Transcript 9.Aquaculture microbiology students version

Aquaculture
microbiology (I)
Topic 9
Ms Sherina
Kamal
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Introduction
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Aquaculture
 also known as fish or shellfish ……………..
 refers to the breeding, rearing, and
harvesting of plants and animals in all types
of water environments including ponds,
rivers, lakes, and ……………….
 Researchers and aquaculture producers are
"farming" all kinds of freshwater and marine
species of fish, shellfish, and ……………….
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Introduction
 Aquaculture
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produces:
• food fish
• sport fish
• bait fish
• ornamental fish
• Crustaceans
• Mollusks
• Algae
• Sea vegetables
• fish eggs
Introduction
the production of seafood from hatchery fish
and shellfish which are grown to market size
in ponds, tanks, cages, or raceways
 Stock restoration or "enhancement" is a
form of aquaculture in which hatchery fish
and shellfish are released into the wild to
rebuild wild populations or coastal habitats
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oyster reefs
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Introduction
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includes the production of
 ornamental fish for the aquarium trade
 growing plant species used in a range of
• …………
• pharmaceutical
• nutritional
• biotechnology products
Introduction
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Two types of aquaculture:
Marine
 ……………
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Introduction
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Marine aquaculture
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refers to the culturing of species that live in the ocean
U.S. marine aquaculture primarily produces:
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Oysters
…………..
mussels
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salmon
Cod
……………
Barramundi
Seabass
Seabream
Introduction
Marine aquaculture can take place:
• in the ocean (cages, on the seafloor, or
suspended in the water column)
• in on-land, manmade systems
• ponds or tanks
• Recirculating aquaculture systems that
reduce, reuse, and recycle water and
waste can support some marine species
Introduction
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Freshwater aquaculture
 produces species that are native to
rivers, lakes and …………..
 dominated by catfish but also
produces trout, tilapia, and …………..
 takes place primarily in ponds and in
on-land, manmade systems
• Re-circulating aquaculture systems
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Aquaculture techniques
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have developed or adapted many specific techniques to improve their
operations
 some drawn readily from other fields
 some which have had to be devised by farmers and technicians
 They range from simple field tricks like moistening soil and rolling it into
an elongated shape to test whether there is enough clay in the soil to
make watertight pond dykes
 through to advanced biotechnology
• gene transfer
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As the sector has expanded to new regions, new species and to achieve
control over more of the life cycle of farmed animals and plants, fish
farmers have proven very innovative in devising solutions to the new
problems they faced
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Aquaculture techniques
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The culture of carp was originally restricted to the home range
of each species, where fry (seed) could be caught from the
rivers and stocked in ponds
A study of how water temperatures, changes in day length and
other factors affected the reproductive cycle of fish
subsequently led to the ability to breed carp far from their
native waters and where the natural conditions would not
normally allow breeding
Manipulation of water temperatures and day length
remains important in the successful hatchery production
of many farmed species to this day
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Aquaculture techniques
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As ……………….. became identified and their action
understood in higher vertebrates, fish farmers began to
experiment too, with extracts of hormone producing organs
in fish, and found that egg development and spawning
could be promoted in many species by the injection of
hormone extracts from pituitary gland
These techniques are used today in the production of fish
 Carp
 Salmon
 ………….
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Aquaculture
techniques
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Oysters and other mollusks are brought to produce eggs by
manipulating water temperatures
Shrimp
 made to develop their ovaries by removing a gland that
produces an inhibitory hormone, sited in the eyestalk
Tilapia
 Hormones are also used in processes like the sex-reversal of
tilapia to produce all-male populations ………………………….
production
 There is a short period in the early life of the fish when their
sex is not fully determined and feeding them with a hormone
treated feed can push them to …………………………………..
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Aquaculture techniques
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Many fish are stripped of their eggs (females) and milt
(males) in hatchery production and the fertilisation is
carried out externally
Typically this is done in a bowl with the eggs and sperm
being mixed with a feather
Shrimp that do not readily mate in captivity are artificially
inseminated by extracting the sperm capsule from the
male and attaching it to a female that has ripe ovaries to
replicate ………………………………….
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Aquaculture Methods
Open-net pen systems
 Closed Systems
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Raceways
 Recirculation systems
 ……………
 Suspended-aquaculture
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Open-net pen systems
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Found offshore in coastal areas or in freshwater lakes,
open-net pens or ‘cages’
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considered a high-risk aquaculture method
• they allow for free and unregulated exchange between the farm
and the surrounding environment
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Farmed ……………..
Open net pens allow free exchange of high concentrations
of waste, chemicals, parasites and disease
Farmed fish can escape and they also attract predators:
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marine mammals, that can get tangled and drown in fish farm
…………..
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Closed Systems
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use a barrier to control the exchange between farms and
the natural environment
Significantly:
 reduces pollution
 ……………………….
 negative wildlife interactions and parasite
 disease transfer from farms to marine and freshwater
ecosystems
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Closed Systems:
Raceways
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Flowing water is diverted from natural streams or a well
used for raising rainbow trout
To be considered a low-risk method
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waste must be treated and fish ……………………….
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Closed Systems:
Recirculation systems
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Water in these systems is treated and re-circulated
almost any type of finfish can be raised
Common species farmed:
 Arctic char
 striped bass
 Barramundi
 Sturgeon
 Salmon
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Closed Systems:
Recirculation systems
This system does not mix with natural water
sources
• mitigates pollution
• parasite transfer
• fish escapes
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Closed Systems: Ponds
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Ponds are semi- or fully enclosed body ………………..
Catfish, tilapia and shrimp Discharged waste must be
filtered and treated to be considered a “low-risk” method
“High-risk” pond farms discharge untreated wastewater
which pollutes the surrounding environment
They can also cause devastating habitat destruction
For example, the construction of shrimp ponds in Asia
and South America has destroyed 3.7 million acres of
mangrove forests along the coast
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Closed Systems:
Suspended-aquaculture
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Farmers grow shellfish on beaches or suspend them
in water by
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Ropes
plastic trays
…………………
The shellfish farmed using these methods are filter
feeders and require only clean water to thrive
Oysters, mussels and …………………
Shellfish farming with suspended-aquaculture is
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often ‘low risk’ if the farmed species is native to the
area and if the farm has sufficient flow to prevent
waste accumulation
Closed Systems:
Suspended-aquaculture
END OF LECTURE
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