Mr McIntosh explains the worry is because ducks often swallow small stones to help with digestion and can easily confuse the lead rounds, leading to lead poisoning.
During opening weekend in Wairoa, reports said seven people were caught using lead shot and 12-gauge shotguns and had their firearms and ammunition confiscated.
Two people were shooting without a gun licence, two had killed over their limit, a group were caught drinking while hunting, and one was in possession of cannabis and utensils while shooting.
The two men who had caught over their bag limit had shot 67 paradise ducks between them. The legal limit is 10 per person.
Mr McIntosh said shooters should simply follow the law or face their firearms being confiscated and a hefty fine.
He added Fish and Game also wants hunters to adhere to their campaign for a "sustainable harvest" and for shooters to stick to their quotas.