The flurry of activity sparked criticism and, after the giant mammal died, authorities were accused of taking too long to act.

It took 13 days from the first sighting before patrol boats were sent to tell sightseeing boats not to go near the whale.

Secretary for Environment and Ecology Tse Chin-wan denied authorities were slow to react, saying no-go zones were not declared because of legal limitations.

Associate professor of oceanography David Baker, of the University of Hong Kong, told the Post that despite those limitations, sea patrols could have been stepped up.

“If the police had, say, a wildlife enforcement task force or a special unit that could be deployed, they could provide a stronger deterrent to the public to abide by local regulations,” he said.

Hong Kong has a code of conduct only for dolphin-watching activities, with advice for boaters and spectators visiting Chinese white dolphins, but compliance is voluntary. Critics have also called the rules ambiguous and hard to execute.

Baker’s research had shown that Hong Kong had “far more than 6,000” marine species, accounting for a quarter of all documented in the whole of the country.

Aside from the Chinese white dolphin and finless porpoise which were considered resident species, there had been previous sightings in Hong Kong waters of critically endangered scalloped hammerhead sharks and vulnerable great white sharks, he said.

Of about 80 whale, dolphin and porpoise species in the world’s oceans, 17 had been found living or dead within Hong Kong waters, he said.

“We think of Hong Kong as a melting pot for different people from all over the world. It’s also a melting pot for marine species migrating all over the ocean,” he said.

He explained the city was at the convergence of three ocean circulations – the Hainan, Taiwan and Kuroshio currents – transporting nutrient-rich seawater to the waters around it.

Baker’s research is in line with that of the university’s Swire Institute of Marine Science, which has found genetic traces of more than 8,000 animal species locally in a long-term study.

More than half of that total recorded had not even been identified locally, said project leader Shelby McIlroy, the university’s research assistant professor of molecular ecology.

The Hong Kong Marine Protection Alliance was one of the advocacy groups that had asked authorities to set up a mandatory 200-metre exclusion zone to prevent threats to the whale from nearby boats.

“There is a need for Hong Kong to expand its marine protected areas to protect all users of the waters, including mammals, corals and other sea life, and to allow the biodiversity to improve and flourish,” said its spokesman, Stan Shea Kwok-ho.

He noted that less than 5 per cent of the city’s waters were currently protected.

Minister Tse said on a radio programme that the government would strengthen public education about whale-watching etiquette and consider amending legislation to empower conservation officers to handle similar future emergencies, including having the right to drive away ships.

But NGO World Wide Fund for Nature Hong Kong urged the government to take a more rigorous approach to protecting marine wildlife.

Since 2018, it has called for 30 per cent of the city’s waters to be designated as protected areas before 2030.

“Port Shelter, where the whale incident took place, is our priority site for marine protection,” said Loby Hau Cheuk-yu, its assistant manager of oceans sustainability.

“Conservation is not only about protecting individual species or some charismatic animals, but also their ecosystems, such as preserving their habitats and mitigating the human impact on such areas.”