User:Mountsainthelena/Effects of climate change on oceans

Impacts on Marine Life

Climate change will not only alter the overall productivity of the oceans but also alter ocean biomass community structure and in general lead to a poleward migration of species. Some species have already moved hundreds of kilometers since the 1950s. Phytoplankton bloom timings are also already altering, moving earlier in the season particularly in polar waters. These trends are projected to continue with further climate change.

There are additional potentially important impacts of climate change on seabirds, fish and mammals in polar regions where populations with highly specialized survival strategies will need to adapt to major changes in habitat and food supply. In addition sea ice often plays a key role in their life cycle. In the Arctic for example providing haul-out sites for seals and walruses and for hunting routes for polar bears. In the Antarctic sea bird and penguin distributions are also believed to be very sensitive to climate change, although the impacts to date are different in different regions.

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add sea turtle as example as what is happening to marine reptiles from climate change.

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Sea turtles are another marine organism that are greatly affected by climate change. As global temperatures rise, sea turtles will increasingly have more female than male offspring. If there is sufficient food, climate change will contribute to the population growth of sea turtles. The changes in global temperature could also shift sea turtle nesting seasons. Nesting seasons can coincide with flooding of particular nesting sites, which forces the turtles into the forest or to a whole other site. If nesting seasons were pushed to just two months later, this problem could potentially be avoided. Sea turtles are dependent on outside sources for heat because their bodies are unable to regulate temperature. When their body temperature gets too low, they can become lethargic and more susceptible to potentially fatal diseases. This is commonly referred to as cold stunning. On the opposite side of cold stunning is acute heat stress. Acute heat stress results in infections, low immune responses and differences in altered metabolic rates and growth. Ocean temperature changes affect other organisms which alter food webs. Altered food webs could lead to changes in availability of food for sea turtles, affecting their survival. Along with ocean temperature changes affecting sea turtles, ocean acidification is another aspect of climate change that affects sea turtles. As the seawater of oceans absorbs CO2 from the atmosphere, the CO2  forms a carbonic acid that lowers pH. Many fish and shellfish populations have dropped due to increased ocean acidity. The acidity causes seawater to be corrosive to the skeletons and shells of many marine organisms which greatly affects reproduction.