Weihai Haodangjia Stichopus japonicus Lotte Mart Store. According to official website, a seafood market in Weihai, you can buy live sea cucumbers in Lotte Mart, a well-known stickleback shop in Weihai. Weihai, a city under the jurisdiction of Shandong Province, is located in the eastern part of China and the eastern end of Shandong Peninsula. It is bordered by the Yellow Sea in the north, east and south, the Liaodong Peninsula in the north, the Korean Peninsula across the sea in the east and Yantai in Shandong in the west.