If they've completely disappeared you
could have been visited by a predator.
Probably a heron as raccoons usually
make a mess of the pond.

General Predator Deterrents:

Electric FiShock Fido fence - made to keep dogs
and cats out of flower beds, fence off the pond,
fairly close to the edge.

Pond Guardian Electric Fence - made to attach to
rocks and lay out over the water of the pond

Scarecrow Motion Activated Sprinkler - sometimes two
are needed. Can be dialed to different settings and put on a timer.
Shock of water coming on startles predators.
Attach to something solid if raccoons push it over.

Netting - sold as bird netting for fruit trees

String Fishing Line - works with some herons

Fish Decoy - works with kingfishers, will give resident fish time to
hide (build a rock cave, or sink a chimney flue or black pipe)

Heron decoy, alligator decoy - must be moved often, works for some
ponders.

Humane traps - for raccoons, for rent or to borrow from many animal
control facilities

You can go to www.froogle.com, enter in the product and find more
information and price information.

* Note - do not attempt to harm herons or any birds of prey. They are
protected by federal law. Fines and jail time will ensue, cutting into
pond dollars and pond time.

kathy :-)
www.blogfromthebog.com