Underwater tracking.

[omledufromage]

It is a little strange that a merfolk underwater searched the ground for tracks when hunting someone, is it not? 
Perhaps the tracking description should change when under water, or on watery places, such as naiadian sea. Maybe tracking should be even more difficult in these kinds of places.

[deda]

Maybe something like "sniffs the currents for the scent" or " inspects the bottom looking for the tracks"

[Kage]

- or blood passes through their gills...so they sense its direction

[Kiri-Jolith]

Ok, let them sniff the current for the scent.