Is the ocean blue while the seawater is salty? Are you sure that you know about our ocean? Here are some of the happening events in our marine ecosystem nowadays. Just make sure you know about these before you claim that you actually know about our ocean and the lives below water.
Pollution happens everywhere in any possible form, and marine pollution is one of it. Marine pollution happens when chemical substances or trash such as plastics enter the ocean which results in damage to the marine ecosystem and affects the health of all organisms. The pollutants include chemicals, spilt oil, industrial waste, sewage discharged, pesticides, and illegal dumping of waste and plastic products.
The Great Pacific Garbage Patch has shown the impact of plastic pollution in the ocean. It is a collection of marine debris (mostly plastics) in the North Pacific Ocean as a result of human litters that ended up in the ocean. The mass of the plastic in the Great Pacific Garbage Patch (GPGP) was estimated to be approximately 80,000 tonnes, which is 4-16 times more than previous calculations, makes it the biggest marine trash vortex in the ocean. All these trash vortexes will continue to grow if no action is taken to clean up the mess. When the plastics degrade into microplastics that are the same size as small sea animals, it will be too late for us to resolve this marine pollution.
Acidification of Seawater
Ocean acidification is a chemical reaction that happens to reduce seawater pH when carbon dioxide (CO2) is absorbed by seawater. Future predictions indicate that the oceans will continue to absorb carbon dioxide, further increasing ocean acidity. This causes many parts of the ocean to become undersaturated with calcium carbonate minerals, which is likely to affect the ability of some organisms to produce and maintain their shells such as oysters, clams, sea urchins, and calcareous plankton. Meanwhile, ocean acidification could severely impact the ability of coral reefs to recover from disturbance as research indicates that by the end of this century, coral reefs may erode faster than they can be rebuilt.
Coral reefs are home to millions of fish and fundamental to our own survival. However, the increase in carbon pollution is warming our oceans and causing corals around the world to bleach as our ocean absorbs carbon dioxide. Coral is bright and colourful because of microscopic algae called zooxanthellae. The zooxanthellae live within the coral in a mutually beneficial relationship, each helping the other survive. But when the ocean environment changes such as ocean acidification and rise of water temperature, the coral stress out and expels the algae and the coral fades until it looks like it’s been bleached. Some corals can feed themselves, but without the zooxanthellae, most corals starve. If the temperature stays high, the coral won’t let the algae back, and the coral will die. Coral may bleach for other reasons, like extremely low tides, pollution, or too much sunlight.
Every day, tonnes of fish are hauled out of the sea. Today, each person eats on average 19.2kg of fish a year – around twice as much as 50 years ago. According to National Geographic, fishers remove more than 77 billion kilograms (170 billion pounds) of wildlife from the sea each year. However, today we are seeing 30 per cent of the world’s fish stocks overexploited, reaching below the level at which they can produce sustainable yields.
The way we consume has been a major reason why overfishing is one of the biggest threats to the balance of lives below water. Our demand for seafood and advances in technology has led to fishing practices that are depleting fish and shellfish populations around the world. Over three billion people depend on marine and coastal biodiversity for their livelihoods. As the ocean is an important food source for the world, we need to urge for a sustainable fishing practice before plastics replace our fish stocks in 2050.
Other Human Activities
Over the decades, human conduct various illegal activities on the ocean that would directly harm the marine lives, which include breaking fishing laws, poaching, ignoring marine protected areas, and polluting. On top of that, all kinds of development projects will also indirectly destroy marine habitats such as sea turtle nesting beaches, seagrass bed and coral reefs.
Meanwhile, poaching for trading has been a big threat to marine lives as it might cause the extinction of endangered marine species. For example, whaling and dolphin drive hunting in Japan especially in Taiji killed nearly 20,000 dolphins, porpoises and small whales every year. Other than that, sharks and turtles are also listed as the endangered marine species as the result of human’s hunting activity. These lives below water are vulnerable and they play an important role in keeping the balance of the biodiversity. One should never support such marine lives trading to help to restore a balanced ecosystem.
As a conclusion, climate change and human activities are affecting not only the land and atmosphere but also the ocean. Global warming heats up everything including the seawater. Everything we do today will leave an impact on the environment if we do not care about the consequences of what we do. Nonetheless, coral bleaching, plastic garbage patch and overfishing are shown in facts that they are really happening now.
These may not affect you now, but it will soon.