It's actually a little scary. The monkeys are scrounging the pelleted fish food that the zoo sells for visitors to feed to the fish. I can't imagine the fish meal (or whatever is in the pellets) can be especially good for the monkeys, and it certainly counteracts the "do not feed the animals" message everywhere else in the zoo. The sheer number of koi is unbelievable--there's actually an audible sound of the thousands of them making sucking/slurping noises. I'd rather fall into a vat of piranhas than into that swarming mass of carp.....
It reminds me of images from picturesque Japanese gardens, except in this case there are primates also begging for the tidbits tossed from the zoo's bridge.