Estimates of Collision Risk of Harbour Porpoises and Marine Renewable Energy Devices at Sites of High Tidal-Stream Energy

Appendix 2: Additional results from subsequent use of Drifting PODs

The promising results from the initial Drifting POD tests in May 2010 (Figs App 3.1a,b) prompted us to return to Kyle Rhea in August 2011 for another trial (Figs App 3.1c,d).

The results of this work:

1) confirmed the findings from the initial test - that the method provides rapid perspectives on porpoise distribution in moving water.

2) confirmed the findings of the more exhaustive visual and acoustic surveys using the Silurian that porpoises are not abundant in the tidal narrows but occur at relatively higher densities in the deeper waters to the south.

Please note that the data collected in the 2011 trial were not part of this hot-spots project (funding from elsewhere) but are included here as they add to and strengthen the general findings from the other techniques outlined above.

Figure App 3.1a

Figure App 3.1b

Figure App 3.1c

Figure App 3.1d