DISCOVERING THE GEM OF THE OCEAN
We are just beginning to understand how complex the ocean is and how it makes all Life on Earth possible.
By working with Ocean Odyssey - a natural history film about the incredible world of ocean currents, I got to meet Ula, a humpback whale whose name means gem of the ocean. As Ula travelled from the Great Barrier Reef to Antarctica on a 1,500-mile migration, I learned about the threats the ocean faces, the ecosystem services it provides, and the reasons why it is so important to protect it.
Ula is a female humpback whale that undertook her journey in transient groups of two or three individuals (pods) that were formed for days at a time. I never got to know her age since humpback whales don’t have teeth and therefore is rather hard to estimate their age. However, I did learn about the countless songs she sang throughout her journey. Humpback whale songs can last up to 7 hours and travel up to 10km, except if you are a calf, then you rather ‘’whisper’’ the song to your mother using low tones to avoid being noticed by predators.
THE GREAT MIGRATION THROUGH OCEAN CURRENTS
Through the ocean currents, Ula migrated from the warm tropics to the frozen ice water of Antarctica. These currents, which are constantly moving and flowing like vast rivers are a source of life. To further understand the magnitude of the ocean currents, let's take into consideration that the largest current in the world, the Antarctic Circumpolar Current, is estimated to be 100 times larger than all the water flowing in all the world’s rivers and it could take a drop of water a thousand years to do the full trip. By taking this comparison, one can only continue to start to comprehend how ocean currents are essential to help species get the food and nutrients they need without having to move long distances and how they spread larvae and other reproductive cells. Without ocean currents, many of the ocean’s ecosystems would collapse.
When Ula started her migration on the ocean current from equatorial waters, the water started to cool down as she swam towards southern latitudes. The colder the current got, the denser it became. By the time the current got near Antarctica, the water started to become ice. The sault on the ocean is not converted into ice and is then deposited under the ice which makes that area extremely dense. The denser water sinks, and as it does, more ocean water moves in to fill the space it once occupied. This process has helped to keep the temperature of our planet right for life on Earth for millions of years.
If the ocean is the blue heart of the planet, then the currents are like the veins and the arteries - Sylvia Earle
THREATS ARE ALL AROUND
Just as we learned how important ocean currents are, Ula showed me the constant threats she and the ocean encounter. On every journey, Ula witnesses devastating changes in the marine environments brought on by a warming ocean. The warmer the ocean, the slower the currents travel and the fewer ecosystem services they can provide. If the ocean continues to warm up, the drop of water mentioned previously could take, instead, double the time to complete the Antarctic Circumpolar Current. Or even worse, maybe become steady forever and kill most of the ocean biodiversity, including perhaps phytoplankton.
Ula also reminds us that oceans produce more than half of the oxygen we breathe, something that very few people know. Every day, billions of tiny ocean plants called phytoplankton produce half of the world’s oxygen supply. Phytoplankton, obtain their energy through photosynthesis, as do trees and other plants on land. Their oxygen production is very significant, despite amounting to only about 1% of the global plant biomass.
Healthy currents and healthy oceans are therefore essential to our survival. Among the threats, Ula also encountered overfishing, coral bleaching, destructive fishing methods, coral mining, boat anchor damage, unsustainable tourism, pollution and the introduction of invasive species. All of which we humans have total control over. Ula struggles to understand how we continuously damage our own home when the fate of all life on earth is in the hands of the ocean currents.
THERE IS HOPE
Little actions, which you have heard a million times before, have tremendous positive consequences for the ocean and our existence. Changing fishing methods, promoting sustainable tourism, eliminating single-use plastic, properly disposing of trash, shopping sustainability (aka, consuming only what you need) and reducing pesticide and fertiliser usage will go a long way.
Ula is certain we can address our self-destructive behaviours and will be supporting our journey towards healthier ecosystems from the depths of the ocean. Much like Ula's name, currents are the gem of the ocean and our existence depends on maintaining their integrity.