The Bay of Bengal is a large bay in the northeastern part of the Indian Ocean, bordered by India, Bangladesh, Myanmar, Sri Lanka and Indonesia. It covers an area of about 2.6 million square kilometers and has a depth of up to 4,694 meters. The bay is influenced by several large rivers that drain into it, such as the Ganges, the Brahmaputra, the Irrawaddy, the Godavari and the Krishna. These rivers bring a lot of sediments and nutrients to the bay, making it rich in biodiversity and productivity.
The ecology of the Bay of Bengal is shaped by the monsoon climate, which causes seasonal changes in wind direction, rainfall, temperature and salinity. The bay experiences two monsoon seasons: the northeast monsoon from November to April and the southwest monsoon from June to September. The northeast monsoon brings dry and cool air from the continent, while the southwest monsoon brings moist and warm air from the ocean. The monsoon winds also affect the circulation and mixing of water in the bay, creating different zones of upwelling, downwelling and eddies.
The Bay of Bengal supports a variety of marine life forms, ranging from plankton and corals to fish and mammals. Some of the notable species found in the bay are sea snakes, dolphins, whales, sharks, turtles, dugongs and mangroves. The bay is also home to some endangered and endemic species, such as the Irrawaddy dolphin, the Ganges river dolphin, the olive ridley turtle and the Sundarbans tiger. The bay also provides important ecosystem services for millions of people who depend on it for food, livelihoods, recreation and cultural values.
However, the ecology of the Bay of Bengal is facing several threats due to human activities and climate change. Some of these threats are overfishing, pollution, habitat degradation, coastal erosion, invasive species, sea level rise and ocean acidification. These threats have negative impacts on the health and resilience of the bay's ecosystems and biodiversity, as well as on the well-being and security of the people who rely on them. Therefore, there is an urgent need for conservation and management actions to protect and restore the ecology of one of the world's largest bays.
# Flora and Fauna of Bay of Bengal
The Bay of Bengal is the northeastern part of the Indian Ocean, bounded by India, Bangladesh, Myanmar and the Andaman and Nicobar Islands. It is the largest water region called a bay in the world, covering an area of 2.6 million square kilometres. The bay is rich in biological diversity, hosting a variety of flora and fauna in its coral reefs, estuaries, fish spawning and nursery areas, and mangroves.
## Flora
The bay supports 334 plant species belonging to 245 genera and 75 families. Some of the major plant groups are algae, orchids and mangroves. Algae are aquatic plants that can photosynthesize and produce oxygen. They are found in both freshwater and marine environments, and are important for the food chain and nutrient cycling. Orchids are flowering plants that have specialized adaptations for pollination by insects, birds or bats. They are often cultivated for their ornamental value and fragrance. Mangroves are trees or shrubs that grow in saline or brackish water along the coastlines and estuaries. They have aerial roots that help them cope with tidal fluctuations and waterlogging. They provide habitat and nursery grounds for many aquatic animals, as well as protection from erosion and storms.
One of the most notable plant habitats in the Bay of Bengal is the Sundarbans, a vast mangrove forest that spans across Bangladesh and India. The Sundarbans is named after the sundari tree (Heritiera fomes or H. minor), which is one of the dominant mangrove species in the area. Other common mangrove species include the goran (Ceriops roxburghiana), the kankra (Bruguiera gymnorrhiza), the gewa (Excoecaria agallocha) and the keora (Sonneratia apetala). The Sundarbans is also home to 13 orchid species, such as the tiger orchid (Grammatophyllum speciosum) and the foxtail orchid (Rhynchostylis retusa).
## Fauna
The bay harbours a wide range of fauna, both on land and water. There are 260 bird species, 120 fish species, 50 reptile species, 8 amphibian species and 32 mammal species recorded in the bay. Some of the globally endangered species that inhabit the bay are the Royal Bengal tiger (Panthera tigris tigris), the Ganges dolphin (Platanista gangetica), the Irrawaddy dolphin (Orcaella brevirostris), the estuarine crocodile (Crocodylus porosus) and the river terrapin (Batagur baska) .
The Royal Bengal tiger is the only mangrove-dwelling tiger subspecies in the world, and is found mainly in the Sundarbans. It is adapted to swim and hunt in the brackish water, and has a distinctive coat pattern that helps it camouflage in the dense vegetation. The Ganges dolphin and the Irrawaddy dolphin are both freshwater cetaceans that live in the rivers and estuaries that flow into the bay. They have long snouts and reduced eyesight, relying on echolocation to navigate and find prey. The estuarine crocodile is the largest living reptile, reaching up to 6 metres in length. It is capable of tolerating saltwater, and can be found in mangroves, rivers, lagoons and beaches. The river terrapin is a critically endangered turtle that lives in freshwater rivers and brackish estuaries. It has a brown or black shell with yellow spots or stripes, and a yellow or orange head.
Other notable fauna in the Bay of Bengal include:
- The olive ridley sea turtle (Lepidochelys olivacea), which nests on some of the sandy beaches along the coast.
- The dugong (Dugong dugon), which feeds on seagrass beds in shallow waters.
- The whale shark (Rhincodon typus), which visits the bay seasonally to feed on plankton.
- The kerilia jerdonii, a sea snake that is endemic to the bay.
- The king cobra (Ophiophagus hannah), which is one of the most venomous snakes in the world.
- The great hornbill (Buceros bicornis), which is one of the largest and most colourful birds in Asia.