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Aquaculture ponds, a
Jamaican study: the impact of birds on fish production
S. Seian Morrison* and Peter Vogel
Department of Life Sciences, University of the West Indies,
Mona Kingston 7, Jamaica, West Indies.
*Corresponding author. E-mail:
seian.morrison@uwimona.edu.jm. Tel: 1 876 927
2290. Fax: 1 876 977 7582.
Accepted 19 November, 2009 |
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The increasing use of freshwater fish farms by water birds
poses conservation and economic problems as birds compete
with man. This study sought to assess bird species diversity
of an artificial wetland and the impact of birds on Tilapia
production. The farm had a relatively high diversity (0.714)
as 16 species of birds foraged on the farm as either
residents or visitors each day. Eight of these birds were
previously identified as problem species on aquaculture
farms and may result in large losses in fish crops.
Predation loss per grow-out period (PLOP) was calculated to
be 20.92% for the fish farm and was due mainly to the Brown
Pelican, Great Egret, Least Tern and Snowy Egret. This was
2.95% less than the average loss per pond and may be higher
as loss due to Black-crowned Night Herons at nights was not
assessed. There was a positive correlation with success,
fish density and distance from the farm house. The findings
indicate that bird predation has a negative impact on
Tilapia production. Farm construction, stocking densities,
the length of the grow-out period, and the use of non-lethal
depredation strategies are important factors in reducing
loss associated with bird predation.
Key
words:
Tilapia, aquaculture, negative impact, predation, water
birds.
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