Preheat the oven to 250 degrees F. Line a baking sheet with foil and arrange the salmon fillets, skin side down, on the foil. Rub the salmon with the olive oil and season with ¼ + ⅛ teaspoon salt.
Bake the salmon until just cooked through, about 15 minutes (this will vary depending on the thickness of the fillets).*
Allow the salmon to cool while putting together the rest of the salad. Remove and discard the skin, and break the salmon into bite-sized pieces.
Increase the oven heat to 350 degrees F. Spread the bread cubes on a baking sheet in a single layer. Bake until the bread is toasted, but still slightly soft on the inside.
While the salmon is baking, place the tomato wedges in a fine mesh sieve set over a large bowl. Sprinkle with ⅛ teaspoon salt and let the tomatoes rest for about 20 minutes. The tomato juices will accumulate in the bowl. Do not discard!
Place the toasted bread in the bowl with the tomato juices and toss to coat.
In a large bowl, combine the tomatoes, bread cubes, salmon, cucumber, capers, arugula, parsley and tomato. Add the dressing and toss to coat. Serve.