AQUATIC ECOSYSTEM

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Fresh water Ecosystems– The salt content of fresh bodies is very low, always less than 5 ppt  (parts per thousand). E.g lakes, ponds, pools, springs, streams, and rivers

Marine ecosystems – the water bodies containing salt concentration equal to or above that of sea water (i.e., 35 ppt or above). E.g shallow seas and open ocean   Brackish water ecosystems- these water bodies have salt content in between 5 to 35 ppt. e.g. estuaries, salt marshes, mangrove swamps and forests.

 

AQUATIC ORGANISMS

The aquatic organisms are classified on the basis Of their one of occurrence and their ability to cross these zones. can be classified on the basis of their life form or location into five groups

  1. Neuston:

These are unattached organisms which live at the air-water interface such as floating Plants, etc.

Some organisms spend most of their lives on top of the air-water interface such as water striders, while others spend most of their time just beneath the air-water interface and obtain most of their food within the water.

E.g., beetles and back-swimmers.

  1. Periphyton:

These are organisms which remain attached to stems and leaves of rooted plants or substances emerging above the bottom mud such as sessile algae and their associated group of animals.

  1. Plankton

This group includes both microscopic plants like algae (phytoplankton) and

animals like crustaceans and protozoans (Zooplankton) found in all aquatic

ecosysteins, except certain swift moving waters

The locomotory power of the planktons is limited so that their distribution is

controlled, largely, by currents in the aquatic ecosystems.

  1. Nekton:

This group contains animals which are  swimmers.

The nektons are relatively large and powerful as they have to overcome the water currents.

  1. Benthos:

The benthic organisms are those found living in the bottom of the water mass.

Practically every aquatic ecosystem contains well developed benthos

Factors Limiting the Productivity of Aquatic Habitats

  1. Sunlight :

Sunlight penetration rapidly diminishes as it passes down the column of water.

The depth to which Light penetrates a lake determines the extent of plant distribution.

Based on light penetration and plant distribution they are classified as photic and aphotic zones

Photic zone:

It is the upper layer of the aquatic ecosystems, up to which light penetrates and within which photosynthetic activity is confined.

The depth of this zone depends on the transparency of water.

photic (or .”euphotic”) zone is the lighted and usually well-mixed portion that extends from the lake surface down to where the light level is 1% of that at the surface.

Aphotic zone:

The lower layers of the aquatic ecosystems, where light penetration and plant Growth are restricted forms the aphotic zone.

Only Respiration activity takes place.(photic-both respiration and Photosynthesis take place )

Aphotic zone is positioned below the littoral and photic zones to bottom of the lake where light levels are too low for photosynthesis.

This deep, unlit region is also known as the profundal zone.

Dissolved Oxygen:

Oxygen enters the aquatic ecosystem through the air water interface and by the photosynthetic. Average concentration of dissolved oxygen as 10 parts per million by weight.

Dissolved oxygen escapes the water body through air-water interface and through respiration of organisms (fish, decomposers, zooplanktons, etc )

The amount of dissolved oxygen retained in water is also influenced by temperature.

Other limiting factors which influence on aquatic productivity are

Transparency:

Transparency affects the extent of light penetration.

Suspended particulate matters such as clay, silt, phytoplankton, etc make the water turbidity. Consequently it limits the extent of light penetration and the photosynthetic activity in a significant way.

Temperature:

The water temperature changes less rapidly than the temperature of air because water has a considerably higher specific heat than air.

Since water temperatures are less subject to change, the aquatic organisms have narrow temperature Tolerance limit.,

Aquatic ecosystems are those that are found in water. They can be found in freshwater, marine, or estuarine environments. Freshwater ecosystems include rivers, lakes, and ponds. Marine ecosystems include Oceans, coral reefs, and mangrove forests. Estuarine ecosystems are found where freshwater and saltwater meet, such as in estuaries and deltas.

Wetlands are a type of aquatic ecosystem that is found in areas where water covers the land, either permanently or seasonally. Wetlands include marshes, swamps, bogs, and fens.

Rivers are flowing bodies of water that carry water from higher elevations to lower elevations. Lakes are bodies of water that are surrounded by land. Ponds are smaller than lakes and are often found in rural areas.

Oceans are the largest aquatic ecosystems on Earth. They cover about 70% of the Earth’s surface. Coral reefs are ecosystems that are found in tropical and subtropical waters. They are made up of coral polyps, which are small animals that live in colonies. Mangrove forests are found in tropical and subtropical coastal areas. They are made up of mangrove trees, which are adapted to live in salty water.

Salt marshes are found in coastal areas where the water is salty. They are made up of salt-tolerant plants, such as Grasses and reeds. Lagoons are shallow bodies of water that are separated from the ocean by a barrier island or reef. Bogs are found in areas where the water is acidic and low in nutrients. Swamps are found in areas where the water is stagnant and there is a lot of vegetation. Marshes are found in areas where the water is fresh or brackish and there is a lot of vegetation. Fens are found in areas where the water is fresh and there is a lot of vegetation. Peat bogs are found in areas where the water is acidic and there is a lot of vegetation.

Freshwater wetlands include swamps, marshes, bogs, and fens. Marine wetlands include mangrove forests, salt marshes, and lagoons. Estuarine wetlands include tidal marshes, mudflats, and salt flats.

Aquatic plants are plants that live in water. They can be found in freshwater, marine, or estuarine environments. Aquatic animals are animals that live in water. They can be found in freshwater, marine, or estuarine environments. Aquatic Microorganisms are microorganisms that live in water. They can be found in freshwater, marine, or estuarine environments.

Aquatic food chains are the relationships between organisms in an aquatic ecosystem. The food chain starts with producers, which are organisms that can make their own food. The next level in the food chain is consumers, which are organisms that eat other organisms. The final level in the food chain is decomposers, which are organisms that break down dead organisms.

Aquatic food webs are more complex than food chains. They include many different types of organisms and many different relationships between organisms.

Aquatic nutrient cycles are the processes by which nutrients are recycled in an aquatic ecosystem. The nutrients that are most important in aquatic ecosystems are nitrogen, phosphorus, and carbon.

Aquatic pollution is the contamination of water by harmful substances. The most common types of aquatic pollution are sewage, industrial waste, and agricultural runoff.

Aquatic conservation is the protection of aquatic ecosystems. It is important to conserve aquatic ecosystems because they provide many benefits to humans, such as clean water, food, and recreation.

Here are some additional facts about aquatic ecosystems:

  • Aquatic ecosystems cover about 71% of the Earth’s surface.
  • About 50% of the world’s Population lives within 100 kilometers of a coast.
  • Aquatic ecosystems provide food for about 1 billion people.
  • Aquatic ecosystems play a role in regulating the Climate.
  • Aquatic ecosystems are home to a wide variety of plants and animals.
  • Aquatic ecosystems are important for recreation and tourism.
  • Aquatic ecosystems are threatened by pollution, Climate Change, and overfishing.

It is important to protect aquatic ecosystems because they provide many benefits to humans. We need to reduce pollution, conserve water, and manage our Fisheries-2/”>Fisheries sustainably. We also need to educate people about the importance of aquatic ecosystems and the threats they face.

1. What is a food chain?

A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another.

2. What is a food web?

A food web is a Network of interconnected food chains.

3. What are the different types of food chains?

There are three main types of food chains: grazing food chains, detrital food chains, and parasitic food chains.

4. What are the different types of food webs?

There are two main types of food webs: terrestrial food webs and aquatic food webs.

5. What are the different trophic levels?

The trophic levels are the different levels of organisms in a food chain, starting with the producers at the bottom and ending with the top predators.

6. What are the different types of producers?

The different types of producers are plants, algae, and photosynthetic bacteria.

7. What are the different types of consumers?

The different types of consumers are herbivores, carnivores, omnivores, and decomposers.

8. What are the different types of decomposers?

The different types of decomposers are bacteria, Fungi, and protists.

9. What is the role of producers in a food chain?

The role of producers in a food chain is to convert sunlight into energy that can be used by other organisms.

10. What is the role of consumers in a food chain?

The role of consumers in a food chain is to eat other organisms and obtain the energy they need to survive.

11. What is the role of decomposers in a food chain?

The role of decomposers in a food chain is to break down dead organisms and return their nutrients to the Environment.

12. What is the importance of food chains and food webs?

Food chains and food webs are important because they show how energy and nutrients are transferred through an ecosystem.

13. What are some examples of food chains?

Some examples of food chains are:

  • Grass → grasshopper → frog → snake → hawk
  • Plant → insect → bird → hawk
  • Phytoplankton → zooplankton → fish → larger fish → shark

14. What are some examples of food webs?

Some examples of food webs are:

  • A terrestrial food web in a forest might include trees, insects, birds, and mammals.
  • An aquatic food web in a pond might include algae, zooplankton, fish, and frogs.

15. What are some threats to food chains and food webs?

Some threats to food chains and food webs are:

  • Habitat loss
  • Pollution
  • Overpopulation
  • Climate change

16. What are some ways to protect food chains and food webs?

Some ways to protect food chains and food webs are:

  • Conserve habitats
  • Reduce pollution
  • Manage populations
  • Mitigate climate change

17. What are some benefits of protecting food chains and food webs?

Some benefits of protecting food chains and food webs are:

  1. Which of the following is not a type of aquatic ecosystem?
    (A) Ocean
    (B) Lake
    (C) River
    (D) Forest

  2. The main difference between a freshwater ecosystem and a saltwater ecosystem is the:
    (A) salinity of the water
    (B) temperature of the water
    (C) depth of the water
    (D) amount of sunlight

  3. The most abundant organisms in the ocean are:
    (A) phytoplankton
    (B) zooplankton
    (C) fish
    (D) coral

  4. The largest lake in the world is:
    (A) Lake Baikal
    (B) Lake Superior
    (C) Lake Victoria
    (D) Caspian Sea

  5. The Amazon River is the:
    (A) longest river in the world
    (B) widest river in the world
    (C) deepest river in the world
    (D) most voluminous river in the world

  6. The Everglades is a:
    (A) tropical rainforest
    (B) temperate rainforest
    (C) mangrove swamp
    (D) salt marsh

  7. The Great Barrier Reef is the:
    (A) largest coral reef system in the world
    (B) largest marine protected area in the world
    (C) largest living structure on Earth
    (D) all of the above

  8. The largest freshwater wetland in the world is:
    (A) the Pantanal
    (B) the Everglades
    (C) the Amazon River basin
    (D) the Congo River basin

  9. The largest saltwater wetland in the world is:
    (A) the Caspian Sea
    (B) the Dead Sea
    (C) the Aral Sea
    (D) the Salton Sea

  10. The most endangered aquatic ecosystem is:
    (A) coral reefs
    (B) mangrove forests
    (C) salt marshes
    (D) wetlands

Answers:
1. (D)
2. (A)
3. (A)
4. (A)
5. (A)
6. (C)
7. (A)
8. (A)
9. (A)
10. (A)