A gyre is another name for a swirling vortex. Ocean gyres are large swirling bodies of water that are often on the scale of a whole ocean basin or 1000 s of kilometers across (hundreds to thousands of miles across).
Lean meats are meats with a relatively low fat content. Skinless chicken and turkey and red meat, such as pork chops, with the fat trimmed off are examples of lean meat.
1 Lean meat is a great source of protein, iron for oxygen transport to muscles, and amino acids including leucine, which, Rosenbloom says, is thought to be a trigger for muscle growth.  Dark-meat chicken, compared to white meat, provides 25% more iron and three times the zinc for a healthy immune system.