Life or Death for the Atolls of the Pacific Ocean ‘No man is an island, entire of itself. Any man’s death diminishes me because I am involved in Mankind’ John Donne If no man is an island, what of the island itself? All are connected to this world of ours, inter-dependent, mutually effected. The low-lying islands (atolls) and their inhabitants have virtually no physical effect on the rest of the world but culturally and biologically they are havens of diversity. In the case of island communities such as the Micronesian islands of the Pacific the effect of climate change as described in the MOOC sessions, will be devastating. Approximately 100 atoll communities of Tuvalu, Kitibati, Marshall Islands, Federated States of Micronesia (FSM) and Palau support almost 250,000 people. Each community has a unique culture, developed over millennia by the ocean distances. Cultural practices developed to respond to the stable climatic conditions and appropriate for the available materials. With modern communication and relative ease of travel, these traditional techniques are being lost and reaction to changing conditions are being made by abandoning the islands for higher ground. These islands are considered the ‘canaries in the coal mine’ for climate change especially sea-level rise and the effect this has on agriculture production. Of less consideration is the effect of acidification of the oceans on the biodiversity of the region and on the coral base of the atolls themselves. Thirdly, is the costal erosion that will inevitably occur as sea levels rise and coral reefs die! In December 2012 a “King-tide” hit the islands of Micronesia. This tide was exceptionally high and was credited as a result of three phenomenon occurring together – a warm bubble of ocean, a prolonged easterly wind which piled water in the western Pacific and a close encounter with the moon. This might be a clear example of the Cascading Effect as suggested in Chapter 7 of the IPPC report under study. The effect of the abnormal tide was to inundate some atolls with salt water. This in turn corrupted the fresh water lens - the drinking water supply for atolls, deposited salt in the soils of the traditional taro patches and in some cases killed 40% of the coconut trees (personal observations by Cooperative Extension Service personnel). As a result, research is presently being conducted in Palau and in the FSM to develop or identify varieties of root crops especially taro that are more salt tolerant. Flooding in the taro patch in Ollei Ngarchelong in June, 2013 However, flooding was again observed in the taro patch during the king tide in June, 2013. After 8 months of growth, taro were harvested in July, 2013 and those grown in the bluu (blocks) near the dike showed very low survival as the dike was not effective in preventing the salt water from coming into the taro patch. (Thomas Taro, Vice President CRE Palau Community College) Acidification of the oceans has only recently been recognized as one of the greatest potential dangers in the changing world caused by CO2 emissions. Dr. Janice Lough in video 6 Week 3 provided some insight into the effect of acidification of ocean waters on coral growth. She stated The biodiversity of coral reefs is overwhelming. The complex structures of coral reefs provide home, habitat, food for many thousands of associated organisms. Coral reefs are found in the warmest parts of the tropical oceans, in shallow, well‐lit, clear, low nutrient, low sediment waters. As with many tropical plants and animals, this makes them much more vulnerable to warming oceans. Another key issue for corals is ocean acidification. This is happening because of the extra carbon dioxide we have put into the atmosphere has actually been absorbed by the oceans. But this has severe consequences for corals maintaining their calcification rates. 350 parts per million of carbon dioxide in the atmosphere is the maximum at which we can sustain coral reefs as they are at present. By the time you reach 450 parts per million, less than 10% of coral reefs as we know them will survive, and by 550 parts, at the end of this century, it seems very unlikely that coral reefs could survive. …. and this has direct flow‐on effects to the currently 500 million people who rely on healthy coral reefs for their livelihoods and incomesAn additional thought would be the effect on costal erosion. Atolls are protected by the surrounding coral reef. If this dies, in combination with sea-level rise, the resulting direct wave action on atolls will be catastrophic. Added is the effect of higher acid sea-water on the basic coral structure of the islands themselves. Will the sand and coral of the islands not disintegrate also? These beautiful, vulnerable islands may well become a thing of the past.
Posted on: Thu, 20 Feb 2014 10:46:27 +0000
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