14 July 2016

Coastal boardwalks can do more harm than good

While coastal boardwalks can allow ordinary people to visit a shore without trampling it, there are also many unintended harmful long-term consequences that can occur.
Along the Changi boardwalk over water,
there is often a dense row of fishing rods and traps in the water.
These can be avoided by holistic planning for ecologically sensitive construction and maintenance, and good management of boardwalk usage.


I firmly believe that the public needs to be able to visit and appreciate some of our wild places. This is important because a love for nature is best nurtured through field trips, guided walks and a direct experience.
Visitors on a Naked Hermit Crab tour of the Chek Jawa boardwalk
Boardwalks are a great way to allow ordinary people easy access. As a volunteer with the Naked Hermit Crabs, I've personally seen how children (and adults) light up with delight when exploring nature at the boardwalks at Chek Jawa and Pasir Ris. I believe such experiences can help inspire more Singaporeans to appreciate and protect our wild places.

But boardwalks can also have unintended impacts: during construction and afterwards.

Ecologically sensitive boardwalk construction

Even with promises of 'careful' construction, my observations of how the Berlayar Creek boardwalk was built in 2011 shows how construction can be anything but ecologically sensitive. Earlier media reports on the Berlayar Creek boardwalk assured that "construction work would be carried out carefully to ensure that the ecosystem would not be affected". The 960m Berlayer Creek Mangrove Trail is touted as an "'Eco-Educational' mangrove trail starts with a lushly landscaped Entrance Plaza at the open area surrounding the future Labrador Park MRT Station."
However, in Mar 2011 I saw an astonishing extent of large steel girders have been placed very close to one another along the entire boardwalk route.
The entire structure was large enough to support three large cranes, plus lots of other large equipment.
In July 2011 I  was astounded at the progress of the construction at Berlayar Creek for the boardwalk.  The humungous steel girders pounded into the shore seems to only be to allow the huge machinery to construct a much narrower boardwalk!
Here's a closer look at the wide, huge, rusting steel girder structure supporting heavy machinery, and the more slender grey structure that looks like the boardwalk itself. Indeed, later on, the steel girder structure was removed, leaving the more slender boardwalk behind. More about the issues surrounding the Berlayar Creek boardwalk.
I was most surprised that in this day and age, the Berlayar Creek boardwalk would be constructed in such a manner. Because I have seen boardwalks being sensitively constructed on shores like Chek Jawa and Sungei Buloh many years earlier.
Chek Jawa boardwalk under construction

Ecologically sensitive boardwalk maintenance

Later on, I discovered that the Berlayar Creek boardwalk maintenance programme included regular applications of anti-fouling paint on the enormous 'legs' of the boardwalk.

Anti-fouling paint have terribly damaging impacts on marine life. From wikipedia: "Anti-fouling paint have contained organotin compounds such as tributyltin, which are considered to be toxic chemicals with negative effects on humans and the environment. Tributyltin compounds are moderately to highly persistent organic pollutants that bioconcentrate up the marine predators' food chain. One common example is it leaching from marine paints into the aquatic environment, causing irreversible damage to the aquatic life." There are less toxic alternatives, but all anti-fouling treatment is toxic (otherwise it will not prevent fouling).

Just around the corner from the Berlayar Creek boardwalk, Marina at Keppel Bay does NOT apply anti-fouling on their pontoons and actually allows beautiful marine life to settle there. Here's what the pontoons at Marina at Keppel Bay look like: with hard corals, soft corals and lots of fish and other marine life associated with reefs.
Corals growing on pontoon at Marina Keppel Bay
Wouldn't it be so much better if lush marine life can also be allowed to grow on the 'legs' of the Berlayar Creek boardwalk? And if this element could have been considered in the planning and construction of the boardwalk?

Management of boardwalk use

Boardwalks within gated parks like Sungei Buloh and Chek Jawa are less likely to be misused. Such boardwalks live up to their intended purposes and do more good than harm.

For boardwalks outside gated parks, the funding for proper management must be factored in during planning so that they do not end up being grossly misused. Funding should cover outreach and education on proper usage, engaging the community on proper usage, developing volunteers to help with the management of the boardwalk, and patrols and enforcement against improper usage. If these elements are not in place, such boardwalks are likely to be grossly misused. And the boardwalk results in more harm to the marine ecosystem than good.

A key example is the Changi Coastal boardwalk. On a typical weekend when the tide is right, segments of the boardwalk over the water is completely taken over by fishermen who lay fishing rods, traps and lines in dense numbers. This is what I saw last weekend 10 Jul 2016. This is not very different from what I saw in 2009 in the same place. This also happens on other boardwalks. Here's some letters from the public about the conflict between fishermen and others on the boardwalks at Berlayar Creek, Changi and Punggol.
Yellow arrows point to lines in the water attached to traps.
These lines are placed on both sides of the boardwalk.
These lines snag and kill all kinds of marine life and not just the targeted fish and crabs. These fishermen do not take everything they catch, often leaving unwanted animals on the boardwalk to die. I have seen seahorses killed this way.
Abandoned fishing line entangled on a sponge
Large traps also squash and damage other marine life, reducing the biodiversity beneath the boardwalk.
Fish trap laid on Changi underwater garden
Abandoned traps and lines also continuously kill wildlife until they are removed.
Abandoned driftnet at Changi
Abandoned fish nets found under Changi Coastal boardwalk.
Victims include birds, which die a slow and cruel death as they get entangled in fishing lines abandoned by fishermen.
Little Heron killed by a fishing line
from the Bird Ecology Study Group blog.
Barn owl entangled in a fishing line
from the Bird Ecology Study Group blog.
Other unintended consequences

Boardwalks bring lots of people to a wild area. Numbers of and kinds of people who would ordinarily not be in that wild area. As a result unexpected protocols emerge that may eventually damage the ecosystem.

One example is how NEA regularly sprays the Chek Jawa mangroves and shores along the Chek Jawa boardwalk because, they say: "The population of Anopheles mosquitoes on Pulau Ubin makes it a malaria receptive area. Anopheles mosquitoes are the principal vectors of malaria. Due to the large number of visitors including tourists from malaria endemic countries and residents to the island, it is imperative that adequate control measures are put in place to prevent a localised malaria outbreak."
Chemical spraying for mosquitoes at Chek Jawa in the mangroves along the Mangrove Boardwalk


All these experiences and observations leads me to be wary of any plans to build boardwalks. We need to take a closer look to make sure the planning, construction, maintenance and management of the boardwalk take into account the long-term health of the ecosystem as well.

Upcoming coastal boardwalks

Plans for coastal boardwalks recently announced include:
I am glad agencies are currently engaging the nature community on these plans so that we can share information and ideas and do what is best for nature and people.

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