3 in 10 marine, land species in Singapore could go extinct: Experts

Due to the warmer waters predicted in the near future, some of the marine species in Singapore such as the giant clams, sea-grass and mangroves could be at risk.
Monica Kotwani, Channel NewsAsia 17 May 15;

SINGAPORE: As many as three in 10 marine and land species in Singapore could become extinct when temperatures and sea-levels rise in the near future, according to biodiversity experts Channel NewsAsia spoke with on Saturday (May 16). This is over and above local species already vulnerable as a result of habitat destruction.

A global study found that up to 16 per cent of the world's species could be wiped out, if global carbon emissions go unchecked. The study also revealed limited data from Asia.

Beneath the murky waters off Singapore island, a reef ecosystem hosts about 250 coral species known to marine experts. Many are already under threat due to habitat loss, but climate change could have a devastating impact.

Experts said rising sea-levels could mean coral reefs will be submerged deeper than before and receive less sunlight, and those that thrive on the sunlight could disappear.

Another threat is warmer water temperatures. A recent local study predicted temperatures could rise by almost five degrees by 2070 if greenhouse gas emissions are not curbed.

Experts are concerned that between 10 per cent and a quarter of the marine species here could go extinct because of warmer waters in the near future. Giant clams, sea-grass and even mangroves are some species at risk.

Dr Huang Danwei, an instructor in the Department of Biological Sciences at the National University of Singapore, said: "We are living in the tropics, so many species are already living at their upper temperature limits because it is already so warm. So, just a very small increase in temperatures in sea water can lead to species going above those limits and thus going extinct. A lot of coral reef species such as reef corals and giant clams rely on a stable temperature regime."

He said if coral species are wiped out or moved to cooler waters, entire marine habitats, such as fish, invertebrates and animals, could also be wiped out. Singapore's coastal areas will also be susceptible to erosion as coral reefs provide protection against strong waves.

On land, plants and animals are also living in very narrow comfort zones. "In addition to the temperature rise, we are going to see more severe dry periods, more intense rainy periods, and this seasonality is very worrying because more so than temperatures, these plants that we see around us are not adapted to drought conditions,” Dr Shawn Lum, president of the Nature Society (Singapore) said.

“And when this happens, we are going to see many of them just unable to cope with dry periods,” he added. Dr Lum also said Nutmeg, Kedongdong or Ambarella tree and the Meranti, which is a timber species, are especially vulnerable.

Many of the plants here have closely related species in places like Myanmar, Southern Thailand and even Northern Malaysia, he said.

Thousands of years ago, entire habitats from these locations may have been able to migrate and replace the plant species here. But Dr Lum said the pace of climate change and modern developments will prevent any large-scale migration from taking place.

He estimated that between 10 per cent and a third of plant species in Singapore will cease to exist and with them, animals that rely on them will also disappear.

The global report pointed out limited data from Asia, only four of the approximately 130 studies used by the report, looked at extinction risks. Both Dr Huang and Dr Lum agreed that more needs to be done in this region - to not just study the impact of climate change on species in the tropics, but also build up capabilities.

- CNA/xk