Role of environmental variables on spawning and recruitment of small pegalics in an upwelling system

The marine ecosystem is dynamic and the variations several abiotic and biotic factors directly and indirectly affect the fish stocks and their population structure. Spawning and recruitment success is to a large extent linked to these environmental variations. It is well known that resources occupy a particular habitat because of their preference to the environmental variables prevalent there and also due the availability of food. We have large shoal forming small pelagic fishes like the sardines and anchovies and the deep water large pelagic and demersals occupying the marine ecosystem from the upper pelagic zone to the benthic realms. Fishing is one of the major activities directly impacting the fish stocks and fishery records show several cases of overfishing leading to stock collapses. Definitely, fishery management tools have supported revival of several of these stocks but have failed to do so in few others. Almost equally important in inducing the biological changes that control maturation, spawning and recruitment are the some ocean atmospheric processes which change inter-annually in the tropics

Biodiversity of bivalves (Invertebrata: Mollusca)

Bivalves constitute an important component of many benthic ecological habitats. They are adapted to withstand the frequ e nt physical and chemical changes characteristic of the marine aquatic ecosystems and as a resul they form an integral part of the benthic community structure. In estuaries, intertidal zones and near shore coastal areas of Kerala, they are well distributed. Geological history records of Kerala havc indicated several transgressions and reg ressions of the sea along the coast resu lting in many standstills during the Pleistocene and Holocene periods

Edible oyster seed production and remote setting- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Throughout the world natural spat collection forms the basis of most oyster culture industries. Along the Pacific Northwest USA coast, hatchery produced seed are used in the cultivation of the Pacific oyster Crassostrea gigas. Natural seed collection is cheaper when compared to the cost of seed produced in the hatchery but is unpredictable. However, in the recent years, more efficient methods of setting the oyster seed in remote areas have been developed and this method is widely practiced no

Book Review: Marine Mammal Species of India

The charismatic marine mammals of Indian waters which include the majestic whales, intelligent dolphins and endearing sea cows are among the least known of the marine living resources. Lack of appropriate literature on identification, nature of their habitat and restrictions on their capture under Wild Life protection Act are some of the constraints faced by researchers studying these spectacular endangered animals. The recent publication of the Central Marine Fisheries Research Institute, “Marine Mammal species of India” is packed with vital information on all the 26 species recorded in the Indian Seas. The Institute has been studying marine mammals since 1947 and particularly from 2003 to 2012 as a programme funded by Ministry of Earth Sciences

भारत में शंबु पालन

भारत में शंबु पाल

Edible oyster farming- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Oysters are one of the most valued seafood and are farmed extensively. Nearly eleven species of oysters are commercially popular and of these Crassostrea gigas is the most important. In Asia during the year 2003, 4.2 million tonnes of oysters were produced of which 3.6 million tonnes was from China contributing to 87% of the continents oyster production . Korea and Malaysia also produce significant quantities of oyster. Concerted efforts to develop the oyster farming technology have been made since 1970 ‘s at the Tuticorin Research Centre of CMFRI. Initially natural seed were used. The development of hatchery technology for large-scale oyster seed production in 1982 at the Shellfish Hatchery of CMFRI, Tuticorin gave further impetus for oyster culture. Several location testing programs for oyster culture have been taken up at many centres along the Indian coast, using both the natural and hatchery seed

Environmental Impact Assessment of Suspended Bivalve culture

Bivalves are sedentary organisms that require substrate for spat settlement and subsequent growth during which lime they filter feed on phytoplankton, detritus, protozoans and bacteria. It is well known that large scale aquaculture can pose complex ecological socio-economic and management problems. As commented by Hastings and Helnte in the introduction to the dedicated issue on “Effects of Aquaculture in the Estuarine Environment

In Conversation with Dr.E.G.Silas - former Director of CMFRI and Vice Chancellor, Kerala Agricultural University

Dr. Eric Godwin Silas, born in Demodhra, Sri Lanka, did schooling at St.Joseph's High School, Trivandrum, completed intermediate from Madurai American College and graduated from Christian College, Chennai

Marine litter impacts on the marine habitats and biota

Marine litter can affect im portant fish habitats such as the nursery and breeding grounds. The two main problems which marine litter pose to marine life are entanglement and ingestion Entanglement results when an animal becomes encircled or ensnared by litter. Entanglement can occur accidentally, or when the animal is attracted to the litter as part of its normal behavior or out of curiosity. Derelict fishing gear can entangle nektor. This problem is increasingly affecting turtles, sea birds and other large biota. This is called ghost fishing

Edible Oyster

Oysters come under the Class Bivalvia which encompasses aquatic molluscs that show a fundamental bilateral symmetry. Oysters inhabit the littoral and shallow subtidal areas and their distribution extends to a wide range of ecosystems including the coral reefs, mangroves and rocky shores. Unlike the mussels and scallops which attach by byssus threads, the oysters are cemented by the left valve to the substrate