Tuesday, February 24, 2015

Increasing Global Temperature and its effect on the Earth’s Oceans

Global climate change affects everything on the planet from the land to the sea. The oceans have been changing for at least the past 30 years due to increasing global temperatures. This affects many things, like the seasonality of sea ice and the organisms living in the oceans to the increases in ocean levels and the CO2 in the oceans.

The increase in temperature is causing the sea ice to melt and change. This is a feeding and breeding place of many artic marine animals. For example the penguin populations depend on the ice to breed and to forage for food. The Adélie penguin population has shown a decrease in numbers with this increase in temperatures. Many marine animals will have to change where they find their food and where they will breed because of the changing ice patterns. On the other hand some organisms are thriving under the increase in temperature like the humpback whale. With some species suffering and others thriving current research finds that reduced biodiversity will result. 

One way that warming sea surface temperatures harm marine life is the destruction of the coral reefs. Coral Bleaching occurs when coral is stressed by changes in its environment. Climate change is one of the biggest threats to coral reef ecosystems. An increase or decrease in temperature can send coral into coral bleaching and infectious diseases are more frequent. The coral bleaching does not kill the coral but it does put it under stress and if this goes on for too long the coral can die. In 2005 in the Caribbean half  of the coral reefs were lost due to an increase in temperature. The increase in temperatures also effected other marine life directly and indirectly. Directly because some species bodies cant function under the temperature increase. Indirectly because with the coral dying they can no longer find food or have a home. This stress was greater than any that had been recorded in the past 20 years.

Ocean acidification is linked to temperature increases around the globe because a CO2 increase in the atmosphere is directly linked to this temperature increase. Ocean acidification occurs when CO2 is absorbed by sea water.  This results in a reduction of the oceans pH, saturation conditions of calcium carbonate minerals, and carbonate ion concentration. So far the oceans pH has fallen by 0.1 pH units. If the CO2 levels in the atmosphere don’t change the ocean will continue to absorb it. Ocean acidification of especially bad for the calcifying species.  These species are the basic building block of most food webs in the ocean. The shells for these organisms will slowly dissolve when in lower pH. Below is a picture of a shell after being put in the estimated pH of the oceans from 2100.
(Photo credit: David Liittschwager/National Geographic Stock.)

Due to the increasing sea levels the wetlands in the San Francisco Bays are disappearing. The sea levels are increasing because the increase in global temperatures is melting the sea Ice. It is estimated that in the next 40 years the major wetlands like Marin County’s Corte Madera Marsh will disappear. These wetlands are drowning due to the rising sea levels caused by global climate change. These wetlands are important to people and many species on animals. It is home to many endangered species and it also helps to protect our homes by controlling flooding. In the past the wetlands would move inland with a rise in sea levels but today urbanization leaves the wetland with nowhere to go.

With increasing ocean temperatures fish are moving either north or south to return to their normal living conditions. In order to track this evidence scientists tracked where the fish were caught most and over time looked for changes in where they were found. For example the red mullet, Mullus barbatus is normally found in the warmer waters of the Mediterranean. But more recently it has been found in cooler oceans like the North Sea. This affects fishermen negatively because there are less fish in the tropics the yield of fish that are caught will fall. 

The increase in the oceans temperature effects several different factors that interconnect. Global climate change is increasing the oceans temperatures and affecting the ice in the artic. This leads to animals struggling to find food and a home. It also leads to the ocean levels rising. The ocean levels rising effects the coastal regions. The increase in CO2 levels is causing a global temperature increase can causing problems for marine life in several different ways by increasing the overall global temperature and effecting the chemical composition of the oceans. This is harmful and causing problems for coral reefs and other organisms that live in and near the oceans.



A.      J., Melbourne-Thomas, J., Corney, S. P., Arrigo, K. R., Barbraud, C., Barnes, D. K. A., Bindoff, N. L., Boyd, P. W., Brandt, A., Costa, D. P., Davidson, A. T., Ducklow, H. W., Emmerson, L., Fukuchi, M., Gutt, J., Hindell, M. A., Hofmann, E. E., Hosie, G. W., Iida, T., Jacob, S., Johnston, N. M., Kawaguchi, S., Kokubun, N., Koubbi, P., Lea, M.-A., Makhado, A., Massom, R. A., Meiners, K., Meredith, M. P., Murphy, E. J., Nicol, S., Reid, K., Richerson, K., Riddle, M. J., Rintoul, S. R., Smith, W. O., Southwell, C., Stark, J. S., Sumner, M., Swadling, K. M., Takahashi, K. T., Trathan, P. N., Welsford, D. C., Weimerskirch, H., Westwood, K. J., Wienecke, B. C., Wolf-Gladrow, D., Wright, S. W., Xavier, J. C. and Ziegler, P. (2014), Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota. Global Change Biology, 20: 3004–3025. doi: 10.1111/gcb.12623 <http://onlinelibrary.wiley.com/doi/10.1111/gcb.12623/citedby >

"What Is Coral Bleaching?" NOAA. NOAA, United States Dept. of Commerce, 1 Dec. 2014. Web. 02 Feb. 2015. <http://oceanservice.noaa.gov/facts/coral_bleach.html>.

"What Is Ocean Acidification?" NOAA. PMEL Carbon Program, n.d. Web. 02 Feb. 2015. <http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F>.

Miller, Craig. "Bay Area Wetlands Slowly Drowning as Seas Rise." Science KQED Public Media for Northern CA. KQED Science, 30 May 2013. Web. 03 Feb. 2015. <http://blogs.kqed.org/science/2013/05/30/bay-area-wetlands-slowly-drowning-as-seas-rise/>.

Radford, Tim. "Fish Migration Reveals Ocean Warming - Climate News Network." Climate News Network. Climate News Network, 20 May 2013. Web. 04 Feb. 2015. <http://www.climatenewsnetwork.net/fish-migration-reveals-ocean-warming/>.

1 comment:

  1. Reduced sea ice is affecting Arctic people as well as wildlife (The ice "does not freeze like it used to. It used to be like 10 to 8 feet thick, way out in the ocean,” providing protection for coastal towns during storms and access for whale hunters).