Oystering Room

Water has buoyancy.
It props up the soil and has a stabilising effect. But if the water is withdrawn and not replaced, the earth sinks.
The more it sinks, the more it sinks.
The more it mixes with seawater, the saltier the soil becomes.
The higher the water rises, the more land becomes sea.
The more liquid leaves the ground, the more houses get grounded.

It is then no surprise that coastal land subsidence follows the over-pumping of groundwater; this is a worldwide phenomenon, from Jakarta to New Orleans. It is however especially common in fish and shrimp ponds across Thailand and the Philippines. In Taiwan, land sinks at a peak rate of 6.7 cm/year.^[1] In other places, the claim is that land sinks about 8 cm/year, with Yunlin County being one of the most affected areas in the past decades.^[2]

Talking to young fish farmers in the endless field of ponds that shape the shores of Pingtung, Taiwan, they tell us about the different transitions that their families and others in the region have experienced. They try to keep up with market demands, profit margins, and consumer expectations. So does their land; they are struggling to keep afloat.

When bananas became popular in the 1970s, rice paddies became plantations, until bananas stopped being profitable  and groves were turned into ponds, this time for eel.

When eels were no longer so desirable in Japan, shrimp took over, until they became too discoloured, and ponds moved on to fish. But once seawater has seeped into the ground and salinity rises, there is no way to reverse back to rice planting.^[3]

Since the 1990s, the southwest coastal regions of Taiwan have kept sinking at an exponential rate.

As the pumping continues, buildings keep losing their ground floors.

Living rooms become garages,
doors become stairs,
roofs touch the street,
windows are buried underground.

In Jiadong County some houses are 3m below sea level.

The 1981 flood was one story high, but the water never left.

Roads have been raised and bridges doubled up.

New houses are now built a flight of stairs up from the street.

Although the fish and shrimp farm industry is one of the biggest contributors to ground collapse, others are also exhausting underground aquifers. Or perhaps that is just how a fish farmer in Taijiang tries to share the blame between the various agro-businesses exhausting the ground, as he guides us through his ponds. In just a few weeks their current inhabitants will be primed and turned into ‘boutique seafood’ for overseas export.

This is the upper end of farmed species like grouper or milkfish. Over the centuries, the farming of these fish has been made efficient by the different imperial powers controlling the island’s resources, ranging from the Dutch colonists who first brought milkfish from Indonesia in the 18th century, to improved artificial reproduction technologies developed by the Japanese over the first half of the twentieth century, including their more modern method to remove bones from milkfish in one process.^[4]

Pumping water for fish and shrimp farms hasn’t been regulated in Taiwan for decades. As ponds try to keep up with global demand, thousands of kilometres of pipes are needed to pump groundwater or seawater. Each pipe is tagged with its owner; Mr. Lee, Mrs. Lin, Mr. Ming… It makes it easier to identify leaks.

If a pipe already buried under multiple layers of pipes breaks, another one is simply added on top. To avoid further pipe entanglement, the regional recovery plan after the 2009 typhoon Morakot used the opportunity to build a central seawater distribution centre. Its director shows us its catchment area from the rooftop. Even if it supplies 600 water clocks and covers 700 hectares with its simplified water distribution system, it’s not clear how many fish farmers still use their DIY pipes. In the meantime, new houses on the road connect the water plant with the township; they are built half a floor higher. Yet, their ground floors are all expected to be lost in the very near future. Drawing water from rivers and creeks is no longer even an option for the aquaculture industry, as water is too prone to pollution in downstream areas near the coast.^[5]

Since shipping containers began transporting live fish over long distances to China and Japan, farmed fish have become even more profitable. They can continue putting on weight while travelling in transient oceans over oceans. Some of the farmworkers that invite us to see the grouper harvest tell us how to gain 20% fish weight quickly through a carefully calculated cocktail of seawater and freshwater before arriving at overseas markets.

The island sinks as you are reading.

Its inhabitants live on average 2m deeper than they would have been fifty years ago. In Pingtung and Jiadong Counties, a young couple, both fish farmers, walk us through the labyrinth of ponds that populate the sinking region, in some places down to -3.2 m. This has pushed some farm retaining walls to be raised by almost 2 metres as they sink just to prevent their fish from flooding the road. Having tried to reduce the environmental impact of their ponds, they tell us, doesn’t really make any difference, as 80% of residents in Jiadong are still farming fish in the most extractive ways.

Different governmental efforts have failed to reduce water extraction, let alone made a marked difference to the reduction in agricultural and industrial groundwater use. Some have even advocated for a Fish Farming Abandonment Programme, offering compensation payments and job training to fish farmers to leave the aquaculture business for good. Such efforts have yielded minimal results.^[6]

As intensive aquaculture makes entire regions subside, one wonders what a transition from pumping-dependent territories could look like.

Walking along the Chenglong wetlands in Yunlin County, we hear about new attempts to move away from single-species farms, and how water quality could be a little more balanced by introducing some bivalves in the ponds. Especially through the use of more seawater instead of pumping groundwater from the area. This would not solve the problem of seawater intrusion inland anyway. As soon as we say we’d like to see the polyculture system functioning, we are handed out a pair of baskets tied up to a float and are invited to take off our shoes, roll up our trousers and walk into the nearest pond to harvest clams from the sandy bottom of the multi-species pond. To feel different critters tickling your ankles while dipping your fingers in the mud is certainly something to remember.

Clams are not the only bivalves that filter the ocean as they breathe. Grown nearshore, oysters do not need freshwater pumping. They are very present all along the southwest coast of Taiwan.

Piles of oyster shells are time portals that lie idle along the roads of Tainan, Yunlin, Chiayi, or Pingtung Counties. They are the remnants of consumed oysters, and when put back into the ocean, the birthing grounds of oysters, soon to be consumed.

These shells are an incredible source of lime, which babies attach to form their own.

They build water.

Like our skin with its microbial communities, oyster shells materially record their environment.

As they filter the sea, they capture information about oxygen, salinity, and other floating substances. They distil what’s around and inside us.

Oysters have managed to get under the skin of human society.

Using their gills to both breathe and feed, oysters inhale water, sorting particles in the water column. Small hairs on their gills then migrate those particles towards their mouths.

Through their digestive activity, oysters draw elements such as mud or algae from the water column and deposit them as sediments, which improves water clarity.

Oysters are the natural hygienists of the sea; they are our most effective water filters. They’ve literally changed the way we see the world.

On a boat ride across the Qigu lagoon outside Tainan, we pass in between poles holding thousands of oyster lines. We share the vessel with Taiwanese tourists that seem curious to learn about this new underwater frontier and who are surprised to learn about how the lagoon itself is also silting up.

Hundreds of oyster poles are now standing abandoned on completely dry land. They are the silent witnesses of a receding coastline, also traceable throughout a succession of historic maps.^[7] The boat keeps going further and further out to take its crew beyond the effects of human influence.

Once the oyster barbecue awaiting boat passengers was over, we were told nobody was allowed on boats out at sea until the end of the martial law in 1986. Oysters had to be farmed near the shore. It was only after military control was lifted that oysters were moved offshore into floating farms. The utilization of coastal space is still contested to this day.

Since the ocean belongs to the government, anyone can open an oyster farm, but oyster farmers often struggle to expand one’s area of operation in a sea that accentuates the friction of living with the coast.

The wall bricks of the Chihkan tower in Tainan, built in the 1700s, still stand on what was once the city’s waterfront but are now all silted up. One can still see pieces of crushed seashells holding the structure together.

San ho tu is a traditional mixture of oyster shells, glutinous rice, and sugar maltose. This ancient system developed as a cementless cement is entirely made out of coastal ingredients bound together. These building foundations push oysters beyond their role as a millenary food system. They are a technique and a technology to circle us back into the sea.

The remains of an old kiln to make san ho tu still stand outside the old city, reminding people how oyster shells have been used in Taiwan to fix cracks and crevasses for centuries – not only in buildings, but also mixed with tung tree oil to seal gaps on damaged boat hulls. Pulverised oyster shells are also an old method of repair and care to exfoliate the skin.

Oysters are the skin of the coast. But they can also hear. When exposed to discomforting vibrations, especially the low frequencies of ships and offshore drilling, oysters move in fear of the noise of lobster predators.^[8]

They shut their mouths to close their ears.

They listen to the waves to know when to open their mouths for incoming food. Oysters reproduce well during thunderstorms. The sound waves may synchronise their spawning in a coordinated act of group sex.

But if oysters close their shells because of human noise, they may be unable to feed, leading to starvation and dwindling populations.

Another experimental farm in the southwest of Taiwan grows more than 300 marine species from a little backyard as a polyculture farm. A self-taught model tested over decades has managed to create a water cycle where home-raised species interact with each other as an inseparable network: giant clams, seagrasses, live corals, foraged mussels, lime caves for the urchins to feed on minerals to grow their spikes, lobsters and their hiding spots, “worker” fish that feed on the rejects of non-worker fish…The system even builds its own water. Avoiding any industrial feed from Chile or Kaohsiung, the food that each species craves at different times of the year is selectively foraged with the tides, following lunar calendars. Monoculture fails because no species can survive on their own.

If fish can be used as a noun to describe the animal itself and a verb to indicate the action of killing the animal, perhaps we should oyster – moving from the mollusc itself towards embracing the act of making a self-sustaining environment, building water around it.

Imagine your body absorbing liquid and releasing oxygen.

Imagine you are removing compounds from the water and building a skeleton with them, taking discarded oyster shells, and rubbing them against your skin.

That’s what it takes to oyster the ocean, to embody shell waste.

Oysters could guide us into a new cosmos without exhausting the ground, and develop our sensitivity to oyster other water futures, rethinking the environmental make-up of our bodies, and ultimately, oyster our living space.

Footnotes

^[1] Joanne Chen, “Land Subsidence Prevention and Reclamation Strategy in Taiwan,” International Forward-looking Water Conference, 08/11/2018.

^[2] Hsin Tung & Jyr-Ching Hu, “Assessments of serious anthropogenic land subsidence in Yunlin County of central Taiwan from 1996 to 1999 by Persistent Scatterers InSAR.” Tectonophysics 578 (2012): 126–135

^[3] Linpien’s Choice, Feb 1986.

^[4] Oscar Chung, “Fishing for the Future – Taiwan Review,” Aquaculture Fisheries 07/01/2009.

^[5] Chung, ibid.

^[6] Peter Lin Sun, Chun-Chou Yang, Tai-Wai Lin, “How to amend land subsidence treatment policies to solve coastal subsidence problems in Taiwan,” Reg Environ Change (2011) 11: 679–691.

^[7] Yi Chang, Ka-wai Chu & Laurence Zsu-Hsin Chuang, “Sustainable coastal zone planning based on historical coastline changes: A model from case study in Tainan, Taiwan.” Landscape and Urban Planning 174 (2018): 24–32.

^[8] Teresa L. Carey, “Even Earless Oysters Clam Up Over Noise Pollution,” Scientific American 28/10/2017