Does predation risk influence habitat use by northern redbelly dace Phoxinus eos at different spatial scales?

Area of Science:

• Ecology
• Aquatic Ecology
• Behavioral Ecology

Background:

• Predation risk influences fish distribution and abundance.
• Understanding spatial variations in predation risk is crucial for fish ecology.

Purpose of the Study:

• Investigate spatial variations in predation risk and abundance of northern redbelly dace (Phoxinus eos).
• Examine macroscale (littoral vs. pelagic) and microscale (structured vs. open water) habitat use.
• Test the hypothesis that P. eos use littoral zones to avoid pelagic predators.

Main Methods:

• Conducted studies in 13 Canadian Shield lakes.
• Used minnow traps to assess P. eos abundance in littoral habitats.
• Employed tethering experiments to estimate relative predation risk in pelagic and littoral zones.

Main Results:

• P. eos abundance in the littoral zone correlated positively with pelagic predation risk.
• P. eos showed a preference for structured over open water habitats in the littoral zone.
• This preference was independent of littoral predation risk but decreased with increasing pelagic predation risk.

Conclusions:

• P. eos utilize littoral zones to evade pelagic predators.
• Habitat selection within littoral zones may involve flexible anti-predator strategies beyond simple shelter use.
• Findings support predator avoidance as a key driver of P. eos spatial distribution.