Seasonal Hydro-Climatic Consequences on Fish Harvests in the Vavuniya Reservoir, Sri Lanka
- 1Department of Bio-Science, Faculty of Applied Science, Vavuniya Campus, University of Jaffna, Sri Lanka
- 2Department of Fisheries, Faculty of Science, University of Jaffna, Sri Lanka
Int. Res. J. Environment Sci., Volume 5, Issue (9), Pages 55-62, September,22 (2016)
Vavuniya reservoir is a tropical lowland shallow irrigation tank located in Vavuniya District, Northern Province, Sri Lanka. As it is situated in the dry zone, experiencing the water scarcity probably due to the climate related changes which in turn affect the seasonal hydro-climatic factors recently. This study focused on the effects of seasonal hydro-climatic factors on fish harvests in this reservoir. The major hydro-climatic factors are monthly total rainfall (RF) and monthly mean water level (WL). RF, WL, catch/harvest and effort data were collected from January 2013 to December 2014. Semester and quarter wise categorization of both years were done based on RF and WL by using moving average techniques. There was no correlation between RF and WL (p= 0. 606 & r = 0.231) due to irrigation. In 2013, the annual fish harvest was 16 130 kg and in 2014 it was 27 005 kg. The WL showed a strong negative correlation and a significant (p=0.037) relationship between most catchability variables compared with RF. Direct and the indirect effect of climate related changes influenced the seasonal pattern of this hydro-climatic factors which in turn affect the fish harvest and fish species survival in this reservoir. Findings of this study reflected the current changes in seasonality and its consequent threats to fisheries. Hence, optimal fish harvests can be achieved via rational understanding of this baseline information in Vavuniya reservoir.
- Chandrapala L. (1996)., Trends and variability of rainfall and temperature in Sri Lanka Reports no. 26., Kinter J.L. and Schneider E.K. Centre for Ocean–Land- Atmosphere Studies, Calverton, Maryland, 90.
- Piratheeparajah N. (2015)., Spatial and Temporal Variations of Rainfall in the Northern Province of Sri Lanka., Journal of Environment and Earth Science., 5(15), 179-189.
- Williamson C.E., Saros J.E., Vincent W.F. and Smol J.P. (2009)., Lakes and reservoirs as sentinels, integrators, and regulators of climate change., Limnology and Oceanography, 54(6), 2273-2282.
- Vincent W.F. (2009)., Effects of climate change on lakes., G. E. Likens, Encyclopedia of inland waters, Elsevier, 55-60.
- Dematawewa C.M.B, Wickremasinghe E.S and Edirisinghe U. (2008)., Some effects of seasonal hydro-climatic factors on catchability of fish in minor-perennial Sorabora reservoir, Sri Lanka., Sri Lanka Journal of Animal Production, 8, 39-52.
- Statistical Handbook of Vavuniya District (2013)., District Planning Secretariat., District Secretariat, Vavuniya, Sri Lanka.
- Patrick A.E.S., Kuganathan S. and Edirisinghe U. (2015)., Effects of hydro-climatic fluctuations on catchability of fish in Vavuniya reservoir, Sri Lanka., Tropical Agricultural Research, 26(2), 402-408.
- Beam J.H. (1983)., The effect of annual water level management on population trends of white crappie in Elk City, Reservoir, Kansas., North American Journal of Fisheries Management, 3, 34-40.
- De Silva S.S. (1988)., Reservoirs of Sri Lanka and their fisheries., FAO fisheries technical paper No. 298, Rome, 128.
- Amarasinghe U.S., Nissanka C. and De Silva S.S. (2001)., Fluctuations in water-level in shallow, irrigation reservoirs: Implications for fish yield estimates and fisheries management., De Silva, S.S., Reservoir and Culture-based Fisheries: Biology and Management. ACIAR Conference 98, Australian Centre for International Agricultural Research, Canberra, Australia, 101-110.
- Coe M.T. and Foley J.A. (2001)., Human and natural impacts on the water resources of the Lake Chad basin., Journal of Geophysical Research – Atmospheres, 106, 3349-3356.
- Manawadu L. and Nelun Fernando (2008)., Climate Change in Sri Lanka., Review Journal of the University of Colombo, 1(2).
- Hirimuthugoda N., Wickramatilake Y.P.S. and Wijerathna W. (2008)., Socio-economic status of fishermen and present fishing industry in Minneriya reservoir- A case study., Sri Lanka Journal of Animal Production, 5, 103-109.
- Pet J.S., Van Desen W.L.T., Machiels M.A.M., Sukkel M., Setyohadi D. and Tumuljadi A. (1997)., Catch, effort and sampling strategies in the highly variable sardine fisheries around East Java, Indonesia., Fisheries Research, 31(1-2), 121-137.
- Moses B.S., Udoidiong O.M. and Okaon A.O. (2002)., A statistical survey of the artisanal fisheries of south-eastern Nigeria and the influence of hydro-climatic factors on catch and resource productivity., Fisheries Research., 57(3), 267-278.