There have been a lot of trees and branches that have washed into the river. I could see a body getting hung up. I still think a search along the banks needs to happen.
The environment in which a dead body is placed also affects its rate of decay. For instance, bodies in water decompose twice as fast as those left unburied on land.
http://science.howstuffworks.com/body-farm1.htm
Warning: this gets graphic
"In fresh water, as a large lake. Would decomposition be faster than above water? What would the possible state of decomposition be after 10 days? Would the body be recognizable?
Having helped retrieve said deceased persons from lakes and rivers, we find that, generally, in the warmer months (at least here in the western U.S.) that a person who drowned will sink as soon as the lungs are filled with water. They tend to sink nearly to the bottom, but, depending on clothing, fattines and other factors, they sometimes float sveral feet above the bottom. Decomposition begins almost immediately, but is dependent primarily on the water temperature. If the body of water is 50 degrees F or better, the body will float to the surface within about 5 to 8 days. the floating is caused by the decomposition gases trapped in various places in the body.
Although there is bloating and discoloration, very little loss of flesh actually occurs. If the body floats without being found for 2 or 3 days, sometimes the gas escapes from the body and it resinks. It may never refloat, but can as the decomposition continues.
As one poster mentioned, fish can play havoc with a dead body, but unless it's in the ocean where larger fish can work on it, this takes a lot of time."
http://www.theanswerbank.co.uk/How-it-Works/Question627631.html
