Negative effect of turbidity on prey capture for both visual and non-visual aquatic predators

1. Turbidity plays an important role in aquatic predator-prey
interactions. Increases in turbidity are expected to reduce prey capture
rates, especially for visually oriented predators. However, there is also
evidence indicating that turbidity may have little or no effect on
predation rates. 2. Here, we conducted a systematic review and
meta-analysis of the relationship between turbidity and capture rate. We
explored possible sources of heterogeneity in the effect sizes (capture
strategy, predator’s body size, relative eye size and turbidity range in
the experiments) while controlling for the dependence among effects sizes
and phylogenetic relationships among predator species. 3. We found a
consistent negative effect of turbidity on prey capture and that turbidity
range (manipulated in the experiments) was the main factor accounting for
between-study variation in effect sizes. Also, capture rates of both
visually and non-visually oriented predators decreased with an increase in
turbidity. In addition, for visually oriented fish predators, the relative
eye size did not influence the effect sizes. 4. Despite the paucity of
studies for some groups of aquatic predators (mainly in tropical regions),
we provide corroborative evidence that turbidity is a critical
environmental factor controlling predator-prey interactions. This result
is especially relevant considering that changes in turbidity is a
human-induced pervasive environmental alteration resulted from, among
other mechanisms, runoff after deforestation, eutrophication or
oligotrophication in reservoir cascades, which imply changes in
predator-prey interactions.