DESTROY NOAH'S ARK

[Jackalope]

Really.

A sea grass that lives in relatively warm, shallow salt water (Mediterranean Sea from 1-35 meters depth) could survive after being submerged in deeper, colder brackish water as well as silt / sedimentation?

You know this, how?

You do realize that the habitat ranges of sea life tends to be a lot narrower than "must live in water", do you not?

Of coarse I know that. You however do not know the conditions any more than I do, I said it was possible and apparently it survived.

The question was not related to what you know, GC, but HOW you know it. You can only think you "know" this by presupposing the very event that is under contention (a global flood).

It isn't necessary for me to know the exact conditions. Do you understand what it is about green aquatic plants that makes them green, what biological mechanism they operate on, and what said plants require in order to survive? Chlorophyll, photosynthesis, and sunlight. Do you understand why photosynthetic aquatic plants who depend on the sunlight found in relatively shallow water cannot survive in deeper water? For the very same reason that a person cannot survive on a teaspoon of food and water a day for very long.

You are correct in that we could not know the exact conditions, but it is not necessary to do so to make some deductions and inductions about the hypothetical event. I know you're aware from other conversations that I am a very experienced scuba diver. I've dove to 40 meters in waters at many latitudes from near-arctic to near the equator in all conditions. The conditions may vary, but there is one factor that is universal: sunlight diminishes rapidly with depth even in the clearest water, and in water with suspended particulate matter (like flood runoff water), it can get very dark very fast - dark enough that even as shallow as 20 meters, I've needed a very large, bright flashlight to see during a summer algae bloom.

There is a very good reason that P. oceania is not found deeper than 35 meters. As you descend down the water column, the distinct differences in sealife found at varying depths is easily observable - and what starts disappearing as you pass through about 30-40 meters is photosynthetic plants.

Even if I make the generous concession that the water conditions were otherwise suitable for aquatic plant survival, the sunlight issue is inescapable.

Genesis claims that the waters were deep enough to cover the highest mountains of the world. How deep was that? How long would aquatic plans have to survive without access to sunlight?

P.S. You know what else kills aquatic plants? Sedimentation. What occurs during flooding? Sedimentation.

Derp.