Bring a large pot of water to a boil. Cook pasta according to package instructions until al dente. Drain thoroughly. Run cold water over the pasta to cool.
Meanwhile whisk Greek yogurt, mayonnaise, lemon zest, lemon juice, Dijon, salt, dill and pepper in a large bowl.
Add the cooked pasta to the Greek yogurt mixture and toss to coat. Add peas, salmon and chives. Toss to coat. Serve immediately or refrigerate up to 4 hours in advance.