LAKE ECOLOGY

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Any – body of standing water, generally large enough in area and depth, irrespective of its hydrology, ECOLOGY, and other characteristics is generally known as lake.

Ageing of Lakes

The nutrient enrichment of the lakes promotes the Growth of algae, aquatic Plants and various Fauna. This process is known as natural eutrophication.

Similar nutrient enrichment of lakes at an accelerated rate is caused by human activities and the consequent ageing phenomenon is known as ‘cultural eutrophication’.

In India, natural lakes (relatively few) mostly ile in the Himalayan region, the floodplains of Indus, Ganga and Brahmaputra.

Lake ‘Sudarshan’ in Gujarat’s Girnar area was perhaps the oldest man-made lake in India, dating back to 300 BC.

Lakes are also classified on the basis of their water chemistry. Based-on the levels of salinity, they are known as Freshwater, Brackish or Saline lakes (similar to that of Classification of AQUATIC ECOSYSTEM).

On the basis of their nutrient content, they are categorized as Oligotrophic (very low nutrients), Mesotrophic (moderate nutrients) and Eutrophic (highly nutrient rich).

Removal of the nutrients from a lake

Flushing with nutrient-poor waters.
Deep water abstraction.
On-site P-elimination by flocculation/flotation with water backflow, or floating Plant
NESSIE with adsorbents.
On-site algae removal by filters and P-adsorbers.
0n-site algae skimming and separator thickening.
Artificial mixing / Destratification (permanent or intermittent).
Harvest of fishes and macrophytes.
Sludge removal

EUTROPHICATION

a syndrome of ecosystem, response to the addition of artificial or natural substances such as nitrates and phosphates through fertilizer, sewage, etc that fertilize the aquatic ecosystem.

The growth of green algae which we see in the lake surface layer is the physical identification of an Eutrophication.

Some algae and blue-green bacteria thrive on the excess ions and a Population explosion covers almost entire surface layer is known as algal bloom. Nitrogen testing is a technique to find the optimum amount of fertilizer required for crop plants. It will reduce the amount of nitrogen lost to the surrounding area.

HARMFUL ALGAL BLOOMS

Algae or phytoplankton are microscopic organisms that can be found naturally in coastal waters. They are major producers of Oxygen and food for many of the animals that live in these waters.

Algal blooms can be any color, but the most common ones are red or brown.

Most algal blooms are not harmful but some produce toxins and do affect fish, birds, marine mammals and humans.

Use of algae

Most species of algae or phytoplankton serve as the energy producers at the base of the food web, without which higher life on this planet would not exist.

Why Red Tide is a misnomer?

“Red Tide” is a common name for such a phenomenon where certain

phytoplankton species contain pigments and “bloom” such that the Human Eye perceives the water to be discoloured.

Blooms can appear greenish, brown, and even reddish orange depending upon the type of organism, the type of water, and the concentration of the organisms.

The term “red tide” is thus a misnomer because blooms are not always red, they are not associated with tides, they are usually not harmful, and some species can be harmful or dangerous at low cell concentrations that do not discolour the water.

What are the causes of these blooms?

Two common causes are nutrient enrichment and warm waters.,

Lakes are classified according to their origin, shape, and size. The most common types of lakes are:

Tectonic lakes are formed when the Earth’s crust is uplifted, creating a depression that fills with water.
Volcanic lakes are formed when a volcano erupts and leaves behind a crater that fills with water.
Glacial lakes are formed when Glaciers melt and leave behind a depression that fills with water.
Riverine lakes are formed when a river changes course and leaves behind a meander that fills with water.
Oxbow lakes are formed when a river cuts off a meander, leaving behind a crescent-shaped lake.

Lakes can also be classified according to their shape. The most common shapes of lakes are:

Oval lakes are the most common type of lake. They are formed when a depression is created by tectonic activity, volcanic activity, or glacial activity.
Irregular lakes are lakes that have a non-symmetrical shape. They are often formed by river erosion or by the collapse of a cave.
Crescent-shaped lakes are lakes that have a crescent-shaped outline. They are often formed when a river cuts off a meander.

Lakes can also be classified according to their size. The most common sizes of lakes are:

Small lakes are lakes that are less than 10 square kilometers in area.
Medium-sized lakes are lakes that are between 10 and 100 square kilometers in area.
Large lakes are lakes that are more than 100 square kilometers in area.

Lakes are important Ecosystems that provide a variety of benefits to humans and the Environment. Some of the benefits of lakes include:

Water supply. Lakes are a source of drinking water, irrigation water, and hydroelectric power.
Habitat. Lakes provide habitat for a variety of plants and animals, including fish, birds, and mammals.
Recreation. Lakes are a popular destination for swimming, boating, fishing, and other recreational activities.
Tourism. Lakes are a popular destination for tourists, who come to enjoy the scenery, the water Sports, and the fishing.
Education. Lakes can be used as a classroom for teaching students about the environment.
Research. Lakes are a valuable resource for scientific research, including studies of Climate change, water quality, and aquatic ecosystems.

Lakes are also vulnerable to a variety of threats, including pollution, eutrophication, acidification, warming, and invasive species. These threats can have a significant impact on the Health of lakes and the ecosystems they support.

Pollution is a major threat to lakes. Lakes can be polluted by runoff from farms and industries, sewage, and urban runoff. Pollution can cause a variety of problems, including algae blooms, fish kills, and changes in water quality.

Eutrophication is a process that occurs when lakes become too rich in nutrients. This can happen when runoff from farms and industries carries excess nutrients into lakes. Eutrophication can cause algae blooms, which can block sunlight and suffocate aquatic plants and animals.

Acidity is another threat to lakes. Acid Rain can cause lakes to become more acidic. This can harm fish and other aquatic life.

Warming is a threat to lakes because it can cause changes in water temperature and water levels. These changes can disrupt the ecosystems of lakes and make them less hospitable to fish and other aquatic life.

Invasive species are a threat to lakes because they can outcompete native species for food and habitat. This can disrupt the ecosystems of lakes and make them less healthy.

Lakes are an important part of the Earth’s ecosystem. They provide habitat for a variety of plants and animals, and they play a role in the water cycle. Lakes are also a source of drinking water, irrigation water, and hydroelectric power. However, lakes are also vulnerable to a variety of threats, including pollution, eutrophication, acidification, warming, and invasive species. These threats can have a significant impact on the health of lakes and the ecosystems they support. It is important to protect lakes from these threats so that they can continue to provide the many benefits that they offer.

What is a lake?

A lake is a large body of water that is surrounded by land. Lakes are typically formed when water collects in a depression in the Earth’s surface.

What are the different types of lakes?

There are many different types of lakes, but they can be broadly divided into two categories: natural lakes and artificial lakes. Natural lakes are formed by natural processes, such as the melting of glaciers or the collapse of a cave. Artificial lakes are created by humans, such as for irrigation or hydroelectric power.

What are the characteristics of a healthy lake?

A healthy lake has a balanced ecosystem with a variety of plants and animals. The water in a healthy lake is clear and clean, and the lake is home to a variety of fish and other aquatic life.

What are the threats to lake ecosystems?

There are many threats to lake ecosystems, including pollution, invasive species, and Climate Change. Pollution can come from a variety of sources, such as agriculture, Industry, and sewage. Invasive species are plants or animals that are not native to a lake and can disrupt the ecosystem. Climate change can cause changes in water temperature and levels, which can impact lake ecosystems.

What can be done to protect lake ecosystems?

There are many things that can be done to protect lake ecosystems, including reducing pollution, controlling invasive species, and restoring damaged ecosystems. We can all do our part to protect lake ecosystems by making choices that reduce our impact on the environment.

What are the benefits of healthy lakes?

Healthy lakes provide many benefits, including clean drinking water, recreation, and a place for wildlife to live. Lakes also play an important role in the water cycle and the climate.

How can we learn more about lake ecology?

There are many ways to learn more about lake ecology. You can read books and articles, watch documentaries, or take a class. You can also visit a lake and observe the plants and animals that live there.

Question 1

Lakes are important ecosystems that provide a variety of benefits to humans. Which of the following is NOT a benefit of lakes?

(A) Water supply
(B) Recreation
(C) Fish habitat
(D) Pollution control

Answer
(D) Pollution control

Lakes are not effective at controlling pollution. In fact, lakes can actually be a source of pollution, as they can trap pollutants and release them into the air or water.

Question 2

Lakes are classified into three types based on their trophic status. Which of the following is NOT a type of lake trophic status?

(A) Eutrophic
(B) Oligotrophic
(C) Mesotrophic
(D) Hypertrophic

Answer
(C) Mesotrophic

Mesotrophic lakes are not a type of lake trophic status. The three types of lake trophic status are eutrophic, oligotrophic, and hypertrophic.

Question 3

Eutrophic lakes are characterized by high levels of nutrients, which can lead to algal blooms. Which of the following is NOT a consequence of algal blooms?

(A) Deoxygenation of the water
(B) Decreased Biodiversity-2/”>Biodiversity
(C) Fish kills
(D) Increased clarity of the water

Answer
(D) Increased clarity of the water

Algal blooms can actually decrease the clarity of the water, as they can block sunlight from reaching the bottom of the lake.

Question 4

Oligotrophic lakes are characterized by low levels of nutrients. Which of the following is NOT a characteristic of oligotrophic lakes?

(A) Clear water
(B) Low biodiversity
(C) High productivity
(D) Low nutrient levels

Answer
(C) High productivity

Oligotrophic lakes are not productive, as they have low levels of nutrients.

Question 5

Hypertrophic lakes are characterized by very high levels of nutrients. Which of the following is NOT a consequence of hypertrophic lakes?

(A) Deoxygenation of the water
(B) Decreased biodiversity
(C) Fish kills
(D) Increased clarity of the water

Answer
(D) Increased clarity of the water

Hypertrophic lakes can actually decrease the clarity of the water, as they can block sunlight from reaching the bottom of the lake.

Question 6

Lakes are home to a variety of organisms, including fish, algae, and bacteria. Which of the following is NOT an organism that lives in lakes?

(A) Fish
(B) Algae
(C) Bacteria
(D) Trees

Answer
(D) Trees

Trees do not live in lakes. They are terrestrial plants that live on land.

Question 7

Lakes are important ecosystems that provide a variety of benefits to humans. Which of the following is NOT a benefit of lakes?

(A) Water supply
(B) Recreation
(C) Fish habitat
(D) Climate regulation

Answer
(D) Climate regulation

Lakes do not regulate climate. In fact, lakes can actually contribute to climate change, as they can release greenhouse gases into the Atmosphere.

Question 8

Lakes are threatened by a variety of human activities, including pollution, development, and climate change. Which of the following is NOT a threat to lakes?

(A) Pollution
(B) Development
(C) Climate change
(D) Overfishing

Answer
(D) Overfishing

Overfishing is not a threat to lakes. In fact, overfishing is more of a threat to Oceans than to lakes.

Question 9

There are a variety of things that can be done to protect lakes. Which of the following is NOT a way to protect lakes?

(A) Reduce pollution
(B) Restore wetlands
(C) Manage water levels
(D) Overfish

Answer
(D) Overfish

Overfishing is not a way to protect lakes. In fact, overfishing is more of a threat to lakes than to oceans.

Question 10

Lakes are important ecosystems that provide a variety of benefits to humans. It is important to protect lakes from threats such as pollution, development, and climate change. We can all do our part to protect lakes by reducing our impact on the environment.