An ecosystem It is that community inserted in a certain environment and in which the living beings that compose it actively coexist. In as much, an aquatic ecosystem is one that exists in the water, then, its living components, vegetation and animals coexist and develop in the same water.
Our planet has two types of waters, salty (oceans and seas) and sweet (lakes, rivers, streams, lagoons, among others), therefore, the animals and plants that live in either of these two types have natural characteristics that will allow them to survive in the conditions that prevail in the aforementioned water ecosystems.
It will not be the same for an animal adapted to life in salt water to accommodate the totally different conditions that arise in fresh water. In cases where there is no adaptation to change, species often disappear.
Any ecosystem needs to subsist on two types of elements, biotic (with life) and abiotic (without life), whose efficient interrelation will contribute to the balance and subsistence of the ecosystem in question.
Among the former, plants, animals, fungi and bacteria stand out, and biotics include air, sun, water, climate, temperature.
When we talk about interaction and the need for all the elements mentioned in the previous paragraph to be present, it has to do with the fact that they need each other to maintain and develop in the aquatic ecosystem.
Thus, vegetables or zooplankton are the staple food of very small fish and aquatic animals such as the whale and at the same time, zooplankton need the energy provided by sunlight to continue living. The smallest fish in turn are the food that the larger ones need and the rest of the aquatic plants also serve as food for the fungi and bacteria that are in that habitat.
It should be noted that aquatic ecosystems have enormous relevance when it comes to the development of various activities such as agriculture, the provision of water for personal consumption and the production of certain products. However, we must mention that unscrupulous and deficient human action, materialized in the contamination of water, is often a concrete and direct threat to the continuity of life and species.
