A year ago, I did a presentation about the ocean in Chiang Mai. This was after I became an Advanced Open Water diver and started doing some more research about my new found passion. What I found was disturbing. I was never aware of what was going on underneath the surface. The Ocean is alive and breathing, rich in marine diversity; at least it used to be. The once bountiful blue is now struggling to remain conscious and people do not realize the threats directed towards the ocean, I certainly didn’t. Pollution, climate change, over-fishing, bottom trawling, habitat destruction, the list goes on and on. But now, I have no excuse. It’s easy to say, “I can’t do anything about it” when you don’t know about what is going on. When I was researching for my presentation, I kept asking, “Why is no one doing anything about it?” And then I thought to myself, “I’ll do something about it.” I would not have known about what was going on if I didn’t educate myself about the issues concerning our oceans. It is important for people not only to recognize the problems facing our oceans but also to appreciate what the ocean has to offer us.
The ocean covers more than two-thirds of the world’s surface. In the past 50 years we have learned more about Earth’s ocean than in all of preceding human history. But, at the same time we learned more, we lost more. Dumping trash at sea is not new. People have thrown their trash overboard for centuries. So why all of a sudden, do we see so much trash on our shores? What has changed is the composition of the trash.
In the past, most trash that ended up in the ocean was made of paper and cloth which decayed, or metal and glass which sank and conveniently disappeared from view. But today, plastic has become the ideal substitute for bags, bottles, and fishing gear because plastic is lightweight, strong, and very durable. But the characteristics that make plastic so successful are also causing the problems in the ocean. The worldwide consumption of plastic lies between 500 billion and 1 trillion annually.
Many animals are highly prone to becoming entangled in plastic debris because of their curious and playful nature. But for the marine animals, entanglement is just part of the problem…marine animals also die from EATING plastic. Turtles, for example mistake floating plastic for their favourite food, jellyfish.
Another problem we face today is Global Warming. Global sea level rise is caused by two factors. One is the delivery of water to the ocean as land ice melts, such as mountain glaciers and polar icecaps. The second factor is the thermal expansion of water within the oceans. As the temperature of the waters in the oceans rises and the seas become less dense, they will spread, occupying more surface area on the planet. Increased temperature will accelerate the rate of sea level rise. Excess carbon dioxide means more greenhouse gases will trap heat from the sun, causing temperatures to rise and ice caps to melt. Polar bears for example, are one of many animals that are affected by global warming. Polar bears live on the arctic ice and spend warming months hunting for seals and then hibernating for 8 months. However, as the ice caps are melting, it is reducing their chances of survival drastically. The average loss of ice is 100,000 square kilometers every single day.
Polar Bears are not the only mammals affected by global warming. Melting sea ice also presents problems for penguins. Rising temperatures affect the food chain. Penguins feed on tiny organisms such as krill shrimp. These tiny organisms survive on algae, but the melting ice and rising temperatures are creating a decrease in algae. It all reverberates back to a loss of food source for penguins.
One of the major issues we face today is Fishing/over-exploitation. 90% of all the big fishes in the ocean have disappeared in the last 50 years. Overfishing is the principle cause of the decline of many fish, shellfish, and other living marine resources around the world.
One of the most common methods of fishing is by using a bottom trawler. Bottom trawling is an industrial fishing method where a large net with heavy weights is dragged across the seafloor, scooping up everything in its path. A single pass of bottom trawl removes up to 20% of the seafloor fauna and flora.
Bottom trawling is severely damaging to the ocean’s ecosystems. The net indiscriminately catches every life and object it encounters. And therefore many creatures end up mistakenly caught and thrown overboard dead or dying, including endangered fish and even vulnerable deep-sea corals which can live for several hundred years. This collateral damage, called by catch, can amount to 90% of a trawl’s total catch.
Another problem we face is the shark fishing industry. Currently we are killing over 100 million sharks every single year. They are only used for their fins for the famous, shark fin soup. They are caught using a hook, and then brought on board and get their fins cut off (while they are still alive) and thrown back into the ocean to drown to death. They either bleed to death, die from starvation because they can’t move, or even get eaten alive by other fishes. This process can sometimes take weeks. Sharks are very vulnerable to overfishing because they have a very late onset of reproduction x 15 or 20 years for the larger sharks. They also have very few young. There are certain species of sharks in some parts of the world that are never sighted anymore. They are just gone. Since the 1970s the populations of several species have been decimated by over 95%!
So why do we need sharks? Sharks mean a healthy ocean. A healthy and abundant ocean depends on predators like sharks keeping ecosystems balanced. Not only that but, living sharks fuel local economies in places like Palau where sharks bring in an estimated $18 million per year through dive tourism.
At current exploitation, global fish stocks are to collapse by 2050.
If we want to we can reverse most of the destruction we have caused to our oceans. In some situations it might only take a decade, in other situations it might take many centuries. Yet in the end we can have productive and healthy oceans again. We do however need to act on it now.
We know that from bacteria to plankton to the blue whale, life in the ocean greatly affects life on land. Imagine the ocean without fish. Imagine what the means to our support system. We need ecosystems, especially one as vast and beautiful as the ocean.
All the species in the ocean have a role in the ecosystem; we may not know what the role of every one of them is, but they have one, and that role could be one of tremendous importance for oxygen or giving us food.
In the end, it’s not just about the fishes, it’s about us enjoying all those wonderful services that we need so desperately — and the dollars they bring to our economy. If we want to be able to eat more fish, and to make more money out of the ocean, we have to keep more fish in it.
So, whether you live on the coast or far from it, whether you eat seafood or not, you and the future of all those you love depends on healthy oceans.
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