class Fish
  include Mongoid::Document
  include Mongoid::Paranoia

  def self.fresh
    where(:fresh => true)
  end
end

puts [
  Fish.fresh,
  Fish.unscoped.fresh,
  Fish.deleted.fresh,
  Fish.unscoped.where(:fresh => true),
].map(&:selector)

{:deleted_at=>nil, :fresh=>true}
{:deleted_at=>nil, :fresh=>true}
{:deleted_at=>nil, :fresh=>true}
{:fresh=>true}