Ocean Acidification

Ocean Acidification is, as its name suggests, a lowering of the pH of the ocean water. This is caused by the dissolution and reaction of carbon dioxide (CO₂) into water; this process is also used in the manufacturing of soft drinks to create a fizzy, acidic taste. However, as one may suspect, a clam living in a pool filled with soda is unlikely to live comfortably. Though the gradually increasing acidity of the ocean is not of the same level of soft drinks, the acidification of the ocean still causes problems as the marine environment becomes changes. However, as concentration of atmospheric CO₂ increases, more is absorbed into the ocean, which pushes the reaction towards the end result of the CO₃²

Calcium carbonate (CaCO₃) is used for the formation of structures in many marine invertebrates, including mollusks and corals. However, CaCO₃ also reacts with CO₂: With these reactions, the end result is that more 2HCO₃^-, the bicarbonate ion, is formed and less carbonate becomes available for use for these marine organisms to use. At the same time, with more protons (H⁺) prevalent in the water, the pH decreases and acidity of the water increases. In the end, the water changes to become an environment that many organisms may have trouble adjusting to, while at the same time diminishing the amount of resources they need in order to build their body structures.

CO2 + H2O à H2CO3	Carbonic Acid
H2CO3 ↔ H+  + HCO3-	Bicarbonate ion
HCO3- ↔ H+ + CO32-	Carbonate ion

The Damage and Degradation of Coral Reefs

            Coral reefs span about 280,000 square kilometers in the ocean, and are referred to as the rainforests of the sea. The reefs are important to the marine environment just like how the rainforest trees are important to tropical regions; both areas house many organisms and provide protection against predators. Coral reefs benefit the environment in many ways such as protecting the shore form the impact of waves from storms, providing food and medicine for the human population, and providing economic benefits in the form of tourism. According to NOAA, coral reefs provide the economy with $375 billion each year on the form of jobs, food, and tourism.

            Coral reefs are on the decline for a variety of reasons. Coral bleaching is cause by the elevation of the sea surface temperature due to global climate change. Coral bleaching can also occur due to ocean acidification, pollution, and high UV radiation levels. Coral that has been bleached appears to be white, dead looking, and results in not being able to support many organisms. Rising levels of carbon dioxide are also attributed to the dying of coral reefs around the world. Carbon dioxide levels are rising due to ocean acidification. Human disturbances in the environment cause diseases, plagues and other invasive species to decimate the reefs.

            Humans also have a direct link to why the reefs are under so much pressure.  Coastal economies partake in over-fishing, some in which use damaging methods such as bomb and cyanide fishing, which damages the reef ecosystem. Nutrient and chemical is also a major factor in the destruction of coral reefs. Fertilizers and other chemicals leaked into the environment disrupt the ecosystem.  France has also been doing nuclear testing in the Pacific Ocean, which harmed the coral population. The development of coastal areas contributes to the demise of the reef population. Industries such as tourism mine coral reef rock and sand beyond their sustainable limits and do not allow the reef to recover.

            Possible solutions to saving the coral reefs are straightforward. Basically, the human population needs to be more considerate to the environment. Industry needs to stop taking more resources from the reefs than the reef can sustain. There also needs to be a halt on the over development on the coastlines. People just need to stop thinking about how they can make money and think about how their decisions can impact the environment. 

Dead Zones

A dead zone is an area of bottom water that has very little to no concentrations of dissolved oxygen. Very few organisms can survive this lack of oxygen; so dead zones can destroy the effected habitat. Dead zones are caused usually when there is an algae bloom. When the massive increase of algae die, they sink to the bottom to be decomposed. In order to decompose the increased amount of algae, the bacteria in the water must use more oxygen then normally. This process eventually can lead to a loss of oxygen in that area. The animals then have to either leave the area or die. The smaller animals that form the base of the food chain usually leave or dye out. Making it almost impossible for many other animals to live there. In addition, when an area loses all or most of its oxygen, microbes that thrive in oxygen-free environments, takes over, forming vast bacterial mats that produce hydrogen sulfide, a toxic gas. Location wise, dead zones usually occur along the coasts where this is runoff from other sources.

            Dead zones sometimes occur naturally but human activity is making them dangerously more frequent. One of the main causes of this increase is the fertilizer-runoff from fields into rivers and eventually the ocean. Fertilizer contains large amounts of nitrogen that when added to the ocean, fuel algae blooms. Another cause is the burning of fossil fuels, such as using gasoline in a car. This burning of fossil fuels results in “smog-forming nitrogen oxides”. When it rains, the rain takes the nitrogen out of the air and usually brings the nitrogen down into the ocean.

            Dead zones can cause not just environmental problems, but also economical problems. A hypoxia (having small amounts of oxygen) problem, that occurred in a small area of water in New York and New Jersey in 1976, caused the local fisheries about $500 million. Additionally, about 83,000 tons of fish and other animals are lost in the Chesapeake Bay dead zone each year, enough to satisfy half the commercial crab catch per year.

            For the problem of fossil fuels using electric or hydrogen cars would easily fix this problem, but the fertilizer problem is more difficult. On solution is to breed crops with an adaptation that takes more nitrogen out of the soil. This would minimize the amount of nitrogen that runs off into water. Some crops, such as canola and corn, already have this advancement, and these special seeds can be bought by certain companies, like Monsanto Company and DuPont’s Pioneer Hi-Bred International. However, it is still difficult to stop. A lot of Nitrogen that ends up in water gets buried in sediment. Even though we have taken measures over time to lower the amount of Nitrogen run-off, this sediment slowly releases Nitrogen over time which then starts the cycle over. The damage becomes even worse during natural disasters. During floods, the water takes Nitrogen that would normally stay on land and brings it back to the water. These sources then deposit even more nitrogen into the water, making the cycle even worse.

            Dead zones are a major environmental and economical problem. They cause a major loss in marine habitats and cost local fisheries and commercial fishes a lot of money lost. Although it is very difficult, there are ways that people can solve the problems of dead zones, such as using genetically engineered plants to driving hydrogen or electric cars. They are a big problem now, and if nothing is done about it, they will continue to get worse.