RIO DE JANEIRO (AP) — Sightings of humpback whales off Rio de Janeiro’s coast are surging as they recover from decimation due to commercial whaling, prompting an acceleration in the demand for whale-watching excursions to spot the huge marine creatures during their annual migration.

The species’ population has jumped from around 2,000 to around 35,000 in approximately 40 years, close to their population before whaling, said Enrico Marcovaldi, co-founder of the Humpback Whale Project. That means they are increasingly being spotted in Rio’s postcard Guanabara Bay.