on the freshwater fishes of the western ghatswgbis.ces.iisc.ernet.in/energy/lake2006/programme...on...
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On the Freshwater On the Freshwater fishes of the fishes of the
Western GhatsWestern Ghats
An experience from Aghanashini River, Central Western Ghats, India
Influences on the fish species richness in forest streams
Sreekantha
EWRG, CES, IISc, Bangalore
Why Aghanashini?
Represents one of the pristine ecosystems of the Western Ghats
The river is not dammed
No discharge of industrial/domestic effluentsinto the river
However;
An example for variety of disturbances and catchment degradation at micro level
Photograph: Gururaja K VPhotograph: Gururaja K V
Western Ghats FishesWestern Ghats Fishes
Over 320 speciesOver 320 species
43.1% (138 species) endemism43.1% (138 species) endemism
27 critically endangered27 critically endangered
55 endangered55 endangered
130 are data deficient 130 are data deficient
Human induced threats to the Western Human induced threats to the Western Ghats fishesGhats fishes
Habitat destructionDeforestationStream fragmentationStream diversionClearance of riparian vegetation
Damming the riversAgricultural activitiesUncontrolled and destructive fishingExotic species introductionInterlinking of river basins
Rainfall and river flow patterns in the Rainfall and river flow patterns in the Western GhatsWestern Ghats
On an average 5000 mm annually
80% during four months of monsoon
Streams - perennial, intermittent and ephemeral
DroughtsDroughts
Photograph: Gururaja K VPhotograph: Gururaja K V
Natural threatsNatural threats
Floods Floods
It’s a challenging freshwater life !
An yearly cycle of flooding and drying
Harsher habitat conditions
Environmental pressures
Sampling approachMonthly data collection for five dry monthsSampling in 11 localitiesSampling with gill nets, cast nets, and drag netsOpportunistic collection Equal effort and covering all microhabitats
Photograph: Photograph: SudhiraSudhira H SH S
Photograph: Photograph: SameerSameer AliAli
Outcomes of the study
1064 individuals and 25 speciesWestern Ghats endemics – 32%Distributed throughout India – 68%Endangered – 20%Vulnerable – 8%Data deficient – 20%Lower risk – 52%
Schistura sp
Glyptothorax lonah
Ompok malabaricus
Syciopterus griseus
Chelenodon patoca
Puntius setnai
Puntius jerdoni
Microphis cuncalus
Accidental Encounters!
Schistura sharavathiensis
Schistura nagodiensis
Relationship between species richness and catchment attributes
Stream order Evidence of fishing
Stream Width Evidence of fish poisoning
Type of stream substrate No. of months of water flow
Canopy Cover Availability of refuge
Riparian vegetation Simpson's dominance
Catchment forest type Shannon's index
Broad land-use within 50m Pielou's index
Types of microhabitats Species richness
Number of microhabitats
Species richness and Stream order
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
Species richness and River flow period
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
Species richness and availability of Refugia
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
Different types of Different types of RefugiaRefugia
Availability of Refugia, and Forest types, type of microhabitats, number of microhabitats, River flow
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
River flow period, and type of stream substrate, Forest type, type of microhabitats, number of microhabitats
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
Catchment area parameters and microhabitats
Stre
am O
rder
Type
of
subs
trate
Veg
etat
ion
cove
r
Ripa
rian
vege
tatio
n
Fore
st ty
pe
Type
s of
mic
roha
bita
ts
Num
ber o
f m
icro
habi
tats
Fish
poi
sons
Rive
r flo
w
Ava
ilabi
lity
of
Refu
gia
Type of substrate 0.58 Vegetation cover 0.48 0.14 Riparian vegetation 0.52 0.18 0.87 Forest type 0.32 -0.07 0.74 0.80 Types of microhabitats 0.26 0.82 -0.23 -0.21 -0.42 Number of microhabitats 0.47 0.66 -0.24 -0.03 -0.20 0.61 Fish poisons 0.04 0.21 -0.24 -0.41 -0.35 0.12 0.53 River flow 0.33 0.68 -0.48 -0.34 -0.44 0.64 0.79 0.41 Availability of Refugia 0.27 0.57 -0.58 -0.54 0.71 0.73 0.66 0.29 0.85 Species richness 0.64 0.57 -0.03 0.01 -0.26 0.34 0.48 0.45 0.69 0.65
Key findings
Habitat parameters play a key role in determining the fish species diversity in streams
Habitat parameters are governed by the quality of the catchment
Refugia plays a major role in the recovery of fish communities apart from providing relatively stable environment
Conservation plan for freshwater fishes of Western Ghats