Fig 1.
Map of study sites and depiction of BRUV deployments.
Map of BRUV deployments off the outer and lower coasts of Cape Cod, Massachusetts, USA. Exposure levels at each site are indicated by the color of the markers.
Fig 2.
BRUV design and image captures.
(a) BRUV assembly on dry land; (b) Still image from BRUV deployment with an opportunistically recorded white shark (Carchardon carcharias) in frame; (c) BRUV assembly, attached to marker buoy and with camera in place. Photo taken during BRUV retrieval; (d) Still image from BRUV deployment with a school of striped bass (Morone saxatilis) in frame.
Fig 3.
Normalized mean occupancy (seconds +/- SE) of white sharks in frame during 60-minute recordings at each site. Colored bars indicate shark exposure levels used for statistical analysis. The total number of deployments at each site is indicated beneath each bar.
Fig 4.
Predicted prey abundance across a gradient of shark exposure.
Predicted prey abundance (MaxN; ± 95% confidence intervals) from a negative binomial Generalized Linear Model (GLM) for six different prey groups across varying levels of shark exposure. Predicted values, as well as mean abundance by exposure level (dashed lines), are overlaid on top of raw observational data. Confidence intervals are not included for prey groups not observed within a given exposure level.
Table 1.
Effects of shark exposure on relative abundance of prey groups.
Fig 5.
Predicted prey arrival times across a gradient of shark exposure.
Predicted prey arrival times in seconds (± 95% confidence intervals) from a negative binomial GLM across varying levels of shark exposure. Predicted values are overlaid on top of raw observational data for the six prey groups.
Table 2.
Effects of shark exposure on prey arrival times.
Fig 6.
Foraging behaviors of smooth dogfish across a gradient of shark exposure.
(a) Predicted occurrence (± 95% confidence intervals) of investigatory bait contact by smooth dogfish (Mustelus canis) at varying levels of shark exposure; (b) Still image from BRUV deployment depicting investigatory contact by smooth dogfish; (c) Predicted occurrence (± 95% confidence intervals) of bait bites by smooth dogfish; (d) Still image from BRUV deployment depicting bait bite by smooth dogfish. Sites were pooled for plotting given the range of smooth dogfish within the study area (smooth dogfish are uncommon at Race Point).
Table 3.
Effects of shark exposure on smooth dogfish foraging behaviors.