This document proposes a case study to monitor water quality in Vembanad Lake using remote sensing, modeling, and field observations. Vembanad Lake is an ecologically important water body in Kerala, India that has experienced increased pollution and disease outbreaks from development. The study aims to identify reservoirs of pathogenic vibrios like V. cholerae in the lake, understand their seasonal and spatial variation, and develop models to forecast disease outbreaks. Researchers will use remote sensing, field measurements, laboratory experiments, statistical modeling, and citizen science with local volunteers. The goals are to generate risk maps of outbreak areas, make recommendations to reduce pathogens and prevent disease, and engage communities through education programs.

1. Water quality of Vembanad Lake: A proposed case study using
remote sensing, modelling and insitu observations

2. Water quality and Microbial pollutants
 Nearly 50% of world and 15% of Indian population live in
cities and towns within 100 km of coast
 Developmental activities have increased pollution and
associated health impact
 CPCB report (2009): 33 Industrial clusters (out of 88) are
situated in Coastal regions of India
 There are 13 major ports, 1511 fish landing centres &
numerous beaches in India
 Bacterial infections associated with recreation and
commercial use of water resources
 WHO Report 2011: Global trends in the incidence of
cholerae have increased steadily since the beginning of
the millennium
 838315 reported cases of cholerae in 2004 – 2008, a 24
% increase compared to 2000 – 2004 (676651 cases)

3. Microbial pollution in Indian waters
 COMAPS program initiated by MoES continuously
monitor the pollution status of 80 locations since 1992
 CSIR-NIO maintains a reference facility (MMRF) of health
indicator bacteria
 REVIVAL – A program under India-UK water quality
research program
 Scientists from UK (PML) and India (CSIR-NIO, ICAR-
CMFRI and Nansen) join hands to identify the
reservoirs of Vibrio cholerae and predict the possible
areas of outbreak
 Microbiology, molecular biology, remote sensing,
citizen science and modelling tools will be used

4. Marine Vibrios
 Diverse ecological functions: nutrient
cycling, colonization on zooplankton,
metamorphosis of organisms
 At least 12 species are pathogenic to aquatic
animals/ human being (V. parahaemolyticus,
V. harveyii, V. alginolyticus, V. fluvialis, V.
vulnificus, V. fluvialis)
 Coastal pollution substantially changed the
distribution, transmission biology and
virulence patterns
 Health risks are further aggravated by their
antibiotic resistance
Infectious disease caused by Vibrios: Source: Miyoshi S, 2014, Fron. Microbiol

5. Importance of Vembanad Lake
• One of the three Ramsar Sites of International Importance in
Kerala, India;
• The largest lake system of southwest coast of India (100 km long)
• Second only to the Arabian Sea in supporting the livelihood of
coastal communities in Kerala;
• Some 10 rivers drain into the Lake, representing a total drainage
area of 15,770 sq km (40 % of the area of the State);
• Its annual surface runoff (21,900 Mm3) is ~30% of the total surface
water resource of Kerala;
• Developmental activities: Universities, Ports, Coir retting, Chemical
industries, Container terminal, LNG storage, Lime shell collection;
• Known for: Agriculture, Fishing, Migratory birds, Biodiversity,
Tourism; and
• Declared as ecologically sensitive area by Government of India

6. Vembanad Lake: Significance of the study
Major Threats
• Industrial pollution: Heavy metals, PAH, pesticides etc
• High nutrients and eutrophication
• Reducing fishery stock and incidence of fish kill
• Large number of tourist boats
• Under DST’s War for Water Mission, Ernakulam and Alappuzha
(Vembanad Lake areas) are identified as key sites to study the effect
of biological contamination on water quality in India
• Because of high pollution, drinking water has to be delivered to local
population of Vembanad Lake
Reclamation has reduced carrying capacity of Lake
from 2.4 km3 to 0.6 km3

7. Vembanad Lake: Significance of the study
Major Threats
• Incidence of water borne disease outbreaks (during
monsoons)
• Pollution by antibiotic-resistant pathogens yet to be monitored
• High levels of faecal contamination
• Episodic cholera outbreaks (especially during monsoons)
• New threats from Chikanguniya and Dengue
Outbreaks in Kerala and in the study area Cholera incidence in Kerala

8. REVIVAL: Broader significance
• Kerala: People in rural areas use surface water for drinking,
bathing, cooking and other domestic needs
• Water is not safe merely because it appears clean: it should meet
minimal chemical and microbial standards of quality
• At least 12 species of vibrio are pathogenic: even when not fatal,
they can be highly debilitating
• Diarrhoeal disease is the second most important cause of illness,
leading to significant loss or working days due to ill health
• Over 70 million working days are lost in India each year due to
effect of water borne disease (UN2005)
• Lack of safe drinking water and basic sanitation are major causes
of morbidity and mortality in rural India: cleanup is a national
priority
• More generally, emerging resistance to antibiotics, and increased
international travel may lead to threats at the global scale
• Similar situations occur in other
countries (Bangladesh, Brazil,
Congo, Haiti, Zambia) where major
water bodies function as reservoirs
of infectious disease.
• Outcomes from the proposed
research could provide a template
for remedial action in such other
countries.

9. REVIVAL: Objectives
• Identify the principal reservoirs of Vibrio cholerae in Vembanad Lake
• Assess the seasonal and spatial variation of the hosts and reservoirs
of pathogenic Vibrios employing remote-sensing and in situ methods,
and explore similar methods for viruses
• Use laboratory and modelling studies to assess conditions that induce
virulence and proliferation of Vibrios
• Develop models to forecast outbreaks of infectious diseases,
especially cholera outbreaks, map results
• Implement awareness programmes on pathogenic Vibrios and viruses
and make recommendations to responsible parties for preventing
cholera and other outbreaks; for design of a rational monitoring
system; and for drafting of related legislation

10. REVIVAL: Remote Sensing
• Remote sensing will be used here as an extrapolation tool, for scaling
up in-water observations to the level of the whole of the Lake system
• Multiple sensors (Landsat-8 OLI, Sentinel-2 MSI, ENVISAT-MERIS,
sentinel-3 OLCI) and methods will be used to monitor variability at
multiple scales
• Initially, use existing methods to map the ecosystems
• Next, in situ project data will be used to test, refine and improve
algorithms (Sathyendranath, 2014) tailored for the region
• Products: chlorophyll concentration, SST, phytoplankton types, floating
vegetation), SST. Time series maps will be generated, to study
sequential changes in this rapidly-altering ecosystem
• Finally, RS outputs will be combined with those from modelling, to
generate time-varying risk maps showing areas vulnerable to
outbreaks of pathogenic bacteria and virus, with priority for cholera, for
which prior studies have shown the way (e.g. Colwell, 1996) Suspended sediment load in Vembanad Lake
Satellite image processed at PML
NERC GloboLakes project output

11. REVIVAL: In situ Observations and Laboratory Experiments
Abundance
Measurements
(every 10 days)
Bacteria
Phytoplankton
Zooplankton
Benthic fauna
Environmental
Measurements
(every 10 days)
Temperature
Salinity
pH
Oxygen
Water clarity
Optical properties
(drones, under-water
instruments)
Laboratory
Experiments
(as needed)
Vibrio isolation
Virulence
Ability to colonise
phytoplankton and
benthic fauna

12. REVIVAL: Modelling
Epidemic Modelling (Forecast)
Model of Codeço (2001), emphasizing the
important role of the aquatic reservoir in the
dynamics of cholera infections. Susceptible
people (S) are infected through exposure to
contaminated water, in other words through
contact with the reservoir. Bacterial
populations in the aquatic reservoir (B)
reproduce at a rate determined by
environmental factors such as temperature
and precipitation
Statistical Modelling based on
Satellite Data (Lake-Level Mapping)
Associations between satellite-derived
variables such as temperature, salinity, sea
surface height, chlorophyll concentration,
phytoplankton types, surface macrophytes,
organic matter and vector density are used
to identify and characterize vector habitats.
Detect anomalies and deviations from the
normal climate patterns.
Bioinformatic Modelling
(Understanding Functional Links)
Infer host-pathogen interactions at the
metabolic pathway level using our
novel computational tool (Kleftogiannis
et al. 2015) coupled with targeted wet
lab experiments, to identify interaction
pathways between human/aquatic
organisms and the pathogen. Gene
expression analysis for Vibrio cholerae
virulent strains will be performed to
select virulent genes characteristic of
the disease outbreak. The selected
genes will be mapped to metabolic
pathway data.
Risk maps will be developed by combining outputs from all three models with
remotely-sensed and in situ data

13. Revival: Citizen Science
• A simple hand-held, pocket-sized device has been developed by the proponents to measure
the Secchi depth in lake, estuary and near-shore environments. Temperature Sensor will be
added
• A hundred units will be provided to volunteers, for deployment from boat routes (transects)
• In addition to collecting additional valuable data, citizen science also helps engage the local
community from the initial days of the project through to the end

14. REVIVAL: Societal Involvement
NGOs will be partners in the
program
District government interested in
the study and the outcome
Industrial involvement
(development of kits for easy
detection of pathogens in water)
Letters of Support from Ashoka
Trust, Mayor of Kochi and a
private diagnostic and research
company (Origin)

15. REVIVAL: Integration

16. REVIVAL: Outputs
POLLUTION
• Database on plankton composition of Vembanad Lake
• Spatio-temporal variation of Vibrio load in the lake
• Identification of principal reservoirs of pathogens in the
lake
• Pathogenicity and antibiotic-resistance profile of Vibrios
• SOLUTION
• Maps and models for prediction of Cholera outbreak
• Suggestions on minimising reservoirs of pathogens in the
lake, and coping with residual sources
• Public awareness programs: multi-sector user
engagement
• Information and recommendations to local government,
based on scientific results and user feedback
PATHWAYS TO IMPACT
• Training of skilled manpower in the area (Project
assistants, Post graduate and PhD dissertations)
• Workshops and conferences for researchers
• Publications in peer-reviewed international journals
• Development of kits for easy detection of
pathogens in the water
• Citizen engagement
GOAL
• Healthy environment, healthy population

18. REVIVAL: Global Significance
Infectious disease caused by Vibrios: Source:
Miyoshi S, 2014, Fron. Microbiol.
• Cholera: A global threat with 37 outbreaks in 2011 (30
countries)
• Last decade witnessed 50 % increase in incidence
• 12 species of Vibrio are known to be pathogenic
• Coastal pollution impacts distribution, transmission
biology and virulence patterns
• Increase in water temperature and flooding under
climate change likely to raise the cholerae incidence
among vulnerable coastal populations

19. REhabilitation of Vibrio Infested waters of VembanAd Lake:
pollution and solution (REVIVAL)
A research proposal submitted for consideration under
India-UK water quality research program

20. REVIVAL: In situ observations
Parameters/ experiments Frequency of observation Tool to be used Lab involved
Abundance of bacteria Once in 10 days Fluorescence in situ
hybridization (FISH)/PCR
CSIR-NIO
Density of phytoplankton Once in 10 days Flow cytometry ICAR-CMFRI
Density of mesozooplankton (This
includes organisms with cell wall
containing chitin)
Once in 10 days Microscopy ICAR-CMFRI
Density of Benthic fauna (epi and
macrofauna)
Once in 10 days Microscopy CSIR-NIO
Isolation of associated vibrios One time sampling Standard microbiology
procedure
CSIR-NIO
Virulence / antibiotic resistance of V.
cholerae
PCR based/ Disc diffusion CSIR-NIO
Studies on ability of Vibrio cholera
to colonies on marine
phytoplankton/ zoo plankton and
benthic fauna
NA Bioassay using representative
models
CSIR-NIO
Optical properties Once in 10 days Drones, underwater optical PML UK,

21. Microbial Reference Facility
 MMRF was established as part of SWQM in 2003 at CSIR-
NIO RCK
 Functions as reference facility of health indicator
bacteria from coastal environment
 Organizing training programs
 Currently there are ~ 1000 isolates from different coasts

22. Species diversity of vibrios in Indian coast
 We received145 isolates of Vibrio isolated from southwest (SW) and Southeast (SE) coast
 The isolates identified using fatty acid profile and 16S rRNA gene sequence analysis
Coast No of
Isolates
Species diversity
SW coast 53 V. cholera, V. furnissi
V. harveyi, V. proteolyticus, V.
alginolyticus, V. nereis, V. hollisae, V.
fischeri, V. campbelli, V. fischeri,
SE coast 92 V. cholera, V. campbelli, V. fischeri, V.
fluvialis, V. hollisae, V. nereis, V.
alginolyticus, V. proteolyticus, V. furnissii,

23. Salt tolerance of Vibrio spp
 Many Vibrio spp are autochthonous to marine
environment
 Moderate salinity, warm temperature, slightly
alkaline pH and high nutrient conditions have been
reported to be associated with the survival of the
pathogen
 Marine vibrios may reach far inland during
hydrological disturbance by cyclones
 Step up regression model highlighted the interaction
effect of environmental variables on distribution of
vibrios in coastal waters Growth curve of a) V. cholera b) V. fischeri c) V. alginolyticus and d) V. hollisae at
different salinity

24. Marine vibrios: Ecological significance
 V. cholera showed higher activities of
chitinase and laminarinase
 These enzymes support them to attach on
phytoplankton and zooplanktons,
crustaceans etc…
Black: low,
Red: medium;
Blue: high