Ongoing “Blue Carbon” Construction Work in the Hwaseong Maehyangri Wetland Protected Area

Dr Nial Moores, National Director, Birds Korea

On February 21st, I visited the Hwaseong Wetlands Flyway Network Site (FNS), designated back in 2018, for the first time in over a year. The main aim was to look at the current conservation status of the FNS ahead of a presentation about a proposed international airport within the rice-fields of the FNS. We were astonished to see heavy construction machinery and dozens of workers on the tidal flat at 37.053°, 126.753° within the Hwaseong Maehyang-Ri Wetland Protected Area, itself within the FNS. Designated as a Wetland Protected Area in 2021 this tidal flat should be under the strictest legal protection. Birdless on this day, the area with the ongoing construction has long been known as the most important roost site in this part of the nation, both by researchers and bird photographers. We therefore asked the site manager what was happening. He explained that this was a central government approved project aimed at increasing the area covered with Suaeda japonica as part of efforts to increase the blue carbon value of the area.

It is extraordinary how little effort is currently being made to conserve shorebirds – a vital component of this Wetland Protected Area – either in the FNS or along the Hwaseong coast. Additional threats include an approved project to build a boardwalk along the coast from Gunpyong to Maehwari, directly impacting a major shorebird roost there; the approved development of a hotel complex and resort in the immediate hinterland of the tidal flat roost site (a project which has already provoked expressions of serious concern from renowned shorebird experts); and the proposal to build a massive international airport within the rice-fields of the FNS, with the runway more or less ending at the reclamation lake (used by many thousands of shorebirds during highest high tides as well as tens of thousands of geese) , and only 2.5km from this same Wetland Protected Area. Is it not possible to learn from the terrible tragedy at Muan International Airport and avoid locating airports within and next to internationally important wetlands?

On February 21st, while there were 1,900 Eurasian Curlew and more than 2,000 Common Shelduck at Maehwari, just outside of the FNS, there were no birds at high tide at all in the main roost area of the Hwaseong Maehyang-Ri Wetland Protected Area.

Below follows an initial response provided on behalf of Birds Korea- to help elicit expert opinions that can be passed on by Mr Jung Hanchul to relevant authorities in an effort to challenge the methodology of this blue carbon project, and to raise awareness of the conservation needs of shorebirds along this part of the coast.

The restoration of saltmarsh can, of course, make an important contribution to biodiversity conservation, to fisheries, and to climate change mitigation including increasing “blue carbon”. Therefore, there are many examples of saltmarsh restoration practice around the world, and a large body of scientific research to support the design and implementation of such projects.  As a conservation scientist who has conducted research on shorebirds including at the Hwaseong-Maehyang-Ri Wetland Protected Area (Moores et al. 2022), and who has contributed to literature on shorebird roosts (e.g., Jackson et al. 2020), there seem to be three major areas of concern: (1) the possible impacts of hard engineering construction on tidal flat health in the immediate area; (2) the impacts on shorebirds during and post-construction within an area depended on both by foraging and especially roosting shorebirds; and (3) the potential impact on other protected areas of permitting such construction to go ahead within a national Wetland Protected Area.

1. None of the examples of saltmarsh restoration that I have seen in e.g., the USA or Europe, have entailed the construction of a wall across an open tidal flat; the driving of heavy machinery on nationally protected tidal flats; or the employment of large teams of workers hammering structures into the tidal flat.  Examples I have seen (because they are common practice) include the measured introduction of changes, made under the direct supervision of teams of well-trained specialists.  In such areas, these teams use well-tested methods of saltmarsh restoration, as documented in peer-reviewed literature including e.g., removal or breaking of existing dykes to restore tidal flow; local addition of sediments; and/ or use of small artificial barriers made of natural materials, wood or geotextiles, to increase sedimentation and reduce erosion. Construction of a seawall across a tidal flat appears to be an experimental hard engineering approach.  In other areas, large vehicles driving on the mud have resulted in compacting of sediments, causing damage to affected invertebrate species; and the addition of walls have caused locally important changes in patterns of erosion and sedimentation, changing levels of salinity the landward side of the wall following heavy rain events. It seems necessary to ask what scientific evidence is there that the approach now being taken in the Hwaseong Maehyang-Ri Wetland Protected Area has been tested and proven to work? How will negative impacts on tidal flat health be avoided?
2. The area currently undergoing construction is one of the most important areas for roosting shorebirds in the ROK during neap tides and tides below about 7m.  The immediate area meets several Ramsar criteria for the identification of internationally important wetlands, including concentrations on some dates of more than 20,000 shorebirds, and regular use by an assemblage of globally threatened species, in concentrations of 1% and more of their populations (see Moores et al. 2022).  While the tide is low, extensive tidal flats are exposed, and there are many options available to shorebirds as they disperse over a wide area to forage.  During high tide, however, the same species are concentrated into much smaller areas, closer to land, making them much more vulnerable to predation.  Although a few species (e.g. Terek Sandpiper) regularly roost on walls, most tidal flat obligate species prefer to roost standing in the water or at the water’s edge (e.g., globally Endangered Far Eastern Curlew); or on gently sloping mud or sand near to the water (e.g., globally Endangered Great Knot) or in drier, higher areas of the tidal flat above the reach of most high tides (e.g., globally Vulnerable Siberian Plover).  Almost all tidal flat obligate shorebird species, including Terek Sandpiper, try to avoid areas of dense vegetation during high tide because all species require an open, unobstructed view of the sky in order to see aerial predators. The addition of a sea wall and of structures with straw walls as now being constructed will create multiple “blind spots” for roosting shorebirds. It therefore seems likely that after this construction, many shorebirds will be unable to use this area for roosting.  Many, or most, shorebirds will therefore be forced to fly to the Hwaseong Reclamation Lake for roosting even during neap tides. Commuting from the tidal flat to this reclamation lake every high tide will make additional demands on the energy expenditure of these shorebirds. For some individuals and species, especially long-distance migrants during northward migration, this additional demand on energy might be unsustainable. Most of the shorebirds that forage in the Hwaseong Maehyang-Ri Wetland Protected Area will be forced to become even more dependent on the Hwaseong Reclamation Lake for roosting.  This artificial wetland, however, is sometimes unavailable for roosting shorebirds because water levels are kept too high. It seems reasonable to ask what research was conducted in order to assess the likely impacts on roosting shorebirds of this “blue carbon” project? And what measures will be taken to reduce the increased energy costs to shorebirds?
3. Wetland Protected Areas are supposed to provide long-term (permanent?) legal protection. That this kind of project has been permitted in the Hwaseong Maehyang-Ri Wetland Protected Area suggests that all other protected tidal flats in the ROK could and might also be targeted by this kind of development project. The cumulative impacts of this kind of development would likely be enormous and negative, both on biodiversity and on peoples’ experience of wetlands. Instead of encouraging people to cherish the Outstanding (Universal) Value of internationally important tidal flats and natural processes, this hard engineering approach suggests that everywhere can and should be controlled by people to pursue whatever policy is considered to be a priority at that time.

Respectfully, in the absence of contrary information, it therefore seems wisest to us if the project can be stopped and reviewed, until measures are taken to ensure the continuing international importance of this area for shorebirds and other tidal flat obligate bird species.

Notes: Visit on 21st was part of preparation for a presentation I made in the National Assembly complex about the high bird strike risk and cost to biodiversity in Seoul on February 24th. The visit was with Mr Jung Hanchul (Hwaseong Wetlands Conservation Researcher & Campaigner, and Birds Korea member), Hankyoreh reporter Ms Kim Jisook and two members of the University Union for Wild Bird Research/ University Bird Clubs Alliance, Mr. Soonho Kwon, who conducted a project on shorebird roosts in the FNS in 2024, and Mr. Joomong Hong.

References

1. Jackson, M., Choi, C-Yeung, Amano, T., Estrella, S., Lei, W-P., Moores, N., Mundkur, T.,  

    Rogers, D. I. & Fuller, R. 2020. Navigating coasts of concrete: pervasive use of artificial   

    habitats by shorebirds in the Asia-Pacific. Biological Conservation, 247 108591, 108591.

2. Moores, N., Jung, H., Kim, H.-J., Hwang, B.-Y., Hur, W.-H., Borzée, A. 2022. The Hwaseong

    Wetlands Reclamation Area and Tidal Flats, Republic of Korea: A Case of Waterbird

    Conservation in the Yellow Sea. Conservation 2022, 2, 526–549. https://doi.org/10.3390/

    conservation2040036