Impact of Non-Native Fish on Native Species in Amazonian Lakes
Author Information
Author(s): Danny Rejas, Monika Winder, Reinaldo Cholima, Thierry Oberdorff
Primary Institution: Department of Ecology, Environment and Plant Sciences, Stockholm University
Hypothesis
Does the presence of Arapaima gigas decrease the trophic positions and isotopic niche widths of native fish species?
Conclusion
The study suggests that the introduction of Arapaima gigas has a low competitive impact on most native fish species, except for piscivorous species which showed lower trophic positions in colonized lakes.
Supporting Evidence
- Lower trophic positions were found for piscivorous species in colonized lakes compared to non-colonized lakes.
- Most native fish species did not show significant changes in isotopic niche width between colonized and non-colonized lakes.
- The diet of piscivorous fishes shifted towards detritivorous prey in colonized lakes.
Takeaway
When a big fish called Arapaima gigas moves into a new lake, it doesn't bother most of the smaller fish, but the fish that eat other fish have to change their diet and eat less.
Methodology
The study compared the trophic position and isotopic niche width of eleven native fish species in colonized and non-colonized lakes using stable isotope analysis.
Potential Biases
Potential biases due to the small sample size of certain species.
Limitations
The study is limited by the sample size and the number of species analyzed.
Participant Demographics
The study focused on native fish species in the Bolivian Amazon.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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