Figure 1.
The location of Bardsey Island within Cardigan Bay (Wales).
The four different viewing points (A-D) and corresponding survey sectors are also shown.
Figure 2.
The dominating current speed (m/s) measured for Bardsey Island.
The current speeds for different areas to the West, East and to the North (Bardsey Sound) of Bardsey Island are shown.
Table 1.
Overview of different survey sites regarding height, sector coverage (size) and summary of systematic effort (number of 10-min scans) during sea states 0–2 with number of harbour porpoise and Risso’s dolphin sightings relative to corresponding inflection points.
Figure 3.
Hours of effort and sighting rates for different tidal states.
HP = Harbour porpoise; RD = Risso’s dolphin.
Figure 4.
Kernel density utilisation grids.
Risso’s dolphin: All data (A); August (B); September (C) and Harbour porpoise: All data (D); July (E); August (F); September (G). Densities are presented in percentiles (50; 60; 75; 95%). Sighting locations are indicated by small circles.
Table 2.
Forward variable selection based on models fitted to harbour porpoise data, based on the cross-validation log-Likelihood (CVLL).
Figure 5.
The estimated effect of environmental covariates on the observed harbour porpoise sighting rate.
Predictions were made by varying the variable of interest (e.g. Lunar cycle in the first figure), but keeping the other values fixed at median values at which they occur in the model data.
Figure 6.
The estimated effect of environmental covariates on the observed Risso’s dolphins sighting rate.
See Figure 5 for more details.
Table 3.
Forward variable selection based on models fitted to Risso’s Dolphin data.