: Over the past centuries, human activity comprising of burning fossil fuel, deforestation and farming instigated by global climate change due to the expansion of greenhouse gasses in the atmosphere.
P: The survival of coral reefs and ocean species has been negatively impacted to a high extent by ocean acidification and rising sea temperatures.
P: Coral reefs are greatly impacted by climate change as the reefs are majorly impacted by ocean acidification by increased C02 and rising sea temperatures by global warming. With the reduction of coral another major impact of climate change is the survival of coral species.
Ocean acidification is increasing
P: Global climate change has resulted in a significant increase in ocean acidification causing a detrimental impact on coral reefs in particular the Great Barrier Reef.
E: The Great Barrier Reef is becoming vulnerable to ocean acidification due to the rise of carbon dioxide in the atmosphere resulting from the burning of fossil fuels where approximately 25% of the carbon dioxide being absorbed by the ocean. (“Ocean Acidification – AIMS”, 2018) When carbon dioxide is absorbed by the water a chemical change occur in the oceans, causing concentrates of hydrogen ions to increase, resulting in ocean acidity levels to increase. This change in seawater is known as Ocean Acidification.
E: The Australian Government – Great Barrier Reef Marine Park Authorities stated “Ocean acidity decreases the capacity of corals to build skeletons, which in turn decreases their capacity to create habitat” (“Impacts of ocean acidification on the Reef – GBRMPA”, 2018). It is evident that the increase in seawater acidity caused by carbon dioxide absorption stemming from human activity is making it difficult for corals to build and maintain their skeletons.
L: Changes in ocean chemistry have extensive effects on the coral reef habitat, as the water is becoming acidic which in turn threatens the survival of this marine organism. Climate change is also responsible for increased ocean water temperature which will be examined next.
Sea temperature is increasing
P: Global climate change is altering sea surface temperatures causing the phenomenon of coral reef bleaching.
E: Human activities have increased greenhouse gas in our atmospheres where the increased amount of stored carbon dioxide along with other heat-trapping gasses have resulted in increased atmospheric temperatures and earth. The increase to the earth temperature has resulted in an increase in ocean temperatures. With warmer oceans, this produces more powerful storms and increased sea levels from the melting ice caps, affecting coral reef ecosystems. With higher than normal temperatures this results in coral bleaching and coral mortality. This bleaching is a result of increased temperatures causing the coral to become stressed by a change in the environment conditions.
E: The Australia Institute of Marine Science supports this notion by stating that “Reef corals, in particular, have a very narrow range of temperature tolerance, and this tolerance can vary according to geography, temperature levels and duration of exposure.” (“Sea Temperatures – AIMS”, 2018). For this reason, the stability of seawater temperature is vital to ocean environment sustainability, in particular the coral reefs which are highly susceptible to water temperature changes as demonstrated by the coral bleaching already affecting the Great Barrier Reef.
L: In addition to the impact on coral, other marine life is also negatively impacted, which will be discussed next.
Increased ocean acidification and temperature is negatively impacting marine life
P: The impact of ocean acidity and increased sea temperature caused by climate change also has a detrimental impact on the survival of marine life in particular shelled fish .
E: The impacts of increased ocean acidity by climate change on species growth, reproduction and survival. More acidic makes it difficult for calcifying species to make their calcium structures such as shells, reefs and exoskeleton. Researcher Ligia Azevedo fro IIASA says “Previous studies have shown that marine species were being negatively affected by decreasing ocean pH levels” (“How will ocean acidification impact marine life? – 2015 – IIASA”, 2018). The thin shell of pteropods (sea snails/slugs) are susceptible to being dissolved due to the high acidy levels. Pteropods are part of food chain for species such as seabirds and a reduction in population would have negative impact on the predators.
E: In addition, fish-body temperature is controlled by surrounding water temperature and the increasing sea ambient temperature affects important biological processes of fish including growth, reproduction, swimming ability and behaviour. Fish reproduction is most effected during a narrow temperature range and therefore not being able to reproduce species causing an interfere food webs and “The result is widespread disruption of interconnected food webs.” (https://www.massaudubon.org/our-conservation-work/climate-change/effects-of-climate-change/on-wildlife/marine-life)
L: The effect of human activity causing climate change has had a highly extensive impact on marine life with ocean acidification and increasing sea temperatures causing coral bleaching destroying habitats and marine life.
T: In conclusion, Global climate change introduced through greenhouse gasses as a result of increased human activity such as burning fossil fuels and deforestation have threatened coral reefs and associated marine life.
RA: The survival of coral reefs and ocean species has been negatively impacted to a high extent by ocean acidification and rising sea temperatures.
KP: Global climate change has caused ocean acidification and increased sea temperatures which have adversely impacted the Great Barrier Reef and marine life.
CS: Evidence presented confirms that “Global climate change has already had observable effects on the environment.” (NASA, 2018)