Fish farming or aquaculture may come with many advantages, but it is also associated with negative effects on the environment. Fish farming primarily relies on the use of natural resources, including water and land that are areas of the overall environment. Other living creatures also share these. So, it is vital to learn the possible effects they could bring to avoid undesirable results.

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How does fish farming affect the environment? Fish farming or aquaculture has positive and negative effects on the environment. Its negative impact includes water eutrophication, destruction or alteration of natural habitats and water quality, as well as transmission and introduction of aquatic animal diseases. Its positive effects include the prevention of fish from becoming extinct and among others.

For those who are planning to involve in fish farming, you must learn the effects of this activity on the environment. Below is an explanation of how it can affect the environment and how to avoid the negative effects.

Negative Effects Of Fish Farming

Local Eutrophication

Among the effects of fish farming is local eutrophication. This phenomenon is the excessive filling of nutrients in the water as well as dissolved substances that contain the elements N, P, and Si that are required by the aquatic plant for growth. As a result, the dissolved oxygen in the water will decrease, leaving other water organisms, such as fish and amphibians, to die.

The cause of local eutrophication is primarily due to the dependence of fish farmers to phosphate and nitrate fertilizers. The fertilizers on golf courses, lawns, as well as other fields may also contribute to nitrate and phosphate nutrient accumulation in nearby waters, leading to eutrophication.

Eutrophication lessens water clarity as well as the underwater light. Concerning that, the Secchi disk is a common way of measuring water eutrophication. This method involves a disc that is lowered into the body of water. The depth wherein the disk is no longer become visible is a measure of the water’s clarity.

Algae in eutrophic lakes don’t get enough light. As a result, they stop providing oxygen and start consuming what is left in the water. When an enormous amount of algae die, bacterial decomposers will make the situation worse by further reducing the oxygen levels in the water. All of these will turn the lake eutrophic that leads to an anoxic and deadly underwater environment for all aquatic creatures.

Spread And Outbreaks Of Diseases

Fish farms encounter common threats to fish health, such as bacteria, parasites, and viruses. Maintaining a large number of fish in a crowded pen creates a conducive environment that develops and spreads infectious diseases.

Fish can become stressed due to the crowded and unnatural environment. As a result, they become more susceptible to disease. The water environment where the fish are kept has limited water flow that starts the spread of pathogens inside the crowded populations. While parasites, bacteria, and other viruses may exist in the natural environment of fish, these pathogens will cause trouble when they occur in the crowded, unnatural water environment such as fish farms.

Impact Of Biodiversity

Fish farming can also introduce farmed fish species into the wild that can change the biodiversity of aquatic ecosystems. While all fish farms have their escape preventive measures, predators like sharks and birds, human error, equipment failure, severe weather, among other complications, show that escapes of farmed fish are unavoidable.

Compared to wild fish, farmed fish are grown through selective breeding so they have a lower genetic variation. For this reason, people are preventing them from escaping from farms so they won’t interbreed with wild fish. When farmed and wild fish interbreed, it will produce a less genetically diverse fish species. As a result, less robust, the population will be formed.

Infertile offspring may also be produced like mules. Aside from that, non-native fish species may compete with native populations for food sources when they become established in their new environment. They may also fight over who is going to populate a particular breeding site.

Positive Effects Of Fish Farming

A wide array of fish species, as well as shellfish and plants, are grown in man-made island systems, ponds, tanks, or open water cages in the ocean. These are taken care of until they reach the size that meets the requirements of consumers.

Fish farming on a large scale can reduce the need for catching and finding wild fish for ornamental and food purposes. This venture has grown exponentially in the past years.

Concerning that, 44.1 percent of all the fish that are produced around the world in the year 2014 are from fish farming. Fish farming is promising when it comes to becoming a long-term food source that can sustain the needs of a growing population.

In terms of its environmental effect, fish farming can prevent fish species from becoming extinct. For example, the Atlantic bluefish tuna has become extinct due to overfishing. It happened because more fish are caught than produced. Fish don’t naturally replenish fast, which is among the primary reasons why people are turning into fish farming.

Fish farming allows suppliers to provide market demand. It helps to replenish fish supply faster compared to the rate that the ocean can produce it.

Preventing The Impacts Of Fish Farming

Fish farming can provide positive effects on the environment and avoid giving a negative impact when done correctly. Companies who are involved in fish farming should strictly follow the policies of aquaculture to prevent diseases from emerging and spreading, keep a normal level of nutrients in the water, and provide a non-stressful environment for fish so they can thrive.

Aside from that, fish farms should also ensure that the fish inside the pens are secure. If the pens are in open cages in the ocean, always impose strict escape preventive measures to keep farmed fish from changing the biodiversity of fish in natural fish ecosystems.


In conclusion, fish farming can help the environment in the right way if done correctly. For this reason, companies and individuals who are involved in this kind of activity should carefully study and apply the right methods in aquaculture. When done in the right way, fish farming can provide a sustainable fish source for the growing demand of the world.