Data for "The effects of suspended sediments, dye, and their variation on fish behavior"

Many freshwater environments are becoming darker as human activities intensify. Suspended sediments released by human-mediated erosion and manufactured dyes discharged into waterways act as pollutants that alter the visual environment. These substances absorb and refract light, reducing visibility levels and potentially interfere with animal behaviors such as predator avoidance, foraging, and social organization. Predicting the effects of such visual pollutants is complicated by the inherent temporal variability of pollutant exposure due to natural factors, such as rainfall, and human influences, such as daily patterns in human water use. Here, we compared how a two-day exposure to stable versus fluctuating levels of suspended sediments and dye impact the normal social, movement, and anxiety behaviors of zebrafish (Danio rerio). Following the behavioral observations, we then assessed the visual perception of the fish under treatment conditions using both clear water and low visibility conditions optomotor response (OMR) assays. Overall, we found that both suspended sediments and dye conditions decreased fish aggression, increased social cohesion, and had minimal effect on anxiety behaviors. In contrast, the effect of fluctuating visibility had mixed impacts on behavior depending on the visual pollutant, with stable sediment exposure decreasing fish movement while fluctuating dye increased fish movement. Similarly, fluctuation counteracted the reduction in fish aggression by suspended sediments and dye but had no clear effect on social cohesion. Meanwhile, exposure to sediments and dye did not affect zebrafish visual perception as measured by our OMR assays, suggesting visual capacity did not change in response to our exposures.