Effort_data_rev.xlsx : data from sampled transects. the column "group" identifies the single survey; "Length_km" is total length of the transect on effort, 
"Transect_g" refers to the transect group; "ferry_info" is the name of the ferry; "ferry_deck" is height of command deck; "Selected" identifies with *
the transect in the final analysis, sea state is average se state condition for the transect (the range is expressed when condition varied along
the transect); "Speed kn" is average speed in knots.
Sight_data.xlsx : data from sightings of fin whales. column groups identifies the single survey, and can
be used to join information from Effort_data.xlsx