Characteristics, Features and Types of Aquatic Ecosystems

What Is the Aquatic Ecosystem?

The aquatic ecosystem is that ecosystem that has water as a basic element of the development and growth of all the species that live in it.

This is composed of elements of flora and fauna that meet under a body of water with properties that generate life. These bodies of water can be oceans, seas, rivers, lakes, swamps, streams, or lagoons.

Aquatic ecosystems, in addition to providing the space where many species subsist, provide a series of inert elements that are fundamental for the life cycle of the species that inhabit them.

The variety and quantity of species that will develop in a given ecosystem will depend on its salinity level, water temperature, sun exposure, depth, its food availability, among other factors.

Characteristics, Features and Types of Aquatic Ecosystems

Coral reefs, one of the most diverse aquatic ecosystems on earth.

Characteristics and Features of Aquatic Ecosystems

Among the main characteristics and features of aquatic ecosystems we can highlight that:

  • They can be freshwater or saltwater.
  • They provide the living space for many underwater species.
  • Its flora is mainly composed of algae and corals.
  • They have a high biological diversity that positions them as the most productive and richest ecosystems on the planet.
  • They fulfill certain essential functions in the life of the planet, such as helping to regulate the hydrological cycle and acting as a filter for pollution.

Examples of aquatic ecosystem

Some examples of aquatic ecosystems are:

  • Mangroves: With dense and dark waters, with little movement, usually clay soils covered with decomposing organic matter, small fish and amphibian life forms predominate, as well as mangroves, trees whose characteristic roots protrude from the water.
  • Cost line: The coasts of the warm seas are particularly abundant in animal and plant life, and therefore are the most common fishing regions. Coral reefs, schools of fish, and various food chains make up its blue waters.
  • Ponds: Characterized by waters with very little movement and a high presence of organic matter from neighboring trees, they tend to host 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 land, are also home to minimal flora (usually bacterial), and different animals adapted to intense colds, such as aquatic mammals, cold-water fish, etc.

Types of Aquatic Ecosystems

1- Oceans

The oceans are ecosystems with a great variety of characteristics. They are considered to cover 70% of the Earth’s surface and are home to a large number of organisms.

There are five oceans on the planet: Pacific, Atlantic, Indian, Arctic, and the Antarctic. The oceans have an average depth of about 4,000 meters and correspond to the largest surface of water that exists on the planet.

The organisms that live in the oceans can be classified into three large groups. First, there are pelagic organisms, which are characterized by developing in the so-called open sea, that portion of the ocean far from the continents.

In the second place, there are benthic organisms, which are those that live at the bottom of the seas, among which algae, some crustaceans, and corals stand out.

And thirdly, planktonic organisms live in the oceans, which are characterized by being carried along by currents and by developing on the surface of the water, where they float.

Algae, larvae, and jellyfish are some of the ocean’s own planktonic organisms.

2- Coral reefs

Coral reefs are considered the aquatic area with the greatest diversity of organisms.

This ecosystem covers less than 1% of the oceans; however, it is the second ecosystem with the highest amount of biodiversity, preceded by forests.

Within the coral reefs inhabit mollusks, a great variety of algae, and some 4,000 different species of fish. At the bottom of the reefs are structures made of calcium carbonate in which a large number of organisms live.

Read: Why Do We Need to Conserve Our Natural Resources

Four types of reefs can be identified: barrier, coastal, atoll, and patch. Barrier reefs are those that are close to the coasts and are separated from them by lagoons. The coastal reefs also called bordering, are generated in the coasts.

The atoll reefs are those that grow around volcanoes that are submerged in the middle of the sea; in the middle of these reefs a lagoon forms.

Finally, patch reefs are those that have a certain distance between them, since the formations are not continuous.

3- Wetlands

These are the ecosystems that are considered to have the highest level of productivity. They are located in spaces where there are shallow waters (they reach a maximum depth of six meters).

Wetlands can be fresh or saltwater and can be in the context of still or moving waters.

This ecosystem can also appear in naturally generated settings, such as deltas, swamps, or swamps; or artificial settings, such as dams or ponds.

Wetlands are characterized by retaining water and can lessen the damaging effects of floods. The vegetation that grows in wetlands is characterized by being hydrophilic, that is, it is capable of remaining underwater for long periods.

A great variety of organisms are found in wetlands: small insects; birds like herons, pelicans, and eagles; fish such as trout and catfish; and medium-sized mammals, such as otters.

4- Estuaries

Estuaries are the deepest areas at the mouth of a river in an ocean. They are characterized because sweet and salty waters are mixed on their surface.

Many nutrients are concentrated in estuaries and it is considered one of the most fertile ecosystems. The mouths of rivers are a clear example of estuaries.

This ecosystem is also considered essential for the prevention of disasters caused by floods, and it is a defense against strong storms.

Estuaries are the setting for other ecosystems, such as wetlands and mangroves.

The mixture of freshwater with saltwater makes estuaries have special peculiarities in terms of the characteristics of the water: it has a greater amount of nutrients thanks to the mixture of both types of water.

5- Lentic

These ecosystems are characterized by being areas of stagnant water and with little movements, such as swamps or lakes.

Depending on the depth of the ecosystem, it is possible that they have more or less biodiversity, due to the action of sunlight on the surface; the greater the possibility of sunlight, the more aquatic plants there will be.

6- Lotics

Streams and rivers are part of lotic ecosystems, which are characterized by having a constant, rapid, and unidirectional flow of water.

Organisms that live in these conditions have great swimming abilities because they must avoid being carried away by currents.

Salmons and sardines are two species that commonly inhabit lotic ecosystems.

Problems That Occur In Aquatic Ecosystems

Problems that occur in freshwater ecosystems

Problems in aquatic ecosystems often occur due to residents or humans, one of which is problems in freshwater ecosystems, namely:

River Water Pollution

Rivers in Many countries have an important role in life, namely as a means of irrigation, drinking water sources, industrial purposes, and others. But in the past five years, water quality has declined. This is because 64 of the 470 watersheds (DAS) in Many countries are in critical condition. River silting occurs everywhere. In addition, many rivers in Many countries are polluted by various wastes including:

  1. Domestic waste, namely household waste in the form of detergent, feces, and garbage that is intentionally thrown into the river.
  2. Industrial waste is in the form of various hazardous and toxic chemicals and heavy metals.
  3. Agricultural waste such as residual pesticides and fertilizers.
  4. Toxins from illegal fishing activities.

Groundwater Pollution

Housing in dense cities in Many countries, many uses ground wells as a source of water for daily needs, replacing the role of PAM. However, groundwater from these wells contains  Fecal Coli bacteria,  coliforms,  and minerals such as iron that exceed the quality standard. The source of the pollution comes from the resident’s feces shelter ( septic tank ). As a result, the condition of the water is yellow and smells. This may not happen if the distance between the septic tank and the well is more than 10 meters. But because the city is a dense area, this becomes difficult to implement and groundwater pollution occurs.

In addition, the disposal of industrial waste adjacent to the resident’s wells also causes the groundwater to be polluted. Groundwater in big cities near the coast is also polluted by saltwater (seawater) due to the massive extraction of groundwater by industry and large buildings. Because a lot of groundwater has been sucked up, finally in the cavity of the former groundwater, seawater seeps and reduces the quality of groundwater that is sucked up by the city.

Impact of Water Pollution

Water pollution has the following effects.

  1. The destruction of various types of fish and damage to aquatic plants. A further impact that occurs is the disruption of the ecosystem which in time will surely harm humans themselves.
  2. Contaminated river water threatens the health of residents along the watershed because it is a source of various diseases.
  3. Floods occur in the rainy season.
  4. The pungent smell of factory waste.
  5. There is a scarcity of clean water.
  6. The occurrence of blooming algae, a condition when the water of rivers and lakes is covered by algae which causes the death of the lower biota of Bloomingalgae caused by the amount of fertilizer dissolved in the water.
  7. Waste from rivers that are carried into the sea will pollute marine life so that which also brings disaster to humans who consume it. As an example of Minamata disease in Japan, a disease that occurs in the Minamata area is caused by the accumulation of heavy metals in the bodies of marine fish that are consumed by people.

Efforts to overcome water pollution can be done with the following steps.

  1. Waste must be minimized and if it can be recycled. If it cannot be recycled, waste must be neutralized so as not to pollute the environment.
  2. Communities and non-governmental organizations must participate in supervising and maintaining water conservation.
  3. The implementation of environmental laws must be firm, violators must be punished with appropriate sanctions.

Problems with marine ecosystems

In addition to water problems that occur in freshwater ecosystems, seawater ecosystems also have problems that occur in the water and the environment that supports it, one of which is the problem on the coast.

Coastal ecosystems are ecosystems that have diverse natural resources because they are a meeting place between land and sea areas. Various types of living things can be found on the beach. In the coastal area can be found mangrove forests, coral reefs, and of course sand beaches.

Mangrove forests can be used as raw materials for making furniture. Coral reefs are a beautiful area, but unfortunately, there are often ignorant hands who can remove coral reefs for sale. The beach sand can be used as a building material. Excessive dredging of coastal natural resources can make the beach unable to function properly. Coastal ecosystems will be destroyed.

To reduce the impact of damage to coastal ecosystems, the following steps need to be taken.

  1. Mangrove reforestation.
  2. Regulations were made to limit sand mining.
  3. The community, especially fishermen, plays an active role in protecting the coastal area.
  4. Giving responsibility for forest conservation along the coast for entrepreneurs engaged in marine tourism.

Problems That Occur in Human-Build Ecosystems

In the human-built ecosystem, problems are often encountered, one of which is the problems that occur in the built ecosystem, namely rice fields. In the rice field ecosystem, there are many problems that arise including:

Soil Pollution

Soil can be polluted by excessive use of fertilizers and pesticides. Soil pollution has a characteristic that there is a change in the soil becoming dry and hard, this is caused by the very large amount of salt contained in the soil. In addition, soil pollution can also be caused by plastic waste because in general, plastic waste does not undergo a perfect destruction process.


In the rice field ecosystem, the problem that often occurs is that there are many pests that interfere with or damage the plants that function as producers, causing the plants to grow less fully and their growth to be stunted. This will greatly affect the economy of our country. The more plants that are affected by pests, the more expensive the selling price of the plant.

Weather or climate

Uncertain weather will greatly affect the rice plants found in the rice field ecosystem. During the rainy season, the number of rat pests will increase so that the production of rice plants will decrease greatly. In summer, the paddy fields will become cracked so that many paddies die due to a lack of water.

Water pollution

Water greatly affects the growth and development of plants and animals in the rice field ecosystem. Not a few rice fields that use irrigation systems have been polluted by factory waste. This causes disruption of the food chain system in the rice field ecosystem.