Kill the pirates... problem solved. Must you kill them all? No, not if they are anywhere near intelligent. You only need kill 'enough' 'enough' being defined as 'enough to make the remaining pirates find something else to do.' Toward this end, whenever possible, pirates should be decapitated (before or after death)... their bodies sent back to land on the tide to wash up on the shore. Their heads should be attached to the mast or railing of the ship taking it... as a clear sign of what happens to pirates when they try and take that ship. Done correctly, this should all end within the month.