Impactos de pisciculturas em tanques-rede sobre a ictiofauna da ...

Sistemas de pisciculturas em tanques-rede modificando a composição bromatológica de peixes
nativos - Autor: Igor Paiva Ramos
Abstract
Cages fish farming activities are expanding in large dams in Brazil. However, such activity
may cause environmental impacts like loss of water quality and sediment, and changes in the
diversity of adjacent biota due to the input of organic matter. This input provides a continuous
supply as ration wastes and feces, implying attractiveness of resident fish in these sites.
Recent work shows that some native fish species present alterations in their natural diets,
which may be composed almost exclusively of artificial food (up to 97%). Thus, we
compared the bromatological composition of an omnivorous species (Pimelodus maculatus),
and a carnivore (Galeocharax knerii), both captured in areas around fish farms, and in an area
without influence of fish farms. The results show significantly higher values (p 0.05) for P. maculatus. There were no
differences (p>0.05) between G. knerii specimens captured in the tank and control areas. It
was concluded that fish farming in cages can cause changes in bromatological composition of
natural omnivorous fish species such as P. maculatus, due to the opportunism of their diets,
without affecting fish species that occupy upper links in the food chain, which is the case of
G. knerii. Thus, it is considered that this is a model that should be refined and explored in
studies related to interference of fish farming in cages.
Key words: environmental impact, cage farms, bromatology, native fish
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