Question
how can i keep a bird i think egret from eating my coi!

Answer
Hi Lisa,
Thanx for your question.  It's truly a tough issue.  Once you have the large water birds checking in on your pond the most you can do to keep them away is to have a dog or cat roaming around in the yard on a consistent basis.  Sometimes using a scarecrow or poles with strips of aluminum or other metallic papers floating in the wind helps keep these birds away.  Unfortunately, unless you have roaming dogs or cats the bigger water birds are not easily deterred.  I wish I could offer you more help.
thx,
Tom