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1. To examine the physical and chemical properties of water.

2. To analyze the importance of recirculation and filtration devices in production aquaculture.

3. To describe the importance of clean, healthy aquaculture environments and identify sources and prevention of pollution.

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Specific Heat Index – the amount of heat needed required to raise the temperature by one degree Celsius

• Include the following:– only natural substance to be found in

liquid, solid and gas forms at normal temperatures on Earth

– freezes at 32° F (0°C) and boils at 212° F (100°C)

– possesses very high surface tension– high specific heat index

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• Surface Tension – the property of liquids which allows their surfaces to behave like thin, elastic sheets; allows water to join together to form drops rather than spread out into a thin film

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• Include the following:– chemical composition of H2O

• two hydrogen atoms for every oxygen atom

– dissolves more substances than any other liquid

– pure water contains a pH of 7.0

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• Determines the use of water for a particular use, such as swimming, drinking and even the culture of fish

• Is affected by the following: – weather– biomass– soil– chemicals– frequency and amount of fish food given

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• Are indoor, tank based systems which allow the formation of tightly controlled environments through the constant exchange of water

• Permit high volumes of fish to be grown • Are often found where suitable land or

water is limited• Involve a more intense approach of

farming, using higher volumes of fish which need more managing

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• Are comprised of the following six components:– production tank– mechanical filtration– biological filtration– pumps and water pipes– quarantine tank– waste

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• Houses the fish which are being cultured

• Should be round with sloping bottoms to ease in removal of solids

• Should undergo at least a 5 to 10 percent rate of exchange everyday, depending on the amount of fish and feeding style

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• Removes solids such as feces and uneaten food from the water

• Ensures waste products do not clog pipes or other equipment

• Removes decomposing material which absorbs oxygen needed for fish survival

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• Converts metabolic wastes such as ammonia and nitrites into nitrates, which will not harm the fish

• Uses bacteria to oxidize the metabolic wastes

• Takes a few weeks to allow the bacteria to colonize and production should be lowered during this period

11 Oxidize – to combine an element with oxygen

• Replenish the production tank if water levels get too low

• Transport water and air throughout the recirculatory system

• Should measure the correct size for your tank to allow for the most efficient transportation

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• Is completely isolated from the rest of the recirculatory system

• Houses new fish in order to prevent the spread of diseases

• Allows for medication to be given to fish without contaminating the rest of the environment

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• Often results from nitrogen formed from feces or uneaten food

• Is removed through mechanical and biological filtration and taken to a separate waste container

• Comes in the following three forms:– settleable: gathers on the bottom of the tank– suspended: floats in the water and will not settle– fine and dissolved solids: float in water and

cause gill irritation as well as health damage in fish

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• Describes the transformation of nitrogen and nitrogen based compounds in nature

• Eliminates ammonia from water, which is extremely toxic to fish– ammonia is the result of uneaten

food and metabolic wastes being broken down

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• Includes the following steps:– fish wastes or uneaten food produce

ammonia– ammonia is eaten by nitrosomonas bacteria,

which excrete nitrites– nitrites are eaten by nitrobacter bacteria,

which excrete nitrates– nitrates are consumed by algae and plants,

which provide feed to fish– fish excrete the plants and the cycle begins

again

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Fish Wastes,Uneaten Feed

Algae,Plants

NitrobacterBacteria

NitrosomonasBacteria

Ammonia (NH3)

Fish Feed

Nitrate (NO3)

Nitrite (NO2)

Ammonia/Nitrogen Cycle

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• Involves maintaining clean production environments

• Is completed through the routine inspection of water quality

• Includes monitoring the eating habits of fish in order to prevent over feeding

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• Are determined through the presence of contaminants as well as the water’s characteristics

• Include the following categories:–biological–physical–chemical–aesthetic

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Aesthetic – pleasing or acceptable to the senses; contaminants which may effect water quality such as taste, color or odor

• Include the following:

– “indicator organisms” such as insects, which begin to disappear as water quality deteriorates

– algae, which may be an indicator of either good or bad water quality depending on the species growing

– bacteria, which may indicate pathogenic organisms are also present

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Salinity – the amount of salt found in a solution 21

•Include the following:–temperature–color–salinity–suspended solids–dissolved solids

• Include the following:– pH– nutrients– dissolved oxygen– organic compounds– inorganic compounds

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• Include the following:– color– odor– floating matter

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PPM – parts per million; the number of “parts” by weight of a material per million parts of water 24

• Is also known as oxygenation• Increases the oxygen content of

water used to house fish through circulating, mixing or dissolving

• May be either of the following:– passive: naturally exposed to air– active: an object inserts air, such

as a bubbling device

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• Used in aquaculture include the following:– diffused air – submersible pumps– propeller aspirator pumps– paddlewheel aerators

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• Is also known as “trickle aeration”• Provides the least cost efficient form of

aeration• Adds oxygen directly to the water• Circulates water from the top to the

bottom• Is not suited for shallow watered tanks

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• Do not add oxygen directly to the water• Pushes poorer quality water to the top• May be paired with an elongated outlet which

raises above the water and sprays the water back to the source

• Are not recommended for large growout ponds

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• Provide good circulation and aeration• Are designed for deeper water• Draw in oxygen and release it into the water• Are suitable for producers interested in providing

more feed in order to increase productions

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• Are the most common aeration system• Efficiency is due to a combination of strong

circulation and large exposure to oxygen• Remove aerated water from the area around the

aerator in order to expose new water to oxygen • Are recommended for larger, shallow growout

ponds

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• May be directly or indirectly caused by farming fish– direct pollution includes natural wastes emitted

from the fish such as feces and feed as well as human aids such as medicine

– indirect pollution comes from sources not related to aquaculture, such as an oil spill or human garbage

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• Involves closely monitoring the tank for any changes

• Includes regularly cleaning the tank and removing all solid waste particles

• May be accomplished through establishing proper filtration and aeration devices

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• Are methods designed to reduce and prevent water pollution

• Help producers comply with production laws

• Include recommendations on how to handle waste water management

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• Should be handled in the following manners according to the Best Management Practices:– implement borders and filters– create a waste treatment lagoon– regulate water in drainage system– create basins to collect waste runoff

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1. What is the term used to describe the property which allows water to join together to form drops rather than spread out into a thin film?

2. What is the pH of pure water?

3. What is the most common aeration system? Why?

4. What are some best management practices for managing waste water?

5. What are three biological indicators of water quality?

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6. Water possesses a low specific heat index.

a. true

b. false

7. Suspended wastes float in the water, but will eventually settle.

a. true

b. false

8. The diffused air system is also known as “trickle aeration.”

a. true

b. false

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9. Color is what kind of indicator for water quality?

a. physical

b. chemical

c. aesthetic

d. both a and c

10. Propeller respirator pumps are designed for

a. shallow water

b. deep water

c. growout ponds

d. none of the above

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• Aquaculture Network Information Center

aquanic.org• NSW Department of Environment & Climate

Change

www.environment.nsw.gov.au• United States Geological Survey

pubs.usgs.gov• Primary Industries & Resources South Australia

govdocs.aquake.org

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• Louisiana State University Agricultural Center

www.lsuagcenter.com

• Queensland Department of Primary Industries & Fisheries

www2.dpi.qld.gov.au

• Department of Fisheries, Government of Western Australia

www.fish.wa.gov.au

• Aquaculture Sample Lesson

www.agednet.com

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Project Coordinator:

Meghan Blanek

Production Manager:

Dusty Moore

Executive Producers:

Gordon Davis, Ph.D.,

Jeff Lansdell

Production Coordinator:

Brandon O’Quinn

Graphic Designer:

Ann Adams

© MMIXCEV Multimedia, Ltd.

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