There are 4 mermaid statues on the Chafariz das Sereias (Mermaid Fountain) in Praça da Sereia (Mermaid Plaza), city of Belém, in Pará, Brazil, at the mouth of the Amazon river.   map

The Belém Mermaid Fountain.

The Belém Mermaid Fountain. Photo by Eric Royer Stoner.

Each mermaid statue holds a cornucopia-like horn, which used to spout water when the fountain was installed around 1904.  The upper level has four herons.

The fountain is considered a monument to the Belle Époque in Belém, but has fallen into disrepair and neglect in recent years and there is no longer any water flowing.

It is made in cast iron, and was installed in its present location in 1904 as part of a redevelopment project championed by Antonio Lemos, Belém’s mayor from 1897 to 1912.

Prior to that, the mermaid fountain was imported from Europe, and was originally installed in the nearby Batista Campos Plaza.

I don’t as yet have information on who the artist was.

References:
http://en.wikipedia.org/wiki/Belle_%C3%89poque
http://www.monumentosdebelem.ufpa.br/index.php?option=com_content&view=article&id=6&Itemid=40