When the mystery is gone, so is the magic. I conceed that an understanding of the cycles and interrelation of those cycles is very important, but not at the expense of destroying the cycles. There will be many things, as yet unheard of, to be discovered in the future. The world as we know it is a living organism that has been around for many millenia and will be around for many more. Life will always adapt and overcome.
Life is extremely hard to destroy.
If there is life under that lake, then it should be left in peace and let live, why should our curiosity disturb it and perhaps mutate it to something it shouldn't be. Surely there is a more less invasive methods of discovering its identity and origin rather than wholesale invasive methods. You'd be pretty annoyed and the invasion would be unwelcome. Also the data that they would gather would be inaccurate, you'd be hostile and not relaxed. Just because life doesn't look like us, feel like us or react like us, doesn't mean that our actions on a pristine environment won't be wrong.