Aquaculture and Its Damage to Mother Earth

Aquaculture is the science of cultivating aquatic organisms in a controlled marine or freshwater environment. Aquaculture began eons ago with the ancient Greeks, but it wasn’t until the 1980s that the practise finally began to rapidly expand. Aquaculture farms take on a variety of forms that include massive tanks, freshwater ponds, and shallow and/or deep water marine environments. Today the farming and harvesting fish is a multi-million dollar business. The most popular marine species farmed are bivalves (like oysters), clams and mussels. Also very popular are crustaceans like crayfish, lobsters, and shrimp. Popular fish are cat fish, salmon, trout, and tilapia.

Aquaculture is very economically successful and it can supply jobs for people all over the world. It can help raise economy for foreign countries that have nothing but an abundance of marine life and prime aquaculture environments. It can also feed families in countries that have nothing else to feed their families. Overall, aquaculture seems to be beneficial to the world. The only problem is that it is destroying our planet, killing our marine life, and it can be harmful to humans when consumed.

Aquaculture imposes a harsh impact on marine life in several ways. First, there is the obvious. The fish in the controlled habitat are mistreated, drugged, and then killed for food. They live short miserable lives in small crowded cages. The overcrowding of the cages leads to several other problems as well. Fish wastes and antibiotics are released from the cages into surrounding waters. These wastes create high levels of nutrients, thus increasing the growth of phytoplankton and algae. This drastically reduces the amount of oxygen in the water, killing fish and other organisms. When cages are overcrowded, there is also a greater amount of parasites and pathogens that create an abundance of diseases. With more fish, there is also more fish waste. Fish waste is high in ammonia, nitrite, and nitrate. Nitrate binds with the hemoglobin in blood in fish and can be very fatal. Another result of overcrowding is stress in the fish. With stress, the fish are more susceptible to disease and death.

Overfeeding can cause polluted water which also can play a role in the death of the fish.

Escaped fish can also cause a problem. Farmed fish are bred to be extensively larger and stronger than native fish. When put into an environment where competition is the only way to survive they will dominate over all fish, thus leaving the native fish without food or shelter. Of course, this will also end in death. When fish escape they may also have a disease. After interaction with native fish and interbreeding, they can pass on the disease to many fish outside of the controlled habitat.

Aquaculture uses small sardines and mackerel to feed the larger fish. This has a huge impact on the population of smaller fish. If the small fish had any kind of disease they can also pass it on to the larger fish. The feed does go bad quickly and when they fish eat the rotten feed they can get very sick and accumulate a disease or virus and pass it on. Then when birds or mammals get into the farms and they eat the infected, farmed fish, they get sick as well.

Another problem that arises with outside birds and mammals that want to feed on the farmed fish is that when they do snack on the fish, the farmers lose some money. This prompts them to use lethal methods to control predators, such as electric fences, wires, or nets.

To help this problem, farmers are urged to keep the water in the farms clean with high flushing rates. They should keep their farms in deeper water where possible. Using dry, easily digested feeds, fed by hand, will help keep the water less polluted. The fewer chemicals the better when it comes to aquaculture. There will always be predators but more humane boundaries are recommended. Devices and techniques include noisemakers, whistles, sirens, or visual repellents. If the sound is a warning, it is best to keep the sound moving around the farm so that the animals don’t get immune.

Aquaculture can be very harmful towards its consumers as well. Farmed fish have 16 times the toxic chemicals like PCBs. It is more prevalent in farmed fish but also wild fish due to escaped farmed fish spreading chemicals and disease. These chemicals are a major increase in the risk of cancer. Also, consumption of farmed salmon results in exposure to a variety or persistent bioaccumulative contaminants with the potential for an elevation in attendant health risks.

Colour is added to salmon to make the fish look more appealing to consumers. There was a series of studies done to find out just how much consumers would pay for the colored salmon. In the end, the choice was clear over the uncolored salmon even though that is just one more unnatural chemical added to the fish.

The accelerated growth of finfish aquaculture has resulted in a series of developments detrimental to the environment and human health. The latter is illustrated by the widespread and restricted use of prophylactic in this industry, especially in developing countries, to forestall bacterial infections resulting from insanitation in fish rearing. The use of a wide variety of antibiotics in large amounts including non-biodegradable antibiotics used in human medicine ensures that they remain the aquatic environment, exerting their selective pressure for long periods of time. This process has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environment in the increase of antibiotic resistance in fish pathogens, in the transfer of these resistance determinants to bacteria of land animals and human pathogens, and in alterations of the bacterial flora both in sediments and in the water column. The use of larger amounts of antibiotics that have to be mixed with fish food also creates problems for industrial health and increases the opportunities for the presence of residual antibiotics in fish meat and fish products.

There is an argument that our current projections of meat and feed demands may underestimate future consumptions patterns. They have come to this conclusion for two main reasons: demand projections are based on income extrapolation with assumed demand elasticity and feed requirements per unit of meat are taken to be fixed. Instead, a proposed structural specification that includes a dietary shift towards meat per capita income increases. This account for a shift from traditional to cereal intensive feeding technologies. The finding is that under the commonly assumed growth rates of per capita income, world cereal feed demand will be significantly higher in the coming 30 years than is currently projected by international organizations. Compared to other factors that are generally expected to affect the future world situation, the quantitative impact of the increased cereal food demand greatly exceeds that of GMO and climate change in the coming of three decades.

Aquaculture is also very harmful to the environment. The severity of impact ranges from a mild enrichment of the water to the covering of benthic organisms and production of toxic sediment layers. Negative impacts of Aquaculture have included the destruction of mangrove areas more than anywhere else. In Asia over 400,000 hectares of mangroves have been converted into brackish water aquaculture for the rearing of shrimp. The mangrove areas are also used as a source of firewood, timber, pulp, and charcoal. These habitats are quickly depleting and restoration is extremely difficult. There are five different categories that the environmental effects can be divided into:

• Biological Pollution- Fish that can escape from aquaculture faculties may harm wild fish populations through competition and interbreeding, or by spreading diseases and parasites.
• Fish and Fish Feeds- Some types or aquaculture use large quantities of wild-caught fish as feed ingredients and thus indirectly affects marine ecosystems thousands of miles from the fish farms.
• Organic Pollution – Some aquaculture systems contribute nutrients loading through discharges of fish wastes and uneaten food.
• Pollution- A variety of approved chemicals are used in aquaculture including antibiotics and pesticides.
• Habitat Modification- Marine aquaculture spreads over 26,000 marine hectares, or roughly 100 square miles. The Destruction of natural habitats and with the water source infected surrounding land suffers as well. Water pollution is a major cause of aquaculture. When flushed into nearby coastal waters a heavy concentration of fish feces, uneaten food, and other organic debris can lead to oxygen depletion and contribute to harmful algal blooms. In Thailand alone, shrimp ponds discharge some 1.3 billion cubic meters of effluent into coastal waters each year. Groundwater quality parameters were studied for pollution due to aquaculture in the east coast India. Over a period of two years, 46 groundwater samples were collected for analysis. They showed international chlorine standards for drinking water. It also showed major contamination and low oxygen levels. It indicated high in ammonia, nitrite, and nitrate.

Overall, they are in fact working to make aquaculture be less harmful to the environment but the changes are very costly to make. With aquaculture being practised in many less evolved countries as their main source of income, it may be a while before aquaculture is transformed. With the changes, consumers will be less at risk and marine life will also be out of harm's way. They have created underwater cages that are lowered to the bottom of the ocean giving the cages high flushing rates and they are much cleaner with feeding and feces. They have been proven to produce the same product as the shallow water and they are about the same cost wise to run. The problem is they are expensive to build and it is a pain to dive down to the cages to feed and clean. We can only hope for the best in the future but it seems that are problems with aquaculture have already been solved we just need to help put the change into action before it’s too late.