The interaction between water turbidity and visual sensory systems and its impact on freshwater fishes.

• Main Author: Fitzgibbon, Sylvia
• Format: Text
• Language: English
• Published: Memorial University of Newofundland 2020
• Subjects: Newfoundland
• Online Access: https://dx.doi.org/10.48336/frqd-vh32; https://research.library.mun.ca/14616/

An aquatic ecosystem’s sensory environment has a profound influence on multiple aspects of the life cycles of its resident species, including mating cues, predation, and sensory systems. This thesis consists of laboratory studies and a meta-analysis that examines how changing aquatic sensory information, by reducing visual information through turbidity manipulation, can impact fish species. The laboratory studies focused on the consequences of changes in turbidity on the predator-prey interactions of two native Newfoundland fish species (three-spined stickleback prey, Gasterosteus aculeatus, and predatory brook trout, Salvelinus fontinalis). The results illustrated that reducing visibility may give a prey species a sensory advantage over a predator, potentially influencing their dynamics. In order to understand the impacts of turbidity on a larger scale, I undertook a meta-analysis on fluctuations in fish communities in relation to shifts in turbidity due to reservoir creation. The analyses indicated that differential changes in turbidity influence the biodiversity and evenness of the visual subset of the fish community. Understanding how changes to the sensory environment can influence aquatic ecosystems is crucial when providing predictions for the potential outcomes of proposed anthropogenic activities altering water turbidity.