Final answer:
There are several large gyres in the present day oceans. The most well-known ones are the Great Pacific Gyre and the North Atlantic Gyre, which are created by a combination of ocean currents.
Step-by-step explanation:
In the present day oceans, there are several large gyres. The most well-known ones are the Great Pacific Gyre in the Pacific Ocean and the North Atlantic Gyre in the Atlantic Ocean. These gyres are created by a combination of ocean currents that cause rotating vortices, which collect and concentrate floating materials like plastic waste.