The marine species have also decreased by two-thirds during the last 50 years[2] due to urban and industrial development and growth of adjacent areas around the bay.
[4] On the other hand, Jiaozhou Bay may serve as a suitable location for studying recoveries of coastal marine ecosystems.
During the Qing dynasty, it developed a large junk trade when a customs station was established near its shores, in Qingdao.
This came into force on 23 August 1914, the day of Japan's declaration of war on Germany, after a Japanese ultimatum for unconditional German evacuation of the colony had expired.
Instead, the Treaty of Versailles acceded to Japanese demands at the Paris Peace Conference and assigned all former German Pacific territories and islands north of the equator to Japan, including Jiaozhou Bay.
[10] This unexpected decision led to China-wide protests known as the "May Fourth Movement", which is now regarded as a significant event of modern Chinese history.