8 things about the ocean you didn't know


Oceans make up 90 percent of Earth's surface and yet, in many ways they still remain a mystery. It is impossible to determine how much we really know about these giants, which is logical if we take into account that 95 percent of the ocean’s volume has yet to be explored. These bodies of salty water harbour the highest diversity and life on the planet known to date, and yet, it is thought that more than one third of all marine species are yet to be discovered.

In an attempt to learn a little bit more about the ocean today, we have gathered some fascinating facts that you might not know about and might surprise you:
1. Phytoplankton -also known as micro algae- provide 50% of the oxygen on Earth. They are similar to terrestrial plants in that they contain chlorophyll and need sunshine to live and grow. In a balanced ecosystem, this tiny algae serves as food for a wide range of marine species making up the basis of the ocean food chain. Phytoplankton serve fish, marine mammals, and ultimately, human consumption.
2. The highest mountain in the world isn’t Mount Everest. With 10,230 meters, a volcano on the Big Island of Hawaii named Mauna Kea breaks this record. However, of its total height, only 4,170 meters rise above sea level. 
3. The Gulf Stream is a warm ocean current that originates in the Gulf of Mexico and extends to the tip of Florida, following the United States’ eastern shores and Newfoundland before crossing the Atlantic Ocean as the North Atlantic current. At it’s quickest speed, this current flows at a rate almost 300 times faster than the typical flow of the Amazon river. This maximum speed is typically about 9 kilometres per hour. However, the Stream’s average velocity remains 6.4 kilometres per hour, and it slows down to a speed of around 1.6 kilometres per hour as it widens to the north. 
4. The ocean has the highest phylogenetic diversity. 30% of phyla - the principal taxonomic category in zoology- are exclusively marine, whereas only one phylum is exclusively terrestrial.
5. Coral reefs are the oceans’ nurseries, which means that they are biodiversity hotspots. Even though they only comprise around 0.5 percent of the ocean bottoms, around 90 percent of marine species directly or indirectly depend on them for their survival. For example, some tropical reefs can host around 1000 species per square meter (m²).
6. Coral reefs are seriously threatened by climate change. Amongst other motives, the rise in temperature makes coral expel the algae that live in them, which causes these sessile animals to turn completely white. This phenomenon is called coral bleaching, and even though a bleached coral doesn’t die, it certainly remains subject to more stress and hence, more possibility of dying. Being life hotspots, corals’ disappearance would have devastating consequences for the planet’s biodiversity. 
7. 80 percent of all sea and ocean pollution comes from terrestrial activities. One of the biggest sources is nonpoint source, which is a result of runoff. Many small sources such as septic tanks, terrestrial vehicles and boats, as well as larger sources like farms and forest areas comprise non point pollution. 
8. More than 90 percent of goods for trade between countries are shipped by sea.
By Belen Blanco