Grinson George
@icar.org.in
Principal Scientist, ICAR-Central Marine Fisheries Research Institute
Indian Council of Agricultural Research
Dr. Grinson George, Principal Scientist at CMFRI, Kochi since 2018 is on deputation as Senior Programme Specialist (Fisheries) to SAARC Agriculture Centre, Dhaka coordinating the fisheries and aquaculture programs for eight South Asian Nations. He has been active in teaching, research, policy, administration, academics, and industry related to fisheries and aquaculture for over 20 years. Specialized in Fisheries Resource Management, he completed post-doctoral research at Plymouth Marine Laboratory, United Kingdom. He served as honorary coordinator CPR Environmental foundation and Juliette Massey Honorary fellow of World Aquaculture Society. He worked at the Ministry of Education, Maldives (2003-04), as a Scientist at CIARI, Port Blair (2005-12), and Senior Scientist at CMFRI (2012-18). His current research focus is on Citizen Science initiatives to address water quality using satellite remote-sensing and marine bio-optics. He is the recipient of Dr. Rajendra Prasad Puraskar by ICAR
EDUCATION
PhD (Marine Science)
MFSc (Fisheries Resource Management)
BFSc
RESEARCH INTERESTS
Aquaculture, fisheries, citizen science, climate change, policy, remote sensing, modelling
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Radhika Balachandran, P.U. Zacharia, G.B. Purushottama, K.S. Sudarsan, Muhammad Shafeeque, R. Ratheesh Kumar, Eldho Varghese, Alphonsa Joseph, R. Rahul, Nanda Kishore,et al.
Elsevier BV
Anas Abdulaziz, Hridya Kuttiyilmemuriyil Vikraman, Devika Raj, Nandini Menon, Grinson George, Reshma Soman, Deepulal Parenkat Mony, Ann Mary, Kiran Krishna, Gireesh Kumar Thundiyil Raju,et al.
Springer Science and Business Media LLC
Gemma Kulk, Shubha Sathyendranath, Trevor Platt, Grinson George, Anagha Kunhimuthappan Suresan, Nandini Menon, Hayley Evers-King, and Anas Abdulaziz
MDPI AG
Water is an essential natural resource, but increasingly water also forms a threat to the human population, with floods being the most common natural disaster worldwide. Earth Observation has the potential for developing cost-effective methods to monitor risk, with free and open data available at the global scale. In this study, we present the application of remote sensing observations to map flooded areas, using the Vembanad-Kol-Wetland system in the southwest of India as a case study. In August 2018, this region experienced an extremely heavy monsoon season, which caused once-in-a-century floods that led to nearly 500 deaths and the displacement of over a million people. We review the use of existing algorithms to map flooded areas in the Lake Vembanad region using the spectral reflectances of the green, red and near-infrared bands from the MSI sensor on board Sentinel-2. Although the MSI sensor has no cloud-penetrating capability, we show that the Modified Normalised Difference Water Index and the Automated Water Extraction Index can be used to generate flood maps from multi-spectral visible remote sensing observations to complement commonly used SAR-based techniques to enhance temporal coverage (from 12 to 5 days). We also show that local knowledge of paddy cultivation practices can be used to map the manoeuvring of water levels and exclude inundated paddy fields to improve the accuracy of flood maps in the study region. The flood mapping addressed here has the potential to become part of a solution package based on multi-spectral visible remote sensing with capabilities to simultaneously monitor water quality and risk of human pathogens in the environment, providing additional important services during natural disasters.
Anas Abdulaziz, Shubha Sathyendranath, Syam Kumar Vijayakumar, Nandini Menon, Grinson George, Gemma Kulk, Devika Raj, Kiran Krishna, Ranith Rajamohananpillai, Balu Tharakan,et al.
American Chemical Society (ACS)
Aquatic ecosystems of tropical countries are vulnerable to fecal contamination that could cause spikes in the incidences of acute diarrheal disease (ADD) and challenge public health management systems. Vembanad lake, situated along the southwest coast of India, was monitored for one year (2018-2019). Escherichia coli, an indicator of fecal contamination, was prevalent in the lake throughout the year. Multiple antibiotic resistance among more than 50% of the E. coli isolates adds urgency to the need to control this contamination. The high abundance of E. coli and incidence of ADD were recorded during the early phase of the southwest monsoon (June-July), prior to the once-in-a-century floods that affected the region in the later phase (August). The extent of inundation in the low-lying areas peaked in August, but E. coli in the water peaked in July, suggesting that contamination occurred even prior to extreme flooding. During the COVID-19-related lockdown in March-May 2021, fecal contamination in the lake and incidence of ADD reached minimum values. These results indicate the need for improving sewage treatment facilities and city planning in flood-prone areas to avoid the mixing of septic sewage with natural waters during extreme climate events or even during the normal monsoon. © 2023 American Chemical Society.
P. Pranav, Grinson George, R. Ranith, N. Nandini Menon, A. Gopalakrishnan, and U. Shameem
Cambridge University Press (CUP)
AbstractThe paper describes the first report of Kandelia candel (Rhizophoraceae), a rare mangrove from Bhavanapadu, a coastal village in Srikakulam district in Andhra Pradesh, India. This species is relatively less abundant along the east coast of India. During our study covering all the 41 mangrove patches in the state of Andhra Pradesh, 16 mangrove species were observed throughout the state and the Kandelia candel was seen only in Bhavanapadu (patch 2). The plant sighted was identified using taxonomic keys and confirmed using DNA barcoding. The identified specimen is deposited in the museum repository at ICAR-Central Marine Fisheries Research Institute (CMFRI), Kochi (accession no. MB.1.1.1.1) and its gene sequence is deposited in National Center for Biotechnological Information (NCBI) (accession no. MH243746). Patch 2 where K. candel was observed is separated away from the other clusters in the principal component one, with the patch showing an average dissimilarity of about 71.79% from the other patches. K. candel is a mangrove highly sensitive to changes in salinity. The presence of a lone member of a rare species in the state at the sampling location raises questions on its endurance in the region. The study underlines the relevance of monitoring the mangroves and advocate adequate conservation measures for proper protection, proliferation and management of this globally dwindling resource.
Varunan Theenathayalan, Shubha Sathyendranath, Gemma Kulk, Nandini Menon, Grinson George, Anas Abdulaziz, Nick Selmes, Robert Brewin, Anju Rajendran, Sara Xavier,et al.
MDPI AG
A growing coastal population is leading to increased anthropogenic pollution that greatly affects coastal and inland water bodies, especially in the tropics. The Sustainable Development Goal-14, ‘Life below water’ emphasises the importance of conservation and sustainable use of the ocean and its resources. Pollution management practices often include monitoring of water quality using in situ observations of chlorophyll-a (chl-a) and total suspended matter (TSM). Satellite technology, including the MultiSpectral Instrument (MSI) sensor onboard Sentinel-2, enables the continuous monitoring of these variables in inland waters at high spatial and temporal resolutions. To improve the monitoring of water quality in the tropical Vembanad-Kol-Wetland (VKW) system, situated on the southwest coast of India, we present two regionally tuned satellite algorithms developed to estimate chl-a and TSM concentrations. The new algorithms estimate the chl-a and TSM concentrations from the simulated reflectance values as a function of the inherent optical properties using a forward modelling approach. The model was parameterised using the National Aeronautics and Space Administration (NASA) bio-Optical Marine Algorithm Dataset (NOMAD) and in situ measurements collected in the VKW system. To assess model performance, results were compared with in situ measurements of chl-a and TSM and other existing satellite-based models of chl-a and TSM. For satellite application, two different atmospheric correction methods (ACOLITE and POLYMER) were tested and satellite matchups were used to validate the new chl-a and TSM algorithms following standard validation procedures. The results demonstrated that the new algorithms were in good agreement with in situ observations and outperform existing chl-a and TSM algorithms. The new regional satellite algorithms can be used to monitor water quality within the VKW system to support the sustainable management under natural (cyclones, floods, rainfall, and tsunami) and anthropogenic pressures (industrial effluents, agricultural practices, recreational activities, construction, and demolishing concrete structures) and help achieve Sustainable Development Goal 14.
Elizabeth Goult, Shubha Sathyendranath, Žarko Kovač, Christina Eunjin Kong, Petar Stipanović, Anas Abdulaziz, Nandini Menon, Grinson George, and Trevor Platt
Springer Science and Business Media LLC
AbstractIn the absence of an effective vaccine or drug therapy, non-pharmaceutical interventions are the only option for control of the outbreak of the coronavirus disease 2019, a pandemic with global implications. Each of the over 200 countries affected has followed its own path in dealing with the crisis, making it difficult to evaluate the effectiveness of measures implemented, either individually, or collectively. In this paper we analyse the case of the south Indian state of Kerala, which received much attention in the international media for its actions in containing the spread of the disease in the early months of the pandemic, but later succumbed to a second wave. We use a model to study the trajectory of the disease in the state during the first four months of the outbreak. We then use the model for a retrospective analysis of measures taken to combat the spread of the disease, to evaluate their impact. Because of the differences in the trajectory of the outbreak in Kerala, we argue that it is a model worthy of a place in the discussion on how the world might best handle this and other, future, pandemics.
P. Pranav, N. Nandini Menon, U. Shameem, K. G. Mini, and Grinson George
Springer International Publishing
Muhammad Shafeeque, Grinson George, S. Akash, B.R. Smitha, Phiros Shah, and A.N. Balchand
Elsevier BV
Abstract South Eastern Arabian Sea (SEAS) is an upwelling dominated region, where the distribution of chlorophyll-a (Chl-a) is mainly controlled by basin scale to mesoscale processes associated with seasonal reversal of winds and currents. The analysis of long-term satellite-derived Chl-a data revealed inter-annual variability in association with extreme climatic events. In the present study, satellite imageries were applied to study the long term Chl-a variability in SEAS followed by ascertaining the influence of extreme climatic events. Chl-a data were obtained from Ocean Colour Climate Change Initiative (OC-CCI) which provides high resolution cloud free data for the Arabian Sea during summer monsoon season (June to September). Satellite measurements of Sea Level Anomaly (SLA), Sea Surface Temperature (SST) and sea surface wind data were also compiled from various sources. The monthly data for the above environmental variables during the years 1998 to 2016 were analysed as representatives of the possible causative physical processes influencing the variability in Chl-a. The time series and Hovmoller analysis revealed that the maximum variability occurred during summer monsoon. This study revealed that the interannual variability in Chl-a was prominently influenced by the underlying processes involved in coastal upwelling. The extreme climatic events such as ENSO and IOD were particularly taken into account to understand the the interannual variability in Chl-a and associated environmental variables. The relative variability in Chl-a and associated environmental variables with these events was prominent during strong El Nino, La Nina and IOD. Cross Correlation Function (CCF) analysis points out that Chl-a content is negatively correlated with IOD to an extent of one month or less whereas, ENSO doesn’t indicate such relations. Hence, the variability associated with IOD showed pronounced influence than ENSO. The study elucidates the interannual variability of Chl-a and the overall influence of associated extreme events in SEAS.
Dhanya Joseph, G. Rojith, P. U. Zacharia, V. H. Sajna, S. Akash and Grinson George
Comparison of chlorophyll data of three sets of CMIP5 models for RCP 4.5 (MPI-ESM-MR, HadGEM2-ES and GFDL-ESM2M) and RCP 6.0 (IPSL-CM5A-LR, HadGEM2-ES and GFDL-ESM2M) were done with satellite derived data (OC-CCI) for the period of 1998–2017 along four Indian coastal regions. The monthly, yearly and zone-wise seasonal comparison between model and satellite data were carried out. Analysis of monthly variations of chlorophyll during 1998–2017 reveals that the satellite data show maximum value of 0.53 mg/m3 in September, whereas all other models show maximum in August. Yearly analysis indicates maximum satellite data in the year 2004, while minimum was observed in 2015. HadGEM2-ES exhibited maximum model value and the lowest was found for IPSL-CM5A-LR. It was observed that the maximum chlorophyll value of 2.56 mg/m3 for satellite data was in the monsoon season and the lowest value of 0.14 mg/m3 was in the pre-monsoon. Seasonal analysis reveals no clear match among model and satellite values in any of the coastal regions. In northwest and northeast regions, the satellite values were found higher than the model values in most of the years, whereas in other regions, the model values were found fluctuating with the satellite values. Owing to the mismatch of the model and the satellite values, the work cautions to apply biases or corrections on usage of RCP model data for regional marine climate change research. Regional and seasonal chlorophyll variations for Indian coastal regions were elucidated for three decades from CMIP5 models and satellite derived data and compared. The northwest region of India exhibits maximum chlorophyll values and variations compared to the southern coasts. The discrepancies among satellite and model chlorophyll data were evidenced from the respective shift of chlorophyll maximum values from September to August. The research emphasis the need to apply necessary bias corrections in regional marine climate forecasts. Regional and seasonal chlorophyll variations for Indian coastal regions were elucidated for three decades from CMIP5 models and satellite derived data and compared. The northwest region of India exhibits maximum chlorophyll values and variations compared to the southern coasts. The discrepancies among satellite and model chlorophyll data were evidenced from the respective shift of chlorophyll maximum values from September to August. The research emphasis the need to apply necessary bias corrections in regional marine climate forecasts.
P. Pranav, Rajdeep Roy, Chiranjivi Jayaram, Priya M. D’Costa, Saroj Bandhu Choudhury, N. Nandini Menon, P.V. Nagamani, Shubha Sathyendranath, Anas Abdulaziz, M.V.R. Shesha Sai,et al.
Elsevier BV
S. Akash, Phiros Shah, Muhammad Shafeeque, A.S. Pooja, P.U. Zacharia, J.K. Ajith, Vivekanand Bharti, T.V. Sathianandan, and Grinson George
Elsevier BV
Grinson George, Nandini N. Menon, Anas Abdulaziz, Robert J. W. Brewin, P. Pranav, A. Gopalakrishnan, K. G. Mini, Somy Kuriakose, Shubha Sathyendranath, and Trevor Platt
Frontiers Media SA
Citizen science aims to mobilise the general public, motivated by curiosity, to collect scientific data and contribute to the advancement of scientific knowledge. In this article, we describe a citizen science network that has been developed to assess the water quality in a 100 km long tropical lake-estuarine system (Vembanad Lake), which directly or indirectly influences the livelihood of around 1.6 million people. Deterioration of water quality in the lake has resulted in frequent outbreaks of water-associated diseases, leading to morbidity and occasionally, to mortality. Water colour and clarity are easily measurable and can be used to study water quality. Continuous observations on relevant spatial and temporal scales can be used to generate maps of water colour and clarity for identifying areas that are turbid or eutrophic. A network of citizen scientists was established with the support of students from 16 colleges affiliated with three universities of Kerala (India) and research institutions, and stakeholders such as houseboat owners, non-government organisations (NGOs), regular commuters, inland fishermen, and others residing in the vicinity of Vembanad Lake and keen to contribute. Mini Secchi disks, with Forel-Ule colour scale stickers, were used to measure the colour and clarity of the water. A mobile application, named “TurbAqua,” was developed for easy transmission of data in near-real time. In-situ data from scientists were used to check the quality of a subset of the citizen observations. We highlight the major economic benefits from the citizen network, with stakeholders voluntarily monitoring water quality in the lake at low cost, and the increased potential for sustainable monitoring in the long term. The data can be used to validate satellite products of water quality and can provide scientific information on natural or anthropogenic events impacting the lake. Citizens provided with scientific tools can make their own judgement on the quality of water that they use, helping toward Sustainable Development Goal 6 of clean water. The study highlights potential for world-wide application of similar citizen-science initiatives, using simple tools for generating long-term time series data sets, which may also help monitor climate change.
Gemma Kulk, Grinson George, Anas Abdulaziz, Nandini Menon, Varunan Theenathayalan, Chiranjivi Jayaram, Robert J. W. Brewin, and Shubha Sathyendranath
MDPI AG
The United Nation’s Sustainable Development Goal Life Below Water (SDG-14) aims to “conserve and sustainably use the oceans, seas, and marine resources for sustainable development”. Within SDG-14, targets 14.1 and 14.2 deal with marine pollution and the adverse impacts of human activities on aquatic systems. Here, we present a remote-sensing-based analysis of short-term changes in the Vembanad-Kol wetland system in the southwest of India. The region has experienced high levels of anthropogenic pressures, including from agriculture, industry, and tourism, leading to adverse ecological and socioeconomic impacts with consequences not only for achieving the targets set out in SDG-14, but also those related to water quality (SDG-6) and health (SDG-3). To move towards the sustainable management of coastal and aquatic ecosystems such as Lake Vembanad, it is important to understand how both natural and anthropogenic processes affect water quality. In 2020, a unique opportunity arose to study water quality in Lake Vembanad during a period when anthropogenic pressures were reduced due to a nationwide lockdown in response to the global pandemic caused by SARS-CoV-2 (25 March–31 May 2020). Using Sentinel-2 and Landsat-8 multi-spectral remote sensing and in situ observations to analyse changes in five different water quality indicators, we show that water quality improved in large areas of Lake Vembanad during the lockdown in 2020, especially in the more central and southern regions, as evidenced by a decrease in total suspended matter, turbidity, and the absorption by coloured dissolved organic matter, all leading to clearer waters as indicated by the Forel-Ule classification of water colour. Further analysis of longer term trends (2013–2020) showed that water quality has been improving over time in the more northern regions of Lake Vembanad independent of the lockdown. The improvement in water quality during the lockdown in April–May 2020 illustrates the importance of addressing anthropogenic activities for the sustainable management of coastal ecosystems and water resources.
Nandini Menon, Grinson George, Rajamohananpillai Ranith, Velakandy Sajin, Shreya Murali, Anas Abdulaziz, Robert J. W. Brewin, and Shubha Sathyendranath
MDPI AG
Turbidity and water colour are two easily measurable properties used to monitor pollution. Here, we highlight the utility of a low-cost device—3D printed, hand-held Mini Secchi disk (3DMSD) with Forel-Ule (FU) colour scale sticker on its outer casing—in combination with a mobile phone application (‘TurbAqua’) that was provided to laymen for assessing the water quality of a shallow lake region after demolition of four high-rise buildings on the shores of the lake. The demolition of the buildings in January 2020 on the banks of a tropical estuary—Vembanad Lake (a Ramsar site) in southern India—for violation of Indian Coastal Regulation Zone norms created public uproar, owing to the consequences of subsequent air and water pollution. Measurements of Secchi depth and water colour using the 3DMSD along with measurements of other important water quality variables such as temperature, salinity, pH, and dissolved oxygen (DO) using portable instruments were taken for a duration of five weeks after the demolition to assess the changes in water quality. Paired t-test analyses of variations in water quality variables between the second week of demolition and consecutive weeks up to the fifth week showed that there were significant increases in pH, dissolved oxygen, and Secchi depth over time, i.e., the impact of demolition waste on the Vembanad Lake water quality was found to be relatively short-lived, with water clarity, colour, and DO returning to levels typical of that period of year within 4–5 weeks. With increasing duration after demolition, there was a general decrease in the FU colour index to 17 at most stations, but it did not drop to 15 or below, i.e., towards green or blue colour indicating clearer waters, during the sampling period. There was no significant change in salinity from the second week to the fifth week after demolition, suggesting little influence of other factors (e.g., precipitation or changes in tidal currents) on the inferred impact of demolition waste. Comparison with pre-demolition conditions in the previous year (2019) showed that the relative changes in DO, Secchi depth, and pH were very high in 2020, clearly depicting the impact of demolition waste on the water quality of the lake. Match-ups of the turbidity of the water column immediately before and after the demolition using Sentinel 2 data were in good agreement with the in situ data collected. Our study highlights the power of citizen science tools in monitoring lakes and managing water resources and articulates how these activities provide support to Sustainable Development Goal (SDG) targets on Health (Goal 3), Water quality (Goal 6), and Life under the water (Goal 14).
Abdulaziz Anas, Kiran Krishna, Syamkumar Vijayakumar, Grinson George, Nandini Menon, Gemma Kulk, Jasmin Chekidhenkuzhiyil, Angelo Ciambelli, Hridya Kuttiyilmemuriyil Vikraman, Balu Tharakan,et al.
MDPI AG
Vibrio cholerae, the bacterium responsible for the disease cholera, is a naturally-occurring bacterium, commonly found in many natural tropical water bodies. In the context of the U.N. Sustainable Development Goals (SDG) targets on health (Goal 3), water quality (Goal 6), life under water (Goal 14), and clean water and sanitation (Goal 6), which aim to “ensure availability and sustainable management of water and sanitation for all”, we investigated the environmental reservoirs of V. cholerae in Vembanad Lake, the largest lake in Kerala (India), where cholera is endemic. The response of environmental reservoirs of V. cholerae to variability in essential climate variables may play a pivotal role in determining the quality of natural water resources, and whether they might be safe for human consumption or not. The hydrodynamics of Vembanad Lake, and the man-made barrier that divides the lake, resulted in spatial and temporal variability in salinity (1–32 psu) and temperature (23 to 36 °C). The higher ends of this salinity and temperature ranges fall outside the preferred growth conditions for V. cholerae reported in the literature. The bacteria were associated with filtered water as well as with phyto- and zooplankton in the lake. Their association with benthic organisms and sediments was poor to nil. The prevalence of high laminarinase and chitinase enzyme expression (more than 50 µgmL−1 min−1) among V. cholerae could underlie their high association with phyto- and zooplankton. Furthermore, the diversity in the phytoplankton community in the lake, with dominance of genera such as Skeletonema sp., Microcystis sp., Aulacoseira sp., and Anabaena sp., which changed with location and season, and associated changes in the zooplankton community, could also have affected the dynamics of the bacteria in the lake. The probability of presence or absence of V. cholerae could be expressed as a function of chlorophyll concentration in the water, which suggests that risk maps for the entire lake can be generated using satellite-derived chlorophyll data. In situ observations and satellite-based extrapolations suggest that the risks from environmental V. cholerae in the lake can be quite high (with probability in the range of 0.5 to 1) everywhere in the lake, but higher values are encountered more frequently in the southern part of the lake. Remote sensing has an important role to play in meeting SDG goals related to health, water quality and life under water, as demonstrated in this example related to cholera.
R Kiruba-Sankar, P Krishnan, Grinson George, K Lohith Kumar, J Raymond Jani Angel, K Saravanan, and S Dam Roy
Springer Science and Business Media LLC
Globally, marine fisheries sector provides livelihood, food security and employment to the fishers engaged in subsistence, artisanal and industrial fishing activities. The dependency on marine fish supplies keeps rising globally leading to intense competition, fishery conflicts and unsustainable fishing practices which threatens the sustainability and leading to the depletion of marine fishery resources. Andaman and Nicobar Islands (ANI) in India is a tropical archipelago cited as an example where marine fishery resources were considered to be highly underutilized vis-a-vis the harvestable potential. Developmental plans often envisage the enormous scope to harness the oceanic fishery resources however, the overriding issues which affect the sustainable fishery management were least understood or addressed. Offshore fisheries were trade and economy based whereas small scale fisheries are livelihood and food security-based, operating with small to medium scale commercial prospects. Radical management approaches in artisanal and industrial fisheries is essential to foster community resilience and sustainable fishery management. The emerging body of evidence suggests the critical need to reliably estimate the fish catches and population dynamics for sustainable fisheries management. Comprehensive opinions on prevailing issues, complexities in governance, challenges faced and the management strategies that need to be adopted were discussed to ensure the robust governance and sustainability of marine fisheries sector.
Muhammad Shafeeque, A. N. Balchand, Phiros Shah, Grinson George, Smitha B. R., Eldho Varghese, Ajith K. Joseph, Shubha Sathyendranath, and Trevor Platt
Informa UK Limited
ABSTRACT The influence of mesoscale dynamics on variability of phytoplankton biomass in terms of chlorophyll-a (chl-a) concentration was studied in the coastal waters of the South Eastern Arabian Sea (SEAS) using long-term satellite data. Satellite-derived chl-a, sea level anomaly, sea surface temperature, and sea surface wind data for the period 1998–2016 were compiled from various sources and analysed to investigate the chl-a variability associated with coastal upwelling and mesoscale eddies. The Empirical Orthogonal Function and Morlet wavelet analyses were performed to estimate the quantitative variability and the result showed strong seasonal and interannual modulation in chl-a concentration and associated environmental variables. The Okubo–Weiss criterion was applied for the identification of mesoscale eddies. The results indicated the presence of cyclonic (cold core) eddies during the summer monsoon season (June–September). The wind-induced upwelling and the cyclonic eddies were most intense during the summer monsoon season, causing higher values of chl-a compared with other season. It is revealed that the variability of chl-a, which might be attributed to seasonal and interannual differences in the surface and sub-surface nutrients, is caused either by coastal upwelling or cyclonic eddies. In particular, the wind-induced upwelling strongly controls the spatial and temporal variability of chl-a compared with mesoscale eddies along the SEAS. The regression model we adopted points out the dominant role played by the wind and its forcing bring about variability in chl-a. The occurrence of extreme climatic events such as El Niño, La Niña and Indian Ocean Dipole (IOD) was noticed during the study period and particularly taken into account to understand the interannual fluctuations in chl-a and associated environmental variables. The relative variability in chl-a concentration was prominent during strong El Niño, La Niña, and IOD. We have attempted to determine the relationship between chl-a with coastal upwelling and mesoscale eddies, the overall importance of such physical forcings, and their influence on bio-production in the SEAS.
Faseela Hamza, Vinu Valsala, Anju Mallissery, and Grinson George
Wiley
Shubha Sathyendranath, Anas Abdulaziz, Nandini Menon, Grinson George, Hayley Evers-King, Gemma Kulk, Rita Colwell, Antarpreet Jutla, and Trevor Platt
Springer International Publishing
It is now generally accepted that climate variability and change, occurrences of extreme weather events, urbanisation and human pressures on the environment, and high mobility of human populations, all contribute to the spread of pathogens and to outbreaks of water-borne and vector-borne diseases such as cholera and malaria. The threats are heightened by natural disasters such as floods, droughts, earth-quakes that disrupt sanitation facilities. Aligned against these risks are the laudable Sustainable Development Goals of the United Nations dealing with health, climate, life below water, and reduced inequalities. Rising to the challenges posed by these goals requires an integrated approach bringing together various scientific disciplines that deal with parts of the problem, and also the various stakeholders including the populations at risk, local governing bodies, health workers, medical professionals, international organisations, charities, and non-governmental organisations. Satellite-based instruments capable of monitoring various properties of the aquatic ecosystems and the environs have important contributions to make in this context. In this chapter, we present two case studies—the Ganga Delta region and the Vembanad Lake region in south-western India—to illustrate some of the benefits that remote sensing can bring to address the problem of global health, and use these examples to identify the capacity building that is essential to maximise the exploitation of the remote sensing potential in this context.
P U Zacharia, V.H. Sajna, G. Rojith, G.N. Roshen, Dhanya Joseph, Somy Kuriakose, and Grinson George
Central Marine Fisheries Research Institute, Kochi
The Indian mackerel Rastrelligerkanagurta(Cuvier, 1816) is one of the most important marine fishery resources along the south-eastern Arabian Sea along the coast of Kerala, south India. The effect of selected environmental variables on the Relative effort (Effort) and weighted catch per unit effort (cpue)of the fish were investigated using simple correlation and Path analysis. Six major oceanographic variables, namely sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), Precipitation (Pr) Indian Ocean Dipole (IOD) and Southern Oscillation Index (SOI) (ENSO index) were selected for the present study. Among these SST had the highest direct negative effect (-0.282, p<0.01), followed by SSS (-0.152, p<0.1) and IOD (-0.006, p<0.01). The highest positive direct effect on the cpue was exhibited by Pr (0.514, p<0.001) followed by SSC and SOI (0.178, p<0.01). The environmental variables also exerted indirect effects on cpue through Effort. The residual variance indicated that there are spurious effects exerted by environmental variables not included in the study. According to the coefficient of determination (R2), the relative importance of the influence of causally dependent environmental variables on the cpue of Indian mackerel is Pr> SSC >SSS.
Racault, Abdulaziz, George, Menon, C, Punathil, McConville, Loveday, Platt, Sathyendranath,et al.
MDPI AG
The World Health Organization has estimated the burden of the on-going pandemic of cholera at 1.3 to 4 million cases per year worldwide in 2016, and a doubling of case-fatality-rate to 1.8% in 2016 from 0.8% in 2015. The disease cholera is caused by the bacterium Vibrio cholerae that can be found in environmental reservoirs, living either in free planktonic form or in association with host organisms, non-living particulate matter or in the sediment, and participating in various biogeochemical cycles. An increasing number of epidemiological studies are using land- and water-based remote-sensing observations for monitoring, surveillance, or risk mapping of Vibrio pathogens and cholera outbreaks. Although the Vibrio pathogens cannot be sensed directly by satellite sensors, remotely-sensed data can be used to infer their presence. Here, we review the use of ocean-color remote-sensing data, in conjunction with information on the ecology of the pathogen, to map its distribution and forecast risk of disease occurrence. Finally, we assess how satellite-based information on cholera may help support the Sustainable Development Goals and targets on Health (Goal 3), Water Quality (Goal 6), Climate (Goal 13), and Life Below Water (Goal 14).
Muhammad Shafeeque, Phiros Shah, Trevor Platt, Shubha Sathyendranath, Nandini N. Menon, Alungal N. Balchand, and Grinson George
Coastal Education and Research Foundation
ABSTRACT Shafeeque, M.; Shah, P.; Platt, T.; Sathyendranath, S.; Menon, N.N.; Balchand, A.N., and George, G., 2019. Effect of precipitation on Chlorophyll-a in an upwelling-dominated region along the west coast of India. In: Jithendran, K.P.; Saraswathy, R.; Balasubramanian, C.P.; Kumaraguru Vasagam, K.P.; Jayasankar, V.; Raghavan, R.; Alavandi, S.V., and Vijayan, K.K. (eds.), BRAQCON 2019: World Brackishwater Aquaculture Conference. Journal of Coastal Research, Special Issue No. 86, pp. 218–224. Coconut Creek (Florida), ISSN 0749-0208. The South Eastern Arabian Sea (SEAS) is an upwelling-dominated region, where the seasonally-reversing winds and currents are the major physical forces driving primary production. The region is characterized by high primary productivity during the summer monsoon season (June to September), when the winds and currents favor upwelling. The coast is notable for the presence of monsoonal rivers. During summer monsoon, nutrient-rich riverine water is discharged in great quantity into coastal waters. The heavy inflow of turbid, nutrient-rich water into coastal regions during the summer monsoon facilitates primary production, augmenting phytoplankton biomass. In the present study, we investigated the relative roles of upwelling and precipitation that drive productivity along the south-west coast of India. The available remote sensing data sets for chlorophyll-a (Chl-a), precipitation, silicate and wind were used for the period 1998 to 2016. The Chl-a anomaly showed positive correlation with upwelling index and precipitation except during 2003 and 2012. During these years, negative anomalies for Chl-a and precipitation were observed even though the upwelling index showed positive anomalies. So the enhancement in Chl-a was nominal during those specific years even when the upwelling was very strong. This indicates the role of riverine nutrients from heavy precipitation during summer monsoon that contributes significantly to coastal productivity apart from upwelling in SEAS.