I saw several like this big Carp in shallow, murky water in Delta Ponds. They are evidently bottom feeders, and seem to grow to huge size. The ones I saw were two feet long, and more. They were also thrashing around in the water and even jumping. Quite a sight. I never dreamed there were fish that big in the Ponds! Photographing through murky water had a negative effect on sharpness.
Here is some information I found on the Internet about the Carp, from Oregon Department of Fish and Wildlife:
"Invasive Species - Carp, Asian Carp or Silver Carp, Bighead Carp. Asian carp can grow quickly to over 50 pounds, directly competing with native fish for food and space. They consume phytoplankton, increasing algae, detrimentally affecting river systems and decreasing recreational opportunities. The species is native to China."