Mercury in Fish

Mercury In Fish

For thousands of years fishing has been vital to civilizations and cultures around the world, and this is still true today. The fishing industry is one of the largest businesses on the planet and there is an estimated 1-3 trillion fish caught annually. This would mean that, on the lower end of things, roughly 2.7 billion fish are caught daily. While not all of the fish are used for food, a major portion of those caught are. The issue with this is that the fish are posing increasing health risks to ourselves because Mercury that is contained in their bodies.

One of the first things that should be mentioned about Mercury would be that it is a naturally occurring element. There is meant to be Mercury on the planet. Most things on earth have trace amounts of Mercury in them, the issue is when excess amounts of Mercury get into things and then issues arise. Mercury is found in coal and is released as a vapor when energy, such as heat, is added to the coal. The Mercury is then released into the atmosphere. It can settle on the banks of rivers or stay in the air. When it rains, the Mercury would fall and enter rivers and streams as well. Mercury then settles on the bottom of the ocean floor.  It would then begin to accumulate in the animals at the bottom of the food chain, such as zooplankton. Small fish would then ingest these organisms and then they would have Mercury inside of them as well. Many of these small fish are then eaten by larger fish in the middle of the food chain. Some of these middle fish are also then eaten by larger fish near the top of the food chain. These larger fish, such as Tuna and Mackerel, are caught and processed to be eaten. The amount of Mercury magnifies through the different levels of the food chain because many animals that have Mercury in them are eaten by one animal. This process is called biomagnification. When humans eat these fish then the Mercury then enters the people. This is very dangerous because then humans would then have dangerous amounts of Mercury in their bodies which would effect them.

  The Mercury that is usually found in the fish is called Methyl-Mercury(Hg-CH3). This type of Mercury can have some fairly adverse effects on humans and infants. The Mercury can impair neurological development. This would mostly effect younger children and unborn infants. Their brains are going through rapid neurological development and the Mercury can impede this development. The brain would not grow and mature as it should. The Mercury could also impact the nervous system. It would effect the neurons, axons, and their growth. This could then impede the motor skills of children. For adults it could also effect the brain by disrupting the brains cognitive thinking and spatial awareness. This would include language, memory, and motor skills all being effected as well. Mercury can severely disable young children and change their overall development.

  Depending on the type of fish and their location on the food chain, species tend to have different levels of Mercury. The commercially caught species that tend to have the largest amounts of Mercury are Mackerel, Tuna, Bluefish, and Marlin. These fish are at the top of the food Chain and so it makes sense that, generally, they have the highest amount of Mercury in their bodies. The fish that tend to have the lowest amount of Mercury are Salmon, Trout, Whitefish, and certain types of smaller Squid. These fish are generally on the lower half of the food chain which would make sense for them to have the lower amounts of Mercury in their bodies. In certain cases the salmon population that was tested had no trace amounts of Mercury in their bodies.

  With much of the fish population not entirely safe to eat, there have been solutions proposed to solve the crisis. One solution is to place special devices into the smoke stacks of Coal plants and places that expel Mercury into the air. The devices would make the Mercury vapor undergo a Fenton Reaction. The vapor undergoes a large chemical process where ultimately the Mercury becomes oxidized. The un-oxidized Mercury vapor is not soluble and is much harder to clean up. Oxidized Mercury is soluble and can easily be cleaned up.  The process wold mean that less Mercury would enter the fish population and so humans would no longer be effected. It is a viable option and one that should be done.

        Another solution to the Mercury levels in fish is fish farming. There are companies that have netted off areas in rivers and oceans in which they breed and raise fish. The fish are then farmed and sent to markets everywhere. Fish farming has some benefits but it also has many drawbacks. The fish that are farmed are clean of many heavy elements. This means that people would not be ingesting Mercury anymore. It would also mean that the oceans, that are increasingly becoming more depleted from fish, would slowly recover from the overfishing that has happened for hundreds of years. Some issues that arise with massive fish farms are that if Mercury somehow gets into the farm then the farm would be accomplishing nothing other then selling Mercury laden fish. Farmed fish are also fed antibiotics to deal with the diseases that occur when fish are put together in close spaces. People would then be eating the antibiotics and steroids that are in these fish. This could also affect the people that eat fish. The fish are generally kept in by nets but if the nets somehow break because of predators or more natural wear and tear then a whole new species could enter a new environment and an entire ecosystem could change. This is a big threat to the ocean environment and wild populations. There are many issues and benefits with fish farms and so there are regulations on how companies farm fish.

  The Mercury levels in fish are also social environmental justice issues. It is the humans who are poisoning the fish and thus in turn are poisoning ourselves. Socially this would not be the right thing to do and it would be our jobs to stop it from happening. The Mercury would also be poisoning the fish and ecosystems that it falls into. This is a huge environmental issue and it is our job socially to stop this from happening. Coal plants also release other chemicals, such as Arsenic, which have other adverse harmful on people, animals, and ecosystems. These chemicals have adverse effect the environment and it is our responsibility to prevent this from happening more and to clean up what has happened. We are poisoning ourselves and it would be in our best interest to stop Mercury pollution and to clean up the damage we that we have caused, at any means necessary.

Bibliography

Anonymous. "Health Effects." EPA. Environmental Protection Agency, 10 Mar. 2014. Web. 21 Nov. 2014. <http://www.epa.gov/mercury/effects.htm>.

Anonymous. "Mercury Levels in Fish | NRDC." Mercury Levels in Fish | NRDC. Natural Resources Defense Council, n.d. Web. 21 Nov. 2014. <http://www.nrdc.org/health/effects/mercury/guide.asp>.

Anonymous. "NRDC: Mercury Contamination in Fish - Know Where It's Coming From." NRDC: Mercury Contamination in Fish - Know Where It's Coming From. Natural Resources Defense Council, n.d. Web. 23 Nov. 2014. <http://www.nrdc.org/health/effects/mercury/sources.asp>.

Anonymous. "What You Need to Know about Mercury in Fish and Shellfish." US EPA. Environmental Protection Agency, 20 Nov. 2013. Web. 20 Nov. 2014. <http://water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_index.cfm>.

Brooke, P., and A. Mood. "Estimating the Number of Fish Caught in Global Fishing Each Year." (n.d.): n. pag. Estimating the Number of Fish Caught in Global Fishing Each Year. July 2010. Web. 20 Nov. 2014. <http://fishcount.org.uk/published/std/fishcountstudy.pdf>.

Lu, Dennis, Edward Anthony, and Yewen Tan. "Mercury Removal from Coal Combustion by Fenton Reactions." Mercury Removal. Elsevier Ltd, 2007. Web. 23 Nov. 2014. <http://www.sciencedirect.com/science/article/pii/S0016236107001317>.

Ryan, Sheryl. "Are Farmed Fish Safe to Eat?" Are Farmed Fish Safe to Eat? Greenopedia, 2013. Web. 23 Nov. 2014. <http://greenopedia.com/article/farmed-fish-safe-to-eat>.