I believe it is keeping these regions warm because the water is flowing from the SOUTHERN part of these regions, like, how it starts from the bottom of the US, (aka Louisiana, Mississippi), and it gradually flows upward, but hot always overrules cold, so the cold water that it is flowing into is becoming warmer as it passes into the warm water from the gulf of Mexico.
Hope that this helps :)
Answer:
Keeping birds from becoming tangled in fishing line.
