Characteristics, Features and Types of Aquatic Ecosystems

An aquatic ecosystem includes a group of organisms that live in water for all kinds of activities and are dependent on one another and their environment for nutrients and shelter. Examples of the aquatic ecosystem include lakes, rivers, etc.

What Is the Aquatic Ecosystem?

The aquatic ecosystem is an 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 are 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

There are mainly two types of aquatic ecosystems which are discussed below:

Types of Aquatic Ecosystem

Freshwater Ecosystem

The first type of aquatic ecosystem is the freshwater ecosystem. The freshwater ecosystem is an ecosystem that you find in lakes where the most freshwater is. It is called a freshwater ecosystem because the water around this ecosystem has taste that is fresh which means it doesn’t contain any salt.

This freshwater ecosystem turns out to have many characteristics and features. The characteristics possessed by the freshwater ecosystem include:

  • Have a low salinity or zero salt content. The salt content in the freshwater ecosystem is very low, even lower than the cytoplasm.
  • The temperature is considerely low. In this ecosystem, the variation or degree of temperature change is not too extreme. This means that between day and night differences are small.
  • Limited sunlight in this ecosystem means in freshwater ecosystems, there is sunlight but in limited quantity. This is because sunlight can only penetrate up to a few meters into the water. As a result, only certain areas or parts can enjoy the sunlight.
  • Influenced by climate and weather. Although the \environment is only slightly affected by conditions in nature, the water environment is still affected. The influence is mainly due to the weather and climate of that particular area where it is located. Although not as much affected by weather and climate as terrestrial ecosystems.

The freshwater ecosystem is divided into 2 types, based on the movement of the water. The two types of freshwater ecosystems are lentic ecosystems and lotic ecosystems. A lentic ecosystem is an ecosystem where the water is calm or does not flow, and a lotic ecosystem is an ecosystem in which the water moves.

Understand the Lentic and Lotic ecosystems

Lentic Aquatic Ecosystem

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

Depending on the depth of the ecosystem, they may 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.

Lotic Aquatic Ecosystem

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.

Marine Ecosystem

The second type of aquatic ecosystem is the marine ecosystem. As the name implies, marine ecosystems are located in sea and ocean waters. Similar to freshwater ecosystems, marine ecosystems also have their characteristics which include:

  • Has high salt contents in it. Unlike the freshwater ecosystem, this seawater ecosystem has high salt components. The salt content of this amount is similar to the concentration of protoplasm.
  • There is life in all of it. This marine ecosystem is a type of ecosystem that contains most parts of the Aquatic ecosystem. All depths in the sea contain life, except at the very bottom of the sea. The very deep seafloor is a place that is not suitable for any life form.
  • As we all know ecosystems are interconnected. This ecosystem is a type of ecosystem that is interconnected and is partly due to the long and wide area. Therefore, this ecosystem is very possible to mix because of the circulation of water.
  • There is a waste of energy a lot. The seawater ecosystem is one type of ecosystem that has a relatively complicated food web. Therefore, there is a lot of wasted energy along the food chain and food web.

Those are the characteristics of marine ecosystems. Similar to freshwater ecosystems marine ecosystems at each depth have their own characteristics. The surface has more production activity than the inside or bottom. This is because on the surface sunlight is easier to enter.

Following are some aquatic ecosystems falling under the freshwater and marine ecosystem categories:

Ocean Ecosystem

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 planktonic organisms.

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 on 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.


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 in 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.


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.

Problems That Occur In Aquatic Ecosystems

Here are some problems faced in the water ecosystem:

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:

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 salt water (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. Clean water is scarce.
  6. The occurrence of blooming algae is a condition when the water of rivers and lakes is covered by algae which causes the death of the lower biota of Bloomingalgae caused to the amount of fertilizer dissolved in the water.
  7. Waste from rivers that are carried into the sea will pollute marine life 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 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 to 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, many problems arise including:

Soil Pollution

Soil can be polluted by excessive use of fertilizers and pesticides. Soil pollution has the 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 many pests 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.

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