Not necessarily if those marine fossils we see today were already fossils when they got stirred up by the "breaking up of the fountains of the great deep" (as the bible describes). Also, remember the flood subsided after 150 days so it would have left a terrible mess of trees, animals, and human remains left out in the sun to rot and decompose. Being left out in the open like this could have caused decomposition much like the American buffalo which left few fossils in spite of numbering in the multi-millions. This mess also could have become part of the world's oil supply. Notice how for some strange reason there is an incredible amount of oil right next to Lebanon in Iraq and Saudi Arabia.
Using the logic of your argument, the same should have been true of fish, squid and shrimp remains left in now dry areas covered by the flood. Thus, these remains in the strata in Lebanon and elsewhere, again, using your argument, couldn't possibly be remains left by the retreating waters.
From the article:
The Mysterious Origin and Supply of OilKer Than
...A so-called fossil fuel, petroleum is believed by most scientists to be the transformed remains of long dead organisms. The majority of petroleum is thought to come from the fossils of plants and tiny marine organisms. Larger animals might contribute to the mix as well...
http://www.livescience.com/9404-mysterious-origin-supply-oil.html
There's nothing mysterious about it.
Also for 150 days or more marine life would have fed on the human and animal remains, so there might not have been much left; and that which was left was left exposed to the sun to decompose, and to possibly be eaten by those animals which were taken with Noah.
They wouldn't have eaten the skeletons. Also, the small numbers of animals - either one pair or seven of each kind - disembarking from the ark in what is now eastern Turkey, would not have been enough animals to have eaten the remains of all those animals, all over the earth.
Logically, if this flood happened, we would find several areas where skeletal remains of land animals are mixed with those of marine creatures.
Your dodge to explain why the remains of land animals weren't mixed with those of the fish, squid and shrimp is typical of pseudoscience. Scientific theories - or, for that matter, any intellectually honest theories - stand or fall on the rigors of pass / fail tests. In other words, if something a theory asserts is true, we would expect certain conditions to also be true. If they are not, support for the theory is weakened, and the theory itself may well be completely falsified.
For example, were we to find embedded in rock of the Cambrian strata a mammal fossil, fossilized by the same material and to the same degree a that of a trilobite embedded in the same rock; that would completely falsify evolutionary theory. Notice that I was fairly precise in what I said about the fossils. We're not talking here about possible mixing of fossils from different strata due the their being carried there by a river or a particular flood. Since the fossils would be part of the same rock, fossilized by the same minerals and fossilized to the same degree, accidental mixing as a cause would be eliminated.
Now, I'm proposing that you come up with a pass / fail test for a scientific theory of the flood, one that, should it fail will falsify flood theory, just as a mammal fossilized in Cambrian strata with trilobites would falsify evolutionary theory.
