Boil the pasta in salted water until al dente (slightly hard), according to the instructions on the package.
Meanwhile, heat the butter in a large saucepan over medium heat, add the shallots, cook, stirring occasionally, for 2-3 minutes.
Add wine and salmon to the saucepan, bring to a boil, then reduce heat, cover the saucepan and cook the fish for about 5-6 minutes. Remove the salmon from the saucepan and transfer to a plate, cover to keep the fish warm.
In a saucepan, add cream and dill. Put salmon, shrimps, and mussels in the sauce, salt and pepper the sauce to taste, cook, stirring occasionally, for a couple of minutes, just to warm up all the ingredients in the sauce.
Throw the pasta into a colander, let the water drain, and then transfer the products to a saucepan with sauce, mix the pasta with seafood.
Serve the seafood pasta in portioned bowls immediately, sprinkled with fresh dill.