In this aerial photo taken on May 28, 2019, workers harvest kelp in Rongcheng city, East China’s Shandong province.[Photo/Xinhua]

Harvested kelp are towed towards a nearby port in Rongcheng city, East China’s Shandong province, May 28, 2019. [Photo/Xinhua]

In this aerial photo taken on May 28, 2019, harvested kelp are towed towards a nearby port in Rongcheng city, East China’s Shandong province.[Photo/Xinhua]

Workers harvest kelp in Ailun Bay of Rongcheng city, East China’s Shandong province, May 29, 2019.[Photo/Xinhua]