View
27
Download
3
Category
Preview:
DESCRIPTION
Ulhas river estuary is subjected to heavy pollution due to the industrial and residential belts established along its either banks incurring huge amount of non-point and point pollution sources. Ambient hydrological conditions assessed during July 2005 to May 2006 and anthropogenic stresses are critical therefore leading to the decline in the fishery diversity as compared to earlier records. The abundant main fin-fishery species were replaced by the pollution tolerant species in due course of time. Several fin-fisheries have been obliterated in the estuary. Majority of the fishermen have abandoned the fishing practices due to non-productive status of the Ulhas river estuary fin-fisheries. The species diversity and species richness of the present diversity were conducive of the former observations.
Citation preview
SPATIAL FIN-FISHERY SPECIES DIVERSITY OF ULHAS RIVER
ESTUARY
Rathod Sudesh D.1 and Dr. Nandini Patil
2
Department of Zoology, B. N. Bandodkar College of Science, Thane, Maharashtra, India
ABSTRACT
Ulhas river estuary is subjected to heavy pollution due to the industrial and residential belts established
along its either banks incurring huge amount of non-point and point pollution sources. Ambient
hydrological conditions assessed during July 2005 to May 2006 and anthropogenic stresses are critical
therefore leading to the decline in the fishery diversity as compared to earlier records. The abundant main
fin-fishery species were replaced by the pollution tolerant species in due course of time. Several fin-
fisheries have been obliterated in the estuary. Majority of the fishermen have abandoned the fishing
practices due to non-productive status of the Ulhas river estuary fin-fisheries. The species diversity and
species richness of the present diversity were conducive of the former observations.
Keywords: Ulhas river estuary, fin-fish, diversity, fisheries
Oral Presentation at Biodiversity Asia-2012, Bangalore, India……..
International conference
Biodiversity Asia 2012- Science, Policy and Governance
2nd Regional Conference of Society for Conservation of Biology- Asia
Indian Institute of Science, Bangalore
7-10, August 2012,
Go to: www.biodiversityasia2012.org
Rathod Sudesh D. and Dr. Nandini Patil
Department of Zoology, B. N. Bandodkar
College of Science, Thane, Maharashtra, India
Study Area
Ulhas river estuary (URE) leis in the vicinity of Thane city, Maharashtra State, India (between the latitude 18° 45’to19°19’, N and longitude 73°21’to72° 45’, E on the world map)
Methodology
Three zones of Ulhas River Estuary (URE)
viz. Z-I; Z-II & Z-III
Study from July 2005 to May 2006 (11
months)
Hydrology
WT, LP, SS, pH, Salinity, DO, BOD, PO4-P
& NO3-N
Anthropogenic activities at sight
Fishery catch survey survey at sight &
markets
Mudskipper Fishing & Dragnet (Bari)
Hand Picking
Mudskipper Fishing
‘Bari’
Barrier Net (Vana); (Pocha); Bag Net (Bokshi)
Gillnet (Busa)
‘Vana’
‘Bokshi’
‘Pocha’Gillnet
Hand Nets & Others
Seed’s net ‘Jholva’- Waddingnet
‘Fug’ – Cast net Lift Net
Mechanized Boat – ‘Padava’ & Canoe ‘Hodi’
Padava
Result – Zonal Hydrology
27.0
27.2
27.4
27.6
27.8
28.0
28.2
28.4
Z-I Z-II Z-III
Water Temp (oC)
0.00
5.00
10.00
15.00
20.00
25.00
Z-I Z-II Z-III
Light Penetration (cm)
0.00
2.00
4.00
6.00
8.00
10.00
12.00
Z-I Z-II Z-III
Suspended Solids (gm/l)
7.40
7.45
7.50
7.55
7.60
7.65
7.70
7.75
7.80
7.85
Z-I Z-II Z-III
pH
Zonal Hydrology
0.00
5.00
10.00
15.00
20.00
25.00
Z-I Z-II Z-III
Salinity (ppt)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
Z-I Z-II Z-III
DO (mg/l)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
Z-I Z-II Z-III
BOD (mg/l)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
Z-I Z-II Z-III
PO4-P (mg/l)
Very High
SS, BOD, PO4-
P, NO3-N and
hypoxia indicate high
pollution status of the
ambient environment
Z-I is highly polluted
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Z-I Z-II Z-III
NO3-N (mg/l)
Impact of Anthropogenic Activities
Sand Excavation
Boats engaged in sand excavation by ‘Dubi’ method
Mangrove Extraction and Boat Building
Zonal Intensity of Anthropogenic
Perturbation
0
2
4
6
8
10
12
14
16
Z-I Z-II Z-III
Solid waste
Sewage/effluent
Civil activities
Sand excavation
Sand landing
Fishing attempts intensity
0
20
40
60
80
100
120
Z-I Z-II Z-III
Zonal Ave Fishing Intensity
Vana
Dol
Bari
Gobiids
HdLine
Gillnets
Species Succession
Hardy species like Mystus gulio, Mugil spp., Therapon
spp., Scylla serrata, Boleophthalmus dussumieri still persist in
Zone-I of the URE
Succession of species such as Oreochromis
mossambicus, Megalops cyprinoides etc. occurred with the
advent of pollution status.
Zonal Fin Fisheries Zonal Catch & Diversity
5250 6981 8656
0
5
10
15
20
25
30
35
40
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Z-I Z-II Z-III
Spp. Diversity
Ave. Landing (kg)
Repercussions of Anthropogenic
Activities: Mangrove siccession
Acanthus ilicifolius
Mangrove
Plastic masking pneumatophores
Repercussions of Anthropogenic
Activities: Fish
Fish Mass-killMudskipper youngones trapped in plastic
Socio-economic Impact
AFP: Actual fishermen population
FPF: Fishermen presently practicing the fishing
9000
4500
8500
438194
653
0
1
2
3
4
5
6
7
8
9
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Z-I Z-II Z-III
AFP
FPF
%
Conclusion
Health of ambient water deteriorates with human
interferences, causing mass kill and eradication of
several species from the URE.
Fin-Fisheries assemblage and diversity declined with
increase in anthropogenic perturbation as evident from
fisheries of Zone-I and Zone-II are low. Zone-I, almost
has become non-productive
With the decline in fisheries fishing activities declined.
Major population fishermen abandoned fishing
Practice.
Acknowledgement
We are grateful to our Principal, B. N. Bandodkar
College of Science for allowing us to present the
paper.
We are indebted to organizing body of the
Conference ‘Biodiversity Asia 2012: Science, Policy
& Governance’ for allowing us to present our work.
We also express our thanks to those all who have
extended their hands in preparation of this
presentation.
Thank You
Recommended