The submarine will most likely find data that shows the highest pressure data and the lowest temperature data (unless of course it's near a hydrothermal vent). This is because due to the depth there's a lot more water above it putting a lot of pressure on the sub, and very little sunlight to heat up the water.
Well new species can come and live there and some animals may have new food but the disadvantage is some of the animals ill die that lived there because of the changes...i hope this helped you
The slightest change in pH can destroy the substance or organism. The pH of a cell's interior helps regulate the cell's chemical reactions. For example, the pH of blood is 7.4, if blood falls to 6.8 or lower or 8.2 or higher, it results in death.