Besoeker wrote:Waters from the deep? If so, where did they go afterwards? Where are they now?
How did fresh water and salt water creatures coexist?
In creation, God made the earth in water and it was covered with water and the cooled crust formed the original surface or the earth as God made the landscape of the earth, thus dividing the land from the water as it is written. Waters from the deep refers to the waters that were under the crust of the earth.
It should be obvious that when the water that had been trapped above the firmament in heaven was released to fall to earth as rain that lasted for those 40 days and the eruption of crust of the earth released a tremendous amount of water to flood and cover the earth. After nearly a year of the earth being soaked the soil became malleable resulting in a change in the earth's surface. Part of the earth sank down by the weight of the extra water forming the oceans and seas as we see today. The underwater volcanic action also resulted in the rise of land to make higher mountains such as Mount Everest.
The psalmist put it this way:
You covered it with the deep as with a garment;
The waters were standing above the mountains.
At Your rebuke they fled,
At the sound of Your thunder they hurried away.
The mountains rose; the valleys sank down
To the place which You established for them.
You set a boundary that they may not pass over,
So that they will not return to cover the earth.
Psalm 104:6-9
But I do not want you to be ignorant, brethren, .....
knowing this first: that scoffers will come in the last days, walking according to their own lusts, and saying, “Where is the promise of His coming? For since the fathers fell asleep, all things continue as they were from the beginning of creation.” For this they willfully forget: that by the word of God the heavens were of old, and the earth standing out of water and in the water, by which the world that then existed perished, being flooded with water. But the heavens and the earth which are now preserved by the same word, are reserved for fire until the day of judgment and perdition of ungodly men.
For in six days the LORD made the heavens and the earth, the sea and all that is in them, and rested on the seventh day; therefore the LORD blessed the sabbath day and made it holy.
(1 Thessalonians 4:13; 2 Peter 3:3-7; Exodus 20:11)
I believe fresh water and salt water creatures are an adaption by the original sea creatures because of the increasing salt over time after the flood.