Quotation marks, also called 'inverted commas', are of two types: single and double. British practice is normally to enclose quoted matter between single quotation marks, and to use double quotation marks for a quotation within a quotation:
The oceans absorb the sun's heat, transferring it to the atmosphere and distributing it around the world via the ever-moving ocean currents. This drives global weather patterns and acts as a heater in the winter and an air conditioner in the summer.
The kelp that has the most importance for our needs is a kelp that grows in the cold Canadian waters of the Atlantic Ocean, it is called Ascophyllum Nodosum. There are many kelps that have great benefits for agriculture but this particular kelp has the gold medal.