So it is not just farmed fish grown in the sea off the coast of northern Penang Island that have died. Wild fish too have perished along the Teluk Bahang shore.
What have we learned so far:
- the damage to the coastal ecology was “unimaginable”
- heavy metals were detected but the level was not high enough to kill fish in the May incident
- there was a shift of phytoplankton diversity; high concentration
- the dissolved oxygen at the affected area is extremely low (below 4mg/L, even below 2mg at some places)
- there are signs of eutrophication (excessive nutrients) in the very shallow bay – may cause the depletion of dissolved oxygen – excessive nutrients in the water (phosphate and ammonia)
- nutrient levels still high
- strong current and waves from Typhoon Lekima might have stirred some toxins from the seabed
- the high mortality is so drastic; it happened during neap tide where the water movement is minimal
- the combined factors of toxin and low dissolved oxygen may have caused a stressed environment for fish
- the earlier incident happened gradually with groupers – followed by other fish like snappers a couple of weeks later
- she cannot not rule out the water quality in Teluk Bahang, which has degraded over the years, as the reason the fish were dying
- the sea stank of hydrogen sulphide and ammonia
- latest: high concentration of ammonia and nitrate up to 7km from the coast; ammonia level in the seawater was 0.07mg/L but at 7km away, it rose to 0.9mg/L
I was told: “Hydrogen sulphide and ammonia are gases released from decomposition of organic matter under anaerobic (oxygen-starved) conditions, probably at the sea floor, and get churned up with disturbance….”
So the big question is, what exactly is the stuff on the sea bed (that was dumped there?) that got churned up whether by the currents or by dredging or whatever?
- fisherman from Bagan Ajam on the mainland spotted thick sedimentation plume behind a maintenence dredger leaving the harbour
- they are supposed to dump the dredged material 13km from the North Channel or 11km from Mukah Head
- maintenance dredging of North Butterworth Container Terminal is done every year
- but why the need for dredging so often to keep the depth at 11-12 metres?
- what is causing the shallowing of the port waters? is there a study to find out the reason?
- who is ultimately footing the bill for this “maintenance dredging”?
Slightly further north at the Tanjung Tokong/Gurney Drive reclamation site, where 890 acres is being reclaimed:
- E & O says it has dumped dredged material in the waters off Mukah Head (the approved dumpsite) until 20 January 2018
- after that, the dredged material was used at the E&O Gurney reclamation site
- Has there been any study of the impact of the first phase of the Sri Tanjung Pinang reclamation?
Directly across the channel from Gurney Drive, a fisherman at Bagan Ajam in mainland Penang told me their fish catch has plummeted by up to 90% in recent years.
What will this do to the price of fish in the local markets?
With our waters already so polluted, silted and with low dissolved oxygen, with fish dying by the thousands in northern Penang Island, do we really want to finish off another precious source of fish off the southern coast of Penang Island by reclaiming 4,500 acres to build three unnecessary artificial islands – along with an additional 1,600 acres of reclamation on mainland Penang.
Bear in mind that the population of Penang is barely rising; so why the need for such massive reclamation when there is still land around Batu Kawan?