Hi F
Take a look at this post I posted back in December 2011:
http://www.websleuths.com/forums/sh...ember-10-2011-Thread-13&p=7440710#post7440710
"Yes they CAN find out wheter she drowned or not even if it is only skeleton remains, read Dr. Badens explanation on this + more in this link:
http://www.newsday.com/news/breaking...eath-1.3388774
Here is a quote concerning drowning:
The examination of skeletal human remains found Tuesday near Oak Beach, besides determining whether they belong to a missing Jersey City woman, can also point to the cause of death, an expert said.
Key forensic clues can survive in bones and teeth even over the 19 months the remains -- if they are Shannan Gilbert's -- would have been exposed to the elements, said Michael Baden, a former New York City medical examiner.
Police theorize Gilbert drowned in a wetland thicket. Baden said water contains diatoms, a type of phytoplankton that if inhaled, can later be detected in bone marrow.
"If they are present and they match what's found in the water, that will indicate she was alive and breathing when she went into the water," he said."
SO that means...
IF Shannan died by drowning she would, no matter what, have diatoms in her bone marrow.
But if you want to be able to find out what pool of water she drowned in, you are right, you need a sample of the water you believe she drowned in, in order to be able to compare if the diatoms in her marrow is concistant with the diatoms in the pool of water you belive she drowned in (she was found in).
BUT if Shannan did NOT have any diatoms in her marrow, then she did NOT drown.