The "Arcturus" did not encounter the thick mats of sargassum in the Sargasso Sea that Beebe was hoping to study, but Beebe and his crew experienced great success dredging creatures from the sea off the coast of Saint Martin and Saba. In the Pacific, they encountered a strange boundary between two currents of very different temperatures, containing a vast diversity of life on the border between the two. He sailed along the border between the currents for several days to document it, theorizing that it could be the cause of the unusual climate which South America had recently been experiencing. Beebe's study of these currents, and their effect on the climate of South America, is the earliest known study of the phenomenon known as El Niño.