Environmental Resources Unit C Animal Wildlife Management

Problem Area 3 Fish Management

Identifying fish facilities and stocking rates. Lesson 6

Identifying fish facilities and stocking rates. What are some different types of structures in which humans can live? What are some of the advantages and disadvantages to each of these structures? What about the types of facilities in which fish live?

Terms Cage Closed System Levee Levee-type Ponds Permeability Rate Raceways Stocking Rate Tank Watershed Ponds

Objectives Identify fish production facilities. Understand how to select sites for aquaculture facilities. Describe the importance of properly stocking a fish production facility.

What are some common fish production facilities? Type of facility to produced fish depends on: –Type of fish raised –Size and scope of operation –Available location Common facilities include: –Levee-type pond –Watershed pond –Raceway –Cages –Tanks

Levee-type ponds Levee-type –Building levees on nearly land. Levee –Manmade structure composed of soil and other earthen materials used to hold water. –Material brought in from an outside source. htm

Levee-type ponds Water for these ponds are from wells. Water is only added when level drops too low. Production of catfish in the southern United States.

Watershed Ponds Damming a natural flowing stream. Constructed by taking advantage of natural hills and valleys. Bottom of pond is uneven causing difficulty when harvesting. Water is added only to replace lost water.

Raceways Structures that allow water to move through rapidly. Takes of advantages of natural streams and springs to provide the water. Takes advantages of sloping land to allow water to move through system. Trout commonly produced in raceways.

Cages Constructed of netting on a wood or metal frame placed in an existing body of water. Can be used in levee- type ponds, watershed ponds, streams, rivers, lakes or oceans. Disadvantage is fish cannot eat material through water must be fed more. Catfish, bream, and tilapia often raised in cages.

Tanks An artificial water enclosure. Available in a wide variety of shapes and sizes. Part of a closed system –Reuses the same water by recalculating it after it has been filtered and re- oxygenated.

How are sites selected for aquaculture facilities? Site selection for an aquaculture facility depends on: –Amount of needed land. –Proximity to market sand suppliers. –Weather of the area. –Availability of necessary infrastructure. electricity, roads, telephone lines –Each type of facility has its own criteria.

Levee type pond requirements Flat land Soil that will hold water. Not prone to flooding. Land high enough to be drained. Slow permeability rate. –Speed at which water flows through the soil. Source of clean water. Clean water is usually from a well. Test well for quality and quantity. If spring is used. Test the flow to ensure enough water is available.

Watershed pond requirements Similar to levee-type. Exception is hills and valleys are wanted. Soils with the ability to hold water. Soils with high clay content are excellent. Additional clay may need to be added. Water source is usually a stream. Test water of stream for water quality and enough flow to meet the needs.

Raceway requirements Biggest factor is the source of continuous flow of water. Usually a stream that can be diverted through raceway. Land to be gently sloping for water to flow through raceway.

Cage facility requirements 1.Water must flow through cages. Fish cannot move through the water so water must move through. 2.Water must be deep enough. Water must move under the cages.

Tank requirements Can be placed almost anywhere. Biggest factor is the proximity to needed supplies, roads and utilities. A good well to provide water. A place to discharge used water. aquaculture/aquastel

Why is properly stocking a fish production facility important? Stocking rate –Pounds of fish per gallon of water. –Quality of water is a large factor. –Vary by species of fish. –Overstocking and understocking can cause problems.

Why is properly stocking a fish production facility important? Overstocking –Can cause fish health problems. –Filters may not be able to effectively clean water. –Can lead to oxygen depletion in water. –Food source may not be adequate enough. Understocking –Can cause production to be below the potential of facility. –Expense of constructing a facility may not be reached fast enough to recover invested money.

Review / Summary What are some common fish production facilities? How are sites selected for aquaculture facilities? Why is properly stocking a fish production facility important?