Which calligrapher is this calligrapher and what does it say?

Ding Hai Qin Gong Zhang Qin Gong's Seal

Zhang Qin Gong, whose courtesy name is Zi Qian. Born in 1957, his ancestral home is Shandong Province. He is a member of the Chinese Archaeological Society, a member of the Chinese Museum Society, and a director of the Chinese Yixue Culture Research Association. Gongguo painting landscape, calligraphy, seal cutting. He studied calligraphy under Jiang Weisong and Du Xianzhen. Shanshui studied under Hei Bolong. He is proficient in poetry and music, and is good at playing the guqin and playing the qin. In his early years, he graduated from the History Department of Shandong University, majoring in archeology. He has been engaged in field archeology and museum work for decades. His works include a five-character long poem on calligraphy and a thousand-character essay on calligraphy, "On Calligraphy and Songs", "Talks on Chinese Guqin", "Lecture Notes on Couplets", etc. He once served as the director/appraiser (chairman of the expert group) of an international auction company in Beijing. Currently, he is the editor-in-chief of "Care for Growth" magazine of the Education Development Center of the China National Working Committee. http://www.hhchina.org/html/wentiyule/shuhuapindao/2010/0107/664.html