Heat oven to 400 degrees. Spread seafood shells on a large baking sheet and roast for 10 minutes. (This step is optional, but it increases the flavor.)
Add the seafood shells to a large pot along with the wine, onion, carrots, celery, garlic, tomato paste, thyme, parsley, bay leaf and peppercorns. Fill the pot with enough water to cover the shells by 1-inch.
Bring to a boil, then reduce the heat and simmer for 1 hour, occasionally skimming off the foam as it floats on the top of the stock. Strain through a fine mesh strainer and discard the solids. You should have approximately 4 quarts of stock.
Add salt and taste. Season with additional salt and pepper, if needed.
Use immediately or store in the refrigerator or freezer.