A recent butterfly effect

The term butterfly effect has entered everyday vocabulary from the mathematics of chaos theory and refers to the possibility of a major event (such as a tornado) starting from something so slight as the flutter of a butterfly wing. This sensitivity to small changes is a characteristic of chaotic systems.  Recent news in Science magazine (9 May 2014) has drawn my attention to sea butterflies -- and the effect that ocean acidification is having on the lives of these tiny, fragile creatures -- and the environmental warning that this portends.  From the details offered in Science, I have constructed this poem of 4x4 square-stanzas:

       Warned by Sea Butterflies     by JoAnne Growney

       Sea butterflies --
       no larger than
       a grain of sand,
       named for the way  

       transparent fins
       reach from their shells,
       flap to and fro
       like butterflies. 

       Ocean acid
       at high levels
       dissolves those shells --
       kills the fragile

       sea butterflies.
       In old coal mines
       canaries died,
       warning miners.

       Today we should
       wake up, pay wise
       attention to
       sea butterflies!