In a bowl, combine the tuna, scallions, cucumber, olives, olive oil and mayonnaise. In another bowl, combine the zucchini with the batter.
Fill a large skillet with enough vegetable oil to reach a depth of 1 inch and heat over medium-high until it registers 350 degrees on a deep-fry thermometer. Drop 1/4 cupfuls of the zucchini mixture in the oil and fry until golden, about 3 minutes; drain. Top with the tuna salad and serve with the lemon wedges.
