Expert: Metal toxicity at sea is harming marine life

GEORGE TOWN: The heavy metal nickel – in a concentration 944% higher than natural – has been found in the sea off Penang National Park in Teluk Bahang.

It is identified as the probable pollutant that led to anoxic or dead zones with hardly any dissolved oxygen (DO) along the island’s north coast since last month and may also be killing live marine specimens in a research lab at the park’s beach.

The nickel-based pollutant is believed to have spread and caused the sea off Tanjung Bungah, not far from Penang Swimming Club, to record a DO level of just 0.08mg/L – too low to support marine life.

Centre for Marine and Coastal Studies (Cemacs) director Professor Datuk Dr Aileen Tan said Universiti Sains Malaysia’s Chemistry Department had found nickel in the waters off Teluk Bahang at 0.472 parts per million (ppm), 944% more than the standard 0.005ppm in typical sea water.

“Something dreadful has happened. Nickel concentrations cannot naturally be this high,” she said.

Lead, she added, was found at 184% above normal or 0.804ppm, when it should be only 0.005ppm. Cadmium was 32% higher at 0.065ppm instead of 0.0002ppm.

Prof Tan said while pure nickel was a metal, nickel compounds exist inorganically as salts or organically as carbon-based molecules.

“So we don’t know what the raw form of the pollutant is,” she said, adding that other heavy metals were found to be at normal levels, such as copper at 0.077ppm, where the acceptable standard is higher at 0.09ppm.

Nickel is carcinogenic, according to Indian scientists in a research paper published by International Research Journal of Environment Sciences, and nickel refinery workers face great risks of developing cancer of the lungs, nose, larynx, kidney and prostate.

Prof Tan said although the nickel is harming the marine environment, it does not bio-accumulate in marine life such as fish, so it will not contaminate seafood.

But it is highly toxic to plant life including sea algae, and Prof Tan said algae could have died in such vast amounts that their decomposition robbed the sea of DO, which in turn kills other marine life.

Since late April, live specimens such as sea cucumber and sea grass species in Cemacs have been showing signs of stress and dying.

Prized groupers worth tens of thousands of ringgit at four floating fish farms near Cemacs have also been dying by the hundreds every day since April 10.

Prof Tan’s team of marine scientists found more disturbing effects of the pollution.

On Tuesday, Cemacs scientists went on their jellyfish monitoring rounds from Teluk Bahang to Pantai Bersih in north Butterworth.

“They couldn’t net a single one. This has never happened. We’ve been monitoring jellyfish using special nets to catch them for study since 2017 and the sea around Penang is well known for being full of them,” she said.

Besides the near-zero DO level in Tanjung Bungah, Prof Tan said the sea off Monkey Beach, a popular tourist spot in Penang National Park, had a DO level of just 2.13mg/L 50cm beneath the surface and 1.84mg/L at the seabed 4m deep.

She said the only area in the north coast with a normal DO level was Batu Ferringhi, which had 5.17mg/L at the surface and 4.88mg/L at the seabed.

“That should be the normal level for our island’s north coast. The other six locations we tested were low at around 3mg/L.There is no industrial activity here and no development is allowed in Penang National Park.

“The only logical explanation for this pollution is that passing ships could be dumping something,” Prof Tan said, adding that for such a high nickel level, the dumping may have happened more than once.

She said port and marine authorities needed to ensure stronger monitoring and enforcement of the shipping lanes off Penang.

She said she had alerted government agencies including the Department of Environment and Fisheries Department, and hoped they would get to the bottom of the pollution source.