In any business the keeping of accurate records is a must. The keeping of records in aquaculture is no different and may be even more important than in other types of agricultural enterprises. In an economically viable aquaculture enterprise, the critter may be smaller and in a wet environment, but the producer is no different from a large scale feedlot operator in the Midwest.

There are many production measures that are the same but have different terms. Fish are moved into the system, they are graded, sampled for growth and sold. Death loss is a familiar term in the cattle business. Mortality is the equivalent in aquaculture. Stocking rate or space requirements are measures used to determine how many cattle may be placed in a certain area. In aquaculture the term is loading. It is not determined by number but by the weight per gallon of water. Cattle are fed a specific diet to meet their nutritional needs based on size. The feeding of fish is not only based on the nutritional needs of the size of the fish. The size of the feed is also related to the size of the fish. Air quality, while not a major issue in most cattle operations, is an important issue in swine and poultry houses. The water quality for the aquaculture operation can and does change from one day to the next, from morning to afternoon. These changes can affect the productivity of the fish.

Records are tools for management. Records can also help a new producer learn about the productivity of an aquaculture system. They help others evaluate the performance of the system and how it can be improved. In the case of an unforeseen disaster, records can provide information on losses that can be used for tax or insurance purposes.

Several forms have been developed to help the producer keep account of the aquaculture system by hand. The Daily Fish Production Report and the Monthly Totals\Averages have also been converted to a spreadsheet format to provide a way to "do the math" and evaluate trends over time.

Forms for Use with Tank or Raceway Systems

Water Quality Chart

This form is used to keep data on a daily basis that affects the environment of the fish. Measurements should be taken in the morning one day and afternoon the next for water and air temperature and oxygen readings. Alternate readings among the different tanks each day. Use a well loaded tank one day and one that has less total weight the next. Rainfall and barometric pressure should be taken at the same time each day. Morning is a good time.

Tank Calibrations

The water flow through a tank or raceway is critical to the productivity of an aquaculture system. It delivers needed oxygen and takes away waste and ammonia. To use this form, use a five gallon bucket and a stopwatch to time how long it takes for water flowing out to fill the bucket. Do this three times. Find the average and divide it into 300 (5 gallons times 60 seconds) to get gallons per minute. If a different size container or a different time is used multiply the size of the container by the amount of time the water was collected to get the numerator for the equation.

Monthly Fish Handling

It is recommended that on a monthly basis the fish in each tank be sampled. Sampling requires the taking of samples of fish from the tank and placing them in a bucket of water (use about 15 pounds of water). Weigh the fish and the water and subtract the weight of the water. Count the fish as they are dumped back into the tank. This process should be repeated no less than three times per tank. Divide the number of fish counted back into the tank by the weight of the fish to get fish per pound. This figure can be used to find out the size of the fish and the loading in the tank. Grading (separating smaller and larger fish) is also required from time to time. Fish being moved because of size should also be weighed and counted. This form can be used to keep track of fish movement during this process, which is then recorded on the Daily Fish Production Report.

Daily Fish Production Report

One of these forms should be kept for each tank. It should be changed each month. The information collected on feed fed, fish movement, and mortality provide a basis to begin to evaluate the productivity of the system. Information is kept on each tank because of the differences in size and loading that affect feeding and the movement of fish. The beginning inventory is taken from the ending inventory of the previous month. The ending inventory is based on the changes that occurred in the tank during the month, such as the sale of fish, the movement of fish in or out of the tank, and mortalities.

Monthly Totals/Averages

This chart can be used to evaluate monthly changes in the system. Take the totals from each of the tanks and transfer the information onto this form. Feed conversion can be calculated by taking the pounds of feed and dividing it by the pounds of net gain or loss in each tank. An average for the month can then be calculated. The average size of the fish in the system is calculated by taking the total number of fish in the system and dividing it by the total pounds. This form is designed for a ten-tank system but could be used for more or less.

Mortality Reference Table

The table is useful when recording mortalities on the Daily Fish Production Report. Measure the length of the fish and use the figure to the right to record the pounds.

Comments:

MONTHLY FISH HANDLING - For use when sampling, grading, or moving fish in or out of the tank.

DAILY FISH PRODUCTION REPORT

NOTES

MONTHLY Totals/Averages
Month

Mortality Reference Table