Pursuant to Rob's comment about utilizing a treble hook to snag line on
entangled water birds:
is there any line trailing behind the grebe?

The Center for Coastal Studies in Provincetown MA has designed a jam grapple
that is able to grab and lock on a free line trailing from entangled marine
life. Although the grapple is heavy and designed for whale disentanglement,
a smaller, lighter version could presumably be designed for monofilament.
The technique has the advantage of not having to make direct approaches to
the animal in distress and thus minimizing evasive responses.

Fred Sharpe
fsharpe at sfu.ca
Corvallis