the introduction of three long range couplings at the cost of three nearest neighbor couplings.Comment: 5 pages (revtex), 7 figures (eps, included

Whale shark landings in Uttar Kannada, Karnataka

The whale shark, Rhincodon typus Smith, 1828, has a circumglobal distribution in tropical and warm temperate seas. Since May 2003 it has been included under Appendix II of CITES, making the trade of this species regulated. The status of this species has since then been upgraded from “Data deficient” in 1996 to “Vulnerable” in 2000 by the IUCN. Currently it is protected under Schedule I Part II of the Wildlife Protection Act of India, 1972