We explain what aquatic ecosystems are and how they are classified (sea, or freshwater). Features and examples.
What is an aquatic ecosystem?
An aquatic ecosystem is all that ecosystem that develops in a body of water of diverse size and nature , which includes seas , lakes, rivers, swamps, streams, lagoons and coasts. They play a vital role in the nature of water , its cycles, as well as the organic content present in it, both from natural and sedimentary sources ( soils).
Aquatic ecosystems are broadly divided into maritime ecosystems (those belonging to the ocean and its coasts) and freshwater ecosystems (rivers, lakes, lagoons and streams), because according to the physical and chemical characteristics of each, they will have a different fauna and flora , adapted to the vital conditions as well as possible.
The marine ecosystems are extremely varied and rich in fauna and flora, in a wide range from microorganisms, marine mammals, fish, mollusks, to large predators and plant forms static and mobile. Recall that from there comes life on the planet. These ecosystems adapt to the depth they are in, and that roughly we can classify into four zones:
- Intertidal . The area in which the sea connects with the mainland, whether by surface or underground, is an area of much change and great movement and erosion .
- Open sea . Also called the pelagic zone, it is the most densely populated region with the highest temperatures, which gradually descend as it descends in height. It covers the ocean surface and the first hundreds of meters deep.
- Ocean floor . Areas of greater coldness and lower incidence of light, in which sand prevails and life becomes more fierce and silent. It is usually under hundreds of meters deep.
- Abyssal or benthic zone . It is the deepest region of the ocean, located in pits and cracks of the ocean floor that lead to regions without sunlight, low presence of organic matter (although it has a constant rainfall of waste from the upper layers), gigantic aquatic pressures and adapted fauna to these conditions, whose forms and mechanisms of survival are usually striking or surprising.
The Freshwater Ecosystems , on the other hand, are divided according to the movement of water in three types:
- Wetlands . Land regions that flood during a good part of the year, and which may also face short periods of drought. They usually favor the encounter of aquatic ecosystems with other terrestrial ones.
- Lentic . Still waters or low flow, such as lakes, lagoons and ponds. They contain more organic matter in suspension in the water.
- Lotic . Running water systems such as rivers, streams, streams, etc. They present greater movement and greater coexistence of species, among fish, reptiles, amphibians, birds, etc.
Characteristics of an aquatic ecosystem
The aquatic ecosystems are numerous and abundant in life, so they usually present complex trophic chains , of animals adapted to the specific conditions of the water: their salinity, their currents, etc. In the case of rivers, much of it will depend on the terrestrial elements dragged or dissolved by the current, as well as the presence or absence of mineral or organic matter in the soils that it travels.
With the exception of amphibians and aquatic reptiles, many of which develop in the water but return to land to spawn (or vice versa), most of the animals in these ecosystems are adapted to permanent immersion in the water , so that depend on its biotic balance.
The same goes for flora, mostly composed of algae, corals and other photosynthetic forms that abound in the most superficial regions, where there is more sunlight. In the marshes, on the other hand, where the water is dark and full of organic debris, life adapts to the low concentration of oxygen.
Examples of aquatic ecosystem
Some examples of aquatic ecosystems are:
- Mangroves . Dense and dark waters, of little movement, usually clayey soils covered with decaying organic matter, small fish and amphibious life forms predominate, as well as mangroves, trees whose characteristic roots stand out from the water.
- Coastline . The coasts of the warm seas are particularly abundant in animal and plant life, and that is why they are the most common fishing regions. Coral reefs, schools of fish and various trophic chains integrate its blue waters.
- Ponds . Characterized by waters of very little movement and high presence of organic matter from neighboring trees, they usually house a huge variety of microscopic life, as well as small fish and insects.
- Polar ocean . The icy waters of the poles, abundant in icebergs and frozen earth, also house a minimal flora (usually bacterial), and different animals adapted to intense cold, such as aquatic mammals, cold-water fish, etc.