Fish Operation Selection Factors

Transcription

1 Handout 2.1a Fish Operation Selection Factors Selecting the type of fish operation is one of the basic decisions that the producer must make. The four major kinds of fish operations include breeding fish and raising the fry for sale as fingerlings (young fish) or bait fish rearing fry and fingerlings to market size breeding and rearing adult sport fish breeding and rearing tropical fish. To select the best type of fish operation, a person must determine the local economic and environmental conditions for fish farming. Economic Factors 1. availability of capital 2. available land 3. markets where fish can be sold 4. labor force availability 5. availability of professional guidance Environmental Factors 1. Warmwater fish need a water temperature above 60 F to take in artificial feed. A water temperature average of 75 F with an optimum temperature of 85 F is effective. 2. Coldwater fish grow best in ponds where the summer surface water temperature is below 70 F. 3. Warmwater fish survive in cold water; however, the rate of growth is slow. 4. Spring-fed ponds may be too cool for optimum catfish growth. 5. In Virginia, the growing season for catfish (water temperatures above 60 F) ranges from about 200 days in the coastal area and some Piedmont counties to about 165 days in most of the Piedmont area to fewer than 150 days per year in the mountains. 39

2 Handout 2.1b Determining Operating Costs Producing fish involves more than stocking fish in water, feeding them, and reaping the profits. In fact, aquaculture is expensive. After evaluating pond sites, water supply, soils, and marketing possibilities, one must also examine the potential profitability of the proposed operation. Estimating Capital Costs To determine the potential capital investment, list all capital costs such as storage and service buildings, feeding equipment, pond aerators, nets, etc. (see Transparency 2.1a). Estimating Operating Costs To estimate the possible cost of operation, calculate costs such as the cost of fingerlings, feed, daily labor, chemicals and drugs, etc. (see Transparency 2.1b). Estimating Potential Profit To estimate the potential profit, follow the numbered steps below. Assume the value per pound is $1.00, the yield is 2,000 pounds per acre, and the number of acres is Calculate the expected gross returns by estimating $ 1.00 per pound the value per pound of marketable fish x 2,000 pounds per acre and multiplying by the expected average yield = $2,000 per acre per acre. Then multiply the value per acre by the number of acres. $2,000 per acre x 5 acres = $10,000 gross returns 2. After deciding on a particular method of depreciation, calculate the depreciable costs, except for land. Subtract this figure from the amount of gross returns. (Assume depreciation is determined as $1,000.) less $10,000 gross returns $ 1,000 depreciation $ 9,000 gross returns after depreciation 3. Calculate the annual operating costs. Subtract the operating costs from the gross returns after depreciation figure. (Assume annual operating costs are $7,500.) 4. Divide the net returns figure by the number of acres to determine the potential profitability per acre. $9,000 gross returns after depreciation less $7,500 operating costs $1,500 net returns $1,500 5 = $300 per acre 41

3 Handout 2.1c Annual Budget: Cage Culture of Catfish Nottoway County Teaching Farm and a Comparison with a Real Farm Situation May 10 to October 31, 1989 (180 days) Variable Costs Fish: 1700 $0.20/fish $ 340 Electricity: $0.08/kwh 75 Feed: 2675 $0.20/lb; 1.75:1.0 feed conversion 535 Miscellaneous: 50 Subtotal Variable Costs $1,000 Interest on subtotal (6 10%/year): $ 50 Labor: 0.5 hr/day for 180 $4/hr 360 Total Variable Costs $1,410 Fixed Costs* Real Farm Demo Depreciation: $ 350 $ 600 Interest: Repairs: Total Annual Fixed Costs Total Variable Costs ,410 Total Cost $1,860 $2,310 Production 1.0 lb/fish (90% survival) Real Farm Demo Break-even prices ($/lb): Total cost $ 1.22 $ 1.50 w/o labor Variable cost $ 0.92 $ 1.50 w/o labor * Fixed costs are the costs associated with owning fixed assets. For the Nottoway Teaching Farm these assets are floating dock ($2,000), dissolved oxygen meter ($450), electrical aerator ($900), nets and equipment ($150), and cages ($500) for a total of $4,000. The 1988 Average Pond-Size Catfish Selling Price was $1.25/lb. Source: Dr. Brian L. Nerrie, Extension Specialist, Aquaculture, Virginia State University 43

4 Transparency 2.1a GROWING SEASONS FOR FISH IN VIRGINIA < 150 days per year days per year 200 days per year 45

5 Transparency 2.1b CAPITAL COSTS OF PRODUCING FISH Land Water supply Pond construction Pond aerators Boats and motors Feeding equipment Oxygen testing equipment Tractors Seine nets Dip nets Waders and boots Mowers Baskets and buckets Taxes and insurance Miscellaneous equipment Trucks Fish hauling tanks and agitators Drain (pipe, valves, and fittings) 47

6 Transparency 2.1c OPERATING COSTS OF PRODUCING FISH Feed Fingerlings Electricity Fuel Maintenance Repairs Transportation Harvest labor Daily labor Chemicals and drugs Insurance Telephone Miscellaneous costs Interest on operating capital 49

7 Types of Fish Cultures Handout 2.2a The aquaculture producer must decide whether to use a natural system or a cultured system. Three types of cultured systems are described below. Monoculture Monoculture is the simplest type of culture system. In a monoculture system, only one species of fish is grown. Fish of different ages may be grown together, or they can be separated into fry, fingerling, and brood stock. Characteristics of the Monoculture System By managing only one particular species, the grower gains knowledge about producing the species. Controlled feeding is made easier with only one species. The grower has greater control over harvesting. If the grower wishes to harvest larger fish for market or breeding, a larger gill net is used. This net allows the fry and fingerlings to escape. Selective harvesting allows the grower to produce fish throughout the growing season. A single disease or parasite may kill all of the fish. Different fish are susceptible to different diseases; therefore, if more than one type of fish is being stocked, the grower is less likely to suffer the loss of all of the fish. In a monoculture system, an epidemic fish disease could easily infect and kill all of the fish if it is not stopped in time. Polyculture Polyculture is the culture of two or more fish species. A good polyculture system uses the natural food sources in a pond efficiently by selecting species that eat different foods from one another. Fish in a polyculture system can be of any size or age as long as a balanced relationship is maintained. Characteristics of the Polyculture System Fish stocked in a polyculture system must be able to live together. Polycultures are more resistant to disease. Diseases usually attack the smaller, weaker fish, while the healthier fish continue to live and grow. Research in Louisiana has found it profitable to mix blue catfish with channel catfish; 53

8 Auburn University recommends growing tilapia with channel catfish. Latest research findings are available from Virginia State University or a county extension agent. The producer needs to study two or more species to ensure an understanding of feeding habits, growth patterns, etc. Monosex Culture In a monosex culture, only one sex of one species of fish is grown. When only males or only females are stocked in a pond, all of the energy of the fish goes into growth not into reproduction. Characteristics of the Monosex System An all-male stocking has a faster growth rate than a mixed stock of males and females. Tilapia are often used in monosex culture. Tilapia reproduce at a very small size, but when separated by sex, they do not develop their reproductive organs, and they continue to grow. One way to stock a monosex pond is to separate the fish one by one according to sex during the breeding season. At this time, fish often change color, making it easier to sort fish by sex. Another method involves growing two different species of tilapia together in a pond. When these fish breed, they produce either a monosex culture or a sterile hybrid. Three successive crosses produce 100% male offspring. 54

9 Handout 2.2b Cage Culture Fish are raised commercially in one of four culture settings: open ponds, raceways, tanks, or cages. Some aquaculturists view cage culture as a recirculating system of intensive fish culture. Fish are stocked and fed in confined areas (cages) with high quality water flowing through the cage mesh. The water volume and associated organisms in the pond serve as a biofilter rejuvenating the pond water. Today, many of America s small or limited resource farmers are looking for alternatives to traditional agricultural crops. Cage culture offers the producer a chance to utilize existing water resources which may have only limited use for other purposes. Cage culture of fish is not foolproof or simple. Cage production can be more intensive in many ways than pond culture and should be considered as a commercial alternative only where open pond culture is not practical. 55

10 Handout 2.2c Catfish Cage Culture Species of catfish are often used in cage culture. Listed below are the advantages and disadvantages of catfish cage culture. Advantages Many types of water resources can be used, including lakes, reservoirs, ponds, strip pits, streams, and rivers that could not otherwise be harvested. (Specific state laws may restrict the use of public waters for fish production.) Harvesting of caged catfish is a rapid and easy process where the cages can simply be removed from the water. This method is particularly desirable in large, deep water ponds or lakes where fish are not easily caught. If the property contains an existing body of water, the initial investment is relatively low. Cages eliminate the need for expensive harvesting equipment such as large seines, nets, and holding tanks. Other species of fish can be raised when fish are grown in cages. Fish such as bass and bluegills are free to develop in the open water. Feeding activity and general health of the fish can be readily observed. Fish disease and parasite problems can be treated efficiently and economically. Fish losses due to predators such as other fish, fish-eating birds, turtles, and snakes are eliminated. Cages provide an easy, economical way to test the suitability of certain ponds and lakes for optimum fish growth and survival. Disadvantages Constructing and maintaining cages represents a relatively high cost. Food and labor costs are high because catfish grown in cages must be fed a nutritionally complete diet on a daily basis to obtain optimal growth. The potential for disease, parasites, and nutritional problems increases in cage culture. Crowded, stressed fish are more susceptible to diseases and parasites and may compete with one another for the available food. High mortality may result if the water quality is reduced or if the water contains a low level of dissolved oxygen. Harmful waste products (carbon dioxide, ammonia, and feces excreted by the fish) may build up around crowded cages, and caged fish are not free to move to uncontaminated waters. Costly aeration equipment may be necessary to prevent the fish from suffocating during periods of low oxygen and high waste buildup. Security can be a problem since fish in cages may be easily stolen by thieves or destroyed by vandals. Interference by other pond uses, such as livestock watering, irrigation, and washing of machinery used in applying chemicals, may contribute to mortality. 57

11 Transparency 2.2a THE DEVELOPMENT OF CAGE CULTURE The origin of cage culture is unclear but may have begun with cages used as holding structures until fish could be accumulated for market. The first true cages for producing fish were possibly developed in Southeast Asia around the end of the 19th century. These cages were constructed of wood or bamboo, and the fish were fed trash fish and food scraps. Modern cage culture began in the 1950s with the advent of synthetic materials for cage construction. Research into cage culture began in American universities in the 1960s. Cage culture is receiving more attention from researchers and commercial producers due to factors such as increasing consumption of fish, declining wild fish stocks, and a poor farm economy. 59