By-catch from the Artisanal Shrimp Trawl Fishery off Negombo, Sri Lanka


Abstract views: 221 / PDF downloads: 70

Authors

  • E. M. M. I. EKANAYAKA Department of Zoology, Faculty of Applied Sciences, University of Sri Gangodawila, Nugegoda, Sri Lanka Jayewardenepura http://orcid.org/0000-0001-8270-1641
  • P. D. S. MADHUSHANKHA Department of Zoology, Faculty of Applied Sciences, University of Sri Gangodawila, Nugegoda, Sri Lanka Jayewardenepura
  • D. C. T. DISSANAYAKE Department of Zoology, Faculty of Applied Sciences, University of Sri Gangodawila, Nugegoda, Sri Lanka Jayewardenepura

https://doi.org/10.54894/JISCAR.39.2.2021.110541

Keywords:

By-catch, Coastal fisheries, Livelihoods, Shrimp trawling, Small-scale fisheries

Abstract

By-catch is one of the serious problems in shrimp trawling. This study analyzes the by-catch of a well-established traditional shrimp trawl fishery that exists in the coastal waters off Negombo, Sri Lanka. Catch, effort data and by-catch samples were collected by making fortnight field visits to the trawl landing site at Negombo from January to December 2019. The total catch (kg) and CPUE (kg hr-1) of shrimp and by-catch, shrimp to by-catch ratio, composition of by-catch and its economic benefits were assessed. By-catch reported lower CPUE values (1.3±0.5 kg hr-1) than shrimp (2.6±0.8 kg hr-1) throughout the study period except in April and July. The estimated shrimp to by-catch ratio in this traditional trawl fishery is 1:0.52. By-catch represents 51 fish species from 17 families, 3 crab species, 2 species of rays and 3 cephalopod species. The total annual by-catch was estimated at 25.55 Mt, which comprised 80% fish, 10% crabs, 3% rays and 7% of other invertebrates. Species belonging to the family Sciaenidae made the highest percentage contribution (26.04%) to the total by-catch followed by Cynoglossidae (15.87%), Clupeidae (11.18%), Pristigasteridae (10.7%) and Leiognathidae (10.51%). By-catch provides livelihoods for fifteen women fish vendors in this area, generating an average daily income of 1, 069.00 LKR and also makes 8% contribution to the average daily income of a shrimp trawl (3, 940.00 LKR). There were no reported discards in this fishery. The findings of this study will be useful in updating existing information and defining measures to manage and better utilize by catch in this small-scale fishery.

Author Biography

  • E. M. M. I. EKANAYAKA, Department of Zoology, Faculty of Applied Sciences, University of Sri Gangodawila, Nugegoda, Sri Lanka Jayewardenepura
    Senior Lecturer, Department of Zoology

References

Alsayes, A., Fattouh, S., & Abu-Enin, S. (2009). By-Catch and discarding of trawl fisheries at the Mediterranean coast of Egypt. World Journal of Fish and Marine Sciences 1(3): 199-205.

Allsopp, H. (1982). Use of fish by-catch from shrimp trawling: future development. In Fish by-catch bonus from the sea: report of a technical consultation on shrimp by-catch utilization held in Georgetown, Guyana, 27-30 Oct. 1981. IDRC, Ottawa, ON, CA.

Alverson, D.L., Freeberg, M.H., Murawski, S.A. and Pope, J.G. (1994). A global assessment of fisheries bycatch and discards. FAO Fisheries Technical Paper No. 339, Rome: pp. 233

Amarasinghe, U.S., Amarasinghe, M.D. and Nissanka, C. (2002). Investigation of the Negombo estuary (Sri Lanka) brush park fishery, with an emphasis on community-based management. Fisheries Management and Ecology 9: 41–56

Andrew, N.L. and Pepperell, J.G. (1992). The by-catch of shrimp trawl fisheries. Oceanography and Marine Biology: An Annual Review 30: 527-565 in: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London

Dall, W., Hill, B.J., Rohlisberg, P.C. and Staples, D.J. (1990). The biology of the Penaeidae. In: Blaxyer JHS, Southward A.J. (eds.) Advances in marine biology, Vol 27. Academic Press, London

Fennessy, S.T., Villacastin, C. and Field, J. G. (1994). Distribution and seasonality of ichthyofauna associated with commercial prawn trawl catches of the Tugela Bank of Natal, South Africa. Fisheries Research 20(2/3): 263-282.

Gutherz, E. J. and Pellegrin, G. J. (1988). Estimate of the catch of red snapper, Lutjanus campechanus, by shrimp trawlers in the US Gulf of Mexico. Marine Fisheries Review 50(1): 17-25.

Hall, M. A., Alverson, D. L. and Metuzals, K. I. (2000). By-catch: problems and solutions. Marine pollution bulletin 41(1-6): 204-219.

Jayakody, D. S. and Costa, H. H. (1987). Studies on the prawn fishery by-catch from the west coast of Sri Lanka. Journal of National Aquatic Resources Agency Sri Lanka (34): 65 - 73

Jayawardane, P. and Perera, H. (2003). Observations on the artisanal stake net fishery for shrimps in the Negombo Lagoon, Sri Lanka. Fisheries Management and Ecology 10: 41–50.

Jayawardane, P., McLusky, D.S. and Tytler, P. (2004). Present status of the shrimp trawl fishery in the seas off Negombo and Hendala on the western coastal waters of Sri Lanka. Ceylon Journal of Science 32: 21–37.

Kelleher, K. (2005). Discards in the world’s marine fisheries. An update. FAO Fisheries Technical. Paper No. 470, Rome.

Kumar, A. B. and Deepthi, G. R. (2006). Trawling and by-catch: Implications on marine ecosystem. Current Science 90(8): 922-931.

Lira, A. S., da Silva-Júnior, C. A. B., Eduardo, L. N., Viana, A. P., Lucena-Frédou, F. and Frédou, T. (2019). Ichthyofauna by-catch of the artisanal fishery of penaeid shrimps in Pernambuco, northeastern Brazil. Boletim do Instituto de Pesca, 45(1): 1-10

Madhushankha, P.D.S. (2014). By-catch from the non-mechanized shrimp trawlers operated in the coastal waters off Negombo, Sri Lanka. BSc Thesis, University of Sri Jayewardenepura: pp. 86

Menon, N. G., Nammalwar, P., Zachariah, P. U. and Jagadis, I. (2000). Investigations on the impact of coastal bottom trawling on demersal fishes and macro benthos. Central Marine Fisheries Research Institute, Annual Report 1999–2000, Cochin, pp. 55–57.

Paighambari, S. Y. and Daliri, M. (2012). The by-catch composition of shrimp trawl fisheries in Bushehr coastal waters, the northern Persian Gulf. Journal of the Persian Gulf 3(7): 27-36.

Philippart, C.J.M. (1996). Long term impact of bottom fisheries on several by-catch species of demersal and benthic invertebrates in the southeastern North Sea. ICES: Copenhagen (Denmark,) 22pp. Council Meeting of the International Council For the exploitation of the Sea, Reykjavik (Iceland).

Rodrigues-Filho, J. L., Branco, J. O., Peret, A. C., Decker, F. K., Luiz, T. F. and Verani, J. R. (2011). Impacts of the seabob shrimp fishery on Stellifer spp. (Perciformes, Sciaenidae) assemblage in Armação do Itapocoroy, Penha (SC), Brazil. Pan-American Journal of Aquatic Sciences 6(2): 170-184.

Saila, S.B. (1983). Importance and assessment of discards in commercial fisheries. FAO Fisheries Circular 765: pp. 62

Stobutzki, I., Miller, M. and Brewer, D. (2001). Sustainability of fishery by-catch: a process for assessing highly diverse and numerous by-catch. Environment Conservation 28 (2): 167-181.

Valinassab, T., Zarshenas, G.A., Fatemi, M.R. and Otobidae, S.M. (2006). By-catch composition of small-scale shrimp trawlers in the Persian Gulf (Hormuzgan province), Iran. Iran Journal of Fisheries Science 15: 129-138.

Van Zalinge N.P. (1984). The shrimp fisheries in the Gulf between Iran and Arabian Peninsula. Penaeid shrimps-their biology and management. ICLARM Contribution 122:71–78.

Villegas, L. and Dragovich, A. (1984). The Guianas-Brazil shrimp fishery; its problems and management aspects. In: J.A. Gulland and B.J. Rothschild (eds.), Penaeid shrimps: their biology and management: pp. 60-70.

Walmsley, S.A., Leslie, R.W. and Sauer, W.H.H. (2007). By-catch and discarding in the South African demersal trawl fishery. Fisheries Research 86: 15-30.

Weerasooriya, K. T. (1977). Trawl nets presently used in the coastal waters of Sri Lanka. Bulletin of Fisheries Research Station of Sri Lanka 27: 19-27.

Zeller, D. and Pauly, D. (2005). Good news, bad news: global fisheries discards are declining, but so are total catches. Fish and Fisheries 6: 156–159.

Zengin, M. and Akyol, O. (2009). Description of byâ€catch species from the coastal shrimp beam trawl fishery in Turkey. Journal of Applied Ichthyology 25(2): 211-214.

Downloads

Submitted

2021-02-17

Published

2021-12-12

Issue

Section

Articles

How to Cite

EKANAYAKA, E. M. M. I., MADHUSHANKHA, P. D. S., & DISSANAYAKE, D. C. T. (2021). By-catch from the Artisanal Shrimp Trawl Fishery off Negombo, Sri Lanka. Journal of the Indian Society of Coastal Agricultural Research, 39(2), 95-104. https://doi.org/10.54894/JISCAR.39.2.2021.110541
Citation