Cook pasta according to package directions and add zucchini to pasta the last 1 minute of cooking. Drain and keep warm.
Meanwhile, skin fish, if necessary. Rinse fish; pat dry. Cut into 1 inch pieces.
In a large nonstick skillet, cook and stir fish in hot oil over medium-high heat for 3-5 minutes or until fish flakes easily with a fork. Remove from skillet. Add milk, cream cheese, tarragon and pepper to skillet. Cook and whisk until cream cheese is melted and sauce is smooth. Return salmon to skillet. Cook and stir gently until heated through. Serve over fettuccine and zucchini.