Actually that mystery has already been solved. They know what modern and North Atlantic species of fish it is. LochNess is connected to the Atlantic Ocean

Believing in Bigfoot or the Loch Ness Monster TODAY is foolish. There was a Bigfoot-like being in our history, but I guess you could also say there were also Nessie-like beings in our history too, but the thing is that we live in a finite environment. That means if we took researching these things seriously, we would most likely have conclusive evidence one way or the other. Aliens are a little different because they are thought to exist "out there" where we can't possibly accurately research. These 2 creatures can't be that good at hiding. "Bigfoot" might have existed before, but not anymore.

A little on Bigfoot:

[news.nationalgeographic.com]

[livescience.com]

[smithsonianmag.com]

A little on Nessie too:

[thescienceexplorer.com]

To test DNA, you need at least a bone fragment, or scales, or hair....let us know when you find them!

It's not a mystery, it's a harmless legend.