Hong Kong environmental groups have criticised a Government decision to remove protections for the vulnerable finless porpoises, by allowing underwater cable installation for the controversial HK$31 billion waste incinerator, near their main marine habitat during their most active season.

The nearby waters of south Lantau Island are important for the Indo-Pacific porpoise, which has been given the “vulnerable” status on the International Union for Conservation of Nature’s Red List of Threatened Species.

An environmental impact assessment (EIA) on the incinerator’s proposed site anticipated that the porpoises would be disturbed if the work went ahead, but predicted mitigation measures would keep any adverse impacts to an “acceptable level”.

One of the measures was to avoid installing submarine cables between December and May to minimise disturbances to the porpoises during these months. Sightings of the marine mammals were most common during that period and the construction could prevent them from feeding or being scared away.

Doris Woo Ka Yi of WWF-Hong Kong commented that: -

“Given that the porpoise is a very shy and sensitive animal, even when the construction vessels are not emitting sounds within [their] hearing range…the boats can actually scare the animal away.”

However CLP Power Hong Kong applied for a variation of an environmental permit to relocate the landing point of the cables between Shek Kwu Chau and Cheung Sha, to avoid affecting the natural rocky shore, which removes the restriction on installation works only being allowed between June and November.

Woo had criticised the Government for approving the plan in May last year without any public consultation - especially as if there were any change of environmental permit that was unfavourable to conserving the environment, no objections could be raised. Despite the fact that a variation of an environmental permit application did not require public consultation, Woo feared such changes would set a dangerous precedent for other projects to disregard mitigation measures outlined in the EIA.

In its application, CLP Power justified the removal of the construction limits, saying a study on the noise emitted during submarine cable installation works showed it had a frequency much lower than the range used by porpoises for foraging and communication.

The Environmental Protection Department said CLP Power’s proposal would avoid affecting the natural rocky shore, intertidal and sub-tidal habitats and backshore vegetated areas at the original landing site, and provided evidence that showed the noise generated from the cable installation “would not affect” the porpoises.

However Viena Mak Hei-man, vice chairperson of the Hong Kong Dolphin Conservation Society, said removing the restriction could spell “disaster” for the mammals: -

“The proponent may claim that this cable lining work is very minor, that it may not create much noise and the boats are very slow, but just a little noise could be damaging for the finless porpoise.”

Mak noted there was a significant drop in porpoise sightings from March 1 to 9 in 2018, when there began to be an increase in vessels and activities associated with site preparation works in the inshore waters of Shek Kwu Chau.

Between 2020 and 2021, government surveyors sighted the porpoises 226 times mostly in waters off southeast and southwest Lantau. This compares with 269 sightings from 2018 to 2019, and 294 the previous monitoring year.

Mak pointed out that two marine parks were established for vulnerable Chinese white dolphins north of Lantau, but since the construction of the Hong Kong-Zhuhai Macau Bridge started in 2012, the dolphins had largely disappeared from the area and moved southwest.

A CLP Power spokesperson has said that the company would adopt mitigation measures to minimise the impact on the marine mammals, including carrying out cable installation works at Shek Kwu Chau in November, and stopping works if any porpoises were spotted in an “observation zone” set up within a radius of 250 metres from the operation vessels.

Courtesy of Kat Mak

Main Source: SCMP