This system. A broad assortment of workss can turn good in the aquicultural beds. Most agriculturists concentrate on herbs e. Petroselinum crispum and basil. The most common clients are restaurant jobbers. Since the system lives in a nursery. Current agriculturists use a assortment of proprietary fast ones to maintain fish healthy.
Some veterinary governments speculate that ultraviolet ozone germicide systems widely used for cosmetic fish may play a outstanding portion in maintaining the Tilapia healthy with recirculated H2O. A figure of big. Pull offing both the biological science and markets is complicated. One hereafter development is the combination of Integrated Recycling systems with Urban Farming as tried in Sweden by the Greenfish enterprise. The fry receive commercial fish nutrient in pellets. European eel Anguilla Anguilla aquaculturalists procure a limited supply of glass eels.
The European eel is threatened with extinction because of the inordinate gimmick of glass eels by Spanish fishermen and overfishing of grownup eels in. As per Issues See besides: Aquaculture of salmon Issues The issue of provenders in fish agriculture has been a controversial 1. Many civilized fishes Tilapia. Top-level carnivores most pink-orange species depend on fish provender of which a part is normally derived from wild caught anchovies.
Brevoortia tyrannis. Vegetable-derived proteins have successfully replaced fish repast in provenders for carnivorous fishes. This can do several signifiers of pollution. Packed tightly. This besides causes emphasis. Most successful aquaculture species are schooling species. Stressing the animate beings is non desirable. Sea lice. Sea lice are ectoparasites which provender on mucous secretion. Large Numberss of extremely populated.
Adult salmon may last otherwise critical Numberss of sea lice. On the Pacific seashore of Canada. A meta-analysis of available informations shows that salmon agriculture reduces the endurance of associated wild salmon populations. This relationship has been shown to keep for Atlantic. The lessening in endurance or copiousness frequently exceeds 50 per centum. Diseases and parasites are the most normally cited grounds for such lessenings.
Some species of sea lice have been noted to aim farmed Coho and Atlantic salmon. Such parasites have been shown to hold an consequence on nearby wild fish. This claim. Because of parasite jobs.
In some instances. Use of antibiotics in nutrient production is thought to increase the prevalence of antibiotic opposition in human diseases. The lice and pathogen jobs of the s facilitated the development of current intervention methods for sea lice and pathogens.
The really big figure of fish kept long-run in a individual location contributes to habitat devastation of the nearby countries. The high concentrations of fish produce a important sum of condensed fecal matters.
Concern remains that attendant bacterial growing strips the H2O of O. Once an country has been so contaminated. This pattern has angered nearby fishermen. Other possible jobs faced by aquaculturists are the obtaining of assorted licenses and water-use rights. In respects to genetically modified farmed salmon. Biologist Rick Howard did a controlled research lab survey where wild fish and GMO fish were allowed to engender.
The GMO fish crowded out the wild fish in engendering beds. The colorant used to do pen-raised salmon appear rosy like their wild cousins has been linked with retinal jobs in worlds. Labeling In Alaska passed statute law necessitating that any genetically altered fish sold in the province be labeled. In In the European Union. Concerns continue over the labeling of salmon as farmed or wild caught.
The Marine Stewardship Council has established an Eco label to separate between farmed and wild caught salmon. Indoor fish agriculture An option to outdoor unfastened ocean coop aquaculture is through the usage of a recirculation aquaculture system RAS. A RAS is a series of civilization armored combat vehicles and filters where H2O is continuously recycled and monitored to maintain optimum conditions twelvemonth unit of ammunition.
To forestall the impairment of H2O quality. Other interventions such as UV sterilisation. Through this system. H2O use. The patterns besides increased feed-use efficiency growing by supplying optimal H2O quality Timmons et al. One of the drawbacks to recirculation aquaculture systems is H2O exchange.
Both methods cut down the sum of nitrate in the H2O. Because of its high capital and operating costs. RAS has by and large been restricted to patterns such as broodstock ripening.
SPF specific pathogen free carnal production. Although the usage of RAS for other species is considered by many aquaculturalists to be impractical. Slaughter methods Tanks saturated with C dioxide have been used to do fish unconscious. Then their gills are cut with a knife so that the fish bleed out before they are farther processed.
This is no longer considered a humane method of slaughter. Methods that induce much less physiological emphasis are electrical or percussive stunning and this has led to the phasing out of the C dioxide slaughter method in Europe. Inhumane methods Harmonizing to T. Hastein of the National Veterinary Institute.
For some species. There is no point in setting up an elaborate system if it is not completely or properly used. As you have already learned in a previous manual see Section 1. Small-scale fish farming, the main subject of this manual, may be undertaken by: subsistence farmers; commercial farmers; and semi-commercial farmers. Subsistence farmers typically produce fish part-time as part of several other part-time agricultural activities.
Their main objective is to produce protein food for their families. Any surplus fish may be bartered with neighbours or sold on the local market to obtain cash. Commercial farmers consider their fish farm as a small business enterprise. Their main objective is to earn money by selling fish at a profit. Other farmers have a fish farm to provide protein food for their family and cash to buy other commodities. Producing fish at a profit usually remains their main objective, but on a reduced scale compared to fully commercial farmers.
For the purpose of this manual, they will be referred to as semi-commercial farmers. The typical characteristics of these three broad categories of small-scale farmers and their fish farming activities are summarized in Table Select the category of particular interest to you and refer to the following sections: as a subsistence farmer, see Sections Read also the rest of this section, which introduces you to important fish stock definitions.
TABLE 41 Typical characteristics of small-scale farmers and their fish farming activities Fish stocks and useful indices for monitoring 9. As a commercial farmer, you will want to monitor your fish stocks closely. For this you have first to learn about the various indices or parameters which are commonly used to measure and compare the performances of various stocks in fish farms such as their growth, production and survival.
The following terms are used to describe the size of a fish stock. They are growing, although some of them may disappear, either escaping from the pond or dying. An important parameter is then: biomass present: on a certain day, total weight of fish present in a pond this is also called the standing crop on that day.
Concerning the changes in a fish stock at harvest or over a period of time: a Output or crop weight is the total weight of fish harvested from the pond. It is the difference between the biomass at the end and the biomass at the beginning of the period. For example,. It enables you to compare productions obtained in various periods. It may be also useful to indicate the average daily production rate, which in this case is 4 Note: in pond farming it is usually not possible to calculate survival rate for a fish stock during the production cycle.
You will therefore have to estimate it and select a suitable value based on past experience, taking into account species, water quality and losses from predation or poaching. By the end of the production cycle days output is A fish stock is made of individual fish for which the following parameters are usually estimated: a Average weight in g is obtained by dividing the biomass in g by the total number of fish present.
It is the difference between average weight at the beginning and end of a period. It is then called the daily growth rate obtained by dividing growth during a period by duration of this period in days. It is calculated either for a given period during the production cycle or for the whole cycle. At least once a day, the farmer should visit the ponds and check that: the water supply entering the ponds is adequate; the pond dikes are in good condition; and the water quality is good, as shown by the behaviour of the fish see Section 2.
The best time for such a daily visit is early in the morning, when dissolved oxygen conditions may become critical see Section 2. See Table 42 for a list of useful items to check. It possible, a second visit should be made to the ponds in the late afternoon, especially during critical periods, when measures can be taken to ensure that the fish remain in good health during night time.
Tasks at weekly or longer intervals 4. More complete checks should be made once a week and periodically Table 42 : to canals and pond dikes, for major maintenance or repair; to compost piles, to refill them as necessary. Whenever the ponds are drained, carefully check and repair all water control structures.
Control the pond vegetation and, as far as possible, various animal pests. Clean the ponds of excessive mud and use it to fertilize your garden. At all times, try to keep the land vegetation properly controlled and use it for composting see Section 6. At this level, monitoring becomes more important. As the culture system becomes more and more complex and the management level intensifies, monitoring becomes also more difficult.
See Table 43 for a list of useful items to check. However, the table may have to be adapted to your own needs.
Daily tasks 2. Make sure to tour your fish farm at least once a day and carefully check the following areas. Judge this by experience: from plankton turbidity see Section 2. Adjust the feeding ration accordingly see Section Watch the fish if feeding directly. Plan this visit of your fish farm early in the morning, especially during periods when dissolved oxygen may become critical see Section 2. In such periods, a second visit in late afternoon should also be made to prepare the ponds for the night.
Once a week, preferably always on the same day of the week, make more complete checks on the water control structures and organize major repairs. If you are fertilizing and liming your ponds regularly, take additional care to check the water quality for temperature , Secchi disc transparency and, if possible, dissolved oxygen, pH and total alkalinity.
Measure plankton and check on its general composition. This is particularly important in nursery ponds. If you have feeds, fertilizers, liming materials, etc. After complete draining of a pond or before refilling it with water, carefully check its dikes and other structures for leaks and damages and repair them properly.
Fully control bottom mud, aquatic vegetation and animal pests as necessary. If your property includes hilly grounds, protect their slopes against erosion see Section 4. You should regularly check on the growth and health of your fish. But if you spend much money on feeding your fish, it is best to check them more often, every two weeks for example.
There are several reasons why you should monitor your fish regularly: to check closely on the general condition and health of the fish; to determine the quality of the growth of your fish and to improve it as soon as possible, whenever necessary; to determine the efficiency of feeding and to improve it immediately, if necessary; to adjust the daily feeding ration see Section To check on the fish stock present in a pond, a reliable sample of it should first be obtained by fishing in one of several ways such as seining or using a cast net, a lift net or a trap net see Sections 8.
Generally fishing is best done at a feeding place, 15 to 30 minutes after distributing some food to attract and concentrate the fish in a relatively shallow part of the pond. Remember that a good sample should contain: all sizes of fish present in the pond, except the very small fry; all species of fish stocked in the pond; a sufficient total number of fish to be truly representative of the population present in the pond. In practice, it means that you should fish at least 1 to 2 percent of the total number of fish present.
For guidance, you may also use the chart below giving average total length TL of fish and minimum total weight of the sample to be obtained. Once you have obtained a good fish sample, proceed as follows. If necessary, take some of them back to your work area for closer examination under a microscope see Section If you have a mixed fish population in the pond you not only need to collect a larger sample but must also proceed in steps.
Then measure each group separately. Then measure each species separately. Later, enter these data into your pond records for example see Section You may then easily calculate various parameters see Section The main motivation for a commercial or semi-commercial farmer is to earn an income from producing and selling fish. How much money is earned, namely the profit, can be related to two basic kinds of factors of production.
These are for example land and water or access to their use , fish ponds and their structures, service buildings, items of equipment such as vehicles, pumps, a food mixer, an oxygen meter, tools and seine nets. These are for example fish juveniles to be stocked, fertilizers, feeds, fuel, spare parts for vehicles and other equipment.
Labour, either the farmer's own or others' labour, is also a variable factor of production. Several kinds of production costs 2. To earn money, a commercial fish farmer must first pay for these factors of production. Everything spent to run the fish farm is part of these costs, typically referred to as operating costs. These are described accordingly as: the fixed operating costs; the variable operating costs.
The fixed operating costs remain the same whatever the amount of fish produced in a given farm. They are related to the fixed factors of production. The most important of these are the depreciation and interest costs associated with the investment and the costs of annual water rights, lease on land, licences and other fixed payments such as interest on loans.
The variable operating costs or running costs are those costs that are directly related to the production of the farm and correspond to expenditure on the variable factors of production described above. Note: an additional category is also sometimes used - semi-variable operating costs - which are those which vary to some extent with production level, but may not be directly linked.
These could include management costs, smaller equipment whose life span depends mainly on its usage, office expenses. The relative importance of these costs varies according to the culture system and the farmer's category. They must then be routinely taken into account and managed. In all cases, however, it is important to identify the costs as realistically as possible, to avoid wasting time, money or other resources on inefficient or unprofitable operations.
Fixed factors of production have a useful life 7. As time goes on, long-lasting factors of production such as ponds, buildings, equipment and vehicles wear out.
In the short term, they are kept in serviceable condition through maintenance, including the purchase of materials and spares, and labour required for repairs. After a certain number of years they have to be replaced or renovated. This period is called the useful life. Useful life varies, as shown in Table Some factors such as buildings and ponds have a very long useful life, while other factors such as wheelbarrows or nets may wear out within only a few years.
TABLE 44 Useful life of fish farm structures and equipment in years, assuming correct utilization Remember that careful use and very good maintenance can increase the useful life of most of these factors of production by at least 50 percent. On the contrary, negligence and inadequate maintenance can greatly reduce useful life.
The depreciation costs When long-lasting factors of production reach the end of their useful life, they are normally replaced. If the item can be sold or still has some value at this stage, it will have a residual value. To replace the item, the farmer will need an amount equal to the replacement cost less the residual value.
The amount of money that should be set aside each year by the farmer for the replacement of a particular item is called its depreciation cost. When this amount is set aside in equal sums each year of useful life it is known as: the annual depreciation cost. Such costs are particularly important for a commercial farmer who has spent a lot of money on constructing ponds and buying various equipment that lasts a long time.
As each item gradually wears out, its value depreciates. Each year the cost of replacing a particular item with a new one decreases by its annual depreciation cost, a fact which you will learn to use later when taking stock of your fish farm see Section To calculate the simple annual depreciation cost for any item, simply divide the replacement cost, minus the residual value if any , by its useful life.
The interest costs If savings are used to pay for the fixed factors of production the investment costs , the farmer loses the potential interest on this money, interest which would have been available from the bank if the money had been placed there instead.
Alternatively, if the money was borrowed from the bank or elsewhere, interest has to be paid for the use of the money. This is called the interest on capital investment. If the farmer has to use or borrow money to cover operating costs before income arrives from sales this money is known as working capital , interest costs would also be involved. Interest costs are usually insignificant for small-scale farmers, but should be taken into account when calculating operating costs for semi-commercial or commercial farms of some importance.
Calculating profit The money a fish farmer obtains through selling fish constitutes an income. Assuming prices are similar, this income increases as the quantity of fish sold - the farm output - increases see Diagram 1, end of section However, to produce fish, a commercial farmer must have access to, and use the factors of production, which in turn cost money. Total costs of production therefore also increase with output. The profit made by a fish farmer is the difference between sales income and total costs of production see Diagram 2, end of section However if you do not include a cost for you or your family's time, the profit will be equivalent to your earnings.
Whenever income is greater than total costs, there is a real profit from fish farming. If this is not the case, there is a loss, and measures will have to be taken to change this situation see Section In Sections From these data, commercial farmers will obtain an estimate of gross and net profits.
They will then be able to assess in a more precise way their performance as a commercial fish farmer and to improve this performance through management practices see Section At the end of the year, the above records will provide information on: the total value of the fish given away; the total value of all fish harvested; the amount gained net profit or lost net loss through fish farming.
Keeping day-to-day records efficiently 3. A simple form can be used day by day to record for one month all activities around the fish farm, every amount of money spent and all the details of fish production. This is called the daily record form Form A. You may prepare a form similar to the example below in a small school copybook, using two facing pages per form.
Prefer squared paper. You will need 12 forms for one year of records. Any activity, such as work done on the fish farm and items of equipment purchased for it, should be immediately noted down together with such relevant data as money spent, number of fish harvested, and number of fish given or sold. It is important to note these details as soon as they are available.
Do not leave it for the next day or even later , because delay will result in errors and bad records. It is best to always carry with you a small pocket notebook and a pencil or pen to be able to note at any time and on the spot whatever you wish to record. At home, preferably on the same day, transfer these draft notes on to your daily record form.
Then cross out from your pocket notebook the transferred data thereby avoiding any duplicate transfer that would also result in errors and bad records. Each form is used for one month.
At the end of the month sum up the various columns to obtain the totals for the month. Example You have two small fish ponds m2 and m2 where you produce Nile tilapia for your family needs and sometimes for bartering or selling locally.
Your fish feed mostly on natural food produced through in-pond composting of your farm wastes. You use casual labour only for major jobs and pay it in kind, mostly with fish from the ponds.
For the month of January , your daily records 8 columns are as shown in Form A. For example, on 3 January, you crop some fish to eat and remove some dead fish - mention from which pond you take them.
On 8 January, note the name of the labourer employed. On 28 January, note to whom you give some fish. If possible, note how much time you and your family spend. This will help you to obtain the average weight of each fish later. This is called your income, in cash.
You harvested fish, of which you gave 19 to casual workers and kept 21 for your family. You sold the rest fish weighing This should equal the total from column 4.Depending on the feed that is given, it can help with desirable colour, growth and overall health and well-being. Collaboration on capacity building and sharing of information and experiences between research institutions and between countries must be initiated. The main motivation for a commercial or semi-commercial farmer is to earn an income from producing and selling fish. Packed tightly.
As a commercial farmer, you will want to monitor your fish stocks closely.
The answer could quite possibly be genetic engineering. Checking on your fish farm management at the end of the year 7. Because of the demand of sufficient fresh H2O. In some instances. Fish are stocked in coops. Tilapia is a tropical fish that requires warmer water to survive.
For guidance, you may also use the chart below giving average total length TL of fish and minimum total weight of the sample to be obtained. Multiply average weight column 22 by number of fish present column This claim. By the end of the production cycle days output is For countries like the Philippines, Thailand and Indonesia, where marine fish comprises a significant portion in the total fish consumption, opportunities exist for introducing value-added aquaculture products, and also for marketing and processing initiatives to make more use of under-utilized freshwater species and to optimize allocation of raw materials and supplies Tietze, Example Following on the above example for April , a completed annual balance sheet Form D is obtained in early , after transferring each month the daily record totals.
There are different species of tuna including, bluefin, yellowfin, and albacore.
However, in spite of the production increase for freshwater fish in particular and total fish supply in general in the past decades, prices of aquatic products have increased in all the countries.
However, the profit value is largely driven by the Asian markets and is culture specific. Concern remains that resultant bacterial growth strips the water of oxygen, reducing or killing off the local marine life.