Abstract:
Climate change is a reality. It is impacting life and support systems on
earth. It is a formidable challenge faced by human beings in recent times and is
impacting holistically ecological processes in lithosphere, hydrosphere, atmosphere
and cryosphere. Hydrosphere, in particular the freshwater ecosystem has relatively
been impacted more. Kalpani ecosystem being an urban stream and life line of
Mardan and Nowshera districts has been rendering invaluable ecological services.
It has been subjected to every sort of use and abuse and so profoundly exhibits the
impacts of climatic changes. The impact, of climatic changes primarily variation in
temperature and precipitation influencing the water discharge, on PCFs and fish
fauna was investigated in detail from February 2007 to November 2008.
To assess and evaluate the impact of climatic changes Kalpani stream was
divided into 10 zones. Standard materials and methods were adapted for fish
sampling, water sampling and data analysis. Sampling resulted in collection of 31
fish species belonging to 9 families. The fish species caught were grouped as per
the research design into: Cyprinid - Crossocheilus latius, Tor putitora, Baralius
modestus, Baralius vagra, Baralius pakistanicus, Puntius chola, Puntius Ticto,
Puntius sophore, Puntius terio, Puntius vittatus, Salmostoma bacaila, Garra
gotyla, Labeo dyocheilus, Labeo dero, Aspidoparia morar, Danio devario, Chela
laubuca, Carassius auratus; and, Non Cyprinid - Triplophysa naziri, Schistura
microlabra,
Acanthocobitis
Heteropneustes
fossilis,
botia,
Mystus
Oreochromis
bleekeri,
mossambicus,
Mystus cavasius,
Channa punctata,
Glyptothorax naziri, Glyptothorax punjabensis, Ompok pabda, and Mastacembelus
xxiarmatus. Water sampling for 21 pxxiiysicochemical factors (PCFs) was carried
out. To establish relationship between fish species and PCFs data was subjected to
statistical analysis using Minitab 14 and CANOCO 4.5 computer software. To
draw future scenario of water discharge data was extrapolated to generate scenario
of 2025 using cftool of matlab computer software.
Under the winter scenario most number of Cyprinid fish (39.18%) were
caught in zone 10, followed by zone 9 (24.75%) with less number of fish caught
(0.68%) in zone 3 and 5, while under summer scenario most numer of Cyprinid
fish were caught (32.03%) in zone 10 followed by zone 9 (13.94%). Under winter
scenario most number of non Cyprinid caught were caught in zone (35%),
followed by zone 9 (23.75%), no fish was caught in zones 4, 5 and 6, while under
summer scenario most numner of non Cyprinid fish caught were from zone 10
(32.21) followed by zone 9 (20.52) while in zones 3 and 4 less number of fish
(1.04 in each) were caught. The results reveal that fish biodiversity and catch
increases from north to south with maximum found in Risalpur and Nowshera
zones alluding to optimum environmental conditions. Tor putitora a fish of high
commercial value was found in all the zones, any improvement either at species
level or population level of Tor putitora would be an indication of improvement in
the environmental conditions of Kalpani. The results suggested that parameters like
temperature, DO, altitude, turbidity and TSS have direct impact on the
assemblages‘, composition, abundance and distribution of fish species. The
regression analysis of intrarelationship suggested that Temperature, DO, altitude,
total hardness, sulphates, conductivity, Fe and Ni, and Zn; Turbidity, conductivity
xxiiand TSS had strong intrarelationship and significantly reduc lethality of pH. The
degraded surface water values are close to threshold values of WHO and NEQS for
Pakistan. In comparison to the study conducted by IUCN, (1994) the stream has
deteriorated to a very high degree; results of heavy metals results were devastating.
DO showed improvement in its status plausible reason for which could be the flash
floods occurring since mid 1990s. The species environment relationship had been
explained through Canonical correspondence analysis (CCA). The first two axis of
the CCA ordination i.e. CC1 and CC2 explains the species-environment
relationship clearly and accounts for 77.9% of the variation in the weighted
average of 19 Cyprinid fish species with respect to summer environmental
variables and 80.37% for Non Cyprinid. The first two axis of the CCA ordination
i.e. CC1 and CC2 explains species-environment relationship clearly and accounts
for 77% of variation in the weighted average of 19 Cyprinid fish species with
respect to environmental variables and 76.6% for Non Cyprinid under winter
scieario for example. The water discharege projections suggest that in 2025
Kalpani freshwater ecosystem would experience increase in the duration of very
low flows due to variation in precipitation in view of increase in global warming,
the fish fauna would be facing local extinction e.g., the endemic fish species with
weak tolerance range in response to certain environmental factors. The overall fish
production may not drop appreciably but the diversity would be low. To verify the
results of future water discharge scenario met data from three meteorological
stations having influence on the Kalpani stream analyzed was found consistent
with the findings of the water discharge data (both current and projected). If the
current trends of both meteorology and water discharge hold true then the future
xxiiiscenario will be one of low flows as has been projected. Non-climatic changes like
sand mining and gravel extraction operations were observed to be highly
unsustainable and will have serious affect on the groundwater recharge quality of
Kalpani stream and result in loss of precious habitat. Zones like Gujar Garhi,
Baghdada, Hoti and Chowki Nisar are already heavily degraded, under the sand
mining and gravel extraction besides pollution.
Declared on the basis of scientific evidence as the 2 nd most dirty tributary
of Kabul River system in 1992-93 the stream is dirtier than ever and the day is not
far away when it will ecologically die under increasing natural and anthropogenic
stressors unless drastic measures at the government and societal level are taken.
Declared as ―biological assets freshwater ecosystems are both disproportionately
rich and disproportionately imperiled‖, and on the basis of data generated and
collected for the study Kalpani stream fully vindicates the statement. It can be
stated with high degree of confidence that Kalpani stream is imperiled and is
dying. The impacts described are based on projected GHGs that will double by the
end of this century and an improvement in the situation keeping in view the track
record of the parties to the Kyoto protocol seem highly unlikely. Thus, it is
incumbent upon KPK to focus on adaptation strategies to protect and conserve
freshwater resources based on carefully conducted targeting research program.
This puts to the front that more research focused on the freshwaters is needed to
enable the policy level and decisions makers to take appropriate measures to save
their biological assets for future generations.