"And God said, 'Let the waters swarm with swarms of living creatures, and let birds fly above the earth across the expanse of the heavens.' So God created the great sea creatures and every living creature that moves with which the waters swarm, according to their kinds, and every winged bird according to its kind. And God saw that it was good. And God blessed them saying, 'Be fruitful and multiply and fill the waters in the seas, and let birds multiply on the earth. And there was evening and there was morning, the fifth day."
This is the Biblical account of the fifth day of the world. This was the day that God filled the oceans, lakes, rivers and skies with all their living creatures. It was the day He filled the ocean's depths with all the mysterious creatures we barely know of and all the mysterious creatures that we don't know anything of. He made the creatures great and small, and He made some to live longer than other. He gave us birds to soar and fly throughout the heavens making traveling through the air appear seemingly effortless, while man still tries his hardest to build machines that can only scratch the surface of the elegance of flying.
It was on the fifth day that God decided to venture into the heights and depths of His creation and fill them with specific life that could only live there. He went to the deepest valleys of the ocean and left His fingerprints on sea creatures we've only just begun to discover, and He went to the highest of heights and filled the skies with birds of all kinds that seem to be able to fly to outer space if they wanted too, as they fly for hundreds upon hundreds of miles.
God made the fifth day a special day because it was the day He told us that, "There is no place I do not know or have not been on my creation. I have covered it in my handiwork. You can go as deep as you want or as high as you want, but you cannot escape Me. I have created all and filled creation with all, and I know every height and depth of it." God truly knows this world better than we ever could. He has made it to be explored, and He's left a never-ending path of creatures for us to discover along the way.
-Cliff
Cliff's Note: God has truly left his fingerprints all over the earth, both at its highest and lowest points.