Recirculation Systems in Aquaculture

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What is the primary function of oxygen in fish?

To convert dry feed into pellets

To break down protein and produce energy (correct)

To produce ammonia and carbon dioxide

To excrete waste products

What is the recommended type of feed for recirculation systems?

Wet feed

Live feed

Dry feed (correct)

Trash fish

What happens to carbon dioxide and ammonia in a fish rearing system?

They are excreted from the gills into the water (correct)

They are absorbed by the fish

They are excreted into the air

They are broken down into oxygen

What is the benefit of improved feed conversion rate (FCR) in fish farming?

Higher production yield and lower impact on filter system Signup and view all the answers

What is the purpose of designing feeds specifically for recirculation systems?

To minimize ammonia excretion into the water Signup and view all the answers

What is a critical aspect of tank design in fish rearing systems?

Meeting the needs of the fish in respect of water quality and tank design Signup and view all the answers

What is the main purpose of a recirculation system in a fish farm?

To treat the water continuously to remove waste products and add oxygen Signup and view all the answers

What happens to the water after it leaves the fish tanks in a recirculation system?

It flows to a mechanical filter and then a biological filter Signup and view all the answers

What is the purpose of aeration in a recirculation system?

To add oxygen to the water Signup and view all the answers

What is the result of the fish eating and digesting food in a fish farm?

The fish grows and develops Signup and view all the answers

What is the purpose of biological treatment in a recirculation system?

To remove waste products and add beneficial bacteria Signup and view all the answers

What can be added to a basic water treatment system in a recirculation system?

Several facilities such as oxygenation, ultraviolet light or ozone disinfection, automatic pH regulation, and more Signup and view all the answers

What is the primary reason for providing ample tank surface area for bottom-dwelling fish?

To accommodate their natural bottom-dwelling behavior Signup and view all the answers

Which species perform better with larger water volumes?

Pelagic species Signup and view all the answers

What happens to the sludge after it flows out of the filter?

It is treated externally in a waste water treatment plant Signup and view all the answers

What is the effect of higher water speeds on pelagic species?

They benefit from it Signup and view all the answers

What is the benefit of a circular tank design?

It creates a circular water flow pattern Signup and view all the answers

What is an advantage of microscreen filtration?

Reducing organic load on the biofilter Signup and view all the answers

What is the recommended pH range for optimal biofiltration?

Between 7.0 and 7.5 Signup and view all the answers

What is the effect of increasing pH on ammonia toxicity?

It intensifies ammonia toxicity Signup and view all the answers

What is an alternative method to increase oxygen levels in fish farming?

Direct injection of pure oxygen Signup and view all the answers

What is the end product of nitrification in a biofilter?

Nitrate Signup and view all the answers

What are the two major factors that affect pH in a water recirculation system?

CO2 production and nitrification Signup and view all the answers

What is a necessary condition for optimal nitrification?

pH levels between 7 and 8 Signup and view all the answers

Why is managing oxygen levels crucial in fish farming?

For fish welfare Signup and view all the answers

What is the purpose of heterotrophic bacteria in the biofilter?

To oxidize organic matter Signup and view all the answers

What is added to the water to stabilize the pH?

A base Signup and view all the answers

Why does the nitrification process affect the pH level?

It produces an acid Signup and view all the answers

Why is nitrogen in the form of free ammonia a concern?

It is toxic to fish Signup and view all the answers