Andros island in the Bahamas has the largest collection of the blue holes. Andros is the largest island in the Bahamas and it more than 200 Blue Holes. Blue Holes are usually sink holes or underwater caves in shape of a circle.
Warm ocean currents raise the temperature in cold areas while the cold currents decrease the temperature in warm ocean areas.The Labrador current which is a cold current, lowers the temperature near the north-east coast of North America.