We spend much time discussing the threats and dangers that plague our oceans. At Oceana we work to protect the oceans not only because of how they sustain us physically but also because of how they leave us in awe. From time to time, I want to take a break from talking about what ails our oceans and instead share with you some of the reasons I find it amazing.
While the oceans have always been vital to cultures around the world, can you believe that it was only in the 1870s that people began to explore and document the diversity of life in the deep sea?
It is no wonder that even in recent years we continue to learn of fascinating marine habitats and creatures whose existence we could not even fathom.
Life of the deep thrives at intense pressure and in almost complete darkness. It is no surprise then that some of these creatures don't require sunlight to flourish.
Up until the late 1970s, we believed that practically everything depended on sunlight for survival. Sunshine is critical for photosynthesis, the process plants use to convert carbon dioxide and water into food, giving off the oxygen that most living things need to survive.
In reality, there are microorganisms that do not depend on light at all to produce food. Instead, they live off of hydrogen sulfide, a chemical that to us is extremely poisonous (on the flip side, oxygen is extremely poisonous to them). In turn, these creatures provide energy for surrounding life (mussels, tube worms, crabs, octopi, eelpout fish, shrimps, clams). This process is called chemosynthesis. Living in a low oxygen environment where sunlight cannot penetrate, some animals of the deep depend on chemosynthesis of microorganisms to thrive. The microbes that use the hydrogen sulfide are either consumed by or live symbiotically with other creatures, providing food for their host animal.
Where in the ocean can hydrogen sulfide be found?
The seafloor has cracks called hydrothermal vents where minerals and gases are expelled from the earth's core at extremely high temperatures - almost 700°F! It is in the area around these vents where these chemosynthetic life forms exist.
One of these deep sea creatures is the giant tube worm. They can withstand extreme changes in temperature. Burying themselves in ocean sediment with only their heads exposed, their tail end is kept extremely warm by the thermal vent water while their heads endure the freezing temperatures of the dark sea. Its like living in the Sahara and Antarctica at the same time! In addition, they have no mouth, no digestive system. Instead, microbes live inside of their bodies and process hydrogen sulfide. This chemical conversion, along with other nutrients picked up in the water around them, allows these worms to survive.
I can't help but be astounded by the rich diversity of life in the oceans. It inspires me to fight as hard as I can to keep it that way. We live in delicate balance with all life and we must all do what we can to sustain it.