The ocean has slowly warmed up by 0.87°C over the past century because of the increased amount of greenhouse gases we produce from our daily activities. Why does this cause the ocean to warm up you ask? Well, carbon dioxide (one of the biggest greenhouse gases emitted) is a heat-trapping molecule which when dissolved in water increases the water temperature from the surface to 700m. Even though the ocean reacts slower to the change in climate the marine ecosystems are far more sensitive to these minute changes.
- Coral is affected by temperature change the most. This is because the increased temperature causes bleaching (turns the coral white), which slows growth and makes them susceptible to disease what can lead to a large-scale coral loss. This is a massive problem because coral is the home of many marine species and without it, the ecosystems will fail.
- Krill is an important link at the base of the food chain for many marine species.Increased water temperature leads to the krill reproducing in smaller numbers. This is not only devastating on the krill but could lead to a mass decrease on species that feed on krill e.g. penguins and seals. Therefore causing food shortage for apex predators such as Great White Sharks.
- Water temperature increase is also associated with invasive species and the spread of disease among marine ecosystems. Invasive species are species which enter a habitat in which they don’t naturally belong. Invasive species may be more suited to these warmer temperatures and will out-compete the original species forcing them to leave or die.
- When water temperature increases, the ice which has been built up over million of years, will begin to melt and run off into the ocean. Again causing sea levels to rise. However, the other major problem of the loss of ice is that many species such as Polar Bears will lose their habitats. Without this habitat, they will find it near impossible to find food and survive.
- When water heats up it expands and becomes less dense increasing water volume. This, in turn, causes rising sea levels. which will affect low-lying habitats such as marshes and will dramatically increase coastal erosion in below sea-level areas such as the Netherlands. Sea levels have risen 2 inches in the last 20 years and 10 inches since the 20th century. It is also said that sea levels can rise 10ft in the next century if the glacials fall apart rapidly.
- Surface water more readily evaporates due to its increased temperature. The increased amount of water vapour can quickly turn a small ocean storm into a larger storm, for example, a typhoon.
- Society, N.G. (No date) Sea temperature rise — pristine seas — national geographic. Available at: http://ocean.nationalgeographic.com/ocean/explore/pristine-seas/critical-issues-sea-temperature-rise/ (Accessed: 7 February 2017).
Viñas, M.-J. and Rasmussen, C. (2017) Warming seas and melting ice sheets. Available at: http://climate.nasa.gov/news/2328/warming-seas-and-melting-ice-sheets/ (Accessed: 14 February 2017).