FLA that lived in aquatic ecosystems equipped with flagellates (Ekelund and Ronn, 1994). There are several species of amoeba that lives in the marine ecosystem as consumers and producers but some are known to harbour with symbiotic algae (Gast et al., 2009). FLA is a single living cell with the organelles and cytoplasm are enclosed by a cell membrane with
1. INTRODUCTION: Algae are often associated as plants that do not have roots, stems or leaves and have basic methods of reproduction. They undergo carbon fixing and oxygenation. Some have primitive animal behaviour such as motility, other algae such as the blue-green algae have cellular functions, structure and behaviour similar to that of a bacteria. The habitats of algae vary widely but most of them are in aquatic environments and are essential in the aquatic ecosystem.
Algae is a plant which range from the microscopic(microalgae) to more than one hundred feet in length. Microalgae include cyanobacteria(blue-green algae) as well as green, brown and red algae. Algae grows in water resources such as brackish, sea and waste water unsuitable for cultivating agricultural crops. Most microalgae grow through photosynthesis which is by converting sunlight, CO2 and a few nutrients, including nitrogen and phosphorus ,into material known as biomass. This is called “autotrophic” growth.
Algae are photosynthetic organisms found in most habitats (usually aquatic). Algae are classed into macroalgae and microalgae. Micro algae are extremely efficient for their size. Microalgae have a much larger mass to surface area ratio than land plants which gives them a better access to carbon dioxide, water and nutrients. Current sources of oil are draining on land and soil that is needed for crops for food produce, algae however can be grown in bioreactors or artificially engineered ponds.
Most marine invertebrates depend on microalgae for their whole life cycle, so commercial and experimental mollusc or fish hatcheries have included a microalgae production system in parallel to their animal production itself. Microalgae are utilized as live feed for all growth stages of bivalve mollusc such as oysters, scallops, clams and mussels and for zooplankton used in aquaculture food webs at large. Over the last four decades, several hundred microalgae species has been tasted as food, but properly less than twenty have gained widespread use in aquaculture. For example the type species of microalgae use in aquaculture are Tetraselmis sp.,Chaetoceros sp., Chlorella sp.Spirulina sp.,Chaetoceros sp., Nannochloropsis sp., Isochrysis sp. and
Algae have recently received a lot of attention as a new biomass source for the production of renewable energy. Some of the main characteristics which set algae apart from other biomass sources are that algae (can) have a high biomass yield per unit of light and area, can have a high oil or starch content, do not require agricultural land, fresh water is not essential and nutrients can be supplied by wastewater and CO2 by combustion gas. A microalga is a class of plants distributed widely in both terrestrial and marine environments. Currently more than 40 different species of microalgae were studied for multiple purposes such as fresh water environmental protection and biomass production content analysis. Because autotrophic microalgae produce
Anyhow the farming system is classified into three respects with the quantity of FEED (Fertilizer) applied (Edirisinghe, 2009). In Extensive culture feed comes from the natural environments (Zero input of feed) and while the Intensive culture it supplied all their feed 100%. In respect with Sri Lanka, some ornamental fish species are cultured in this method and it is a monoculture
In the year 1974 aquaculture became commercial. For breeding purpose a pond was built in Bique especially for prawns. This development quickly expanded likewise because of presenting Whiteleg Shrimp homesteads and incubation facilities. The main lakes were contructed in Veraguas region, trailed by a 34 hectare ranch in Aguadulce and an incubation facility for bringing post hatchlings up in the town of Veracruz. In the year 1995 a law was released which stated aquaculture as farming.
It is the world’s fastest growing segments of agriculture system in past decades, with an overall growth rate of 11% a year since 1984. The farming of fish which is the most common form of aquaculture, involves raising fish commercially in ponds, tanks, river enclosures usually for food. In Nigeria, fish culture is carried out on small to large commercial scale. Present annual aquaculture production is about 50-60,000 tonnes contributing only 5% of total domestic production while capture fisheries account for over 855 of national production. The demand for fish in Nigeria has increased from 1-2million metric tonnes in 1989 to about 2.5million metric tonnes, while the present production is only 20% of the estimated yearly potential.
By combination both of this method, it can say that aquaponic is the sustainable agriculture, because it reuse the non-renewable resources. During fish respiration, the oxygen and carbon dioxide has exchanged in a cycle, while the waste product from fish has highly nitrogen or ammonia content. Highly concentration of ammonia within the fish habitat will slow the growth rate of fish and it also can damage the tissue of fish or in other words, the fish will die if there is no management on water quality (Masser, Rakocy and Losordo, 1999). So, water from the fish tank is pump into the plant beds and this water contain highly nitrogen levels. Beneficial bacteria that present in a plant bed has help the process of water cleaning.