ESTUARY ECOSYSTEM

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  • located where river meets the sea.
  • the most productive water bodies in the world
  • The complete salinity range from 0-35 ppt is seen from the head (river end) to the mouth (sea end) of an estuary
  • Coastal lakes which have their connection with the sea through small openings are better known as lagoons or backwaters acting as a natural water filter

 

Estuary Formation:

grouped into four geomorphic categories based on the physical processes responsible for their formation:

1) rising sea level; (2) movement of sand and sandbars; (3) glacial processes; and (4) tectonic processes.

India Estuarine Ecosystem

The Country has 14 major, 44 medium and 162 minor rivers drains into the sea through various estuaries.

Major estuaries occur in the Bay of Bengal.

Most of the India’s major estuaries occur on the east coast. In contrast, the estuaries on the west coast are smaller.

 

MANGROVES

are the characteristic littoral plant formation of tropical and subtropical sheltered coastlines.

are trees and bushes growing below the high water level of Spring Tides which exhibits remarkable capacity for salt water Tolerance.

basically evergreen land Plants growing on sheltered shores, typically on tidal flats, deltas, estuaries, bays, creeks and the barrier islands. require high solar radiation and have the ability to absorb fresh water from saline/ brackish water. produces pneumatophores (blind roots) to overcome Respiration problem in the anaerobic Soil conditions

  • Leaves are thick and contain salt secreting glands.
  • exhibit viviparity mode of Reproduction. i.e. SeedS germinate in the tree itself (before falling to the ground). This is an adaptative medianiSintoovercome the problem of germination in Saline water.
  • crystals of salt on the back of the leaves; others block absorption of salt at their roots

The mangroves of Sundarbans are the largest single block of tidal holophytic mangroves of the world. famous for the Royal Bengal Tiger and crocodiles.

The mangroves of Bhitarkanika (Orissa), which is the second largest in the Indian sub continent, harbour high concentration of typical mangrove species and high Genetic diversity have (additional) special roots such as prop roots, pneumatophores  which help to impede water flow and thereby enhance the deposition of sediment in areas (where it is already occurring), stabilize the coastal shores, provide breeding ground for fishes. protects coastal lands from tsunami, hurricanes:and floods release Oxygen back to the Atmosphere, along with a little methane gas

 

CORAL REEFS

Coral is actually a living animal.

has a symbiotic relationship (each gives something to the other and gets something back in return) With ‘zooxanthellae’ microscopic algae which live on coral [i.e. instead of living on the sea  floor, the algae lives up on the coral which is closer to the ocean surface and so that the algae gets lots of Light.

The Tissues of Corals themselves are actually not the beautiful colors of the coral reef, but are instead clear (white). The corals receive their  coloration from the zooxanthellae living within their tissues.

  • There are two types of corals: hard corals and soft corals, such as sea fans and gorgonians. Only hard corals build reefs.
  • The builders of coral reefs are tiny animals called polyps. As these polyps thrive, grew, then die, they leave their limestone (calcium carbonate) skeletons behind. The limestone is colonized by new polyps.
  • found in tropical and sub-tropical water, there are also deep water corals in colder regions
  • The United Nations Environment Programme reports that there are more cold water coral reefs worldwide than tropical reefs.
  • There are only about 6 different coral species associated in building with these reefs.
  • The largest cold-water coral reef is the Rost ‘Reef off Norway occur in shallow tropical areas where the sea water is clean, clear and warm.
  • one of the most productive and complex coastal Ecosystems with high biological diversity classified depending on their locations into fringing, patch, barrier and atoll.
  • The fringing reefs are contiguous with the shore and they are the most common – by occurring reef form, found in Andamans.
  • Patch reefs are isolated and discontinuous patches, lying shoreward of offshore reef structures as seen in the Palk bay, Gulf of Mannar and Gulf of Katchchh.
  • Barrier reefs are linear offshore reef structures that run parallel to coastlines and arise from submerged shelf platforms. The water body between the reef and the shore is termed as lagoon. Barrier reefs are seen in Nicobar and Lakshadweep.
  • Atolls are circular or semi-circular reefs that arise from subsiding sea floor platforms as coral reef building keeps ahead of subsidence. The examples are the atolls of Lakshadweep and Nicobar.
  • Among the four major reef areas of India, Andaman and Nicobar Islands are found to be very rich in Species diversity followed by the Lakshadweep Islands, the Gulf of Mannar and finally the Gulf of Kachchh.

 

 

Coral Bleaching

 

Bleaching, or the paling of coral colour occurs; when (i) the densities

of zooxanthellae decline and (ii) the concentration of photosynthetic pigments within the zooxanthellae fall.

Ecological causes of coral bleaching

  • Temperature (Major Cause)
  • Sub aerial Exposure-Sudden exposure of reef flat corals to the atmosphere during events such as extreme low tides, ENSO-related sea level drops or tectonic uplift can potentially induce bleaching.
  • Sedimentation
  • Fresh Water Dilution
  • Inorganic Nutrients(e.g. ammonia and nitrate)
  • Xenobiotics -Zooxanthellae loss occurs during exposure of coral to elevated concentrations of various chemical contaminants, such as Cu, herbicides and oil.
  • Epizootics

 

Key Initiatives To Protect Marine And Coastal Environments

 

  1. Coastal Ocean Monitoring and Prediction System (COMAPS)
  • Being implemented from 1991. Assesses the Health of coastal waters and facilitates management of pollution-related issues
  • Programme was restructured and modified in 2000 2001 to include pollution monitoring; liaison, regulation and legislation; and consultancy Services.

2.Land Ocean Interactions in the Coastal Zone (LOICZ)

 

  • Launched in 1995. Investigates the effects of global change on the coastal zone
  • Aims to develop, on a scientific basis, the integrated management of coastal environments
  1. Integrated Coastal and Marine Area Management (ICMAM)
  • Launched in 1998
  • Aims at integrated management of coastal and marine areas.
  • Model plans for Chennai, Goa and Gulf of Kutch being prepared
  1. Society of  Integrated Coastal Management (SICOM)
  • Launched in 2010
  • Major national initiative to protect coastal ecosystems
  • A professional body with experts in various aspects of coastal science and management
  1. Institutions for Coastal Management
  • The Notification on Coastal Regulation Zone (CRZ), 1991 (as amended from time to time) aims at protecting coastal stretches in India.
  • India has created institutional mechanisms such as National Coastal Zone Management
  • Authority (NCZMA) and State Coastal Zone Management Authority (SCZMA) for enforcement and monitoring of the CRZ Notification.
  • These authorities have been delegated powers under Section 5 of the Environmental (Protection) Act, 1986 to take various measures for protecting and improving the quality-of the coastal environment and preventing, abating  and controlling environmental pollution in coastal areas.

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An estuary is a partially enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between riverine and marine environments. They are highly productive ecosystems that support a wide variety of plants and animals.

Estuaries are defined by their physical characteristics, including their salinity, tidal range, and sediment load. Salinity is the amount of salt in the water. Estuaries are typically brackish, meaning that they have a mix of fresh water and salt water. The tidal range is the difference between the high tide and low tide. Estuaries typically have a large tidal range, which helps to mix the fresh water and salt water. Sediment load is the amount of sediment that is carried into the estuary by the rivers and streams. Estuaries typically have a high sediment load, which helps to create the muddy or sandy bottoms that are characteristic of these ecosystems.

Estuaries are classified into three types: riverine, coastal, and lagoonal. Riverine estuaries are the most common type. They are formed where a river meets the ocean. Coastal estuaries are formed where a river meets the ocean and there is a barrier island or spit that blocks the open sea. Lagoonal estuaries are formed where a river meets the ocean and there is a barrier reef or sandbar that blocks the open sea.

Estuaries are important ecosystems because they provide a variety of benefits to humans and other organisms. Estuaries are nursery grounds for many fish and shellfish species. They also provide habitat for a variety of birds, mammals, and reptiles. Estuaries filter pollutants from the water and help to protect the coastline from erosion. They also play an important role in the global carbon cycle.

Estuaries are threatened by a number of factors, including pollution, development, and Climate change. Pollution from agriculture, Industry, and sewage can harm the plants and animals that live in estuaries. Development can destroy estuary habitats and fragment the ecosystem. Climate Change can cause sea levels to rise, which can inundate estuary habitats and make them more vulnerable to pollution.

There are a number of things that can be done to protect estuaries. We can reduce pollution, develop sustainably, and mitigate the effects of climate change. We can also educate people about the importance of estuaries and encourage them to get involved in their conservation.

Estuaries are vital ecosystems that provide a variety of benefits to humans and other organisms. We must protect them from the threats they face so that they can continue to provide these benefits for future generations.

Here are some additional facts about estuaries:

  • Estuaries cover about 10% of the world’s coastline.
  • Estuaries are home to more than 2,000 species of fish and shellfish.
  • Estuaries provide habitat for a variety of birds, mammals, and reptiles.
  • Estuaries filter pollutants from the water and help to protect the coastline from erosion.
  • Estuaries play an important role in the global carbon cycle.
  • Estuaries are threatened by a number of factors, including pollution, development, and climate change.
  • We can protect estuaries by reducing pollution, developing sustainably, and mitigating the effects of climate change.
  • Estuaries are vital ecosystems that provide a variety of benefits to humans and other organisms. We must protect them from the threats they face so that they can continue to provide these benefits for future generations.

What is an estuary?

An estuary is a partially enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries are areas of transition between riverine and marine environments, and as such, they are home to a wide variety of plants and animals.

What are the different types of estuaries?

There are three main types of estuaries:

  • Drowned river valleys: These estuaries are formed when a river valley is flooded by the sea, as a result of rising sea levels or the sinking of the land.
  • Bar-built estuaries: These estuaries are formed when a river deposits sediment at its mouth, creating a barrier that separates the river from the sea.
  • Tectonically formed estuaries: These estuaries are formed when tectonic activity creates a depression in the land, which is then filled by seawater.

What are the characteristics of an estuary?

Estuaries are characterized by their high salinity, which is due to the mixing of freshwater from rivers and streams with saltwater from the ocean. Estuaries also have a high tidal range, which means that the water level changes significantly between high tide and low tide. This tidal action helps to mix the water and nutrients in the estuary, and it also provides a habitat for a variety of marine life.

What are the benefits of estuaries?

Estuaries provide a number of benefits, including:

  • They are important spawning and nursery grounds for fish and shellfish.
  • They provide habitat for a variety of birds and other wildlife.
  • They filter and clean the water, and they help to regulate the water temperature.
  • They are important for recreation, such as fishing, boating, and swimming.

What are the threats to estuaries?

Estuaries are threatened by a number of factors, including:

  • Pollution: Estuaries are often polluted by runoff from farms, cities, and industries. This pollution can harm the plants and animals that live in the estuary, and it can also make the water unsafe for human use.
  • Development: Estuaries are often developed for housing, industry, and other purposes. This development can destroy the estuary’s habitat and disrupt the natural processes that occur there.
  • Climate change: Climate change is causing sea levels to rise, which is inundating some estuaries and making them more saline. This change can harm the plants and animals that live in the estuary, and it can also make the water unsafe for human use.

What can be done to protect estuaries?

There are a number of things that can be done to protect estuaries, including:

  • Reducing pollution: We can reduce pollution by reducing runoff from farms, cities, and industries. We can also filter and treat wastewater before it is released into the estuary.
  • Protecting habitat: We can protect the estuary’s habitat by designating it as a protected area. We can also plant native plants and restore damaged areas.
  • Managing development: We can manage development in the estuary by zoning for appropriate uses and requiring developers to protect the estuary’s habitat.
  • Adapting to climate change: We can adapt to climate change by building seawalls to protect the estuary from flooding. We can also plant salt-tolerant plants and restore areas that have been lost to sea level rise.

Estuaries are important ecosystems that provide a number of benefits. We need to protect them from pollution, development, and climate change.

  1. Which of the following is not a type of estuary?
    (A) Salt marsh
    (B) Mangrove swamp
    (C) Coral reef
    (D) Lagoon

  2. Estuaries are important because they provide a habitat for many different types of plants and animals. Which of the following is not a plant that is found in estuaries?
    (A) Seagrass
    (B) Mangrove
    (C) Kelp
    (D) Coral

  3. Estuaries are also important because they help to filter water and protect coastlines from erosion. Which of the following is not a way that estuaries filter water?
    (A) By trapping sediment
    (B) By absorbing pollutants
    (C) By providing a home for filter-feeding organisms
    (D) By providing a home for predators that eat filter-feeding organisms

  4. Estuaries are facing many threats, including pollution, development, and climate change. Which of the following is not a threat to estuaries?
    (A) Oil spills
    (B) Dredging
    (C) Sea level rise
    (D) Overfishing

  5. What can you do to help protect estuaries?
    (A) Reduce your use of plastic products.
    (B) Support organizations that are working to protect estuaries.
    (C) Learn more about estuaries and share what you know with others.
    (D) All of the above.

  6. Estuaries are a type of ecosystem that is found where freshwater meets saltwater. They are important because they provide a habitat for many different types of plants and animals, and they help to filter water and protect coastlines from erosion. Estuaries are facing many threats, including pollution, development, and climate change. There are many things that you can do to help protect estuaries, such as reducing your use of plastic products, supporting organizations that are working to protect estuaries, and Learning more about estuaries and sharing what you know with others.