The critically endangered Yangtze finless porpoise has seen steady growth in two protection reserves in Hubei province since 2015, and its population will exceed 100 by the end of this year, accounting for one-tenth of the total, reserve officials said on Monday.

The Tian'ezhou Natural Reserve in Hubei province is home to 90 finless porpoises and is expected to welcome nine newborn calves this year, Zhang Zhenhua, head of the reserve, said on Monday, the International Day of Biological Diversity.

"We will see 10 Yangtze finless porpoises born annually, and keep the total around 100," Zhang said, "We will move some out to other regions or natural reserves if needed in the future."