Detail note on freshwater and saltwater ecosystems

Freshwater ecosystems

Freshwater means water that has a low concentration of salt and water is able to use biodiversity. Freshwater resources are ponds lakes and streams and everybody which against to sea is called freshwater biomes. Freshwater is useful for many types of animals and plants which have compositions such as temperature, oxygen, sunlight, and food.

Water found in freshwater biomes is not extended if we compare it with the sea but it has the most important for living things. Especially it has great importance for a dry environment like desert there isolated ponds made for the purpose of to save the plants and animals life to provide water.

Characteristics of Freshwater biomes

  • Ecosystems which are called aquatic such as Wetland Rivers and lakes all these resources make freshwater biomes in the whole world. These biomes are identified by their property that is less salt in this water in contrast to saltwater. We classified freshwater biomes according to some facts that are temperature sunlight rainfall and vegetation.
  • In freshwater concentration of salt is one gram only in one litter water. Most salt is sodium chloride which has importance for living organisms. Freshwater also has great importance for humans because humans use this water to full fill their desires.
  •  Freshwater biomes including lakes, stream rivers, etc. mostly freshwater ecosystems have running water this water has many types of fish.

Location in the world

If we see it in the world then freshwater biomes are located in the whole world. South Africa has a large lake known by the name of Victoria. And another large and famous lake is found in Canada. The world’s largest lake is found in Siberia which has much property.

Types of Freshwater biomes

Three main types of freshwater biomes are given below;

Lintec, Lotic, and wetland

Lentic: Lentic means standing water and slow-moving water means those ecosystem water is standing or moving at a slow speed called lentic examples of lentic lakes, ponds, and pools.

Lotic: lactic means fast running water means biomes in which water is running at a very high speed called lotic such as rivers and streams are examples of the lotic ecosystem.

Wetland: Third is wetland these are areas their soil is saturated and annually fluctuation occur. Time by time.

 Difference between lentic and lotic Ecosystems

  • The word lentic derived from a Latin word which is means slow or standing water its examples is pools and ponds on the other hand lotic derived from Latin which is mean washing .its examples are rivers and streams.
  • Lotic biomes are those in which water runs fatly like streams, rivers, and creeks, etc. Lentic biomes are those in which water is standing or slow moves like pools, ponds, and lakes, etc.

Components in Freshwater Ecosystems

Following components of freshwater ecosystems: Producers, consumers, and decomposers.

Factors of freshwater biomes:

Abiotic factors; are those nonliving things and they affect the organisms which are living.  Abiotic made the environment in which biotic things survive and fulfill their needs of life and remain there easily. A Biotic factor may be both types chemical and physicals .like chemistry of water, purity of water, ph level, rainfall level, sunlight, etc.

Biotic Factors are fishes algae fungi etc. some other factors are plants, animals, and birds.

Animal life and their adaptation

The main animal is fish which live in freshwater others are worms, snails, snakes, frogs, turtles, mollusks, otters, alligators, marsh birds, beavers and many types of insects are the animals of freshwater. Some animals like dolphin spiders are also live there.

Adaptations: animals of freshwater adapted themself with long and sticky legs and long tongues which help them in catching the prey from the depth of water.

Plants and their adaptations

Some plants of freshwater are algae water lilies duckweed which is on the surface of the water. Others are cattails that found a bank of the shore. They float on water because swim balladeer helps them to swim. Mangroves and Estuaries are examples of freshwater ecosystem plants.

Adaptation: many plants haves swim bladders that help them to swim on the surface some have long roots. If the salt concentration is more than 1 percent then some plants do not remain to live in these environments.

Wetlands is that area where water is standing, slow-moving, or fast-moving according to fluctuation. These are found in zones that are temperate. This is meaning they get a high level of rain.

On the other hand lakes and rivers which are located in different valleys and hilly areas, they get a low level of rain. If we see annually then rainfall is 10 – 80 inches in one year.

Climate: rivers spread in many places and they made their pathway by the land. In summer the temperature of freshwater is 65 – 75 F and in winter 35 -45 F.


Freshwater is necessary for the survival of life. Many animals’ plants and humans use this water to full fill their needs. Needs such as for drinking, for crops, for factories use, etc.

Human impact:

Those freshwater ecosystems which are located near the towns cities and factories are damaged badly by pollution and other factors. These swats are dumping factories, the smoke of engine and pesticides. Some pesticides are absorbed in the soil but some go to the rivers and streams meet with water of rain.[1]

Saltwater Ecosystems

  • The other name of saltwater biome is Marine biomes whose water contains a very high amount of salt. Like the freshwater ecosystem, salt biomes are also home to living and nonliving things like jellyfish and phytoplanktons.
  • Marine means the place where the animals and plants interact with each other and nonliving thins these places are sea and oceans.
  • Saltwater biomes mean water whose have salt in and is found on earth. The overall whole earth is covered by 70 percent water and in which 97 percent of water is saltwater. The largest ecosystems are the marine ecosystem from aquatic.


  • Marine biome is also balanced and complex like other aquatic ecosystems. If we divided these different parts then each part plays a role to make the system maintain and balance .all organisms which live there depend on this system and survive them by the physical and chemical factors.
  • The main property of the marine biome is that is the largest all of aquatic biomes. Examples are sea, oceans, intertidal ecology, lagoons, coral reefs, mangroves and marsh zone, etc. If we contrast saltwater with freshwater then freshwater has a low concentration of salt and saltwater has a high concentration of salt.
  • Saltwater biomes have large sizes and wide ranges. Coral reefs which remain in it have the percentage25 percent of all marine animals. And occupying less than 1 percent.


Location in the world: overall word marine ecosystems are 5 including the south ocean, Indian Ocean, Atlantic Ocean Arctic Ocean Nand Pacific Ocean.

Types of saltwater biomes

If we see in the world the only one type of open ocean. And many other types are such as the tidal ocean, coral reef shoreline, the floor of the ocean, swamps salt marsh, mangroves, estuaries, and hydrothermal.

Factors of saltwater biomes

Two types of factors Abiotic factors and biotic factors

Abiotic factors: Abiotic factors; are those nonliving things and they affect the organisms which are living. Abiotic made the environment in which biotic things survive and fulfill their needs of life and remain they’re easy for a lifetime. The abiotic factor maybe both types chemical and physicals .like the chemistry of water, purity of water, ph level, rainfall level, sunlight, etc.

Biotic factors: Biotic factors of salt water are sunlight, wind jellyfish, phytoplankton, coral reefs, temperature, moisture, starfish sponges fungi, plants, squids, and dolphins.

Components in saltwater Ecosystems

Following components of saltwater ecosystems: Producers, consumers, and decomposers.

Plants and their adaptations

Life basis is created by phytoplankton on earth. Only one form of marine biome is phytoplankton.

Some other plants are Forest of kelp they are those places where many types of species are live. Another type is rockweed they are those which are found on the bottom. The third type is seagrasses which are found underwater. And the last is tree of mangrove.


Plants of the sea which are found in the sea have unique properties for adaptations such as they are juicy and break the salt into two ions chloride and sodium ions. Some of them store salt in their body and out from their body when they involve in the process of respiration. Some types of plants leave has juicy they store water in it those plants which found on the side bank of the sea.

Animals of Saltwater biomes and their adaptations

Fishes of saltwater: marine water is including Flatfish. Starfish, eels, sunfish, rockfish, seahorse, grass, clownfish tuna, sharks, fishes, grouper and stingray.

Mammals of saltwater biomes; clams, otters, squid, manatees, blue whales, seals, dolphins, conch, snails, mollusks, oysters, octopus, slugs, cattle fish, and walruses.

Adaptations: They found a special way to survive underwater or breath and pull the saltwater in his body for these purpose animals of saltwater has a special organ which is called gills. This organ helps to live in water by breathing. Many animals have slipping bodies for the purpose of swim in the water. Another work of slipping body is that they help to stop the friction.

Salt and Osmosis: Most saltwater animals have the same number amount of salt in their bodies and outside their bodies .for this same amount of salt humans and other mammals all do not drink saltwater. This saltwater damages the important body organs badly.

Rainfall; If compare with world rainfall then half rainfall in the ocean is due to two reasons. The first reason is that the sea has a large size and other is that cycle of water move fast and made the water biomes. The annual rainfall is 100 inches record.

Importance of saltwater

Saltwater is very important because it gives half oxygen to the earth. It gets carbon from the environment and returned oxygen for this regard it has much importance. Many of us do not know about the importance of salt water which is due to oxygen. Saltwater has water is very important for the forest in this regard.

Human impacts

Impacts human activities on saltwater biomes: Human activities badly affected the seawater and damages the seawater and living things that live there. Seawater is affected by pollution industrial wastes combustion of engines pesticides etc. [2]

Written by: Dr. Muhammad Mohsin Ahsan

Reviewed by:
Dr. Muhammad Tahir Ph.D. (PU)
Post Doctorate

American Museum of Natural History, New York, USA



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