Live food aquaculture training course

1
Algae its role, species and production
requirements
2
Role of algae in aquaculture

• First link in the chain of live food manufacture
  and nutrition.
• Culture diet for rotifers
• Enrichment diet for rotifers
• Green water technique
• Provides a direct source of nutrition for larvae
• Provides background rotifer feeding
• Other zootechnical benefits

3
Role of algae in the green water larval rearing
technique

• An anti-bacterial agent
• In situ biological filter and producer of oxygen
• Light filter
• Promoter in the location of prey organisms
• Stimulation of enzymatic synthesis and onset of
  feeding in young larvae

4
Practical usage of algae in the hatchery

• Maintenance of master/stock rotifer cultures
• Feeding or co-feeding of rotifer mass cultures
• Enrichment diet for rotifers prior to feeding the
  larvae
• Used in the larval rearing tanks as Green water
  techniques

5
Species commonly used in aquaculture (a)

• Chlorophyceae green algae
• Chlorella salina (8 µm)
• Chlorella sp.
• Dunaliella sp.
• Nannochloris atomus (4 µm)
• Prasinophyceae greenish coloured algae
• Tetraselmis chui (14 µm)
• Tetraselmis suecica ( 12µm)
• Eustigmatophyceae greenish yellow algae
• Nannochloropsis oculata ( 3 µm)
• Nannochloropsis sp. (4 µm)
• Nannochloropsis gaditana (4 µm)

6
Species commonly used in aquaculture (b)

• Prymnesiophyceae - golden brown flagellates
• Isochrysis galbana (7 µm)
• Isochrysis sp. (Tahitian) (9 µm)
• Monochrysis
• Pavlova lutheri (7 µm)
• Cryptophyceae naked flagellates
• Rhodomonas sp. (17 µm)
• Chroomonas salina (17 µm)
• Bacillariophyceae diatoms
• Chaetoceros calcitrans (5 µm)
• Skeletonema costatum (9 µm)
• Thalassiosira pseudonana (9 µm)

7
Various algal species (CCAP-M, Oban)
Chaetoceros sp.
Nannochloropsis salina CCAP 849/2
Dunaliella
Rhinomonas reticulata var reticulata
(Rhodomonas) CCAP 995/2
8
Sources of algae

• CCAP Culture collection of algae and protozoa,
  Oban, UK. www.ife.ac.uk/ccap/
• Algobank Microalgae Strain Bank, Universite de
  Caen, France. www.unicaen.fr
• SAG Sammlung von Algenkulturen, Gottingen,
  Germany www.gwdg.de/botanik/phykolgia
• CCMP Provasoli-Guillard National Centre for
  culture of marine phytoplankton, Westboothbay
  harbour ME, USA. http//ccmp.bigelow.org
• UTEX Culture collection of algae at the univesity
  of Texas at Austin www.bio.utexas.edu/research/ute
  x

9
Calculating algal requirements
10
Calculating the volume of algae required for
rotifer production. (6 million juveniles at 20 x
106 cells/ml Nannochloropsis)

• Stock cultures
• Approx. 150 - 300 litres per day
• Mass cultures
• Using algae and yeast there is an average daily
  requirement of 100 litres of algae for every 100
  million rotifers produced.
• A 6 million hatchery would use 2 x 109 rotifers
  per day gt 2m3 of algae per day. (3 production
  runs of 2 mill)
• Rotifer enrichment.
• If all the rotifers were enriched at 2million/ml
  need 1m3 of tank space and at least 1m3 of algae.

11
Calculating the volume of algae required for
green water larval rearing (6 million juveniles
at 20 x 106 cells/ml Nannochloropsis)

• 20 L of algae per m3 of larval rearing per day at
  20 x 106 cells/ml
• A 6 million production hatchery will have
  approximately 185 m3 of larval rearing.
• Daily larval rearing requirement of 3.7 m3

12
Daily algal requirement
Rotifer stock cultures 0.3 m3
Rotifer mass cultures 2.0 m3
Rotifer enrichment 1.0 m3
Green water larval rearing 3.7 m3
Total requirement 7.0 m3 /per day
13
Typical cell densities achieved
14
Algal culture techniques
15
Fluorescent shelf and overhead metal halide
lighting
16
Transparent walls and lighting
17
Shelf lighting
18
Under shelf and side lighting
19
Fluorescent sack lighting
20
Natural light greenhouse structures
21
Indoor bag cultures
22
High density culture systems
23
Photo-bioreactor algal culture