Marine ecosystems in most coastal areas of Shandong have been disrupted over the past 50 years by overfishing and the deterioration of coastal environments, endangering the fish resources. But local and national leaders are now leading a push to transform the area's fishing economy with marine ranches. With nearly 1,000 square miles of ocean areas suitable for the construction of high-quality ocean ranches, Yantai has emerged as hotbed in the emerging technology, Chinese officials say.