Threats to the Marine Environment

Lesson 2 - Threats to the Marine Environment

Text by Alan Deidun; Design and images by Martin Galea De Giovanni

	Anchoring

	Pollution

	Noise Disturbance

	Alien Species

	Land Reclamation

	Aquaculture

	Over-exploitation

	Dredging

	Diving

	Global Warming

	Protecting the Oceans

	International Cooperation

	Interesting bites

	Glossary

	Home

Alien Species

Release of alien species - ships take in large quantities of water as ballast in their bellies in order to stabilize them in rough weather so that they do not capsize. This ballast water is then emptied once the destination port has been reached.

This process is a convenient way by which alien (non-native species) can travel (free of charge!) from one region to another of the earth.

Alien species harm local ecosystems by competing with native (local – belonging to a particular place; e.g. the panda is native to China) species, which, in turn, are not adapted to these ‘new’ arrivals.

An example of an alien species is the green alga Caulerpa racemosa, which has invaded the Mediterranean Sea from the Red Sea, via the Suez Canal. Alien species have the element of surprise on their side since native species have never met these species before.

Suez

The Suez Canal