Algal Culture – unicellular andmulticellular (seaweeds)

Total Plant Aquaculture = 15,781,000 mt

• Unicellular or micro-algal production - ?

• Multicellular – seaweeds = 13,241,000 mt84% 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

PhotosynthesisLIGHT ENERGY

Carbon dioxide + water {CHLOROPHYLL} Oxygen + Sugar12 (CO2 + H2O) {CHLOROPHYLL} O2 + C6H12O6

Phytoplankton (micro-algae) are microscopically smallsingle-celled plants free floating in the water. Diatoms area 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

4*Monchrysis lutheri

5*Isochrysis galbana,(T.ISO)

5.5*Thalassiosirapseudonana (3H)

8.5*Tetraselmin suecica5Phaeodactylumtricornutum

6.5Dunaliella tertiolecta6*Chaetoceros gracilis

2Nannochloris occulata2.5*Chaetoceros calcitrans

7Chlamydomonascoccoides

6*Skeletonema costatum

Size μFlagellates Size μDiatoms

Table 1. Algal species commonly used as food inaquaculture. Those marked with an asterisk are mostoften fed to oysters and clams.

Provasoli-Guillard National Center forCulture of Marine Phytoplankton

CCMP's L/20 MediumSterilize 1.0 L filteredseawater in teflon bottle.After the seawater hascooled, aseptically add thefollowing stock solutions.

(see recipe)f/2 VitaminSolution

0.05 mL

(see recipe)f/2 Trace MetalSolution

0.1 mL

(see recipe)Alkaline SoilExtract

5.0 mL

37.2 g/LdH2O

Na2EDTA*2H2O0.1 mL

26.8 g/LdH2O

NH4Cl0.1 mL

5.0 g/LdH2O

NaH2PO4*H2O0.1 mL

75.0 g/LdH2O

NaNO30.1 mL

Stock Sol.CompoundQuan.

Adjust pH to 7.8-8.2 with HCl

In a flask add twoparts by volumedistilled water (dH2O)to one part richorganic garden soil(containing no recentapplications ofchemical fertilizer orpesticides). Add 2-3 gNaOH/liter. Autoclavefor 2 hours, and filterwhen cool. Thisconcentrated extract isdiluted 1:50 in dH2Ofor the final workingstock. (Seawater maysubstituted for dH2O ifthe extract is to beused for marinespecies).

180.0 g/LdH2O

MnCl2*4 H2O1.0 mL

10.0 g/L dH2OCoCl2*6H2O1.0 mL

22.0 g/L dH2OZnSO4*7H2O1.0 mL

6.3 g/L dH2ONa2MoO4*2H2O1.0 mL

9.8 g/L dH2OCuSO4*5H2O1.0 mL

-Na2EDTA*2H2O4.36 g

-FeCl3*6H2O3.15 g

Stock Sol.CompoundQuan.

f/2 Trace Metal Sol.

To 950 ml distilled H2O add:

Alkaline Soil Extract

Final volume to 1.0L with dH2O. Autoclave

-Thiamine HCl200.0 mg

0.1 g/LdH2O

Biotin10.0 ml

1.0 g/LdH2O

Vitamin B121.0 ml

StockSol.

CompoundQuan.

f/2 Vitamin Solution

To 950 mL dH2O add:

Make final volume up to 1.0 L withdH2O. Filter sterilize & refrigerate.Note: Vitamin B12 and Biotin areobtained in a crystalline form. Toprepare the Vitamin B12 StockSolution, for each 1.0 mg of VitaminB12 add 0.89 mL dH2O). To preparethe Biotin Stock Solution, for each1.0 mg of Biotin add 9.6 mL dH2O

Micro-algal culture

Algalgrowthcurve

ANS - 18; Algal culture

Blue-green algae – Spirulina

70 million dollar California industry

Earthrise is the world's largest Spirulina farm, covering a 108acre site. Earthrise produces over 500 metric tons of drypowder 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 sizeand larger than a football field.

Clean fresh water and nutrients are added daily tofeed the algae, mixed by 50-foot paddlewheels ineach pond.

Culture conditions, such as alkalinity are optimizedfor 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 (orcoastal) environments. The group dominates many benthicmarine biotas, sometimes reaching from the ocean floor to itssurface. In general, they are not free-floating organisms, butare attached to rock, coral, or other firm surfaces.

The group is found primarily in colder waters of the northernhemisphere, with the largest forms occurring in coolerwaters, rather than in the tropics. Many familiar species, suchas rockweed, are intertidal, and are exposed to the air atlow tide.

1There are a few pelagic (= floating) seaweeds, the best known example isSargassum which is prominent in the Sargasso Sea

Red seaweeds – Nori (Porphyra)high in agar and carrageenan

While only 562,000 tonneswere produced in 2008the value was $ 940million making nori themost valuable of thecultured seaweeds

The name come from thestrong red color of theyoung thallus stage,however as it grows thethallus becomes a darkpurple.

↑ protein - 25 - 35% of dry weight

75% of protein & carbohydratesdigestible

↑ vitamins and minerals (vitamin C

content 1.5 X that of oranges and itis a good source of iodine)

Nori – coldwater sp. – 10 – 18oC

Since the 17th centuryJapanese fishermenplanted "hibi"

1949, the filamentousConchocelis-phase ofPorphyra was discribedby the Britishphycologist, KathernM. Drew-Baker

Nori production cycleoptimum growth 10 – 18oC

Britishphycologist,Kathern M.Drew-Bakerin 1949,found thefilamentousConchocelis-phase in thelife history ofPorphyra

Page 2

• May to SeptemberSporophytes are seeded on

mollusk shells (May) in longconcrete tanks with 20 – 30 cmof fertilized seawater in depth.

Optimum growth of theconchocelis phase is 20 – 25 oC

September to OctoberThe sporophytes release

conchospores, which areseeded on special cultivationnets that have been placed inthe tanks.

Water in the tank agitated toobtain an even distribution ofthe conchospores

Cultivation of the conchocelis stage

Cultivation of the thallus stageThe seeded nets are fixed to rafts for growoutAs 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 removecontaminants

Chopped into small pieces and washed again brieflyThe thallus suspension is poured into a metallic

framework with a plastic net at the bottom to produceindividual sheets when dryed.

These sheets are then packaged and sold.

Brown seaweeds or “kelps”

Laminaria (Japanese kelp) eatenas a vegetable & grown as acommercial source of alginates)– Production = 4.8 million tonsin 2008 with a value of $ 2.8billion

Unidaria (wakame) also eatenas a vegetable particularly insoups - Production = 1.8 milliontons in 2008

ANS - 18; Algal culture

Both Laminaria and Undaria are cold-water species andthus are winter crops. Laminaria < 16oC and for Undaria ~12 oC is optimum

Macrocystis (giant bladder kelp)

An important brown algal species along the California coast is: ♦

Found along the Pacific coast of North America from central Californiato Baja California.

This species may grow to lengths of 60 m (200 ft) with its upperfronds forming a dense canopy at the surface.

Kelp begins life as a microscopic spore, which grows into a tiny maleor female plant called a gametophyte. These plants produce eggs andsperm, which fertilize and grow to form the large plants (sporophytes)

The large sporophytes then release many new spores to start theprocess over again. The minimum amount of time needed to completethe Macrocystis life cycle is believed to be 12 to 14 months althoughin the environment, grazing by animals and shading by other plantsaffect 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. Thefact that it is found in deep water habitat allows large harvesting boats tooperate more easily. The surface canopy can be harvested several times ayear without disturbing the submerged vegetative and reproductive partswhich are located below the harvesting levels thus ensuring the kelp willcontinue to reproduce and the surface canopy will be regenerated by theyounger fronds growing below the surface.

In the early 1930's the algin-extraction industry was developed. Algin, ahighly efficient thickening, stabilizing, suspending and gelling agent.

The harvesting of kelp in the state is regulated by the California Departmentof Fish and Game with the maintenance and improvement of the kelp bedsimportant considerations. The State of California has imposed a number ofrestrictions on harvesting activities. Kelp harvesters are permitted to cut onlythe upper 1.2 meters (4 feet) of the water column. This regulation is to limitdamage to the kelp's reproductive structures and allows vegetative re-growth from the unharvested fronds below the surface on cut plants. Standsof kelp throughout the state are designated by number and some are leasedby harvesting companies while others remain open to anyone with aharvesting permit. The kelp beds are leased for a period of 20 years. Nomore than 25 square miles or 50% of the total kelp bed area, whichever isgreater, can be exclusively leased by one company.