21⁰-23⁰ N latitude
Largest estuarine ecosystem in India, with an area
• It forms world’s largest delta (sundarban), endowed
with largest mangrove vegetation (4,264 km2)
Distributary of the river Ganga
Positive, mixohaline in nature
Average tidal elevation is 5.7m
For estimating fish landings, CIFRI divided this
estuarine system into the following zones:
zone 1-Nabadwip to Konnagar (upper zone of the freshwater
Zone 2- Konnagar to Diamond harbour (middle zone of the
Hoogly estuary or the ‘gradient zone’)
Zone 3- Diamond Harbour to the mouth of the estuary
including entire lower Sunderbans (lower or marine zone of
Zone 4- includes river Rupnarain.
Zone 5- includes river Matlah around port canning.
Physico-chemical parameters of the estuary
16 0 C – 330 C
mostly clay silty loam
Temperature and salinity are the most significant factors that determining
The maximum and minimum temperatures recorded in the pre-monsoon
and post-monsoon respectively, in all zones except Zone 4 ,where the
maximum temperature prevails during monsoon
172 species recorded,73- freshwater and 99 occupy the
Fish fauna classified into:
- residents (mullets, threadfins, sciaenids, sea bass)
- migratory or transient (Hilsa, Pama pama, pangasius,
Dominated fish spp.
Other important fish species :
Polynemus paradiseus, P.indicus, Eleutheronema
tetradectylum, Lates calcarifer, Pangasius pangasius, Liza
parsia, L.tade, Rhinomugil corsula, Pampus argenteus ,Coilia
dussumeiri, Mystus spp. , Johnius dussumeiri , Clupisoma
garua, Wallago attu, Sperata seenghala, Ompok bimaculatus
and Rita rita etc.
Prawns: Penaeus monodon, P. indicus, Metapenaeus
brevicornis, M. monoceros ,Parapenaeopsis sculptilis, P.
stylifera, Macrobrachium spp.
Crabs : S. serrata, P. pelagicus
The average annual prawn and fish yield increased from
3,204 t (1960-63) to 117,639 t in 2010-11.
• Maximum average catch (82%) is obtained during winter
months of Nov-Jan
• Minimum average catch (3.5%) is during the summer months
• Zone-wise total annual catch (92 to 95%) comes from ZoneIll, while, Zone 1, II and IV together contribute 5 to 8%
The average hilsa production have been increased from
1427 t (1957-74) to 10,083t (2003-04)
About 80-90% hilsa are captured during July- Oct.
The peak spawning period is noticed during Sep- Nov.,
although this species is prolific spawner
Winter migratory Bag net fishery: The fishermen migrate to the
lower zone of estuary and they remain engaged in fishing during the
end of Oct. to middle of Feb. The total landing of this fishery with an
avg. 28536.7 tones. This fishery contributed 60-65% of total yield of the
estuary. The net used is locally known as been jal (a migratory bag net).
Source of seed
• A potential source of cultivable fish and prawn seed which are
being used as stocking material for brackish water
P. monodon (Bagda), P.indicus, Metapenaeus. monoceros, M.
brevicornis, Liza spp. Lates calcarifer , M. rosenbergii, Hilsa
Deteriorating ecological characters due to anthropogenic
Overexploitation of faunal resources
Destruction of mangroves
Siltation and formation of sand bar
Flood and shortage of fresh water discharge
Hydraulic structure (dams, barrages, weirs)
wanton destruction of juvenile hilsa
• There is a urgent need to protect estuarine
envt. From pollution hazards (Agri., Industrial.
and Domestic effluents).
• Estuarine envt. should be judicially exploited
so that the fish, prawn and their recruits are
• Mangrove preservation
• Intensive seed collection should be stopped