An institute that tracks the population of Humpback whales that live along Brazil’s coastline says the number of the once-threatened mammals has tripled over the last 10 years.

The Humpback Whale Institute says there are now almost 10,000 humpbacks off the Brazilian coast. In 2002, the institute counted only 3,000.

Fat from the whales once was used as fuel for public lighting and in construction. Hunting was banned in 1966, when only about 1,000 whales were left.

Restoration efforts have helped the species recover in spite of global warming, accidents with boats and fishing nets.