Please make sure you have seen the lesson on Ecosystems
to better understand Aquatic Ecosystems
It is believed that about 70% of the surface of the planet earth is covered by water. The greater part of the earth’s water is ocean (sea water). Only 3% of water on the surface is fresh; the remaining 97% resides in the ocean. Of freshwater, 69% resides in glaciers, 30% underground, and less than 1% is located in lakes, rivers, and swamps. This means water on earth, as a habitat for many tiny organisms, medium and large water animals is very significant, and together, become the Aquatic Biome.
Water on earth is not all the same. They vary widely in terms of the chemical makeup, the nature of its flow or stillness, temperature and so on. This means that plant and animal life in these waters will be different too.
What is an Aquatic Ecosystem?
Aquatic ecosystems is an umbrella term for all ecosystems that exist in water. Aquatic Ecosystems, simply, is an ecosystem type that depend on water (both marine and fresh water) most or part of the time. A scientist who studies inland water ecosystems (limnology) is called a limnologist.
The opposite will be terrestrial ecosystems, which basically is all ecosystems that exist on land.
Water-based ecosystems can be put into two main groups namely Freshwater Ecosystems and Marine Ecosystems.
Marine Ecosystems describe the biotic and abiotic interactions that occur in the oceans. Marine waters are very different from freshwaters because of the high salt content of seawater.
Freshwater ecosystems include two major components: Lentic and Lotic Systems. Lentic systems describe all standing water ecosystems. Lotic systems describe all flowing water ecosystems. In both Lentic and Lotic ecosystems, abiotic factors such as light, temperature, pH, alkalinity, pressure, depth etc of the water are extremely important and determine what kind of living and non-living interactions can exist there.
In all the above water types, living activities occur in different zones: such as the surface of the waters, middle parts and at the bottom of the water. The scientific names for life forms in the water are Plankton, Nekton, and Benthos. Then, there are also interactions on the surface of, and along these waters.
As you can tell already, there are complex food webs that exist in aquatic ecosystems. Now, shall we take a closer look at these three terms: Plankton, Nekton, and Benthos.
Distribution of Water on the Earth’s Surface
https://www.e-education.psu.edu/earth103/node/701 Accessed on December 2018