Jayakody Arachchige Sumith
PhD candidate (May 2009 to present)
Hometown: Sri Lanka
Profession: Research Officer, Office of the Registrar of Pesticides, Department of Agriculture
Education: B.Sc. (Agriculture) Honors 1986-1992, University of Peradeniya, Sri Lanka; Certificate Training (Environmental Chemicals) Feb- Sep 2000, Japan; M.Sc. (Environmental Engineering) 2006-2007, Asian Institute of Technology, Thailand
Research: "Impact of Agriculture and Pesticides on Indigenous Riverine Fish Species in the Uma Oya (Stream) in upper Mahaweli River basin in Sri Lanka."
I am investigating the health of three cyprinid fish species viz. Ceylon Stone Sucker (Garra ceylonensis Bleeker), Striped Rasbora (Rasbora daniconius Hamilton-Buchanan) and Giant Danio (Danio malabaricus Jerdon) in response to agricultural activities.
Ceylon Stone Sucker is an endemic fish species while Striped Rasbora and Giant Danio are indigenous and all of have comparatively wide distribution in Sri Lanka and so in the Uma Oya (stream). It is located in an intensive vegetable cropping area in the upcountry Sri Lanka which has been pervasively impacted by agricultural and runoff inputs; besides, several confounding variables originating from human impacts such as urban contaminants, altered riparian vegetation and the presence of exotic fish species have also been identified.
This study will incorporate such parameters on temporal and spatial scales in order to estimate the potential imapcts of agricultural acitivities on age structure, gonadosomatic index, fecundity, hepatosomatic index, condition factor etc. on selected fish species. Fish brain acetylcholinesterase activity will be tested in vitro for possible pesticide impacts.
In addition, stream water quality, temperature, sediment and flow variations will be monitored on seasonal basis and water samples of stream sections will be analysed for pesticide residues. The results of this study will be useful basis for ecological health assessments in river systems in the Southeast Asia.
Recent scientific publications
Study design considerations for assessing the health of fish populations impacted by agriculture in developing countries: a Sri Lankan case study; Contribution to Hydrobiologia.
Fish assemblage structure of two contrasting stream catchments of the Mahaweli River basin in Sri Lanka: Hallmarks of human exploitation and implications for conservation; Contribution to Environmental Monitoring and Assessment.
Survey of current pesticide use practices in an intensive mixed vegetable-rice growing catchment, Uma-oya, Sri Lanka: Potential impact on stream fish species.