there have been many poems about mermaids

I heard mermaids are found this way.

She who is not always near the shore

or in between abandoned mastless ships

sails torn or anchors lost.  She who is

said to be sometimes found in cities

taking the beautiful in pictures, as if

wanting to find and place the missing. 
  
                                                 C. Carreon, Through a camera lucida





Already there are many poems about mermaids, even though these are by far less than the stories about them already told.  Told by way of caution, disbelief, or awe.

If one stares at open sea long enough, they are easy to believe: creatures that resemble like you and me, though freer, under the sea; 

but only maybe 

because it could be a tail or fin of any:

sealion, snake, whale, shark.