Benefits of aquaculture

Some benefits of aquaculture include:

• Reducing fishing activities and allowing the fish population in oceans to be able to reproduce and increase

• Large amounts of species of fish can be produced for consumption without depleting the fish supply in oceans

• Aquaculture farming allows organisms to be grown in a pollutant free environment and controls the nutrients given to ensure healthy growth – this can also maximize the yield

• Employment is provided on aquaculture farms with a range of different jobs

Although aquaculture offers many benefits, there are also views that condemn the practice. Some disadvantages argued are:

• Organisms are genetically modified in some farms

• Large amounts of waste (excess nutrients, faeces from organisms) are collected in one area and sometimes released into the environment causing pollution

• Diseases can be spread easily among the same species and even be transmitted to the organisms in the outer environment.

How can aquaculture help to solve the problem of over-fishing?

The major and most significant impact of aquaculture will be the role it plays in reducing the amount of fishing activities taking place in the oceans. If aquaculture farming is practiced throughout the world, it will prevent the need for fishermen to catch large amounts of fish to satisfy demand. Aquaculture farming usually involves the production of fish and shellfish species that are high in demand. If the majority of the fish supply comes from aquaculture farms, there will be no further depletion of the fish supply in the sea and these fishes will be able to reproduce and grow thereby increasing to a more sustainable level.

Although arguments have been made against aquaculture as a solution to overfishing, this practice would not show immediate results. It takes time to implement and to build this process. It is considered as a sustainable practice, therefore the results will be seen in the long term.

                                                                           

Logo for “Project Coastal Crisis” by the Aquarium of the Pacific and Designmatters Program of the Art Center College of Design. “Sustainable Aquaculture – Choose Well for the Future”.

References: http://www2.unb.ca/chopinlab/imta/news/aquarium_longbeach/index.html

What is aquaculture?

According to the National Oceanic and Atmospheric Administration, “Aquaculture -- also known as fish or shellfish farming -- refers to the breeding, rearing, and harvesting of plants and animals in all types of water environments.”

Aquaculture takes place under controlled conditions and in a controlled environment therefore ensuring that there are no pollutants in the water and also regulates the nutrients which the organisms receive. These conditions allow harvesting of fish in moderation in order to maintain a supply that can continue to reproduce.

• Freshwater aquaculture- the rearing of freshwater organisms, for example, tilapia and trout. This usually takes place in on-land tanks or ponds.

Retrieved 15 October, 2015, from FoodChoice http://www.fishchoice.com/featured-seafood-supplier/tropical-aquaculture-products-inc

• Marine aquaculture- This is the rearing of salt water organisms. Eg. tuna, shellfish and other salt water fishes.

                         >   Offshore aquaculture- fishes are kept in cages that are submersed in deep                 water or in shallow areas for shellfish and flat fishes.

Aquaculture Methods. Retrieved from GoodFishBadFish http://goodfishbadfish.com.au/?page_id=33

Aquaculture in France. Retrieved 15 October, 2015, from Flickr https://www.flickr.com/photos/julien-carnot/8576553550

                        >    On-land aquaculture- tanks are set up on land with a recirculating system.

Land-based salmon farm in the UAE. Retrieved 15 October, 2015 from http://www.intrafish.com/news/article1397390.ece

Aquaculture practices can either be:

• Intensive- the cultivation of large amounts of fish which requires high quality feed and continuous maintenance.

• Extensive- this involves less maintenance as food is sometimes obtained naturally and the organisms reared are usually in smaller amounts.

References:
http://www.nmfs.noaa.gov/aquaculture/what_is_aquaculture.html
 http://www.eschooltoday.com/aquaculture/what-is-aquaculture.html

Over-fishing

• What is Over-fishing?

Over-fishing can be defined as the practice of excessive fishing to a point in which the fish stock is exhausted. This is usually when the amount of fish being caught cannot be replenished by natural reproduction.

• How does Over-fishing occur?

                         >Global demand

                          >Intensity of fishing activities:

                  -overcapacity

                  -unsustainable fishing

The increasing human population is a major factor which leads to over-fishing as food supply and the size of the population go hand in hand. As the population size grows, the demand for food will also increase. According to the Worldometer website, (“World Population,” accessed October 8, 2015, http://www.worldometers.info/world-population/) the world population is growing at a rate of 1.13% and the average population change is approximately 80 million per year. With these drastic changes in growth, focus will be placed on the most cost effective and reliable food supplies. Although fishing can support major sectors of the world’s economy, the improper practices used can result in only short term benefits. Many fishing companies own large vessels which stay out at sea for days to fish. In aggregate, these vessels will catch tons of fish before returning to port. This is known as overcapacity. They use unsustainable methods such as trawling (dragging a huge net through the water) which destroys marine life living in the seabed and also catches other sea animals.

• What are the effects of Over-fishing?

               > Decrease in biodiversity
                              >Ecosystem instability
                              >Economic loss

                                         >Food security problems

The most significant effect of over fishing that should be considered is the impact that it has on the biodiversity of the aquatic environment. Biodiversity can be defined as the variety of organisms in an ecosystem and it can be categorized into genetic diversity, species diversity and ecosystem diversity. As the fish stock dwindles, both species and genetic diversity decreases. Biodiversity is very important as each species has its own role to play in an ecosystem. For example, sharks are the apex predators of an ecosystem. They help keep the ecosystem in balance by feeding on the most available fish species.  If the shark population decreased drastically, the population of other fish species would rise to a point where there will be problems for food and space. This single change in the shark population can cause a chain reaction in the ecosystem. Biodiversity is also linked to ecosystem stability which is the ability of an ecosystem to recover quickly after any sudden changes or disturbances. Therefore if many species of fish are continuously being depleted, it will be more difficult for other aquatic organisms to adapt to these changes. Fishing is also a major source of revenue for many countries throughout the world. With reducing fish stock, there will be major economic loss which can affect other sectors of the country. As for the social effect of over-fishing, these include a decline in food security as well as the increased unemployment of fishermen. This will therefore make it more difficult to sustain a livelihood for many people.