Marine ecosystems

Elements of a basic marine ecosystem.
(c) University of Waikato, NZ.

The interaction of animals, plants and their environment is known as an “ecosystem”, and the study of how they interact, for example, what sort of animals you might find in a particular environment, is called “ecology”.  Planet Earth is one big ecosystem that can be divided down into smaller (e.g., terrestrial and marine ecosystems) and smaller (e.g., rainforests and coral reefs) ecosystems. Ecosystems are finely balanced; they are very complex and made up of many parts, but every part of an ecosystem, from a rock to a jellyfish to a particular water current, has a role to play.  Organisms depend on and are controlled by the physical and chemical environmental conditions in an ecosystem, and they can also change their environments in various ways.  Sometimes by changing one part of an ecosystem, the whole ecosystem can change – a common example of this is changing the nutrient input (chemical conditions) in a water body, leading to eutrophication.


Bottom-trawling by fishermen can have devestating impacts
on deep-water coral reefs. (source:Greenpeace)

The marine ecosystem is the largest ecosystem after the whole of Planet Earth because water accounts for more than 70 % of Earth’s surface.  The marine environment (our oceans and seas) account for more than 97 % of that! The marine ecosystem can be divided into smaller ecosystems, such as rocky shores and submarine canyons.  HERMIONE scientists are looking at several marine ecosystems found around Europe, from submarine canyons to hydrothermal vents.  You can find out more about these ecosystems by clicking on the following links: open slopes and deep basins, submarine canyons, seamounts, cold-water coral reefs and chemosynthetic ecosystems.

It is important that scientists find out as much as possible about ecosystems all over Earth – where they are and how they work – in order to protect them.  This is because humans can large negative impacts on ecosystems. For example, some fishing practices, like bottom trawling, can destroy vulnerable ecosystems such as cold-water coral reefs. We know that these reefs support an enormous amount of life and diversity and that they can be important nurseries for young fish. We are also now discovering that they could be important sources of medicines to treat human diseases like cancer, so it's important that we learn as much as possible about ecosystems like these - what they have to offer and how we are affecting them.  There are many other ways that humans can have negative effects on ecosystems - you can read more about our impacts on marine habitats by reading our section on anthropogenic impacts