When reading a poem closely to interpret its meaning and nuances,what can give clues about the theme of the poem

When interpreting a poem, you must observe the rhythm of the stanzas first and identify the symbolism of each of the stanzas. Those first few steps can help identify the overall theme of the poem. It is also important to go through the poem line by line, to look for the center point of the meaning behind. 

1.) The sun heats the water the most near the equator.
2.) The winds move the heat and water.
3.) This creates ocean currents.