Aquaculture microbiology (I) Topic 9 Ms Sherina Kamal

Introduction 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 ……………….

Introduction Aquaculture 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 oyster reefs

Introduction includes the production of ornamental fish for the aquarium trade growing plant species used in a range of ………… pharmaceutical nutritional biotechnology products

Introduction Two types of aquaculture: Marine ……………

Introduction Marine aquaculture refers to the culturing of species that live in the ocean U.S. marine aquaculture primarily produces: Oysters ………….. mussels 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 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

Aquaculture techniques 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 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

Aquaculture techniques 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

Aquaculture techniques 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 ………….

Aquaculture techniques 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 …………………………………..

Aquaculture techniques 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 ………………………………….

Aquaculture Methods Open-net pen systems Closed Systems Raceways Recirculation systems …………… Suspended-aquaculture

Open-net pen systems Found offshore in coastal areas or in freshwater lakes, open-net pens or ‘cages’ considered a high-risk aquaculture method they allow for free and unregulated exchange between the farm and the surrounding environment 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: marine mammals, that can get tangled and drown in fish farm …………..

Closed Systems 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

Closed Systems: Raceways Flowing water is diverted from natural streams or a well used for raising rainbow trout To be considered a low-risk method waste must be treated and fish ……………………….

Closed Systems: Recirculation systems 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

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 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

Closed Systems: Suspended-aquaculture Farmers grow shellfish on beaches or suspend them in water by 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 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