Combine tangerine juice, lime juice, maple syrup, and red pepper flakes in a saucepan. Reduce by half. Cool. Add 1/4 cup olive oil and season with salt, and set aside.
In a bowl, combine honeydew, cantaloupe, mango, orange segments, and onions. Add orange juice, extra-virgin olive oil, and mint. Season with salt and set aside.
In a saute pan, heat the olive oil, and sear tuna until medium rare. Toss with tangerine mojo and serve with salsa.