The Definition of a Marine Ecosystem

Marine Biology 101: Ecosystems

sea turtle
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An ecosystem is the collection of living and non-living things in an area, and their relationship to each other. It is how animals, plants and the environment interact together and thrive. Studying ecosystems is known as ecology. A marine ecosystem is one that occurs in or near salt water and is the kind that is studied in marine biology. (Freshwater ecosystems, on the other hand, are comprised of freshwater environments such as those in rivers or lakes.

Marine biologists study those types of ecosystems as well.)

Because the ocean covers 71 percent of the Earth, marine ecosystems make up a large part of our planet. They vary, but all play a valuable role in the planet's health, as well as the health of humans.

About Marine Ecosystems

Ecosystems can vary in size, but all have parts that interact with and are dependent upon each other. Upsetting one component of an ecosystem may affect other parts. If you've ever heard of the phrase ecosystem approach, it is a type of natural resource management involving making decisions regarding the whole ecosystem, rather than various parts. This philosophy realizes that everything in an ecosystem is interconnected. This is why environmentalists and marine biologists must consider entire ecosystems even though they may focus on one creature or plant in it -- everything is tied together.

Protecting Marine Ecosystems

Another vital reason to study ecosystems is to protect them.

Humans can have significant negative impacts on our environment that can wind up destroying ecosystems and harming human health. The HERMIONE project, a program that monitors ecosystems, notes that certain fishing practices can harm cold-water coral reefs, for example. That is a problem because the reefs support a variety of living systems including providing a home for young fish.

The reefs could also be sources of potential medicines to fight cancer -- another reason to protect them. Human impacts are ruining the reefs, which are a vital ecosystem for humans and the environment as a whole. Knowing how they function, and how to support them prior to and after components are destroyed, is imperative to assist these ecosystems.

In seagrass meadows and kelp forests, for example, robust biological diversity is key to the ecosystems. In one experiment, scientists reduced the number of seaweed species. That caused the total algal biomass to decrease, which lowered the amount of food.  When scientists decreased the species that graze on microalgae that grew on seagrass, the species ate less from areas that had fewer microalgae. As a result of that, the seagrass in those areas grew slower. It affected the entire ecosystem. Experiments like this help us learn how reducing biodiversity can be extremely harmful to sensitive ecosystems.

Types of Marine Ecosystems

Examples of marine ecosystems include: