Recent studies in Australia have show that the Great Barrier Reef is 50% of its former size (Great Barrier Reef: Half its Coral Lost 2012). On a local scale, this represents a large loss in species and diversity in this region. This could impact not only the environment in the region, but human fisheries too. Reefs are the building blocks of life in an area. It draws fish to the region, and a change in a reef ecosystem possibly could have an impact on fish migration too the area. However, what can it signal on a global scale. Studies suggest that the increase of carbon in the atmosphere causes an increase of CO2 in the ocean as well (Biology Department 2013). This increase of carbon in the ocean can reduce calcification (Riebesell ET. Al. 2011). Calcification is how reefs build themselves, which are dominated by scleractinian corals (Biology Department 2013). These corals build by secreting a form of calcium carbonate, aragonite (Riebesell ET. Al. 2011).
The adding of CO2 removes bicarbonate ions from the ocean reducing calcification rates (Biology Department 2013). The Earth could be approaching the negative-threshold level for scleractinian corals. The pH of the ocean could increase as a result of this as well. This will elicit a response from many organism of the sea. The loss of the coral is clearly visible and the organisms of off Australia’s habitat is being destroyed (Figure 1). This example in the Great Barrier Reef could be signaling a global change in these ocean ecosystems.
Also, invasive species are playing a large role in the coral reduction (Great Barrier Reef: Half its Coral Lost 2012). The invasive crown-of-thorn starfish has destroyed many coral by feeding on them (Figure 2). Action has to be taken to prevent the loss of the reef and the other reefs. Coral reefs are vital to the ocean ecosystem.
Figure 1: Picture of part of the dying reef in Australia. One can clearly see how the ecological dominant is coral rubble.
A link to a video on the Great Barrier Reefs decline:
Biology Department. (2013, Spring). Coral Reefs. [slide 8-28] Retrieved from Online Laboratory Website:laulima.hawaii.edu
Fabricius, K. (2012, October 4). Great barrier reef: Half its coral lost.Web
Riebesell, U., Zonderman, I., Rost, B., Tortell, P., Zeebe, R., & Morey, F. M. M. (2011). Reduced calcification of marine plankton in response to increased atmospheric co2 . The Warming Papers, 1, 396-406.
www.aims.gov.au. (02 O). Retrieved from http://www.aims.gov.au/latest-news/-/asset_publisher/MlU7/content/2-october-2012-the-great-barrier-reef-has-lost-half-of-its-coral-in-the-last-27-years