Aquaculture and Its Impact on the Environment

Authors: Brianna Healey, Pre-Veterinary Sciences; Will Dell’Erba, Forestry; Kurt Leavitt, Building and Construction Technology

Americans consume 4.8 billion pounds of seafood annually, and 90% of the fish consumed in the U.S. comes from China and overseas (Fish Watch, n.d.). Recently, seafood consumption has gone up steadily as fish are viewed as a healthy protein source (NOAA, n.d.). While this is good for our personal health, it is causing extreme impacts on ocean fish populations. Scientists predict that if overfishing continues at its current rate, wild populations will be down 90% by the year 2050 (One green planet, n.d.). The pressure must be taken off the ocean and freshwater fish that we love to eat, and a viable solution to this problem is aquaculture. Aquaculture is now necessary to meet the demands for seafood in the United States (Cousteau, 2014).

Overfishing not only limits the world’s supply of fish for consumption, but it also creates low genetic diversity in the oceans. This may not sound like much, but low genetic diversity can lead to extinction of marine life, which causes an imbalance in the ecosystem. Genetic diversity is important for the long-term evolution and can serve as a basis for adaption to environmental change (Bell & Okamura, 2005). It is estimated that over 70% of the world’s fish species are either endangered or extinct (Nuttall, n.d.). Aquaculture is a clear solution to overfishing, as it lets us grow the exact fish we want and need for consumption, and we can do so without interrupting the natural environment. It is also possible to select for genetic diversity in an aquaculture facility, which can be beneficial to the natural environment as well.

Aquaculture refers to the cultivation of fish for human consumption, or more simply, the farming of fish (NOAA n.d.). Aquaculture can look very different from operation to operation. One of the main distinctions in aquaculture is closed versus open systems. Open aquaculture systems often involve a large cage in the ocean where fish are reared, fed, then caught for processing. Closed aquaculture systems are systems that are land-based and utilize filtration and recirculation systems, thus removing the pollution risk of effluent being dumped into natural waterways (Goodfishbadfish, n.d.). This rapid growth has led to hasty regulations that may not be properly controlling the amount of waste and pollution it produces. Considering that 50% of the seafood consumed globally is farmed, and that that percentage will continue to rise, it becomes clear that the problems with aquaculture must be solved (NOAA, n.d.). The aquaculture industry is still developing, and needed to learn over 30 years what land farmers had 6,000 years to perfect (WWF, n.d.).

Aquaculture is necessary to maintain demand and to keep overfishing under control, however many current aquaculture operations negatively impact the environment. Nobody wants to replace one negative practice, such as overfishing, with a solution that could potentially cause a different set of problems. Eutrophication is a common issue that comes along with aquaculture. Eutrophication refers to the excess enrichment in a given ecosystem of nitrogen and phosphorous. Aquaculture causes eutrophication in multiple ways. In open water aquaculture systems, the excess fish feed introduces extra nitrogen and phosphorous directly into the water (Talbot & Hole 1994). Closed off inland systems contribute to eutrophication as well, as they tend to dump effluent directly into natural waterways (Talbot & Hole, 1994).

Aquaculture pollution through eutrophication is an unfortunate side effect of a rapidly growing and under-regulated industry. The emissions of marine animal waste from aquaculture facilities into the ecosystem will not only affect other fish, but will also result in nutrient pollution. For example, one of the most harmful aquaculture systems is open net-cage farming, which often takes place on the coasts of large bodies of water. It involves the use of large mesh fishing nets to hold the farmed fish, and there is no way to prevent waste from escaping into the water. This waste can contain antibiotics, pesticides and fish feces which pollutes the open water and makes it unsafe for human drinking, recreational use, and for other wildlife. (Farmed and Dangerous, 2013). With many prevalent aquaculture industries lacking the applicable technology or funding to fix the contaminated water body, nutrient pollution only becomes a growing issue. Over the past decade as interest has increased in fish farming however, regulatory laws have been passed by the EPA and other agencies. Research shows that when a quality feed is carefully managed in a well-designed system, nutrient discharges are reduced by as much as 50% (Miller, 2002).

Aquaculture can also negatively impact the environment through overfeeding fish and marine life. Lack of regulation combined with a lackluster feed plan can result in numerous negative influences on the environment. Nutrients that are not absorbed by the marine life are released out into the environment and the ecosystem must adapt to this pollution (White, 2013). In addition, feed can also account for up to 60% of the total production costs in commercial aquaculture. Aquaculture feed management is absolutely vital because the schedule that fish farmers follow to feed their fish is directly correlated to economic and environmental sustainability (White, 2013). The universal and primary concern among aquaculturists is finding a way to distribute feeds that meet the nutritional standards of the fish at ration sizes that promote both growth and proper feed conversion ration (FCR) (White, 2013).

Another negative impact aquaculture has on the environment is through discharge. Just like any other animal production system, aquaculture generates waste throughout the process. Aquaculture waste can be separated into solid and dissolved waste, specifically carbon, nitrogen, and phosphorous (Amirkolaie, 2011). Solid waste is derived from uneaten and/or spilled feed and from fish feces. Dissolved waste comes mostly from metabolites excreted by the fish (Amirkolaie, 2011). These two types of pollutants grow within a location and eventually will reduce the water quality of that particular system, while also leading to an influx of disease-carrying fish. In order to have a system with sufficient and healthy water quality, waste must be discharged in unison with effluent water (Amirkolaie, 2011). In flow-through systems such as ponds, raceways or cages, an artificial channel is created by pushing water through the system continuously to maintain a higher quality of water for the fish by constantly giving them fresh water (Aero-Tube, 2014). However, this means that dissolved and solid wastes are discharged to the surrounding environment, often without any regulation (Martins, 2010).

Aquaculture is so poorly regulated at the state, national, and global level that it is causing a negative effect on the natural environment that we as humans use and enjoy. One of the major effects of nutrient discharge is that it causes algal blooms. These algal blooms are toxic to humans and animals and can affect many aspects of one’s life. These blooms could make local water unsafe for drinking and recreation, and kill local wildlife (SeaWeb, n.d.). Recently in Toledo, Ohio, up to half a million residents were without safe drinking water because of a bloom of cyanobacteria that made the local tap water unsafe.  This event was caused by aquaculture operations in the area, along with help from farm pollution and climate change. These algal blooms are a recurring event in this area as well, with earlier breakouts in the same area in 2011 (Rees, 2014). This is only one example of how disastrous algal blooms can be.

Because of aquaculture’s increasing negative effect on the environment, getting rid of the industry all together would potentially eliminate the pollution it causes. It is true that the “contaminant stew” caused by aquaculture is hurting the oceans and other bodies of water. This contamination also affects the health of other fish and aquatic creatures that live there (PETA, n.d.). Despite these arguments, aquaculture is now necessary to meet the demands for fish and seafood products in the United States because the oceans are so over-fished (Cousteau, 2014). Humans and other animals rely on fish products for food and vitamins, and it is a vital part of our economy. An increase in aquaculture would mean a surplus of jobs in coastal communities, as well (NOAA, 2011). The new aquaculture operations would need people to manage them, regulate them, and a lot of laborers to help build them and run them once they are finished. A lot of construction workers will be needed in the beginning stages of this plan, and it will create jobs for people who don’t have or need experience with fish. Once these systems are built they will need staff to keep up with day to day maintenance of the facility and the care of the marine life growing there. It would be beneficial to use automated feed systems as they are more accurate and create less waste, but there would still be a lot of need for staff that will help make sure the system is running optimally (Atoum, 2015). It will also be important to make sure there are people keeping track of the waste from these operations. If the systems are well regulated, not only can aquaculture positively affect the environment but it can also help the economy as well.

In order to fix the pollution caused by aquaculture, it would make sense to start in the U.S., instead of trying to set global restrictions right away. A lot of the fish consumed by Americans come from overseas, but by making the U.S. an example for positively run aquaculture operations we can start to have a global influence as well. Our proposal for fixing the current aquaculture systems in the United States is to introduce a set of regulations and a pollution tax on aquaculture operations of all types. The Clean Water Act states that, under the EPA, different industries must follow strict guidelines regarding their contribution to polluting the environment (Goldburg, Elliot & Naylor, 2001). By default, aquaculture would fall under a lot of these guidelines already set in place by the Clean Water Act. However, aquaculture has never had specific restrictions set by these guidelines. It is possible that the policy makers did not have enough access to data that properly reflected the importance of sustainable aquaculture at the time (Finegold, 2009). Aquaculture does have several regulations controlling it, but it is not enough. In 1972 the Coastal Zone Management Act provided management for the aquaculture operations on the coasts of the U.S., and set to manage waste from these farms. In 1980, the National Aquaculture Act established a policy that it is in the nation’s best interest and policy that we should encourage the development of aquaculture in the U.S. This plan included an educational program run by the Secretary of Commerce to help enhance publicly owned aquaculture operations (NOEP, 2007). These guidelines have made some progress in the field, but not enough to make a significant impact. We would like to change that by specifically including aquaculture in the Clean Water Act because it already includes all of the regulations we would like to impose.

The Clean Water Act imposes a strict set of guidelines controlling the amount of pollution an operation can produce. An example of these guidelines is nutrient trading in the Chesapeake Bay. Although this is regarding agriculture operations, the same regulations would work for aquaculture. We would like to do exactly as they did and set a Total Maximum Daily Load (TMDL) that would monitor the amount of nitrogen and phosphorus each operation contributed to the environment (Chesapeake Bay Commission, 2012). We plan to impose a tax for those operations that exceed their allotted amount of nitrogen and phosphorus discharge. We would like to use that tax money to help make the aquaculture operations in the United States better through funding better filtration and feeding systems to help limit their waste. The tax money received from aquaculture operations will go towards several things. Some systems need more help with funding their start up than others. By using this tax money and government subsidies to help more systems work well we can help make aquaculture good for the environment, and cost effective.

One of the biggest potential setbacks of this proposal is the cost of putting it into action. It is a common argument that the cost of funding these regulations may outweigh the benefits they offer. However, there are examples of benefits of these regulations in situations like the nutrient trading in the Chesapeake Bay, and many others across the United States (USDA, 2011). Some studies even suggest that regulating these systems can result not only in lower environmental pollution but also lower costs to the economy as well (Van Houtven, 2012). The cost of dealing with nutrient pollution over time will far outweigh the cost to regulate and decrease the pollution in the first place. In time this proposal will pay itself off by providing clean and healthy food, decreasing water pollution, alleviating the effects of overfishing, and creating many jobs in coastal communities (NOAA, 2011). As mentioned earlier, 90% of the fish consumed in the U.S. come from China and overseas (Fish Watch, n.d.). Introducing more efficient and well run aquaculture operations we can work towards becoming a nation that is independent in its food resources.

Aquaculture as it is right now poses a huge threat to our environment. However, overfishing of our lakes and oceans and high consumer demand means it is a necessary industry in our economy. If we can get aquaculture in the United States to become a well-regulated and efficient industry, we can provide a relief for the environment. An efficient aquaculture system not only limits its own environmental impact but it also helps repair the overfished oceans and lakes. Regulation of aquaculture can create better products for human consumption, and can benefit the economy by creating jobs in all sorts of fields. Aquaculture is necessary for our country, and by making sure it is run properly it can be beneficial for our environment too.

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