Deeptha Amarathunga

• Ph.D.
• Former Senior Scientist at National Aquatic Resources Research and Development Agency

The prevalence and fate of microplastics in macrophytes are insufficiently understood, and data on the abundance of microplastic (MP) accumulation in macrophyte ecosystems are urgently needed to fill this knowledge gap. The main objectives of this study were to quantify and characterize the microplastics that accumulate in macrophytes, associated s...

Large plastic items in the environment are degraded into tiny pieces known as microplastics (MPs). MP contamination in tropical lagoon ecosystems poses a significant pollution threat. The mud crab, Scylla serrata, is an important crustacean in the tropical lagoon, valued as a key source of edible seafood in Asia and Europe. The potential MPs of one...

Microplastics are pervasive pollutants in marine ecosystems worldwide and are increasingly recognized as a significant environmental threat. Sri Lanka, an island nation, is not exempt from this issue. While microplastic pollution has been extensively studied in the southern and western parts of Sri Lanka, limited data is available for the northern...

Microplastics have emerged as a significant global environmental concern in the recent decade. The aim of this study was to elucidate microplastic contamination of commercial fish species in a natural lagoon environment. Microplastic contamination was examined in the gastrointestinal tracts and gills of 157 commercial fish from 18 species with vary...

A multitude of anthropogenic and industrial uses lead to the extensive dispersion of heavy metals in aquatic environments. The protracted presence and poisonous nature of heavy metals inflict negative impacts including organ malfunction and the inactivation of enzymes in aquatic organisms. The bottom-dwelling mud crabs are frequently used as bioind...

Most of the residents in Anuradhapura consume untreated water from surface and groundwater sources, raising concerns about potential health risks. The water quality was assessed in major irrigation tank cascade system (Kalawewa, Rajanganaya, Nachchaduwa, Nuwarawewa, and Tissawewa) Anuradhapura and interconnected canals, wells, and springs. The obje...

Microplastic pollution (MP) in marine environments around the globe is severe and insufficient precautions have yet to be taken for its prevention. The focus of this study was on quantifying MPs from beach sediment and seawater samples and identifying their distributions and types along the western coast of Sri Lanka from the Kelani River estuary t...

Infrastructure is often a limiting factor in microplastics research impacting the production of scientific outputs and monitoring data. International projects are therefore required to promote collaboration and development of national and regional scientific hubs. The Commonwealth Litter Programme and the Ocean Country Partnership Programme were de...

Microplastic pollution (MP) in marine environments around the globe is severe and enough precautions have not been taken so far for its prevention. The focus of this study is to quantify MPs from beach sediment and seawater samples and to identify their distribution and types along the western coast of Sri Lanka from the Kelani River estuary to the...

The ecological surveys with special reference to the dynamic of macrobenthos in the estuaries have not been comprehensively studied in Sri Lanka. Hence, this study was conducted to determine the correlation between physicochemical parameters and macrobenthos diversity and evaluate the pollution level in the estuary using macrobenthos diversity. Mac...

Microplastic (MP) pollution is a serious global issue affecting freshwater systems, coastal regions, and oceans. These non-biodegradable materials have a detrimental impact on marine species and ecosystems, disrupting their feeding, breathing, and reproduction. In this study, 120 samples of two species of shrimp, Penaus monodon and Penaus indicus,...

Sandy beaches act as an interface between land and sea and can serve as an indicator of the level of contamination in the marine environment. The beach can be both a source and a sink for marine litter contamination. Long-term accumulation of buried plastic marine litter (BPML) can produce microplastics by mechanical destruction and/or UV-degradati...

Examining fishing harbour sediment is crucial for understanding its impact on marine environments and community well-being. Therefore, the present study aimed to assess the concentration in sediments for trace elements, organic matter content, microbial pollution, and other harmful substances. Samples were collected using Ekman grab sampler and col...

Heavy metal contamination poses a serious threat to coastal ecosystems. The comprehension of these metals' effects and how they bioaccumulate via food webs is still insufficient. This research aimed to examine the concentrations of heavy metals (Cu, Zn, Cr, Fe, Cd, and Mn) in four coastal macrophytes (Halodule pinifolia, Chaetomorpha sp., Ulva i...

Marine litter and microplastic pollution have been recognized as a serious environmental concern in recent decades. This study investigated the distribution and accumulation patterns of marine litter and microplastics on beaches in the Crow Island and Wattala coastal areas during the Northeast monsoon. In this study, any anthropogenic and persisten...

Microplastics in salt

The research emphasizes some of human activities, specifically fishing and harbor operations, have led to significant coastal pollution in fishery harbors of Beruwala and Mirissa located in Western and Southern coasts, respectively of Sri Lanka. The pollutants accumulated in these harbors include crude oil, raw fish fragments, and other waste produ...

Microplastic contamination in fish is a growing concern due to its potential negative impacts on human health and the environment. When microplastics are released into the environment, they can be accumulating in fish and via the food chain, either through direct ingestion or indirect process. This study aimed to investigate the occurrence and abun...

Analysis of water in fishery harbour basins is particularly important as harbour basins can be a serious source of marine pollution. Galle fishery harbour is a deep-sea industrial fishery port located in an international place for tourism and mooring facilities for visiting yachts. The harbour consists of a large number of service facilities and st...

Plastic debris, a fast-growing urban waste segment, cause pollution by breaking into microplastics (MPs) of less than 5mm. The Microplastics (MPs) are classified as primary, microscopic virgin granules used to make plastic items and secondary, resulting from degradation of large plastics. The present study was planned to characterize and quantify M...

Marine litter currently poses a growing threat to the marine and coastal environment all over the world. Most marine litter consists of materials that degrade slowly, if at all, continuous input of large quantities of those items results in a gradual build-up in the marine and coastal environment. Fourteen districts of Sri Lanka are covered by coas...

Microplastic pollution is a serious global issue affecting freshwater systems, coastal regions, and oceans. These non-biodegradable materials have a detrimental impact on marine species and ecosystems, causing disruption to their feeding, breathing, and reproduction. In this study, 120 samples of two species of shrimp, P. monodon and P. indicus, fr...

Plastic pollution, including microplastics (MPs), poses a global threat to environmental and human health. However, studies on ingested microplastics in aquatic animals in freshwater ecosystems are still scarce in Sri Lanka. This study aims to provide evidence and generate baseline data regarding the abundance of MPs contamination of fish in the Be...

Microplastics (< 5 mm) is a persistent pollutant that are present in both marine and freshwater environments and biota throughout the world. Negombo and Kokkilai Lagoons are the most productive areas in Sri Lanka. The present study was conducted to examine the abundance and characteristics of microplastics in Perna viridis in Negombo and Kokkilai L...

Microplastics (MPs) act as physical anthropogenic pollutants and their ability to act ascontaminant vectors in biological matrices has become a serious ecosystem and human healthconcern. The present study, for the first time, has screened and detected MPs in the gastrointestinaltract and gill of a select group of commonly consumed fish species from...

Microplastics (MPs) are tiny plastic particles less than 5 mm in size. The danger imposed by MPs continues to rise in the world due to an increase in anthropological pollutants in the environment. The tremendous socioeconomic value and biodiversity of the lagoon have been threatened by a significant accumulation of plastics, particularly MPs. MPs h...

Microplastics (MPs) pollution in marine environment is an emerging threat to marine biota. Marine pelagic fish species such as tuna and tuna-like species caught during offshore fisheries in open seas, are known to be more commercially important and could be contaminated by MPs. As such, MPs could pose a risk to fish by themselves and to human healt...

Rapid urbanization and mismanagement have led to a surge in plastic pollution in crucial aquatic ecosystems globally therefore accumulation of debris in aquatic ecosystems is rapidly increasing and they are becoming ultimate sinks for the contaminants. This results in a long-term and widespread threat causing a great challenge for remediation. Poor...

Rapid urbanization and mismanagement have increased plastic discharges into ecologically important aquatic environments globally. Negombo Lagoon is one of the most productive and commercially and ecologically important ecosystems in Sri Lanka. This study proposed to assess microplastics (MP) abundance and distribution in surface water and sediment...

Microplastics (MPs) are becoming increasingly problematic for the environment around the world. However, the prevalence and fate of microplastics in Macrophytes are insufficiently understood. MPs can impale Macrophytes, restrict light and gas passage, increase toxin concentrations, disturb metabolic processes, and inhibit nutrition cycles. This res...

Microplastics contaminations in mangrove ecosystem in Negombo lagoon, Sri Lanka Abstract Mangroves play a significant role in filtering microplastics (MPs) (<5 mm) that come from terrestrial, marine, and atmospheric sources and serve as a vital barrier between land and sea. The combination of high primary production and intricate hydrodynamic con...

Mangrove ecosystems can be considered as pools of carbon stocks as a result of sequestering, carbon stored in biomass and underlying sediments. This study assessed species diversity, community structures, and blue carbon potential and carbon dioxide equivalent in a tropical mangrove forest, Panama lagoon, Sri Lanka. The line transect method was sys...

Kelani River is the principal consumable water source for 80% of the population in the Colombo district and an important ecosystem complex for the freshwater fish biota of Sri Lanka. However, it is the most polluted river in the country. The present study was conducted to determine the water quality parameters and pollution of the upper and lower c...

Lagoons are known to act as a source and a sink of microplastics in the environment. The extent of their occurrence is, however, still largely unknown. This study reports available scientific evidence on the occurrence and abundance of microplastic in lagoon ecosystems, globally. This study identified knowledge gaps as well as recommendations to ov...

The main objective of this study was to assess the difference of water quality of Bomuruwella reservoir before and after the dredging operations of the reservoir, which was carried out between June and September 2014. Water sampling was conducted from February to December 2014 on monthly basis at randomly selected 10 sampling locations. Dissolved o...

Microplastic (MP) pollution is a growing issue in Sri Lanka. However, few findings have been reported in the Northern coastal belt of Sri Lanka. This study provides the first evidence of the prevalence and abundance of MPs in the Northern Sri Lankan coastal waters of Mathagal, Point Pedro and Charty Beach in Jaffna. Floating MPs were collected usin...

Lanka Microplastic are emerging contaminants in the environment and it has many impacts on different sectors such as marine environment, rivers, reservoirs, soil, sediment, plants, fish, etc. Frequent maritime disasters have increased in the recent past in the Indian Ocean. Recently, X-Press Pearl ship disaster on 20 May 2021 caused unprecedented p...

Mangrove ecosystems can be considered as pools of carbon stocks as a result of sequestering, carbon stored in biomass and underlying sediments. This study assessed species diversity, community structures, and blue carbon potential and carbon dioxide equivalent in a tropical mangrove forest, Panama lagoon, Sri Lanka. The line transect method was sys...

Kelani River is the second largest watershed in Sri Lanka and the major water source for Colombo District which is the most industrialized city in the country. Kelani River is deteriorated in many ways and also could be polluted with heavy metals that can bioaccumulate through food webs and cause chronic toxicity to humans and other organisms. Ther...

Plastic particles that are less than 5 mm in dimension are referred to as microplastics (MPs). The formation of MPs can occur either by fragmentation of macroplastics (secondary MPs) or the production of micro-sized plastics (primary MPs) for intended applications. MPs have been identified as an emerging threat to the environment. MP pollution in m...

Abundance of buried microplastics in sand profiles and pellet pollution index at Sarakkuwa beach, at west-coast of Sri Lanka was studied as a case study due to the receival of plastic nurdles and debris from the MV X-Press Pearl ship disaster in May 2021. Sand collected at 7 locations to a depth of 2 m in different depths for a beach segment of 200...

The present study aimed to quantify the treatment capacities of medicinal plant materials integrated into low-cost water treatments system (LCWTS) to treat well water in the coastal regions of Jaffna and Dikowita in Sri Lanka. Terminalia arjuna roots, Strychnos potatorum seeds, and Phyllanthus emblica leaves were employed to design LCWTS. Paired t-...

Kelani River is the most polluted river in Sri Lanka and the lower catchment is more polluted than the upper catchment. In the present study, freshwater fish species of the lower catchment of the river were investigated for the use of assessing the water quality. Cast net sampling and identification recorded 34 freshwater fish species from the lowe...

The objectives of the research was to assess the coastal pollution by plastic nurdles, pyrolitic debris, associated potential toxic elements (PTEs) concentrations and mitigatory efforts by the worst ever maritime accident of a chemical and plastic boarded container vessel; MV X-press Pearl. Field sampling was carried out three times during May, Jun...

Kelani river is an important ecosystem complex for the freshwater fish biota of Sri Lanka and one of the most polluted rivers in the country. However, for Kelani River, the distribution of fish and their responses to fluctuations or stresses to water quality have not been investigated. Therefore, the study intends to analyze and compare the species...

Abstract The lagoon ecosystem of Sri Lanka has come under pressure from agricultural, fisheries and other development activities in recent decades. The Panama lagoon (6° 45' - 6° 46' N and 81° 48' - 81° 49' E) has been identified as a relatively pristine, shallow coastal lagoon in the Eastern coast of Sri Lanka. It is of high ecological importance...

The Kelani river, is the second longest and most polluted river in Sri Lanka which subjected to many pollution studies. The present study was conducted to evaluate the water quality results obtained for upper catchment of Kelani river using multivariate statistical techniques to understand the correlation of selected parameters. Water quality param...

Peoples are often used their extra land for the cultivation of annual crops. Most of the farmers used agrochemicals for their farming lands. Also, tea plantations were used agrochemicals for their cultivations. The excess agrochemicals drain with runoff and ultimately end up with a shallow or deep reservoir. The Gregory Lake is located in the Nuwar...

Water scarcity, inappropriate sanitation and wastewater pollution are critically important issues in most of the coastal regions in Sri Lanka. Both shallow and deep groundwater is frequently brackish, and fresh water wells have been increasingly salinized by tidal fluctuation and seepage mostly in dry seasons. Sandy soil increase the contamination...

Phytoplankton are photosynthetic, single celled and drifting or floating organism size ranging 0.2µm to 200µm. They play a major role in the global carbon cycle. Some phytoplankton are toxic for the human and animal and release toxins into marine water called marine biotoxin. These toxic-chemicals accumulate in the animal bodies and transfer to the...

This status report developed by the Land Resource Division of the Ministry of Mahaweli Development and Environment of Sri Lanka is released on the occasion of launching of the United Nations Global Campaign on Sustainable Nitrogen Management through a High-Level Segment and Science–Policy–Political Dialogue, to be held from 23-24 October 2019 in Co...

The small fish stall’s are releasing their fish effluent containing wastewater into the natural environment without any appropriate treatment. There is less attention to treat the wastewater generated from those small scale fisheries. Therefore, study objective is to construct an artificial wetland to reduce pollution from fish wastewater by small...

Fisheries industry plays an important role in the economy of Sri Lanka by providing livelihood for more than 2.5 million coastal communities and more than 50% of animal protein requirement of the people in the country. Beruwala fishery harbour contributes highly to the fish landings in Kalutara District of the country. However, there are limited st...

A study of dredging impacts on water quality in Bomuruella Reservoir, Nuwara Eliya Hettige, N.D. 1*, Weerasekara, K.A.W.S.1, Amaratunga, A.A.D.1 1Environmental Studies Division, National Aquatic Resource Research and Development Agency (NARA), Crow Island, Colombo 15, Sri Lanka. *Corresponding author: Email – nadeeshahettige7@gmail.com Abstract...

Abstract Dedduwa is economically and ecologically important natural water body located in Bentota, Sri Lanka and this water body is inter connected with the sea. This study was conducted to understand the nutrient behaviour in the Dedduwa estuary and to study its impact on the aquatic environment. Water samples, sediment samples and plankton sampl...

Oil spill incidents occur due to various natural and anthropogenic activities in the world with devastating impacts on surrounding ecosystems perhaps, with irreparable losses. Two major oil spill incidents are recorded in the Sri Lanka recent pass at Koggala and Lunawa lagoon at Theldiyawatta, Muthurajawela of Sri Lanka on 8th September 2006 and 31...

To understand pesticide loading from farmlands, evaluation of farmers' perceptions and land use patterns of pesticide loading from the upper catena of the tropical tributary river study was conducted using Rapid Rural Appraisal (RRA), which utilized semi-structured questionnaire surveys and key personnel interviews to collect data from the farmers...

Histamine, a biogenic amine is a chemical hazard in fish and histamine food poisoning is found to be associated with high level consumption of scombroid fish, such as skipjack tuna. The present study tries to investigate the histamine levels in skipjack tuna by using a gravimetric and colourimetric methods, as simple and rapid methods. Skipjack tun...

Chlorpyrifos is a highly toxic organo-phosphorous insecticide and its fate and mobility are influenced by volatilization, leaching, adsorption, and degradation etc. This research study is focused on the adsorption process of Chlorpyrifos and its impact to aquatic invertebrates after the adsorption. Four soil samples were obtained from different loc...

Diazinon is an organophosphate categorized under insecticide. When pesticides are applied, they are subjected to different complex processes and there is lack of understanding of pesticide behaviour under tropical conditions. Adsorption is one of the main processes of the pesticide behavior and part of the pesticide is adsorbed onto soil. The main...

The Gin river wetland marsh has been identified as one of the most dynamic ecosystem in Sri Lanka, providing habitats for associated floral and faunal communities under a permanent or temporary accumulation of water. Study was focused to understand the structure, composition and threats of the Ginthota wetland marsh, by identifying the biodiversity...

There has been a considerable amount of research investigating suspended sediment (SS) and water quality in river basins. However, there has been less attention to the suspended sediment behaviour in tropical river basins, especially in Sri Lanka. The Gin river basin is one of the major river basins in Sri Lanka and catchments consist of multi-land...

Coastal water bodies in the North Western Province (NWP) of Sri Lanka are highly utilized for shrimp farming, fisheries activities, recreational activities and bathing. Objectives of the study were assess the current water pollution status of selected coastal areas located in the NWP , to identify the factors affecting for water pollution and to id...

Phytoplankton diversity and abundance changes as a function of physico-chemical parameters in aquatic ecosystem; hence these may serve as indicators of water quality. The objective of the study was to determine the diversity and distribution of phytoplankton in relation to the water quality of the Batticaloa lagoon. Sampling was carried out on a mo...

Panadura estuary situated in the western province in Sri Lanka where Bolgodalake opens into Indian Ocean harbours a lot of aquatic biodiversity. Therefore, main objective of this study was to identify the diversity of benthic macro-invertebrates, to assess the correlation between physico-chemical parameters and macro-benthic invertebrate diversity...

Maduganga lagoon is the third Ramsar wetland in Sri Lanka which is located in Galle district.Due to various recreational activitiesbiodiversity of wetland is facing a threat of pollution. The present study was to evaluate pollution levels in Maduganga lagoon with respect to physico-chemical water quality parameters and diversity of benthic macro in...

The objective of this study was to determine the current status of water quality in three selected fishery harbours named Hikkaduwa, Galle, and Hambantota located in the Southern coastal stretch of the country. It also aimed to provide recommendations to prevent harbour water pollution and minimize post-harvest loses due to spoilage and finally to...

Uma Oya, which has the highest watershed of the Upper Mahaweli discharges into Rantambe reservoir. Uma Oya may have been polluted as it drains a large portion of agricultural lands. A preliminary study was conducted from April to October, 2007 sampling six randomly selected sites to determine the status of water quality of Uma Oya as baseline data....

Many different models were developed to simulate the downstream toxicity by applying upstream pesticide concentrations. However, model parameters such as land use on pesticide loading and photodegradation of pesticide under high concentrated suspended sediments are rarely being assessed. Therefore, this study conducted to elucidate the downstream p...

A sudden appearance of dead fish in an aquatic environment is a sign of environmental stress and most people believe that the fish have been poisoned of the water body. Factors that promote fish kills include rapid loss of oxygen or sudden increase of ammonia, temperature, cloud cover, algal blooms, and thermal stratification. The main objective of...

The pressure on the environment has been increased due to pollution in coastal area in Sri Lanka during the last few decades. The coastal stretch of the Eastern Province of Sri Lanka is haphazardly used by coastal communities and is highly vulnerable to coastal pollution due to increasing urbanization and industrialization activities. Water quality...