Fisheries Science

, Volume 78, Issue 2, pp 209–219 | Cite as

Bottom shrimp trawling impacts on species distribution and fishery dynamics; Ungwana Bay fishery Kenya before and after the 2006 trawl ban

  • Cosmas Munga
  • Stephen Ndegwa
  • Bernerd Fulanda
  • Julius Manyala
  • Edward Kimani
  • Jun Ohtomi
  • Ann Vanreusel
Original Article Fisheries


The Malindi–Ungwana Bay fishery Kenya is one of the most important marine fisheries of the Western Indian Ocean. There are two fishing grounds: Formosa and Malindi, with a designated 5-nM no-trawl zone offshore. However, the fishery was faced with numerous resource use conflicts and a decline in catches, culminating in a trawl ban in 2006. This study analyses catches and fishery dynamics before and after the 2006 trawl ban. Results show that artisanal landings declined before the ban, but rapidly recovered within 2 years after the ban was imposed. However, shrimp landings in the artisanal fishery remain low. Commercial shrimp landings gradually declined before the ban: ~550 t in 2001 to 250 t in 2006, and the shrimp: fish bycatch ratio was 1:1.5 compared to early reports of 1:7 in 1999. SIMPER analyses shows that 6 and 16 families (groups) accounted for 91.0 and 90.2% of the similarity in catch within the Formosa and Malindi fishing grounds, respectively. Formosa was important for Claridae, Cichlidae and Protopteridae, while Malindi recorded Carangidae, Siganidae, Carcharhinidae and Lethrinidae as the main families. Future studies should therefore embark on analyses of the factors driving the spatio-temporal distributions of the species and assess the impacts of bottom trawling on fishery dynamics before the trawl ban can be lifted.


Malindi–Ungwana Bay Kenya Bottom trawl Artisanal fishery Catch per unit effort SIMPER analysis 



This publication was made possible by Flemish VLIR ICP scholarship funding from the Marine Biology Division of Ghent University, Belgium. The authors express their gratitude to the director of Kenya Marine & Fisheries Research Institute for the logistical support, and the Fisheries Department-Kenya for providing the archived data and statistics on the Malindi–Ungwana Bay fishery. To all fellow researchers at KMFRI and the fishers who took part in these surveys in one way or the other, we cannot adequately thank you, but we do hope these studies will go a long way in solving the resource use conflicts and problems of management in the marine and coastal fisheries of Kenya.


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Copyright information

© The Japanese Society of Fisheries Science 2012

Authors and Affiliations

  • Cosmas Munga
    • 1
    • 2
  • Stephen Ndegwa
    • 3
  • Bernerd Fulanda
    • 2
    • 4
  • Julius Manyala
    • 5
  • Edward Kimani
    • 2
  • Jun Ohtomi
    • 6
  • Ann Vanreusel
    • 1
  1. 1.Marine Biology SectionGhent UniversityGhentBelgium
  2. 2.Kenya Marine and Fisheries Research InstituteMombasaKenya
  3. 3.Fisheries Department-KenyaMombasaKenya
  4. 4.The United Graduate School of Agricultural SciencesKagoshima UniversityKagoshimaJapan
  5. 5.Department of Fisheries and Aquatic SciencesMOI UniversityEldoretKenya
  6. 6.Faculty of FisheriesKagoshima UniversityKagoshimaJapan

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