Essay On Increase Abundance Of Crustose Coralline Algae Due To Ocean Acidification

Global temperatures are steadily rising due to anthropogenic causes; this increase in temperature is causing changes to ocean properties that can impact the organisms that call this medium their home. One of the most evident impacts of climate change on the world’s oceans is the resulting raise in ocean surface temperatures. Rising ocean temperatures can directly affect biogenic reef building organisms like corals which produce some of the most diverse and productive ecosystems in the world. Previous studies within this field have determined that climate change is a notable stressor for these corals causing large scale bleaching events; where they release their photosynthetic symbionts. Once the symbionts of these organisms are released corals begin to starve and ultimately die resulting in

Coral reefs exist all over the world and are generally known as being one of the most diverse, intricate and beautiful of all existing marine habitats. They have many varying structures which are developed by algae and are symbiotic with various reef building corals which are referred to as, zooxanthellae (algae). There are many other factors such as, coralline algae, sponges and other various organisms that are combined with a number of cementation processes which also contribute to reef growth, (CORAL REEFS, 2015).

Coral bleaching is normally characterized by the expulsion of the zooxanthellae algae, loss of algal pigmentation, or both. Coral bleaching events have had serious effects on corals and reefs worldwide. What is crucial to the understanding of zooxanthellae expulsion and bleaching is how the density of zooxanthellae within the coral is changing, if at all, under the prevailing range of environmental conditions (Gates and Edmunds, 1999). Over the last twenty years, there has been a dramatic increase in both the frequency and intensity of coral bleaching events. Sixty major bleaching events have been reported between 1960 and 1979, whereas only nine were reported prior to 1979 (Huppert and Stone, 1998). Given the dependence of the coral on this symbiotic algae, it is important to determine the cause of these bleaching events. According to Helvarg (2000, p.12):

Since early 1998, climate change has been demonstrating its effects in increasing the ocean 's temperature (West & Salm, 2003). Warm water stress corals causing the phenomenon known as coral bleaching, by which expulsion of colourful symbiotic algae the zooxanthellae, vital for

Not only does this increase in ocean acidity result in shell degradation, but it has also been shown to breakdown existing coral reefs, as well as limit the building of new coral reef structures all over the planet. Corals, like calcifying species, rely on a steady supply of calcium carbonate in order to build and maintain it 's strong structures. This preventable destruction would not only be breaking down some of the most ancient ecosystems, but also some of the most diverse ecosystems on the planet. Occupying less than one percent of the ocean floor, coral reefs are home to more than twenty-five percent of marine life. Thanks to their diversity, coral reefs provide millions of people with food, medicine, protection from storms, and revenue from fishing and

Coral reef ecosystems around the globe are threatened by human interferences and climate change. This has led to many scientists conducting studies on global coral reef ecosystems to gain a better understanding of the cause and effects of coral reef damage. In both Hodgson’s (1999) and Carpenter et al.’s (2008) studies, they are aware of the continuous degradation of global coral reef ecosystems. Hodgson's study involved conducting a survey on global coral reef ecosystems to see whether human actions were affecting the health of supposed pristine Coral reefs. Carpenter et al. incorporated Hodgson’s study into a compiled study about the possible extinction of reef building corals due to climate change and anthropogenic effects. Carpenter’s

The increased levels of acid inhibits the ability of marine animals which disrupts life within the systems food web. One species severely impacted by rising temperatures and excess carbon dioxide (ocean acidification) is reefs, in particular coral reefs. The higher temperatures lead to coral bleaching which is a stress mechanism that expels the colourful algae that inhibit them. Some individuals are able to recover, however many die resulting in an entire ecosystem to virtually disappear. If bleaching persists other damaging diseases will affect corals such as black band disease, white plague, white band disease and white pox which all have the ability to kill the coral which could potentially lead to the death of the extended ecosystems it

Broken and abraded coral has been clearly injured and or killed. However this abraded coral is less resistant to diseases and will have slower reproduction and growth due to redirected energy.24 Originally studies focused on coral breakages, however more recent studies have found that just the re-suspension of sediment can affect the health of reef. The removal of sediment from the coral surface results in the redirection of energy and makes the coral more vulnerable to disease.33 The study of this is more difficult and less reliable as weather has a huge impact on sediment suspension. Observations by Barker and Roberts accounted for sediment re-suspension, but the extent of damage caused to the coral was not

In “Sponge erosion under acidification and warming scenarios: differential impacts on living and dead coral”, Amber Stubler, Bradley T. Furman, and Bradley J. Peterson acknowledges that climate change and ocean acidification will disproportionately impact the growth of calcifying organisms in coral reef ecosystems. Simultaneously, sponge bio-eroders, will be a growing threat as seawater pH level decreases. Stubler, Furman and Peterson emphasizes that while species vary in degree of vulnerability, the effect of acidification on coral health, calcification, survival, and reproduction has been revealed to be negative. Concurrent inflation of sea surface temperatures as result of elevated C02 will impact coral calcification and survival on reefs.

The effects of ocean acidification on calcification are of particular concern due to a doubling of pre-industrial pCO2 conditions (560ppm), likely occurring within this century. Coral calcification is expected to decrease between 20-60% (Erez et al. 2011, Comeau 2014, Kleypas 2006, Langdon and Atkinson 2005, Reynaud et al. 2003, Langdon et al. 2000, Hofmann et al. 2010) and reduction in coral calcification of this magnitude could have devastating impacts to the surrounding ecosystem and fundamentally alter the structure and function of coral reefs. Coral growth and

Coral reefs have been a phenomenon for many years, often puzzling marine biologists between random acts of coral bleaching or the death of a coral reef in its entirety. Global warming and rising sea temperatures has had a major effect on coral communities, often causing mass coral bleaching events that wipe out coral communities. The migration of invasive algae, Symbiodinium, has allowed for the protection of coral reefs against rising sea temperatures. Although protecting the coral reefs from bleaching events, the presence of Symbiodinium trenchii causes a decreased rate of calcification, the process by which new coral reefs are built. A study conducted in the Persian/Arabian Gulf sampled coral located in the hottest sea locations. These samples underwent genetic testing and Hume et al. (2015) concluded that a new species of Symbiodinium was present in the gulf. Another study performed by Keshavmurthy et al. (2014) in Taiwan took samples from eight water regions. The samples underwent Restriction Fragment Length Polymorphism, along with other genetic tests. It was determined that thermally tolerant clade C was present in the tested water regions. Much of the abnormal existence of Symbiodinium among various coral reefs demonstrates the impact of invasive species among ecological environments. The impact of the algae on the environment has both helped and hindered coral communities. As

Corals harbour millions of sea creatures that can only thrive in warm shallow waters in tropical or subtropical oceans. Andrea Grottoli (2001) describes corals as good climate archives because they are widely distributed, their banding patterns are strong dating tools, and their records can span several centuries (from 5 to 25 Myr ago). Corals secrete layers of calcium carbonate (CaCO3) which form their skeletons. The organisms that produce CaCO3 are sensitive to temperature changes in the ocean; thus, when the water temperature changes, the CaCO3 densities in the skeletons also change (Grottoli, 2001). The layers from corals have annual banding patterns which help date the changes that scientists discover. Light-coloured layers appear during the summer when growth is rapid and dark layers form in the winter when growth is slowed down (Figure 1). By studying these banding patterns, scientists can determine the season and temperature of the water these corals grew in and date them accordingly. Scientists drill into corals and take samples which provide accurate information about sea level, temperature and salinity at different times in history. Therefore, by interpreting this data obtained from corals, scientists are provided with a way to reconstruct past climate changes.

1993; Lirman 2001; Box & Mumby 2007), increased localized sedimentation (Nugues & Roberts 2003), interfering with the settlement of coral larvae through space preemption and/or biofilm production (Birrell et al. 2005; Birrell et al. 2008; Box & Mumby 2007; Vermeij et al. 2009), and allelopathy or chemically mediated competition (deNys et al. 1991, Morrow et al. 2011). Macroalgae can cause physical stress (Quan-Young & Espinoza-Avalos 2006) decreased photosynthetic abilities (Titlyanov et al. 2007), reduced fecundity (Foster et al. 2008), and harbor potential coral pathogens (Nugues et al. 2004). The ability of macroalgae to competitively damage stony corals also depends on the species of macroalgae (Maypa & Raymundo 2004; Birrell et al. 2008), and other compounding factors such as irradiance, sedimentation, dissolved nutrients, and level of herbivory on the reef.

      Coral reefs are continuously being both built up and decomposed, so different parts of a reef are in varying stages of succession (Richmond, 1993). Coral reefs are very fragile, because reef-building organisms cannot thrive if the surrounding water changes significantly. Coral reefs require very specific conditions in order to grow: a solid structure for the base; warm and consistent water temperatures (averaging between 20 and 30 degrees Celsius); stable salinity; moderate wave action; and clear water that is low in nutrients and plankton. The water on a healthy coral reef is clear because there are very few nutrients, so plankton that would cloud the water are few. In general corals grow slowly, but they are extremely efficient at living and reproducing in these conditions (American Zoologist, pg 524-536).

It is thought that worldwide climate change could play a role in the increased amount in coral reefs bleaching.