one pond goldfish gulping air

[brettpim]

One of our pond goldfish is frequently gulping air.  It will rest on the bottom of our shallow area very still and then swim vigorously to the surface, take a gulp of air and swim a bit, often releasing a bubble. This has been going on for some days. Other fish in pond seem fine (10 large goldfish and approx 30 baby goldfish). Water chemicals all check out fine. Water clear.  Lots of algae but this happens every year in late summer.

we are looking for advice, how to diagnose and how to treat
thanks

[woof99]

Hi there!
You might want to ask for Goldfish advice at;
http://thegab.org/

There are the Goldfish experts! 
Good luck!