It is decided by many Marine Ecologists that the greatest threat to marine ecosystems in this day and age, is overfishing. Humans appetite for fish exceeds the limits of the Oceans, with devastating impacts on the worlds marine ecosystems.
Oceans cover 71% of the Earths surface, and bring life to this planet. They make impacts on climate, generate oxygen, and are the lifeline to this water planet. While the Oceans only cover 71% of the globe, we have taken around 90% of the big fish species out of it such as sharks, tuna, swordfish, and more. Humans are taking more fish out of the Ocean in a race against time that makes it impossible for the Oceans and species inhabiting them to replenish (reproduce) to even make an attempt at restoration.
Due to this, 29% of the worlds fisheries have crashed from low catch of fish. As a result of these shut-downs, fishermen have created more high-tech equipment in a desperate fight to find more fish, but this equipment also kills marine ecosystems.
New fishing tactics in this search for more fish are also taking fish that are unwanted or undesired and are thrown back into the sea, at least 16 billion pounds each year worldwide. In the above picture, you see a prospering reef full of color… then you see a destroyed ecosystem that marine species depend on for life.
Overfishing does not play in this destruction alone though. Fish that are left in the Ocean are being poisoned and contaminated with toxins such as Mercury. This starts out infecting little fish and move up the line to big fish like the sharks, swordfish, tuna, and dolphins. These toxins make these fish unsafe to eat and can cause multiple undesired symptoms to humans. Oil spills, surprisingly, are only responsible for 12% of the Oil that is released into the seas each year. 36% comes down drains and rivers, as well as runoff from industry and cities. Deliberate dumping is also responsible for a portion of oil and chemicals being released into the Ocean.
Almost every marine organism, from the tiniest plankton to whales and polar bears, is contaminated with man-made chemicals, such as pesticides and chemicals used in common consumer products.
Scientists have been finding higher and higher levels of man-made chemicals in marine mammal bodies, which have corresponded with increases in mass die-offs, otherwise inexplicable population declines and strandings. They have found that many of these events are associated with immune system dysfunction, suggestive of broad environmental distress in the oceans.
How have the entire planet’s oceans become so contaminated? Environmental toxins are spread by wind, rain and currents. This means that what we do on land— what we do in the air— what we do in our homes— takes a toll on the Oceans and its life in some way.
For more on how you can stop overfishing and pollution visit Na.Oceana.org