Threats to
marine ecosystems
Threats to
marine ecosystems
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Marine ecosystems support marine life as well as our jobs, our hobbies, our food, our oxygen.

Each ecosystem is composed of different species, in different types of habitats. There are many ways in which humans exploit these marine environments and cause massive damage to these fragile ecosystems.

Understanding how ecosystems are affected by our activities is essential to know how to reduce our impact and adapt our behavior accordingly. Taking an interest in our impact on ecosystems and the consequences for us is a key step in protecting marine life.

Plastic pollution

Every minute, 15 tonnes of plastic waste are dumped into the oceans, so 8 million tonnes each year. It is urgent to act now!

Pollution of ecosystems by plastics is a problem of great complexity and scientists are not yet able to fully assess its consequences on the balance of ecosystems and on the health of consumers. The social and economic impacts are also considerable. A commitment from the public authorities is necessary to improve the management of municipal waste. Everyone’s awareness and commitment are also essential.

Oil spills

This type of industrial and ecological disaster generally occurs after the sinking of an oil tanker, an accident on an oil platform in the open sea or a wild degassing. The hydrocarbons released into the water then float on the surface and spread over large areas before reaching the coast.

Oil spills are dangerous for the marine environment, greatly disrupting marine flora and fauna, with:


Current estimates indicate that overfishing has affected more than 85% of the world’s fishery resources and that most fisheries are exploited far beyond their sustainable capacity.

Although this is about to have long-term effects on human consumption, there are also a number of other effects, such as:

Habitat destruction

Destruction of habitats in the marine environment by coastal development is underestimated.

Each construction won on the sea destroys an underwater habitat by covering or damming. A high density of works won over the sea on small shallow areas represents a quantitatively major damage to underwater environments. This destruction is irreversible.

Evaluating the negative effects of constructions on the sea on marine ecosystems is often seen as an hostile approach. As a result, few studies deal with this conflicting and politically sensitive topic, few financial and human commitments are devoted to this subject. Thus, taking into account the impacts caused by developments gained on the sea is neglected.


Eutrophication is the process by which nutrients accumulate in a habitat.

Eutrophication of aquatic environments is an environmental imbalance caused by the increase in the concentration of nitrogen and phosphorus in the environment. Too much nitrogen and phosphorus in the water causes algae to grow faster than ecosystems can handle. Significant increases in algae harm water quality, food resources and habitats, and decrease the oxygen that fish and other aquatic life need to survive. Large growths of algae are called algal blooms and they can severely reduce or eliminate oxygen in the water, leading to illnesses in fish and the death of large numbers of fish. Some algal blooms are harmful to humans because they produce elevated toxins and bacterial growth that can make people sick if they come into contact with polluted water, consume tainted fish or shellfish, or drink contaminated water.

Ocean acidification

CO2 or carbon dioxide is not only responsible for global warming. In fact, not all of the CO2 we emit from burning oil, coal or gas stays in the atmosphere. A significant part (25%) is absorbed by the oceans. For the planet’s climate it’s pretty good.

Without the oceans, global warming would be even more significant. But the role of shock absorbers played by the world’s seas comes at a price. It is precisely the absorption of these phenomenal amounts of CO2 by the oceans that causes their acidification. Since the start of industrial development, the acidity of the oceans has increased by almost 30%.