The top 10 ocean issues
- 21 November 2017 | Environment
Although they cover over 70 percent of the surface of the planet, the oceans of the world are under serious threat. Discover the ten biggest problems in the oceans right now.
Around eight million tons of garbage are dumped into the ocean every day, and 80 percent of marine pollution comes from land.
These figures have an enormous impact and disastrous consequences on marine biodiversity. But there's more. Take a look at the top 10 ocean issues:
The ocean is increasingly becoming a plastic soup that is killing hundreds of marine animals on a daily basis.
Sooner or later, these millions of plastic pieces will end up in our stomachs.
The size of the Great Pacific garbage patch ranges between 700,000 square kilometers (270,000 square miles) and 15,000,000 square kilometers (5,800,000 square miles).
The amount of litter left on the beaches or thrown into inland waterways, such as rivers and streams, will end up in the ocean.
The situation is more serious when it comes to non-biodegradable waste, such as plastics, which break up into smaller particles, microplastics, and are mistaken for food by many marine species.
The microplastics present in hygiene products and domestic and industrial cleanings products will also have the same destination.
The islands of garbage are already a reality in some areas of the oceans.
Many fertilizers and pesticides used systematically in agriculture end up falling into the ocean.
Some of these products cause irreversible and fatal changes to the species; for example, they affect the reproduction process. Also, if ingested by humans, they can cause health issues.
4. Overexploitation of Fishing Resources
Studies indicate that there has been a considerable reduction in the populations of some species of fish. For example, overfishing of cod in Canadian waters has almost led to the extinction of the species.
In addition to overfishing, there is also a serious lack of fishing activity management or non-compliance with the rules.
The absence of a definition of the size of the animals or the time of capture, which allows the capture of juveniles or females with eggs, are some of the recurring problems.
Overfishing of species with long life cycles at the top of food chains, like sharks and tuna, or species used for luxury cooking and alternative medicine also cause irreversible changes in the harmony of marine life.
5. Unsustainable Aquaculture
Intensive aquaculture at sea promotes the proliferation of pollutants in marine waters.
The production of fish and bivalves involves the use of antibiotics and other chemicals, some of them toxic to the ecosystem.
This situation is clearly visible in Asian waters due to the intensive production of Vietnamese clams.
6. Marine Engineering and Oil Drilling
All changes in the marine environment caused by construction, deep hole drilling, and many others human-related interventions cause acute changes in the habitat, various disturbances and generate pollutants.
All these factors contribute to the destruction of the natural element and compromise the survival of marine species.
7. Destruction of Habitats
Some habitats provide and represent a unique shelter for reproduction. Marine forests are being destroyed for various reasons, including the use of aggressive fishing gear and methods like trawling.
8. Ocean Acidification and Coral Bleaching
Climate change has a profound impact on the oceans. The increased levels of CO2 in the atmosphere cause changes in the pH of the oceans.
This situation is particularly evident in tropical regions where marine ecosystems are extremely sensitive and rich in biodiversity, and where habitats are undergoing irreversible changes, most notably in coral reef areas.
9. High Levels of Mercury
Excess mercury causes severe illness in marine life and humans. It is a pollutant that accumulates in the food chain and reaches humans through the ingestion of fish.
High levels of mercury can cause serious diseases. As a result, the consumption of several fish species like the black scabbardfish and tuna should be regulated.
10. Sea Temperature Rise
Rising sea temperatures cause dramatic changes in marine ecosystems, with severe and lethal consequences for many species.
The phenomenon is also responsible for changing migratory routes, causing imbalances in food chains. For instance, raising the water temperature by just 0.5 ºC causes the death of coral reefs.
Healthy coral reefs work as "maternities" and shelter areas for a wide variety of species that provide food for humans, and on which many fishing communities depend.
Explore interesting facts and figures about the oceans.