Ten years after 43 parties signed the Dark Sky World Heritage Wadden Area declaration of intent, measures have reduced light pollution in parts of the Wadden area, while experts say further improvements are needed. The partnership has sought to limit excessive artificial lighting, including outdoor lights, advertising, illuminated signs and office lighting. A representative of the Frisian environmental federation said lighting is being used more consciously in several coastal locations, but cited the growth of industrial sites as an ongoing problem.