Algal Culture unicellular and multicellular (seaweeds) Total Plant Aquaculture = 15,781,000 mt Unicellular or micro-algal production -? Multicellular seaweeds = 13,241,000 mt 84% of total plant aquaculture
Culture conditions necessary for growth of algae and seaweeds A. Light B. Carbon dioxide C. Appropriate temperature D. Nutrients E. Salinity F. Mixing Photosynthesis LIGHT ENERGY Carbon dioxide + water {CHLRPHYLL} xygen + Sugar 12 (C 2 + H 2 ) {CHLRPHYLL} 2 + C 6 H 12 6
Phytoplankton (micro-algae) are microscopically small single-celled plants free floating in the water. Diatoms are a special group of algae with cell walls made of silicate. Some species use flagella or cilia to move within the water. Isochrysis = 5 microns in diameter Chaetoceros = 6 microns in diameter Note: the diameter of a human hair = 40 120 microns
Diatoms Size μ Flagellates Size μ *Skeletonema costatum 6 Chlamydomonas coccoides 7 *Chaetoceros calcitrans 2.5 Nannochloris occulata 2 *Chaetoceros gracilis 6 Dunaliella tertiolecta 6.5 Phaeodactylum tricornutum 5 *Tetraselmin suecica 8.5 *Thalassiosira pseudonana (3H) 5.5 *Isochrysis galbana, (T.IS) 5 *Monchrysis lutheri 4 Table 1. Algal species commonly used as food in aquaculture. Those marked with an asterisk are most often fed to oysters and clams.
Provasoli-Guillard National Center for Culture of Marine Phytoplankton Quan. Compound Stock Sol. CCMP's L/20 Medium Sterilize 1.0 L filtered seawater in teflon bottle. After the seawater has cooled, aseptically add the following stock solutions. 0.1 ml 0.1 ml 0.1 ml 0.1 ml 5.0 ml 0.1 ml 0.05 ml NaN 3 NaH 2 P 4 *H 2 NH 4 Cl Na 2 EDTA*2H2 Alkaline Soil Extract f/2 Trace Metal Solution f/2 Vitamin Solution 75.0 g/l dh 2 5.0 g/l dh 2 26.8 g/l dh 2 37.2 g/l dh 2 Adjust ph to 7.8-8.2 with HCl (see recipe) (see recipe) (see recipe)
Alkaline Soil Extract In a flask add two parts by volume distilled water (dh2) to one part rich organic garden soil (containing no recent applications of chemical fertilizer or pesticides). Add 2-3 g NaH/liter. Autoclave for 2 hours, and filter when cool. This concentrated extract is diluted 1:50 in dh2 for the final working stock. (Seawater may substituted for dh2 if the extract is to be used for marine species). Quan. 3.15 g 4.36 g 1.0 ml 1.0 ml 1.0 ml 1.0 ml 1.0 ml f/2 Trace Metal Sol. To 950 ml distilled H2 add: Compound FeCl 3 *6H 2 Na 2 EDTA*2H 2 CuS 4 *5H 2 Na 2 Mo 4 *2H2 ZnS 4 *7H 2 CoCl 2 *6H 2 MnCl 2 *4 H 2 - - Stock Sol. 9.8 g/l dh 2 6.3 g/l dh 2 22.0 g/l dh 2 10.0 g/l dh 2 180.0 g/l dh 2 Final volume to 1.0L with dh2. Autoclave
f/2 Vitamin Solution To 950 ml dh2 add: Quan. 1.0 ml 10.0 ml 200.0 mg Compound Vitamin B12 Biotin Thiamine HCl 1.0 g/l dh 2 0.1 g/l dh 2 - Stock Sol. Make final volume up to 1.0 L with dh2. Filter sterilize & refrigerate. Note: Vitamin B 12 and Biotin are obtained in a crystalline form. To prepare the Vitamin B 12 Stock Solution, for each 1.0 mg of Vitamin B 12 add 0.89 ml dh 2 ). To prepare the Biotin Stock Solution, for each 1.0 mg of Biotin add 9.6 ml dh 2
Micro-algal culture
Algal growth curve
Blue-green algae Spirulina 70 million dollar California industry Earthrise is the world's largest Spirulina farm, covering a 108 acre site. Earthrise produces over 500 metric tons of dry powder annually and sells in over 40 countries. ANS - 18; Algal culture
The 30 Spirulina ponds have food grade liners. Each is 5000 square meters, over an acre in size and larger than a football field. Clean fresh water and nutrients are added daily to feed the algae, mixed by 50-foot paddlewheels in each pond. Culture conditions, such as alkalinity are optimized ANS - 18; Algal culture for Spirulina growth.
Macroalgae (multicellular) Red seaweeds such as nori or Porphyra Brown seaweeds or kelps ; high in algin Red & brown seaweeds dwell almost exclusively in marine (or coastal) environments. The group dominates many benthic marine biotas, sometimes reaching from the ocean floor to its surface. In general, they are not free-floating organisms, but are attached to rock, coral, or other firm surfaces. The group is found primarily in colder waters of the northern hemisphere, with the largest forms occurring in cooler waters, rather than in the tropics. Many familiar species, such as rockweed, are intertidal, and are exposed to the air at low tide. 1 There are a few pelagic (= floating) seaweeds, the best known example is Sargassum which is prominent in the Sargasso Sea
Red seaweeds Nori (Porphyra) high in agar and carrageenan While only 562,000 tonnes were produced in 2008 the value was $ 940 million making nori the most valuable of the cultured seaweeds The name come from the strong red color of the young thallus stage, however as it grows the thallus becomes a dark purple. protein - 25-35% of dry weight 75% of protein & carbohydrates digestible vitamins and minerals (vitamin C content 1.5 X that of oranges and it is a good source of iodine)
Nori coldwater sp. 10 18 o C Since the 17th century Japanese fishermen planted "hibi" 1949, the filamentous Conchocelis-phase of Porphyra was discribed by the British phycologist, Kathern M. Drew-Baker
Nori production cycle optimum growth 10 18 o C British phycologist, Kathern M. Drew-Baker in 1949, found the filamentous Conchocelisphase in the life history of Porphyra
Cultivation of the conchocelis stage May to September Sporophytes are seeded on mollusk shells (May) in long concrete tanks with 20 30 cm of fertilized seawater in depth. ptimum growth of the conchocelis phase is 20 25 o C September to ctober The sporophytes release conchospores, which are seeded on special cultivation nets that have been placed in the tanks. Water in the tank agitated to obtain an even distribution of the conchospores Page 2
Cultivation of the thallus stage The seeded nets are fixed to rafts for growout As the thallus grows, it will be cut near the holdfast allowing further growth, allowing a harvest every couple of weeks.
Processing of Porphyra The harvested thalli are wasted in seawater to remove contaminants Chopped into small pieces and washed again briefly The thallus suspension is poured into a metallic framework with a plastic net at the bottom to produce individual sheets when dryed. These sheets are then packaged and sold.
Brown seaweeds or kelps Laminaria (Japanese kelp) eaten as a vegetable & grown as a commercial source of alginates) Production = 4.8 million tons in 2008 with a value of $ 2.8 billion Unidaria (wakame) also eaten as a vegetable particularly in soups - Production = 1.8 million tons in 2008
Both Laminaria and Undaria are cold-water species and thus are winter crops. Laminaria < 16oC and for Undaria ~ 12 oc is optimum ANS - 18; Algal culture
Macrocystis (giant bladder kelp) An important brown algal species along the California coast is: Found along the Pacific coast of North America from central California to Baja California. This species may grow to lengths of 60 m (200 ft) with its upper fronds forming a dense canopy at the surface. Kelp begins life as a microscopic spore, which grows into a tiny male or female plant called a gametophyte. These plants produce eggs and sperm, which fertilize and grow to form the large plants (sporophytes) The large sporophytes then release many new spores to start the process over again. The minimum amount of time needed to complete the Macrocystis life cycle is believed to be 12 to 14 months although in the environment, grazing by animals and shading by other plants affect this rate of development. Giant kelp prefers depths less than 40 m (120 ft) temperatures less than 20 oc (72 of) hard substrate such as rocky bottoms bottom light intensities within 1% that of the surface.
Giant bladder kelp or Macrocystis is the easy to harvest for several reasons. The fact that it is found in deep water habitat allows large harvesting boats to operate more easily. The surface canopy can be harvested several times a year without disturbing the submerged vegetative and reproductive parts which are located below the harvesting levels thus ensuring the kelp will continue to reproduce and the surface canopy will be regenerated by the younger fronds growing below the surface. In the early 1930's the algin-extraction industry was developed. Algin, a highly efficient thickening, stabilizing, suspending and gelling agent. The harvesting of kelp in the state is regulated by the California Department of Fish and Game with the maintenance and improvement of the kelp beds important considerations. The State of California has imposed a number of restrictions on harvesting activities. Kelp harvesters are permitted to cut only the upper 1.2 meters (4 feet) of the water column. This regulation is to limit damage to the kelp's reproductive structures and allows vegetative regrowth from the unharvested fronds below the surface on cut plants. Stands of kelp throughout the state are designated by number and some are leased by harvesting companies while others remain open to anyone with a harvesting permit. The kelp beds are leased for a period of 20 years. No more than 25 square miles or 50% of the total kelp bed area, whichever is greater, can be exclusively leased by one company.