Download - PPT on Corals of Andaman
-
7/31/2019 PPT on Corals of Andaman
1/20
TOPICCORAL REEFS OF ANDAMAN ISLAND
CLASS F. Y. B.COM.
DIV C
ROLL NO. 359
ENVIRONMENTAL STUDIES 2011-12
CORAL REEFS OF ANDAMAN ISLAND
-
7/31/2019 PPT on Corals of Andaman
2/20
CORAL REEFS OF
ANDAMAN
-
7/31/2019 PPT on Corals of Andaman
3/20
TABLE OF CONTENTSR.
NO.
PARTICULAR SLIDE
NO.
1 INTRODUCTION TO ANDAMAN. 4
2 ANDAMAN & CORAL REEFS . 7
3 WHAT IS CORAL ? 9
4 (a) TYPES OF 3 MAIN CORAL REEFS . 10
4 (b) TYPES OF OTHER REEFS. 11
5 CORALS OF ANDAMAN. 13
6 IMPORTANCE OF CORALS. 14
7 THREATS TO CORALS. 18
-
7/31/2019 PPT on Corals of Andaman
4/20
ANDAMAN ISLAND
INTRODUCTION
Located in Bay Of Bengal.
Geographical Area 8300 Sq Kms.
Emerged Part of a Mountain Chain lying on aridge.
Extend from Irrawaddy delta area of Burma ,continuing the trend of Arakan Yoma range.
-
7/31/2019 PPT on Corals of Andaman
5/20
They consist of 350 islands, of which only 38 areinhabited along with a number of exposed islets androcks.
The principal of these are the North Andaman, Middle
Andaman with Ritchies archipelago to the east, SouthAndaman, little Andaman, Baratang and Rutlandisland.
Barren island lies to the east with Narcondum andother extinct volcanoes to the north (Reddiah, 1977).
The larger islands are mountainous and several arefully forested.
-
7/31/2019 PPT on Corals of Andaman
6/20
Mangroves form extensive coverage along
the shores.
Annual rainfall is about 3000 mm and salinityof the waters is around 33 ppt.
The coral reefs are of fringing type andexcept for a few investigation reports thereefs of the area still largely remain unknown.
A deep oceanic ridge along 10N separates
the Andaman Group and the Nicobar group ofIslands. The general orientation is north-south
-
7/31/2019 PPT on Corals of Andaman
7/20
Andaman & coral reefs
Coral reefs are underwater structures madefrom calcium carbonate secreted by corals.
Corals are colonies of tiny living animals found inmarine waters that contain few nutrients.
Most coral reefs are built from stony corals,which in turn consist of polyps that cluster in
groups. The polyps are like tiny sea anemones, to which
they are closely related.
-
7/31/2019 PPT on Corals of Andaman
8/20
-
7/31/2019 PPT on Corals of Andaman
9/20
What is coral ?
Its a living organism!
It is an invertebrate
2 different types:1. Reef Building: Hermatypic
2. Solitary: Ahermatypic
Coral is cousins to jellyfish and anemones(Cnidarians)
Today we will talk mainly about reef buildingcoral
-
7/31/2019 PPT on Corals of Andaman
10/20
Corals can build three main types ofreefs:
1. Fringing: grows close to shore
2. Barrier: also grows close to shore but has a
lagoon separating it from the shore
3. Atoll: a ring of coral that surrounds alagoon, often grows on a submergedmountain or volcano
-
7/31/2019 PPT on Corals of Andaman
11/20
Types of other reefs Patch reef this type is an isolated, comparatively
small reef outcrop, usually within a lagoon orembayment, often circular and surrounded by sand orseagrass. Patch reefs are common.
Apron reef a short reef resembling a fringing reef,but more sloped; extending out and downward from apoint or peninsular shore
Bank reef a linear or semicircular shaped-outline,
larger than a patch reef
Ribbon reef a long, narrow, possibly winding reef,usually associated with an atoll lagoon
-
7/31/2019 PPT on Corals of Andaman
12/20
Table reef an isolated reef, approaching an atoll type,but without a lagoon
Habili - this is a reef in the Red Sea that does not reachthe surface near enough to cause visible surf, although itmay be a hazard to ships (from the Arabic for "unborn").
Microatoll certain species of corals form communitiescalled microatolls. The vertical growth of microatolls is
limited by average tidal height. By analysing growthmorphologies, microatolls offer a low-resolution recordof patterns of sea level change. Fossilized microatolls canalso be dated using radioactive carbon dating. Suchmethods have been used to reconstruct Holocene sealevels.
Cays are small, low-elevation, sandy islands formed onthe surface of coral reefs. Material eroded from the reefpiles up on parts of the reef or lagoon, forming an areaabove sea level.
-
7/31/2019 PPT on Corals of Andaman
13/20
Corals of andaman
Andaman has a fringing(grows close to shore) typeof coral reefs .
-
7/31/2019 PPT on Corals of Andaman
14/20
Importance of coral reefs
Habitat for 1/3 of marine fishes
Habitat for tens of thousands of other
animals
The rainforests of the oceans
-
7/31/2019 PPT on Corals of Andaman
15/20
Importanceof corals towards :
Protection of coastal line.
Economic resources
Biodiversity
-
7/31/2019 PPT on Corals of Andaman
16/20
PROTECTION TO COASTLINES
absorb energy of ocean waves
reduce erosion of shoreline
storm damage
Flooding
ECONOMIC RESOURCES
Fisheries for foodFisheries for jobsTourismBuilding materialsAquarium trade
-
7/31/2019 PPT on Corals of Andaman
17/20
Biodiversity The rainforest of the sea .
Genetic diversity .
Pharmaceutical.
-
7/31/2019 PPT on Corals of Andaman
18/20
Threats to coral reefs
Natural disturbance: hurricanes , tsunamietc.
Predators like parrotfish ,butterfly fish , snailetc
Bleaching of corals due to loss ofzooxanthellae, high exposure to UV rays , etc.
-
7/31/2019 PPT on Corals of Andaman
19/20
PHOTOS ON THREAT TO CORALS.
19
Blast Fishing & Fishpoisoning
Coastal overdevelopmentMarine pollution
Global warming - bleaching
Overfishing Aquarium & Curio trade
-
7/31/2019 PPT on Corals of Andaman
20/20
Thank You