Evolution and Climate Change in the Oceans
In evolutionary biology, species can respond to changes in their environment in four distinct (but not mutually exclusive) ways.
They can:
Although some consider climate change ( or "Global Warming") to be debatable or at least exaggerated, there is good evidence to show that climate change is indeed occuring at an alarming rate and that it will greatly impact both marine and terrestrial environments.
In modern times, climate change often refers to the increase in the Earth's average temperature. Since the 20th century, the Earth's average temperature has increased by about 0.7° Celsius and is expected to continue to increase by about 0.2° Celsius per decade. This increase in temperature is expected to affect many things from fetal development and reproduction to species range and survivability often in a negative manner.
Depletion of the ozone layer is the main reason that global temperature is steadily increasing and is predicted to continue to do so. As such, this topic goes hand-in-hand with the topic of temperature change.
As the temperature of the ocean increases, the amount of dissolved oxygen in it decreases. This has many implications for marine wildlife. Without sufficient oxygen, organisms struggle to survive. Many organisms' habitats are very close to their thermal limitations and if temperature rises rapidly, lack of oxygen and other effects will limit the options these organisms have.
Marine salinity levels are influenced by a number of factors including rainfall, evaporation, inflow of river water, wind, and melting of glaciers. Salinity can have a great impact on the type of organisms that live in a body of water. Additionally, salinity plays a critical role in the water cycle and ocean circulation.
Ocean carbon dioxide levels directly correlate to ocean acidity levels. About 30-40% (Feely, R. A.; et al.) of the carbon dioxide humans emit into the atmosphere dissolves into the Earth's waters. From 1751-1994, the ocean's acidity has decreased from 8.25 to 8.14 (Jacobson, M. Z). This decrease in acidity affects marine organisms in a variety of detrimental ways.
The rise in sea level is due to thermal expansion and the melting of land-based ice. Changes in sea level have a variety of effects ranging from the submerging of islands and its terrestrial inhabitants to coral reefs not receiving sufficient light due to a change in depth.
Traits of a Species
Ocean currents are the directed movements of water in the ocean and can be caused by wind (for currents closer to the surface) and temperature, salinity, or density differences (currents deeper in the ocean). Climate change can have a vast effect on ocean currents because of the change in temperature it causes, which results in change in ocean water temperatures and a subsequent distortion in current flow.
Movement refers to the change in an organism's typical habitat as it "searches" for a more hospitable environment in which to eat, live, and reproduce. Movement is one of the four ways that an organism or an entire species can respond to a change in their environment and it is heavily affected by climate change. Generally, marine organisms move towards the poles and away from the equator.
Gene flow refers to the movement of alleles due to migration of individuals between two populations. This topic is closely related to the topic of movement.
Natural DisastersOften the egg or larval stage of marine ectotherms are the most susceptible to changes in the marine environment. Because of this, reproduction will likely be greatly affected by climate change.
Climate Change Outside of the Scientific RealmThere seems to be an increase in the amount of highly damaging natural disasters both inside and outside of the US. These natural disasters impact the climate and habitat of many organisms. Climate change might be the cause of the increase in horrifying natural disasters. On this page you can find more information on the relationship between climate change and many different forms of natural disasters.
Climate change threatens many marine-dependent sectors of the economy such as fisheries, transportation, and tourism. As climate change continues, its negative effects on the economy will worsen. Many countries, however, continue to implement practices that result in short-term economic boosts but long-term environmental decay.
As the world learns about the reality and possible consequences of climate change, this daunting phenomenon is becoming the topic of more and more movies, documentaries, and even television shows.
In light of the current election and the class discussion during the week of November 5th, a new "beat" topic has been added that organizes the current thoughts of climate change in politics. NOTE, this is not a place to debate politics, but rather a place to outline the different views that are present in the political system today and the ideas for solutions that have been implemented.
Each of these topics came from humble beginnings with one class, one professor, and one white board.
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