|
Pollution and land activities threaten our seas
By Elizabeth John
New Strait Times
30th May 2004
It is the brilliance of oceans that makes the Earth look like a beautiful blue gem in space, but perils mount that threaten to render this beauty lifeless.
Elizabeth John writes why we should take heed of our threatened seas this World Environment Day.
OCEANS cover 70 per cent of the Earth’s surface and are home to more than 90 per cent of all living matter, yet they remain the most mysterious and least protected part of the planet.
Increasingly threatened by pollution, oceans suffer the effects of our activities on land — from the waste we discard and fertiliser we use to the oil that runs into the sea from streets and factories.
It is the same ocean that billions depend on for their primary source of food.
The fish we usually eat are becoming scarce, animals that live in and off the sea are choking on the plastic we carelessly discard, and coral reefs that were once safe havens for the denizens of the deep are dying in the heat of rising temperatures.
That is why this year, Wanted! Seas and Oceans: Dead or Alive? is the theme for World Environment Day which falls on June 5.
The problems that brought about this weighty question applies as much to Malaysians as it does to populations elsewhere because the seas surrounding Malaysia are suffering the same fate as many of the world’s oceans.
The seas and oceans are living systems that support a multitude of life and perform important functions. The decrease in this diversity of life is an indicator of a dying system.
Many scientists believe that such a phenomenon is rapidly occurring in our oceans, explains University Sains Malaysia’s deputy dean of School of Biological Sciences Professor Dr Zulfigar Yasin.
The Straits of Malacca, the South China Sea, the Sulu Sea and the Andaman Sea may be affected in different ways but there is a common trend of habitat degradation in all these environments, much of it due to human activities.
Overfishing, destructive harvesting of ocean resources, marine-based pollution are examples of direct effects while coastal development and riverine run-off indirectly influence our seas.
In Malaysia, the greatest threat to the seas is indiscriminate coastal development and pollution from coastal activities.
In the Straits of Malacca, heavy maritime traffic causes oil pollution in the waters, adds Zulfigar.
Traffic is indeed heavy with as much as 15 per cent of world trade vessels passing through it, according to Professor Dr Law Ah Theem and Hii Yii Siang of the Institute of Oceanography in their article on oil pollution in Malaysian waters.
"Most of us look at the sea as we would land but the sea has a third dimension — that of depth," says Zulfigar.
It is a depth that hides all our waste. The sprinkling of styrofoam and plastic on beaches is only a small indication of the heap of refuse that lies at the bottom of our seas, he says.
Many of the problems confronting our seas stem from this view — that the seas are simply a vast reservoir able to accommodate and dilute limitless amounts of pollutants.
As pollution and land-based activities take their toll on the marine environment, its support of life is diminished.
We have lost delicious fish like the terubok, of which there is just a small stock in the estuaries of Sarawak, says Zulfigar.
Giant clams – the largest clam in the world — used to be abundant with seven of the world’s eight species found in Malaysian waters.
Now close to extinction, no one even remembers its common name, kima.
Zulfigar says statistics have also shown that of the few thousand loggerhead turtles that landed a few years ago on Terengganu beaches, none has come to shore last year.
"These are the few species known to have disappeared perhaps because of their commercial value. Others have disappeared even before we managed to name them," he laments.
Just how bad is the situation?
Rather worrying, is Dr Mohamad Pauzi Zakaria’s prognosis for our estuaries and seas.
A 1997-2000 study he conducted to identify the sources, distribution and transport pathway of oil pollution along the east and west coast of Peninsular Malaysia shows that our inland waters and estuaries are contaminated with used engine oil or lubricant for vehicles.
He says in the study, most estuaries revealed a high concentration of a chemical compound called Polcyclic Aromatic Hydrocarbons (PAH).
While PAH is produced naturally in the environment, it can also be produced by the burning of fossil fuels and waste, oil spills and run-off of oils from streets and factories that are carried by rainwater into waterways.
The levels of two chemicals in the compound called benzo (e) pyrene and benzo (a) pyrene are so high in the Sungai Kelang estuary that they are comparable to the concentrations found in the Tokyo Bay area — one the world’s most polluted, says Pauzi of University Putra Malaysia’s Department of Environment Science.
The two chemicals can cause cancer and mutations and disrupt endocrine functions.
Estuaries being one of the most productive ecosystems and home to shellfish, shrimp and juvenile fish, Pauzi also undertook to study the pollution content in life-forms there.
The cockle and mussel tissues studied revealed moderate levels of benzo (e) pyrene and benzo (a) pyrene.
So the very things we have dumped into the sea are returning to us in the food we eat. It is nature’s way of telling us that what goes around, comes around.
The effect of this can be surprising and unpleasant, says Pauzi. Studies are now showing that if PAHs get into our system either through the food we eat, air we breathe or water we drink, it can cause endocrine disruption.
Because PAHs have molecular structures similar to the human hormones oestrogen and testosterone, its presence inside us can fool the body.
Pauzi says scientists are beginning to see that this confusion could have an impact on the sexual behaviour and features of some animals.
In their article published in the Department of Environment’s quarterly bulletin Impak, Law and Hii wrote that oil is destructive to the marine environment.
Its water soluble portion is extremely toxic and carcinogenic to a wide spectrum of marine organisms.
And when petroleum hydrocarbons intrude into an ecosystem, they alter most of the ecological processes and result in long-term chronic effects on marine organisms, they said.
In his work, Pauzi also looked at another more obvious problem faced along the Malaysian coastline — tar balls.
He found tar balls along the coasts from Langkawi to Johor, which he says, shows that there are many ships spilling oil in the Straits of Malacca..
Some of these tar balls are real long-distance travellers, he discovered.
In his study, published in the Environmental Science and Technology journal and Marine Pollution Bulletin, Pauzi used molecular marker techniques able to pinpoint the exact source of the tar balls, and found that 35 per cent of those collected along our coastline originate from Middle East crude oil.
Some of the lesser celebrities of the sea like sea grasses are also reeling from threats posed by pollution and human activities, including reclamation, sand mining and development on land.
Central to the web of life, sea grass meadows are a primary source of food for animals like the now rare dugong, says Dr Japar Sidik Bujang of University Putra Malaysia.
Sea grasses support an array of seaweeds and tiny filter-feeding animals and provide food for small fish which feed larger fish.
Many economically important fish, shellfish and crustaceans are found in sea grass meadows.
Sea grass converts sunlight into oxygen and release it into the water for marine and estuarine animals. It also provides habitat and shelter, helps stabilise the shoreline and maintains water quality.
Sea grass forms the basis of a complex ecosystem supporting life-forms from dugong to plankton in the seas and oceans.
But with the Malaysian coastal zone subjected to a high degree of resource exploitation and pollution, the sea grass beds are susceptible to damage and destruction, says Japar who co-ordinates the Sea Grass Research Team.
There is no specific legislation for sea grass, neither is it protected in a specific reserve. It is under threat in coastal areas of Johor, Kelantan and Negri Sembilan, among others.
When the sea grass beds disappear, so do the animals that depend on them. This may seem unimportant but the consequences could reach epic proportions.
As an expert who studies organisms associated with the seabed (benthos) explains, when these "littlest" of creatures at the lowest rung of the food chain are lost, it will cause a breakdown in the entire food chain.
"The loss of benthic communities which serve as food for fish will affect fish populations, then fisheries and later, mankind, through a chain reaction," says Associate Professor Dr Aziz Arshad, who heads UPM’s Marine Science Laboratory.
While the sea is respected for its resilience, says Zulfigar, we cannot expect it to hold out forever.
Divers will tell us that the sea is not what it used to be, adds Zulfigar, who has spent a lifetime studying our waters.
"It is not a romantic reminiscence of things past but a true comparison of the changes that have occurred over time in our waters.
It is about time we looked beyond the calm surface into the deeper troubled waters of the sea. It is time to mull over that question — whether we want the seas dead or alive.
Time to consider that whatever we thoughtlessly dump into oceans today may just come back to bite us someday.
Top
|
