Jeong Yak-jeon
Jeong Yak-yong's elder brother who, exiled to Heuksando in the Catholic Persecution of 1801, surveyed its sea life in the Jasan eobo
Through Yi Byeok, Yi Seung-hun and others he took up Western learning and Catholicism. Exiled to Heuksando in the Catholic Persecution of 1801, he never returned and died in exile. In the Jasan eobo he recorded the names, forms and habits of the fish, shellfish and seaweeds of the Heuksando waters from his own observation.


