Lecuture 1.2 – case 5 fish
Self- study:
Aquaculture continues to be one of the fastest growing (2015-2020 overall
increase of 18%).
Aquaculture: is the cultivation of aquatic organisms. Also known as
aquafarming, implies the cultivation of aquatic populations under
controlled conditions. Aquaculture implies individual or corporate
ownership of the cultured stocks.
Mariculture: aquaculture practiced in marine environments.
Marine biotechnology : The farming of marine organisms, often
invertebrates such as sponges, corals, sea fans and algae for nonfood
purposes.
Capture fishery: The capture/harvest of aquatic plants or animals from
their natural environment. The way of catching and the period of catching
can be constrained by regulations. Capture fishery in the aquatic
environment is similar to ‘hunting’ or ‘collecting’ in land based
environments.
Differences and similarities between aquaculture and capture fisheries:
In common that they extract aquatic organisms from the aquatic environment
(natural or man-made). Products from capture fisheries and aquaculture are
considered ‘seafood’ which passes through a common ‘Product Value Chain’ for
processing and distribution to consumers.
Capture fisheries only make management decisions concerning the act of fishing:
- Fishing area (12 miles of coast)
- Fishing period (during light, not during spawning season)
- Fishing method (type of gear, mesh size and hook size
Aquaculture management actions can act on ‘all’ production processes, exerting
a minimum level of control in addition to ‘capture’. Process control can relate to
the organism and to the production environment. Aquaculture is the equivalent of
farming on dry land.
Main disciplines of aquaculture:
- Genetics, broodstock management
- Larval rearing
- Live food culture
- Reproduction
- Disinfection
- Feeds& feeding
- Engineering
- Health care, disease management
- Husbandry, stocking density
- Water quality management
- Algae and bacteria management
Global per capita fish consumption is about 16.6 kg per year, which is a
significant increase from the 9.1 kg consumed in 1961.
, Globally the per capita consumption of protein increased from 65 g per day in
1970 to 76 g in 2003 of which fish provides on average 4.5 g protein per day.
What makes aquatic animals special?’
Water is a high density medium (compared to air), with a low concentration of
oxygen and very rich in organisms and varying within narrow limits. This puts
high requirements on water quality management and food quality in aquaculture:
- Cold blooded
- Difficulty in using carbohydrates The principal energy source are lipids
(fat)
- Gas exchange through gills or cutaneous (skin) diffusion
- Many different modes of reproduction
- Most animals derive structure from calcareous material
FISH is our principal source of -3 fatty acids. Important polyunsaturated fatty
acids (PUFA) for human nutrition include linolic acid, linolenic acid, arachdonic
acid, eicosapentaenoic acid and docosahexaenoic acid. The PUFAs with 20 and 22
C-atoms are only available in seafood.
Influence of fatty acids on biological functions:
- Stress resistance
- Immune response
- Ion balance
- Neural activity
- Vision and brain function
Oxygen is involved in all aspects of animal life. The amount of oxygen in water is
about 20 times less than in the air and extracting oxygen from water is more
difficult than from air. Unlike in air, the amount of dissolved oxygen in water
fluctuates greatly and is being the prime limiting factor for survival, feeding,
growth and reproduction in water breathing fish.
The minimum concentration of dissolved oxygen in water at which the
physiological oxygen demand of fish for feed intake is limiting is termed ‘incipient
dissolved oxygen’ (iDO).
Oxygen is essential for aerobic metabolism
to derive energy (ATP) from protein, fat and
carbohydrates for growth and maintenance.
The consumption of feed gives rise to heat
production which is proportionate to the
post-feeding oxygen consumption of an
animal. Besides the direct involvement of
the oxidative metabolism in the control of
food intake, it is widely accepted that the
enhanced oxidative metabolism due to
food/energy intake has putative negative
effects on the animal in the long term.
Self- study:
Aquaculture continues to be one of the fastest growing (2015-2020 overall
increase of 18%).
Aquaculture: is the cultivation of aquatic organisms. Also known as
aquafarming, implies the cultivation of aquatic populations under
controlled conditions. Aquaculture implies individual or corporate
ownership of the cultured stocks.
Mariculture: aquaculture practiced in marine environments.
Marine biotechnology : The farming of marine organisms, often
invertebrates such as sponges, corals, sea fans and algae for nonfood
purposes.
Capture fishery: The capture/harvest of aquatic plants or animals from
their natural environment. The way of catching and the period of catching
can be constrained by regulations. Capture fishery in the aquatic
environment is similar to ‘hunting’ or ‘collecting’ in land based
environments.
Differences and similarities between aquaculture and capture fisheries:
In common that they extract aquatic organisms from the aquatic environment
(natural or man-made). Products from capture fisheries and aquaculture are
considered ‘seafood’ which passes through a common ‘Product Value Chain’ for
processing and distribution to consumers.
Capture fisheries only make management decisions concerning the act of fishing:
- Fishing area (12 miles of coast)
- Fishing period (during light, not during spawning season)
- Fishing method (type of gear, mesh size and hook size
Aquaculture management actions can act on ‘all’ production processes, exerting
a minimum level of control in addition to ‘capture’. Process control can relate to
the organism and to the production environment. Aquaculture is the equivalent of
farming on dry land.
Main disciplines of aquaculture:
- Genetics, broodstock management
- Larval rearing
- Live food culture
- Reproduction
- Disinfection
- Feeds& feeding
- Engineering
- Health care, disease management
- Husbandry, stocking density
- Water quality management
- Algae and bacteria management
Global per capita fish consumption is about 16.6 kg per year, which is a
significant increase from the 9.1 kg consumed in 1961.
, Globally the per capita consumption of protein increased from 65 g per day in
1970 to 76 g in 2003 of which fish provides on average 4.5 g protein per day.
What makes aquatic animals special?’
Water is a high density medium (compared to air), with a low concentration of
oxygen and very rich in organisms and varying within narrow limits. This puts
high requirements on water quality management and food quality in aquaculture:
- Cold blooded
- Difficulty in using carbohydrates The principal energy source are lipids
(fat)
- Gas exchange through gills or cutaneous (skin) diffusion
- Many different modes of reproduction
- Most animals derive structure from calcareous material
FISH is our principal source of -3 fatty acids. Important polyunsaturated fatty
acids (PUFA) for human nutrition include linolic acid, linolenic acid, arachdonic
acid, eicosapentaenoic acid and docosahexaenoic acid. The PUFAs with 20 and 22
C-atoms are only available in seafood.
Influence of fatty acids on biological functions:
- Stress resistance
- Immune response
- Ion balance
- Neural activity
- Vision and brain function
Oxygen is involved in all aspects of animal life. The amount of oxygen in water is
about 20 times less than in the air and extracting oxygen from water is more
difficult than from air. Unlike in air, the amount of dissolved oxygen in water
fluctuates greatly and is being the prime limiting factor for survival, feeding,
growth and reproduction in water breathing fish.
The minimum concentration of dissolved oxygen in water at which the
physiological oxygen demand of fish for feed intake is limiting is termed ‘incipient
dissolved oxygen’ (iDO).
Oxygen is essential for aerobic metabolism
to derive energy (ATP) from protein, fat and
carbohydrates for growth and maintenance.
The consumption of feed gives rise to heat
production which is proportionate to the
post-feeding oxygen consumption of an
animal. Besides the direct involvement of
the oxidative metabolism in the control of
food intake, it is widely accepted that the
enhanced oxidative metabolism due to
food/energy intake has putative negative
effects on the animal in the long term.
