Heat 1 tsp oil in large nonstick skillet over medium heat. Season the salmon with 1/4 tsp each salt and pepper, and cook until opaque throughout, 4 to 6 minutes per side. Transfer to a plate; refrigerate until cool, about 15 minutes.
Meanwhile, place the couscous in a large bowl. Add 1 cup hot tap water, cover and let sit for 5 minutes. Fluff with a fork.
Using a vegetable peeler, remove 3 strips of zest from the orange. Thinly slice the zest and add it to the couscous along with the snap peas, onion, parsley, mint, remaining tbsp oil, 1/2 tsp salt and 1/4 tsp pepper. Squeeze in 2 tbsp orange juice and toss to combine.
Using a fork, flake the salmon into large pieces. Gently fold the salmon into the couscous.