If it doesn't exist, can it be endangered?

Everyone loves a mythical lake monster. And no, this isn't about Nessie.

Hunting Season Opens for Mythical Creature
By KARL RITTER, Associated Press Writer Fri Nov 11,12:35 AM ET

I did a bit of inquiry, and found that there is a pseudo-science (at least, it sounds like one) called cryptozoology - the study of hidden creatures. I don't see why it couldn't be a true science or discipline, in a sense - after all, scientific expeditions to trawl Loch Ness, etc. have been carried out (and haven't found anything I think). It would be a mixture of history, anthropology, and natural science for most creatures. The problem is probably most of those who subscribe to this cryptozoology would be of the non-scientific kind (which is ok for them, but detrimental to being taken seriously by skeptics).

In any case, a good site for those interested in such things is the PBS site for a NOVA programme:

NOVA Online: The Beast of the Loch Ness
There's a write-up on "fantastic creatures" in general, including those which were eventually found, and a great 3-pager on Nessie, including a treatment of the "surgeon's photo" which is supposed to be a hoax, and the sonar-equipped expeditions to find the creature.

The episode for television follows a 1997 sonar expedition.