Forest inventories reveal a decline in standing volume of the two main commercial mangrove species – sundari (Heritiera spp.)
and gewa (Excoecaria agallocha) — by 40% and 45% respectively between 1959 and 1983.
Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates, it appears that there is a consistent pattern of depleted biodiversity or loss of species (notably at least six mammals and one important reptile) in the 20th century, and that the "ecological quality of the original mangrove forest is declining".

The endangered species that live within the Sundarbans and extinct species that used to be include the royal Bengal tigers, estuarine crocodile, northern river terrapins (Batagur baska), olive ridley sea turtles, Gangetic dolphin, ground turtles, hawksbill sea turtles and king crabs (horse shoe).
Some species such as hog deer (Axis porcinus), water buffalos (Bubalus bubalis), barasingha or swamp deer (Cervus duvauceli), Javan rhinoceros (Rhinoceros sondaicus), single horned rhinoceros (Rhinoceros unicornis) and the mugger crocodiles or marsh crocodiles (Crocodylus palustris) started to become extinct in the Sundarbans towards the middle of the 20th century, because of extensive poaching and man hunting by the British.
There are other threatened mammal species, such as the capped langurs (Semnopithecus pileatus), smooth-coated otters (Lutrogale perspicillata), Oriental small-clawed otters (Aonyx cinerea), and great Bengal civets (Viverra zibetha).
Forest inventories reveal a decline in standing volume of the two main commercial mangrove species – sundari (Heritiera spp.) and gewa (Excoecaria agallocha) — by 40% and 45% respectively between 1959 and 1983. Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates, it appears that there is a consistent pattern of depleted biodiversity or loss of species (notably at least six mammals and one important reptile) in the 20th century, and that the "ecological quality of the original mangrove forest is declining".
The endangered species that live within the Sundarbans and extinct species that used to be include the royal Bengal tigers, estuarine crocodile, northern river terrapins (Batagur baska), olive ridley sea turtles, Gangetic dolphin, ground turtles, hawksbill sea turtles and king crabs (horse shoe). Some species such as hog deer (Axis porcinus), water buffalos (Bubalus bubalis), barasingha or swamp deer (Cervus duvauceli), Javan rhinoceros (Rhinoceros sondaicus), single horned rhinoceros (Rhinoceros unicornis) and the mugger crocodiles or marsh crocodiles (Crocodylus palustris) started to become extinct in the Sundarbans towards the middle of the 20th century, because of extensive poaching and man hunting by the British. There are other threatened mammal species, such as the capped langurs (Semnopithecus pileatus), smooth-coated otters (Lutrogale perspicillata), Oriental small-clawed otters (Aonyx cinerea), and great Bengal civets (Viverra zibetha).
Sundarbans