Gently pick over the lump crab meat to remove any shells. Chop the cooked shrimp into bite-sized pieces.

Dice the celery and red bell pepper, slice the green onions, and finely chop the dill.

In a small mixing bowl, whisk together mayonnaise, Greek yogurt, Dijon mustard, lemon juice, garlic powder, salt, and pepper until smooth.

In a large mixing bowl, combine crab meat, shrimp, celery, bell pepper, green onions, and dill. Pour the dressing over the mixture.

Using a spatula, fold the dressing into the seafood mixture until evenly coated.

Cover and refrigerate for at least 30 minutes to allow flavors to meld.

Serve on a bed of lettuce, in avocado halves, or with crackers. Garnish with lemon wedges and fresh herbs.