CONCLUSION

Worldwide, open net-cage fish farming industries use publicly owned coastal waters to support what are essentially intensive private feedlot operations that dump drug-laced sewage into the ocean.

Governments looking for new opportunities in rural, economically depressed coastal areas often have encouraged the industry. But increasingly, citizens are questioning if any benefits are offset by the alarming array of environmental, social, economic and health costs.

 

 

• Sewage from farms pollutes surrounding waters.
  
• Drugs, including antibiotics, are required to keep farmed fish healthy.
  
• Escapes of farmed fish (alien species) threaten native wild fish.
  
• Net loss: Farmed fish are fed pellets made from other fish - depleting other fish species on a global scale.
• Sea Bream Farming and the Coastal Economy in Turkey

Communities on the BC coast rely on a healthy marine environment in order to support industries such as tourism, sports and commercial fishing, all of which are impacted by current commercial fish farming practices.
There are several problems associated with current fish farming practices.

Summary of problems:

Some observers see aquaculture as an opportunity to take the pressure off wild fish stocks, while addressing the growing imbalance between fish production and food requirements for an expanding world population. While aquaculture can be beneficial in some cases, this is not the case when carnivorous species are farmed.

Salmon, for example, are carnivores, and are fed pellets made from other fish. Apart from the ecological and health concerns associated with salmon farming, farmed salmon actually represent a 'net loss' of protein in the global food supply as it takes from two to five kilos of wild fish to grow one kilo of salmon.

The vast majority of global aquaculture production, about 85 percent, uses non-carnivorous fish species - like tilapia and catfish - produced in land-based ponds for domestic markets. Most ponds are ecologically integrated into the agricultural, industrial, and community fabric, meaning, for example, that wastes become fertilizers rather than pollutants.The fish farming industry must be transformed to use safe, fully enclosed systems that trap wastes.

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POLLUTION

• organic
• chemical

ORGANIC:

• The main source of organic pollution from salmon farms is fish excrement and uneaten feed. Studies show that 25 - 50 per cent of the dry feed consumed can end up as feces(1) Other contributions to organic waste are fish mortalities that sink to the seabed(1), and fish blood from farms that harvest and bleed fish on site(2).

• The accumulated waste can smother the organisms and set up anoxic (oxygen depleted) conditions in the seabed sediment. This effect has been measured beneath fish cages and up to 50 metres from them. As the waste decays, oxygen is consumed and other gases released such as methane, hydrogen sulphide and carbon dioxide. Oxygen depletion can also occur in the water column from the decomposition of waste that is suspended instead of being deposited on the seafloor.
  
  
• A more troubling contribution comes from nutrients such as nitrogen (N) and phosphorous (P) contained in the waste. Nutrient pollution, especially nitrogen, has been identified as a primary cause of degradation in marine waters(5). The extra nutrients from the organic waste stimulate the growth of marine plants and algae, which deplete dissolved oxygen when they die and decompose.

The average person excretes 4 kilograms N and 1.1 kilogram P per year. Typically, for every tonne of farmed salmon produced, 55 kilograms of N and 4.8 kilograms of P are excreted into the marine environment. The 49,600 tonnes of farmed salmon produced in BC in 2000 contributed as much nitrogen as the untreated sewage from 682,000 people or as much phosphorous as the sewage from 216,000 people.

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CHEMICAL

• The sources of chemical pollution from salmon farms include antibiotics and other drugs, pesticides, feed additives, paints used on netcages and boats to prevent marine growth (antifouling paints), and disinfectants. Many of the chemicals used in aquaculture have been adopted from other industrial sectors and have never been evaluated with respect to their effects on marine ecosystems.
  
  
• To reduce the number of times the nets have to be cleaned, farmers will apply antifouling paints to the nets. The most commonly used paint in B.C. is copper based, where the copper is the active ingredient. The copper can make its way into marine waters by slow leaching of the paint or when the paint is striped during net cleaning. Another toxic metal that is emitted by salmon farms is zinc. This is because zinc sulphate is added to salmon feed as a way to help the fish avoid contracting cataracts.
  
  

• A look at the scientific literature reveals that the so-called "safe" levels are significantly above the concentrations that have been shown to have toxic effects on marine organisms.
  Some examples are:
  · Serious damage to a type of shrimp occurred at 0.150 ppm of copper (9).
  · The germination of a type of seaweed was prevented at copper concentrations of 0.320 to 0.470 ppm copper and 18ppm zinc (10).· Sea urchin embryos were killed at 1.4 to 11.4 parts-per-billion copper (depending on exposure time), and 0.327 ppm zinc (11).
  · At 0.8 ppm zinc, 23% mortality was observed in a sediment dwelling marine amphipod (12).
  · It's been found that zinc and copper can act synergistically, with toxicity increasing when the metal are present together.

  The metals inhibit the chemoreceptors of marine animals, affecting food ingestion. They also can affect the nervous system, disrupting prey capture and manipulation (14).
  
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  DRUGS
  
  
• For parasite infestations such as sea lice, a variety of pesticides may be used either by passing the fish through a bath containing these chemicals, or by adding it to the feed. A potent pesticide that is added to feed is ivermectin.Ivermectin has the ability to disrupt neurological processes. It also can bind to biological membranes, increasing their permeability to chloride ions (a main component of sea water) (7). It therefore has the potential to be toxic to a wide variety of marine organisms. Once administered, this chemical makes its way into the marine environment where it has been shown to be very toxic.
  
  
• In addition to the above-mentioned drugs, there can be other additives in the feed such as colouring agents (to make the farmed salmon flesh pink), binders and antioxidant preservatives. There is also an increasing use (limited at the moment) of immunostimulats. These are chemicals that can boost the immune system of fish. There is little or no data on the environmental or human health effects of these feed additives.
  
  
• The most common antibiotic used is oxytetracycline, with 6.4 metric tonnes used on B.C. salmon farms in 1998 (2). Others include fluorfenicol and a class known as sulfonamides.
  
  It has been shown that oxytetracycline is poorly absorbed by the intestinal tract of the salmon (3). Consequently much of the drug is excreted unchanged into the marine environment, where it distributes itself between the sediment and water column, or is ingested by wild sealife (4). Studies show that some antibiotics, including oxytetracycline and fluorfenicol, persist in the environment, and marine sediment acts as a long-term reservoir for them (5). Antibiotics can significantly alter the microbial community found in marine sediment. Not only can the total amount of bacteria be reduced, but also the relative abundance among the different species is altered.
  
  One area that has received a great deal of study, is the increase in antibiotic-resistant bacteria in sediment under fish farms, in farmed salmon, and in wild organisms caught near salmon farms. Increases in antibiotic-resistant bacteria leads to increased use of antibiotics on the salmon farm, increasing the environmental risks.
  
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ESCAPING FISH

When farmed salmon escape, they pose several problem to wild species:

• Escaped salmon can be carriers of disease and parasites, which pose a threat to wild salmon populations.
• When the species farmed is native to an area there may still be an impact from escaped farmed salmon breeding with populations of wild salmon that are genetically adapted to specific streams.
• In British Columbia there is a greater danger arising from the fact that most of the salmon farmed are Atlantic salmon. Evidence exists that escaped Atlantic salmon can breed in BC's wild streams. The potential negative consequences of this could be dramatic.

How Many Farmed Salmon Escape?

Once they have escaped their netpens, farmed salmon can travel great distances. A total of 556 Atlantic salmon have been caught in Alaskan waters to date. No salmon farms exist in Alaska and the nearest BC farm is over a thousand kilometers to the south. One Atlantic salmon was even caught in the Bering Sea.

Growing salmon in marine open netcages exposes the farm operation to certain risks that can lead to escapes. The netpen system can be damaged due to storms, persistent sea mammals such as seals and sea lions that try to get at the fish, industrial accidents, and even sabotage.

The more salmon escape, the greater their impact on the environment. In terms of environmental impact then, the two most important causes of escape are weather and industrial accidents

· Fish escapement and the transfer of disease from farms to the marine environment are other serious concerns. In British Columbia on Canada's west coast, it is estimated that well over one million fish have escaped from net cages since the early 1980s.

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Sea Bream Farming and the Coastal Economy in Turkey

 

Market Value

As result of farm sea bream flooding the market, the price of wild sea bream has dropped dramatically. This means that fishermen earn less and local economies suffer.

Commercial Fisheries

Small coastal fishing communities up and down the Aegean coast of Turkey, vused to thrive and prosper. Now many of them have literally hung their nets out to dry. Those in favor of fish farms argue that fish farms benefit the economy because they provide an alternative to the forestry and fishing industries. However as the industry moves to a more mechanized system, there are fewer jobs available on the farms.

Tourism

The tourism industry is one of the most important operations in Turkey and marine tourism is its fastest growing sector. This industry provides jobs and revenue to coastal communities. Eco-tourism can be designed and managed in careful ways to ensure long-term . But the presence of industrial fish farms in beautiful areas such as Bodrum disrupts the beautiful sea that people come from around the world to see and enjoy these beauties.The fish farms were located in the bays, not in open waters till 2003, invading the coats for more than 14 years. In addition to this, the location of the fish farms at the moment are also close to the coast, causing serious pollution in villages like Güvercinlik as the currents carry the pollution directly to the coast. The fishermen also are not educated polluting the area they are living in, and throwing all kinds of garbage into the sea which are also carried to the coast by currents and the wind.

"Fish farms are not compatible with Bodrum's number one industry beach and marine tourism. The farms are industrial sites noisy, sprawling, visually intrusive, and polluting. This makes for a very unpleasant encounter during a backcountry trip even without knowledge of the ecological threats they pose."

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