സമുദ്രത്തിലെ ജൈവസമ്പത്തും ഉല്പാദനവും (The organic wealth and fish production in the sea)

It is well known that all life in the sea depends primarily om the conversion of carbon and nitrogen into protoplasm. This process is mainly carried out by the microscopic plants known as phytoplankton or micro-algae. They absorb the nutrients from the surroundings and convert them into starch, fat and protein with the help of chlorophyll pigments and sunlight. Just as on land, in the sea also, animal life is not possible without plants. Plants form the food of herbivores and the herbivores nourish the carnivores. No life including fish can exist in seawater without phytoplankton. They are the primary producers and their importance lies in the fact that they are photosynthetic organisms and sewe as the first link in the food chain. They are known as the grass of the sea and are the most important among the prime synthesizers of food in water

Life-feed culture - micro algae

Marine micro algae are the floating microscopic plant components of the seawater which forms the basic food of almost all the larval organisms, either crustaceans, molluscs or fishes. They are the primary producers of the sea belonging to various Classes of algae. The important components of micro algae are the diatoms, dinoflagellates, silicoflagellates (phytoflagellates), coccolithophores, blue-green algae and the 'hidden flora' the nanoplankters. Among these, the diatoms and phytoflagellates are significant organisms since they form the primary link in the food chain of the sea. It is known that the success of any hatchery operations depends mainly on the availability of the basic food, the micro algae

Micro algae culture as live feed-Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Marine micro algae are the floating microscopic plant components of the seawater which forms the basic food of almost all the larval organisms, either crustaceans, mollusks or fishes. They are the primary producers of the sea belonging to various Classes of algae. The important components of micro algae are the diatoms, dinoflagellates, silicoflagellates (phyto-flagellates), coccolithophores, blue-green algae and the ‘hidden flora’ the nanoplankters. Among these, the diatoms and phytoflagellates are significant organisms since they form the primary link in the food chain of the sea. It is known that the success of any hatchery operations depends mainly on the availability of the basic food, the micro algae

Marine microalgae

The microscopic plant components of the sea, excluding the macroscopic seaweeds, form the microalgae or phytoplankton. They arc the primary producers synthesizing the basic food for all the larval forms in a marine ecosystem. They belong to the Class Algae, which besides chlorophyll possess other characteristic pigments. The important components of microalgae are: Diatoms (Bacillariophyceae), Dinoflagellates (Dinophyceae), Bluegreen algae (Cyanophyceae), Phytoflagellatcs (Chlorophyceae, Haptophyccac, Cryptophyceae) and Nanoplankters (Chiarella, Nannachlaropsis). Besides, two other subclasses - Silicoflagellates and Coccolilhophores also belong to the microalgae since they are autotrophic organisms. Culture of microalgae is an essential component in any type of hatchery system. Blooms of toxic phytoplankton causes severe hannful effects to the aquatic system and sometimes causes mass mortality of fishes in coastal waters. Based on the productivity of an ecosystem, potential harvcstable resources can be estimated. Recent estimates based on phytoplankton production indicated that vast exploitable resources are available from the Indian seas

Microalgae culture

For the successful culture of microalgae, various chemical culture media have been used depending on the type of organisms cultured and their growth phase

Estimation of primary productivity- Winter School on Towards Ecosystem Based Management of Marine Fisheries – Building Mass Balance Trophic and Simulation Models

The primary production can be defined as the amount of organic materials, which by the activity of organisms in unit time is synthesized in a unit volume of water by the phytoplankton using the solar energy and extending from the sea surface to the bottom of the euphotic zone. The micro algae remove dissolved carbon dioxide and micro nutrients from the water and using solar energy convert them into complex organic compounds of high potential energy with the help of photosynthetic pigments, the chlorophylls. The primary productivity will be confined practically entirely to that brought about by phytoplankton. The growth and distribution is controlled by many factors which may be physical factors like light, temperature, currents etc., chemical factors like salinity, dissolved oxygen content, pH, nutrients such as nitrite, nitrate, phosphate and silicate and trace elements, organic minerals etc., biological factors like grazing and reproduction, hydrological events like upwelling, sinking, turbulence etc., and seasonal variations like winter, summer, spring and autumn

Methods of culturing phytoplankton

It is an established fact that the success of any hatchery operation will depend mainly on the availability of the basic food, the phytoplankton. The maintenance and supply of the required species at appropriate time form a major problem facing the algal culturists. The procedure for the phytoplankton culture involves aspects such as the isolation of the required species, preparation of the suitable culture media, maintenance of the culture in the laboratory scale, as well as large scale under controlled conditions of light, temperature and aeration and their constant supply in different phases of growth

Toxic algal blooms - - Winter school on recent advances in diagnosis and management of diseases in mariculture, 7th to 27th November 2002, Course Manual

Incidents of phytoplankton blooms, either harmful or harmless, discolouration of coastal waters, either red, pink, brown and green, has been a regular feature along the Indian coasts, especially in the west coast of India. The red tide or red water phenomena are generally intermingled with changes in chemical properties of coastal waters. Introduction of nutrients during the summer monsoon period through river run off and coastal upwelling are major factors influencing the algal blooms. Most cases of blooms have been harmless, since the aquatic fauna will try to avoid the area and fall in fish catches have been reported every time. However, in recent years, a few cases of fish mortality have been reported in the West Coast, due to algal blooms and effects of PSP and DSP depending on the organisms bloomed. Thus the problem of harmful algal blooms along the Indian coast is more serious than apparent and needs urgent attention to check further escalation due to eutrophication

The organic wealth and fish production in the sea - Phytoplankton production

It is well known that all life in the sea depends primarily om the conversion of carbon and nitrogen into protoplasm. This process is mainly carried out by the microscopic plants known as phytoplankton or micro-algae. They absorb the nutrients from the surroundings and convert them into starch, fat and protein with the help of chlorophyll pigments and sunlight. Just as on land, in the sea also, animal life is not possible without plants. Plants form the food of herbivores and the herbivores nourish the carnivores. No life including fish can exist in seawater without phytoplankton. They are the primary producers and their importance lies in the fact that they are photosynthetic organisms and sewe as the first link in the food chain. They are known as the grass of the sea and are the most important among the prime synthesizers of food in water

Production and exploitation of living marine resources

An unprecedented increase in the wo r ld population during the past few decades has made the scientists to predict that by the year 2000 A. D., the world population will increase from the present 2.7 billion to 7 billion. Agriculture and natural resources can be enhanced to sustain a p opulation of that size, but the p eople, no doubt, will begin to s uffer from chronic deficiency of protein and fat