11 January 2017

How are Pasir Ris mangroves and seagrass meadows after the oil spill?

There are mangroves at Pasir Ris, as well as lush seagrass meadows! This afternoon, James of Sea Shepherd Singapore and I had a quick look to see how these were doing since the oil spill last week.
Mangroves at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
The rare Bakau Mata Buaya that is found here is still alive and the mangroves were only slightly oiled. The seagrasses are mostly alright although there patches were bleaching. As usual, the low water mark is lined with plastic trash (that unlike oil will never decompose). The trash is now covered in oil.



On 5 Jan, I saw this shore near the shipyard at Loyang being cleaned of oil.
Oil spill in the Johor Strait (5 Jan 2017) from Pasir Ris Carpark A
Here's a video clip of the oil that landed.
Oil spill in the Johor Strait (5 Jan 2017) from Pasir Ris Carpark A
On 8 Jan oil was still seen here. Ann N Kong shared "7 Jan (Sat) was ok at the same spot. But evening of 8 Jun (Sun) was pretty bad."
Photo by Ann N Kong.
Today at low tide, I saw small patches of oil and sheen among the seagrasses in the same area.
Seagrass meadows at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
Oil that is not removed from the shore seeps into the sand and continues to leak out. As brown stains, and rainbow sheen.
Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
Does this also happen with oil that is dispersed by dispersants (broken up into smaller particles that are no longer visible, but the oil is still there)?
Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
Oil also sticks to trash and until the trash is removed, the oil remains on the shore. While the high shore is regularly cleaned every day, there is a permanent layer of trash at the low water mark that just builds up all the time.
Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
While microbes found naturally in the seawater will eventually break down the oil into less harmful compounds, plastic is forever. Plastic pollution in this sense, is more harmful than oil.
Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017


Bakau Mata Buaya

One of the world's rarest mangrove trees grows at Pasir Ris! The beautiful Bakau mata buaya (Bruguiera hainesii) which is listed as 'Critically Endangered' not just in Singapore but globally too! I was relieved to see it was alive and doesn't seem to have any oil on it. It is now probably the last large Bakau mata buaya on the mainland. The one at Sungei Buloh is dead.
Bakau mata buaya (Bruguiera hainesii) fallen flowers
Today, it was blooming. I saw flowers in the tree, also some fallen on the ground, and a few propagules too. The tree was doing well, blooming profusely when I last saw it in Feb 2015 (2016 was swallowed up by coral bleaching surveys).
Bakau mata buaya (Bruguiera hainesii) flowering
But I am worried by the peeling bark at the base of the trunk of the tree.
Bakau mata buaya (Bruguiera hainesii) with peeling bark on its trunk
Also, a kayak is stowed near the tree, and another tree near it is toppling over and may drag the Bakau Mata Buaya down with it.
Bakau mata buaya (Bruguiera hainesii) with kayak stored nearby
Today, I was surprised that there was hardly any trash around the tree!
Area near Bakau mata buaya (Bruguiera hainesii) NOT trashy!
In Feb 2015, the tree (pink pointer) is surrounded by marine trash. I only came across one propagule on the ground. It was hard to look for them in the litter laden shore.
It appears the mangroves at Loyang escaped the worst of the oil probably because the spill reached it during neap tide. See this narrow oil line on the tree trunk which is just above the short saplings which escaped being oiled.
Area near Bakau mata buaya (Bruguiera hainesii) NOT trashy!
This large Api-api putih tree on the high shore got some oil on the base of the trunk.

Seagrasses of Pasir Ris

There are lush meadows of seagrasses on this shore.
Seagrass meadows at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
Today I saw some seagrasses bleaching at the tips. 'Bleaching' happens when the seagrasses turn transparent when lose their chlorophyll, the green pigment that helps them undergo photosynthesis. More on the TeamSeagrass blog.  But most of the seagrass meadows looked alright.
Seagrasses 'bleaching' at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
A closer look of the bleaching seagrasses seen today. In Feb 2015, I also saw seagrasses at Pasir Ris bleaching. The last time I saw this happen was when Chek Jawa was hit by a massive oil spill in 2010.
Seagrasses 'bleaching' at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
Today, the seawall was still alive with living seaweeds, snails and slugs.
Life on seawall at Pasir Ris, Loyang after oil spill in Johor Strait, Jan 2017
In the distance there was a man on a kayak tending to a long fishing net laid in the water.
Man on kayak tending fish net at Pasir Ris

Pasir Ris Park Mangrove Boardwalk

I stopped briefly at the mangrove boardwalk at Pasir Ris Park before the survey.
Pasir Ris Mangroves after oil spill in the Johor Strait, Jan 2017
I didn't see any signs of oil spill. There were lots of herons fishing, fishes swimming, I saw several jellyfishes, and also some Giant mudskippers and Rodong snails. All seemed normal there.


Here's photos by James Chua of our survey, on the Sea Shepherd Singapore page.


Posts about the Johor Strait oil spill in Jan 2017

Related posts on water quality at Pasir Ris

    Previous posts to check up on the Bakau mata buaya at Pasir Ris

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