The Rise of Oceanic Acidity Level and Its Effects on Coral Reefs
The most biodiverse form of habitat in the oceans is the spectacular reefs made from corals.Their existence enhances the survival of thousands of other living organisms in the oceanic environment.Most of these organisms are used by deities as food.
The reef-building corals also referred to as the hard corals have a stone like structure made up of calcium carbonate, a composition of minerals that mostly exists in the shells of numerous marine organism such as snails, clams and oysters.
Just like these molluscs, calcium that exist in the sea water is essential for the corals to build their hard skeleton and critical especially in the initial stages of the life of coral polyps where they settles on a hard material and the process of building the skeleton commences. Studies carried out in the marine environments indicate that there is a decline in settlement of larvae by 52-73% on the reefs due to reduction in oceanicpH. Studies show that there exists a negative impact on the hard coral’s calcification rate as a result of oceanic acidification. This essay will focus on how increased oceanic acidity affects coral reefs.
A number of environmental factors that have an effect on the coral reefs have been researched on in order to create an insight into the way the coral reef fragile ecosystem can survive into the rising oceanic acidic conditions in the present years (Meissner, Lippmann & Gupta, 2012). Recently, global warming was being seen as an imminent threat to the coral reefs. However, the phenomenon of oceanic acidification (OA) has proved to be one of the factors that by far affect the existence and survival of coral reefs.
Oceanic acidification (OA)is as a result of the weak acid that is formed after the dissolution of atmospheric carbon iv oxide into oceanic water. In the recent years, studies have shown that the pH of oceanic water has declined from a pH of 8.2 to 8.1 within a span of 100 years.
With the use of models, it is predicted by that by the year 2100, the pH value will have decreased up to 7.6. Such a drop in the pH value is a big threat to the coral reefs whose life relies on the chalk that is highly soluble in acidic water (Meissner, Lippmann & Gupta, 2012). Currently, the initial signs of oceanic acidification (OA) have started revealing themselves in the long-term records of climate that are hidden within the skeletons of huge colonies of coralsgrowing o earth since the industrial revolution eras.
In a bid to predict how oceanic acidification impact on the coral reefs, a lot of research has been carried out by performing experiments involving corals that are then incubated in environments that have an elevated level of carbon dioxide that replicates the type of conditions that are expected within the next 50 to 100 years (Andersson, & Gledhill, 2013).
The experiments have proved to be successful in identifying how this organism would respond with significant geochemical or ecological consequences. It was noted that under increased oceanic acidity, there is reduced calcification and the growth of seagrasses and macroalgae increases.
Such an analysis makes predictions on how the structure of the reefs will change in future and how the oceanic ecosystem will be affected. OA in the future will limit the ability of the fish to use their sense of smell in predator detection and locating the best places where larvae can develop (Andersson, & Gledhill, 2013). OA will, therefore, have an effect on how the coral reef habitats look as well as their inhabitants
PH as one of the environmental factors is by large affected by climate change. It is anticipated that the coral reefs on the oceans will experience intense events of El Nino and warmer waters as well as changing patterns of precipitation affecting the availability of light, water run-off and nutrients loading.
It is critical to understand how the changes act together in a bid to govern the response of OA. Numerous experiments carried out indicate that the interaction of temperature, light and choice of the species of corals have an effect on how calcification rate tends to decline with oceanic acidification (Meissner, Lippmann & Gupta, 2012).
Scientists have also been able to get an insight from nature regarding how OA affects the reefs. Natural carbon dioxide seeps are produced by volcanic activities creating a site of reefs with a naturally elevated carbon dioxide. Such a case has been seen in Pupa New Guinea where it has been observed that the hardcover of the corals is the same as that of the sites in the neighborhood at ambient carbon dioxide (McClanahan &Cinner, 2008).
However, diversity in corals has been seen to be lower in places with elevated carbon dioxide. Also, changes in PH can arise from biological and tidal activites. It has been noticed that there is a difference in diversity of the coral reefs in subtidal and intertidal reefs (Meissner, Lippmann & Gupta, 2012). It is however clear that some of the corals have already adapted to environments that have characteristics resembling those of the future marine environments.
A rise in oceanic acidity has therefore indicated that the rate at which the corals grow has reduced over time around the world. The growth of the reefs measured by coral calcification indicates that the rate at which calcium carbonate forming the skeleton of the corals is being deposited has continued to reduce. Calcification sustenance is essential for repair of the reefs as well as coral recovery due to physical, biological and chemical erosion (Meissner, Lippmann & Gupta, 2012).
The rise in the amount of carbon dioxide is said to be good for seagrass and bad for the corals. The rise in atmospheric carbon dioxide will ultimately result in numerous changes in the oceanic chemistry with acidification being one of those changes. Such acidification is associated with reduced coral growth due to reduced calcification thus leading to a reduction in the diversity of the corals (De’ath, Lough &Fabricius, 2009).
Acidification of the ocean is also associated with increased growth of the seaweeds that then compete for space with the corals. Also the algae Crustose Coralline are negatively affected by a rise in carbon dioxide in their early stages of development. The algae act as the most favoured settling site for the coral’s larvae. The negative effect of carbon dioxide increase reduces the abundance of the algae resulting in less corals settling (De’ath, Lough &Fabricius, 2009)
The life of the corals is at risk due to reduction in coral availability, diversity and complexity as a result of increased oceanic acidity. Since the industrialization era to the current day, oceanic PH has been said to reduce and it is anticipated that the trend will continue in futurethus negatively affecting the corals. In order to have similar corals as those that existed in the past, something has to be done in order to reduce oceanic acidity and save the life of these vital organisms in the ocean
- Andersson, A. J., & Gledhill, D. (2013). Ocean acidification and coral reefs: effects on breakdown, dissolution, and net ecosystem calcification. Annual Review of Marine Science, 5, 321- 348.
- De’ath, G., Lough, J. M., &Fabricius, K. E. (2009). Declining coral calcification on the Great Barrier Reef. Science, 323(5910), 116-119.
- McClanahan, T. R., &Cinner, J. E. (2008). A framework for adaptive gear and ecosystem‐based management in the artisanal coral reef fishery of Papua New Guinea. Aquatic Conservation: Marine and Freshwater Ecosystems, 18(5), 493-507.
- Meissner, K. J., Lippmann, T., & Gupta, A. S. (2012). Large-scale stress factors affecting coral reefs: open ocean sea surface temperature and surface seawater aragonite saturation over the next 400 years. Coral Reefs, 31(2), 309-319.