The application of biosecurity measures in aquaculture overcomes most of the diseases. Approaches in aquaculture are to take place by stock reduction density controlling diseases of fish in aquaculture. The first step to measuring low stock densities are when ectoparasites infection break out with increasing water flow achieving a higher flow of the parasites. Removing microorganisms involves disinfection by physical and chemical agents. By applying disinfectants, the microbes living on the surface of fish eggs will die. Controlling the spread of aquatic animal pathogens these agents usage in aquatic rearing acts as a part of biosecurity pathogens. To Controlling diseases, cleaning and drying of ponds are mandatory. Ponds having high-quality clean water is most satisfying to produce healthy fishes in aquaculture. Use only neutralized chlorine to avoid killing of fishes.
How does ammonia level increase?
Give a limited amount of food to be absorbed within the first 10 minutes of consumption. The amount of food lying in the water will lead to overfeeding. Providing food multiple times will produce more waste from them. The filter needs to be washed and sanitized not delaying the process of removing dead fishes. No fish overstocking allowed to reducing ammonia. Ammonia level increases when the fish rest at one place, stop eating and swimming as before, will appear up to the topmost surface to take in oxygen, the fish fins start becoming red, the water begins to appear milky due to high ammonia levels. Accumulation of fish production leads to ammonia that is toxic in nature. The fish gets lethargic and will fall in a coma and die if there because of high concentration levels of ammonia.
Stop feeding or reduce feeding rate
The primary source of nearly all the ammonia in fish ponds is the protein in feed. When feed protein is completely broken down (metabolised), ammonia is produced within the fish and excreted through the gills into pond water.
The toxic form of ammonia (NH3) is a dissolved gas, so some producers believe pond aeration is one way to get rid of ammonia because it accelerates the diffusion of ammonia gas from pond water to the air.
It has long been thought that liming ponds decreases ammonia concentrations. In fact, using liming agents such as hydrated lime or quick lime could actually make a potentially bad situation much worse by causing an abrupt and large increase in pH.
Fertilise with phosphorus
Most of the ammonia excreted by fish is taken up by algae, so anything that increases algal growth will increase ammonia uptake. This fact is the basis for the idea of fertilising ponds with phosphorus fertiliser to reduce ammonia levels.
Imbalance in pH levels
The fish need to survive with a pH level of at least 4 and 11, to maintain the acidity level of the water or soil, the pH level is essential. The growth and reproduction of the fish will be affected if the pH level falls or rises. The pH level should not be too high nor too low if it is the living organisms will die. The sensitive species are affected more due to imbalance of pH levels.
Due to the high availability of light, the growth of algae increases in shallow ponds but will reduce ammonia because of high lighting. Deeper ponds contain water in higher quantities producing less ammonia because there is more water to dilute the excreta that comes from the fish. The most common reason why ponds have excessive algae blooms is nutrient pollution like excessive nitrogen, phosphorous, carbon, and potassium. Generally, the amount of phosphorous controls the amount of algae found in your pond. These are the chemicals pond plants use, combined with carbon dioxide and water, to grow and make new leaves.
Proper Water Treatment
If an algae problem already exists, water treatments are an easy and efficient option. Green murky water and string algae can be contained using repeated applications of an effective water treatment, like Algae controller from Narsipur Chemicals. Also using a Water Clarifier, will help reduce the formation of Excess Algae.
Regular cleaning of Pond
Maintaining a clean pond may seem like a chore but it will help stop the growth of algae. Clear debris and string algae by using a garden hose to remove it off rocks and from waterfalls, or get rid of it by hand or net.
Effects of weather and climate
Cloud Cover, Winds & Hurricanes
Cloud cover, especially completely overcast skies, reduce the amount of light available for photosynthesis by phytoplankton in ponds. This can result in lower concentrations of dissolved oxygen at the end of the daylight period and a lower concentration of dissolved oxygen during the night when photosynthesis ceases.
In areas where strong winds are a common phenomenon, these winds create wave action that greatly accelerates the rate of gas exchange with the atmosphere. This improves oxygenation and diffusion of potentially toxic and gaseous metabolites such as ammonia, carbon dioxide and hydrogen sulfide from the water.
Drought can cause serious problems in aquaculture and especially at facilities depending upon surface sources of freshwater. Ponds filled by overland flow (storm runoff) may decrease greatly in volume. This crowds the culture animals into less volume, and it also concentrates potentially toxic metabolites.
Ice cover in winter can be a serious threat to aquatic animals held in ponds. Aquaculture ponds have higher concentrations of organic matter than typically found in small, natural water bodies where ice cover has no serious effect on the aquatic fauna.
New Aqua Tank Syndrome
Before a tank has developed the appropriate chemistry to support healthy fish, heavy concentrations of nitrates and ammonium in the water can be fatal. In time, natural bacteria in the water will balance out these contaminants, but until that balance is achieved, fish may die unexpectedly.
Test a new tank regularly for nitrate and ammonium levels, and change the water as needed to reduce levels so they are safe for fish.
Problems with Aquaculture
The kinds of aquaculture people are worried about is their installation. Chemicals, antibiotics are used to try to keep them from getting infectious diseases. Chemicals used to remove various parasites, sea lice. Using chemicals is harmful to the marine environment. Not having a strong current flow in the water will make the waste material to lay down at the bottom. The oysters or mussels are much less of a problem and much beneficial. People are doing lots of restoration for shellfish in areas with water quality problems. These are less damaging and beneficial to the marine environment.
Written By – Hemant Bhoir