Built from the Sea: Marine Building Materials and Indian Ocean Cultures

By Roxani Margariti.

The blocks that make up this ruined but elegant archway are made of quarried coral, one of the materials we will discuss in this post. The photograph was taken by travel blogger Rowan Veale in 2022 in Suakin, a storied island port on Sudan’s Red Sea coast, of which more below! Image courtesy of Rowan Veale..

Our previous posts have discussed a wild variety of products that humans derive from the sea.  But in addition to food, medicine, implements of various kinds, fabrics, and adornments, the sea has provided humans with substitutes for brick and mortar, for stone and timber!  Alternative building materials find their way from the sea to dry land, blurring the boundary between the two realms.

Chumbe lighthouse was built in the early 1900s. It rises above the little island’s lush vegetation and nowadays the newly built lodges of a private nature reserve and resort on a coral island in the Zanzibar channel.  It is said to be the only lighthouse in the region to retain its original structure, and it is made of locally quarried coral blocks! Image by Sheyneg shared on Flckr

Coastal people, the world over and across time to our days, have marveled at the washed out bodies of impressive marine creatures, most notably whales.  They have preserved and displayed their skeletons, and have sometimes used their bones in various structures on terra firma. 

The remains of a primordial type of whale at Wadi al-hitan, the Valley of the Whales, in Egypt.  Here modern-day conservation and heritage practices have created a stunning park and UNESCO site out of the fossils of archeo-cetaceans (or very ancient whale-like species!) discovered in stages since the early 20^th century.  Display of distinctive parts of marine creatures is not a modern phenomenon: as a cetacean scapula discovered in the Greek Agora and a Roman report that giant “sea monster” bones were shipped from Palestine to Rome attest, people in the past came across such charismatic remains, marveled at them, invested them with symbolism, and used and displayed them in a variety of settings.  Photograph by Ahmed Mosaad, in Wikimedia commons.

Moreover, builders on the world’s sea coasts have used timber flotsam to make new things; shipwrecked planks and parts of boats that washed up on shores or disintegrated on beaches have found their way in buildings on land.

A merchant ship is blown off course to an exotic island in the 39^th chapter or maqama (translated in English as “séance” or "assembly"), part of the famous Arabic literary work written in the 11^th or early 12th century and disseminated in multiple manuscripts, a fact that shows its popularity in the middle ages.  This painting appears in a beautifully illustrated manuscript of the Maqamat made in Iraq in 1227.  The illustrator chose to highlight the exotic island but also the prow of the ship carrying the story’s hero.  Look closely at the structure of the boat and you will see small parallel lines like stitches across the seams of the vessel’s planks.  These represent the distinctive lashings that held together planks, characteristic of Western Indian Ocean “sewn boat” construction (which we have mentioned before on our blog).  In real life, boats could be blown off course, wrecked, or simply fall into disrepair and disintegrate on a beach; their timber could remain valuable, however.  Timber planks showing the characteristic features of sewn construction have been found in secondary use, embedded in medieval buildings in Oman as we shall see below.  Image Paris, Bibliotheque nationale de France, MS 5847, f. 121r.

Although not of marine origin strictly speaking, these wooden fragments too become part of architectural styles and building techniques that are distinctly maritime and exemplify the continuum between land and sea.  On the other hand, also used in construction especially of littoral places is the timber of mangrove, the salt-loving species of tree whose roots thrive in sheltered tropical and subtropical shallows.

Finally, blocks hewn out of live and fossilized coral make up entire buildings and even cities on the shore. Coral towns of the Western Indian Ocean offer a dramatic example of this kind of architecture.

The island city of Suakin (or Suwakin) in the Red Sea (modern-day Sudan), here depicted in a 16^th-century manuscript of Portuguese commander Joao de Castro’s account of the region, was built primarily out of coral blocks.  Image in the public domain from the collection of maps in Dom João de Castro, Roteiro do Mar Roxo. Tábuas dos Roteiros da Índia, Biblioteca Geral Digital of the University of Coimbra, Portugal.

The ruins of Suakin’s densely built coral city are the result of several phases of development since its first appearance in the historical record in medieval times; the port’s built fabric expanded greatly in Ottoman times.  The site has been the subject of recent archaeological investigations as well as the focus of Turkish soft power through Ottoman cultural heritage managment overseas.  Image from an article about the restoration of the city in the Turkish daily Sabah.

This post explores how all these materials offered up by the sea have made their way in the architecture and built environment of port towns and coastal settlements in the Red Sea, the Arabian Sea and the Western Indian Ocean more broadly speaking.  We will focus particularly on pre-modern and early modern times, from antiquity through the middle ages to the 16^th century. But, as always, both Dimitra and I are interested in the diachronic aspect as well!

Eating fish and building with fishbones? Tales of the Ichthyophagoi

Image of a “fisheater” from an 11^th- or 12^th-century hybrid manuscript that contains a text entitled Marvels of the East (in Latin with Old English translation) and illustrates exotic people of the east, presumably the Indian Ocean world, through the eyes of the Anglo-Saxon beholders that produced the work.  British Library Cod. Cotton Tiberius B V, 80r. Image by Marten Kullman, flcker.

Ancient authors personify the blurring of land and sea in their description of the Ichthyophagoi, whom we have encountered before on our blog (along with their neighbors the Chelophagoi!).  The “nation of the fisheaters” (των ιχθυοφάγων το έθνος) is a broad designation used by Agatharchides of Cnidus (2^nd century BCE), Diodorus Siculus (1^st century BCE), Strabo (1^st century BCE-1^st century CE) and Arrian (1^st-2^nd century CE) to describe people living along the shores of the Western Indian Ocean.  Their “primitive” nature in the eyes of Greek and Roman authors was in full display in their dietary habits; hence the exonym they were given focusing on a diet that was purportedly exclusive of anything but fish. They were also portrayed as using fish and the sea in profoundly uncivilized ways.  The biased view of the reporters regarding the Ichthyophagoi was dim: although eating exclusively from the sea, they are portrayed as not smart enough to have advanced fishing technology.  Instead, the ancient authors claim that they collected fish rather than actively fishing for them.  Given the clear ideological charge of these descriptions, and the authors’ drive to define these “exotic” populations as radically different from their own “civilized” selves, we cannot put too much stock in the value judgments of fishing methods and the like.  Besides, there are elements of the reports that regardless of the authors’ goals and biases, reveal interesting cultural features of the people intended.  In addition to eating mostly fish, the Ichthyfagoi are said to also built their dwellings from the sea, specifically with fishbones!  Diodorus Siculus, for example, tells us that the Ichthyophagoi who cannot find caves to dwell in, collect the ribs of great whales that the sea washes out, lean them against each other with the curved side outward, and weave seaweed through them (see original Greek here).  Is it possible to cross-reference such assertions and arrive at a kernel of truth?

Another classic and rather detailed description of the practices of the Ichthyophagoi appears in the work by Arrian known as the Indica.  In the Indica, Arrian transmits the first-hand accounts of the maritime adventure of Nearchus.  As the naval commander of Alexander of Macedon’s Indian campaign, Nearchus led what was originally a river fleet along the coast of Baluchistan and Iran to the Persian/Arabian Gulf.  Of the Ichthyophagoi in this region he says that,

“The most fortunate (richest) among them build their houses out of the big fish that the sea expels.  They pick their bones and use them instead of timber and used wider bones as doors.  Among the multitudes and the poorest among them, their habitations are made with the spines of smaller fish.”

Arrian, Ινδική, 29.16. (see here for the original Greek)

If we believe Arrian’s report, the Ichthyophagoi in this area (Gedrosia in the ancient texts) had differential, socially-determined access to what the sea provided in terms of fishy building materials.  Although surely exaggerated, more fantasy than fact, this report does convey the notion that the Ichthyophagoi lived in stratified societies. Moreover, using substantial fragments of cetaceans to build structures of all kinds is attested across cultures; any parallels that come to mind please share!

This map by Symeon Netchev highlights the maritime aspects of Ibn Battuta’s travels and includes some of the places with marine building materials dealt with in this post.  Note the passage quoted from the Moroccan traveler’s description of the island of Hormuz that includes a fishbone marvel.  Symeon Netchev for the World History Encyclopaedia.

Our example comes from more than a millennium after the Graeco-Roman world’s descriptions of the Indian Ocean Ichthyophagi.  The intrepid traveler from the Muslim West Ibn Battuta marvels at an unusual sight in the port city of Hormuz, on the island situated across the homonymous straits:

“I saw a marvelous thing there by the gate of the congregational mosque.  Between the mosque and the market was the skull of a fish as big as a hill, with eyes as big as doors.  You could see people going in through one eye and coming out the other.”

Ibn Battuta, Travels (for Arabic text see p. 164 here)

The port city on Hormuz island became the center of an independent kingdom that controlled the straits at the entrance of the Persian Gulf from the 14^th to the 16^th century until it fell under Portuguese control.  Both images here come from this later period and depict the port in a rather fantastical Europeanized form.  The top image is in a famous collection of city views, Civitates Orbis Terrarum (Cities of the World), created by Georg Braun and Frans Hogenberg and published in Germany in the 16^th-17^th century, three centuries after the visit of Ibn Battuta.  The bottom image, a similarly stylized but more detailed image accompanying an 18^th-century German travel narrative, shows a fishing fleet in the lower left corner.  Both images from the historic cities website run by Hebrew University of Jerusalem and Jewish National and University Library.

It is hard to be sure but Ibn Battuta is presumably writing about a whale skull that was placed at a prominent spot between the port city’s two hubs, the main mosque and the market.  Incidentally, Ibn Battuta also tells us that the food of the people of Hormuz was “fish and dates.” This echoes the stories about the Ichthyophagoi and the emphasis on the fish-eating habits of the inhabitants of southern seas but without the clearly negative judgment of the classical Mediterranean sources.  We have neither physical remains nor an image of this fishy arch of Hormuz, but if we take a look at a whale skeleton, such as that of the blue whale named Hope at London’s Natural History Museum, we can surely visualize the effect Ibn Battuta conveys.

This evocative image of the 25.2-meter-long skeleton of the Wexford whale at London’s Museum of Natural History helps us picture the Hormuz “fish” skull that according to Ibn Battuta had eye openings big enough for people to pass through.  For the story of the blue whale once stranded at Wexford, Ireland, in the 1890s and now a star exhibit in the Museum of Natural History, see this video.  Photograph by Diego Delso in Wikimedia commons.

In another revealing parallel, the whalebone arch at Whitby in north Yorkshire was built in the mid-19^th century as a memorial to the local fishing industry and may give us a sense of why medieval Hormuz might similarly have chosen to highlight whale bones--in the Whitby case clearly a mandible--in the construction of the city gate.

A short article on the very same topic as our post in Hakai Magazine illustrates this revealing example of a reconstructed whale bone house at Cornwallis Island, in the Arctic Circle.  So far away from the Ichthyophagi and Ibn Battuta’s Hormuz, the same basic principle—of not letting any part of the marine bounty go to waste—applies!  Image from Alamy stock photo and Hakai Magazine.

Wreck and recycle: building with boat remains

The standard biography of the prophet Muhammad, known in English as the Life of the Apostle of God, is not known for its maritime stories.  But fascinating tidbits do crop up here and there showing the maritime background of the tribes of the Hijaz, which after all lived along Arabia’s western edge and the Red Sea’s eastern coast.  It was in this region that the prophet of Islam preached his divine message. A small detail in the story of the rebuilding of the Kaaba, Islam’s central shrine in Mecca, caught my eye.

Muhammad, with the cubic structure of the Ka’ba in the background, helps the Meccan chiefs overcome their dispute and, using a cloth that they can all hold on to, jointly place the sacred black stone back into the walls of the Ka’ba.  The roof of the structure is not emphasized here except by a stylized scroll decoration.  But the traditional narrative of the Prophet’s biography clearly states that ship timbers were used in the restoration of the roof.  For those of you surprised that the Prophet is depicted in this 14^th-century Mongol (Ilkhanid) manuscript of Rashid al-Din’s Universal History (Jami’ al-tawarikh) now in Edinburgh, see an analysis of the illustrations by renowned Islamic art historian Christiane Gruber here.  For the image in the original manuscript at Edinburgh, see here

It happened before Muhammad’s prophetic mission began, and the story goes like this:  The Ka`ba, a cubic structure in the middle of Mecca, had been built in time immemorial by Abraham and his son Ismail as the shrine to the One God.  According to Islamic tradition, the Meccans later forgot its original monotheistic nature and at the time of Muhammad’s life were worshipping various deities at the shrine.  Being a center of worship and a major revenue maker for the city, the Kaaba had nonetheless fallen into disrepair and was pray to looting.  The Meccans decided to repair it, and a major part of the repairs involved giving the structure a wooden roof.  That became possible when a ship “belonging to a Greek merchant had been cast ashore at Judda (Jeddah) and become a total wreck.  They (the Meccans) took its timbers and got them ready to roof the Ka’ba.” The rest of the story focuses on the process of the repairs in which the sacredness of the building had to be respected, and on Muhammad’s role as a go-between when disputes arose among the tribal leaders about who would have the honor to complete the repairs.  Minor in the context of the narrative, the detail about the source of the Ka’ba wooden roofing reveals a practice of recycling of shipwreck planks that would have made sense in a land that was almost devoid of timber.

Image of boat planks embedded in a wall from an article by Tom Vosmer and Luca Belfioretti who published the findings of these recycled elements used as lintels, shelving, and ceiling beams in buildings at al-Balid, a medieval site in Oman.  Additional timbers of this kind were found at the major port site of Qalhat to the east of al-Balid.  As Vosmer notes in a separate article these were timbers that were “no longer viable for boats or had been salvaged from wrecks.” See the references at the end of the post.

I wouldn’t linger on this detail were it not for other textual and, more importantly, material evidence of this recycling practice.  A 12^th-century legal deposition preserved in the medieval Jewish repository known as the Cairo Geniza details the fate of shipwrecked estates belonging to merchants sailing from Yemen to India.  The witnesses called to testify with regard to the fate of wrecked vessels along the southern coast of Arabia speak of timbers washed up on the shores; they even suggest that these can be recognized as belonging to particular ships.  While not directly describing the practice of putting such flotsam to secondary use, it is clear that coastal people were looking out for and collecting planks and other parts of wooden ships that washed up on the arid shores of Arabia. It stands to reason that such material would have been put to good secondary use.

More definitively, we also have examples of ship timbers embedded into walls of buildings in South Arabia!  Scholars have pointed out these timbers at the medieval sites of al-Balid and Qalhat in Oman and have examined the holes and grooves in them that constitute characteristics of sewn boat construction.  They have used them primarily to analyze this particular boat building tradition in the region.  As maritime archaeologist Alessandro Ghidoni avers in his recent book on the subject, the question of the secondary use of these timbers still merits its own study.

Actual marine timber also plays a role in land-based building construction, however!  What I call marine timber is the wood of mangrove, a term that describes several species of remarkable, salt-resistant trees growing in the sheltered waters and intertidal areas of the tropical and subtropical global south (though some species exist further north, as well).

Mangrove roots thrive in shallow saline environments.  Images of African and South Indian mangrove from Wikimedia commons.

The earliest mentions of mangrove appear in Hellenistic and Roman sources describing the Red Sea—and in some cases explicitly associating them with the lands of the Ichthyofagoi!  Pierre Schneider has tabulated the somewhat confusing evidence provided by different ancient Mediterranean authors about mangrove.  Based on his work, we note that in these sources mangrove is often described as olive trees or bay trees, due to the elongated shape of their leaves and the small round fruit that some of them bear.  Clearly, these authors were grasping for analogies with things they knew from their Mediterranean context.  The philosopher Theophrastus (4th-3rd century BCE), whose musings and confusion about corals we encountered in our first post on those ambiguous creatures, mentions a variety of plants that grow in sea water in various regions of the western Indian Ocean in his botanical treatise Περί φυτῶν ἱστορία (“on inquiry into plants”), the same work where he talked about corals, mischaracterizing them as we have seen!  Schneider has identified these descriptions of the salt-loving trees that Theophrastus places in the Red Sea with the species Avicennia officinalis, Avicennia marina or Rhizophora mucronate, the more prevalent species in that region.  Additional species thrived along the Eastern Coast of Africa, especially the Lamu archipelago and further south the Rufiji Delta, where dense mangrove forests have been subjected to large-scale logging.

How were mangroves used in the ancient and medieval period?  Theophrastus tells us about the medicinal use of mangrove tree and fruit sap.  A little later, Agatharchides of Cnidos made the connection with the “primitive” material culture of the Ichthyophagi, who he says used these trees to construct shelters or dwellings.  Clearly these authors were combining their negative valuation of cultures of the southern seas with real information about the uses of mangrove in architecture. In the period of urban expansion and port building that was ushered by the rise of the Islamic caliphates and its successor states a thousand years after the accounts of Greek and Roman authors, the dense mangrove forests of East Africa witnessed extensive logging. Muslim geographer al-Istakhri, writing in Arabic, tells us that the houses of the most important center of trade, Siraf on the Persian gulf were built with teak and “timber from the land of the Zanj;” the Zanj is an appellation used by Arabic authors for sub-Saharan East Africa, and so it’s clear, as the excavator of Siraf David Whitehouse notes, that what al-Istakhri is talking about is mangrove—in his estimation a material used for luxurious rather than primitive building construction!

The characteristic beaklike prow identifies this splendid vessel, pictured in Zanzibar in the late 19^th century, as a mtepe.  On the beach lies a hefty cargo of mangrove poles.  The vessel itself is most likely made of mangrove timber in the Indian Ocean “sewn construction” method; its seams would have been covered with a solution containing mangrove bark.  Image at the Essex Peabody Museum in Salem, from wikimedia commons.

In more recent times, East African mangrove timber has been harvested and exported from thick mangrove forests, such as those of the Rufiji Delta.  Mangrove poles have been used in both marine and terrestrial construction.  A major East African type of merchant ship, the mtepe, was often built using mangrove.

Like coral banks, which we will discuss next, mangrove forests serve as nutrient-rich habitats for an incredible variety of species.  Fish, mollusks, and birds all find shelter and nourishment in mangrove mazes.  These marine forests also stabilize coastlines and protect them from erosion. And like coral banks they are endangered by climate change, development, encroachment of human settlements, and overexploitation, a theme that we will return to at the end of this post.

Building with coral

As we noted in our first post on coral, the tiny and fragile coral polyps build their calcareous shell, what we perceive as coral, and in time construct a variety of solid structures including coasts and islands.  In the 19^th century, as naturalists began to understand the animality of corals, both scientific and other writers romantically described coral as “tiny architects,” a metaphor that Charles Darwin himself employed!  Malcolm Shick, who discusses the human reception of corals as builders in his marvelous book Where Corals Lie, provides a fascinating glimpse into the social, moral, and religious messages that Victorians conveyed through their descriptions of coral polyps as industrious little builders working under God’s direction.

Stunning coral megaliths, indigenous builders, and Victorian missionaries: this 1880s photograph taken on the main island of the South Pacific Tonga archipelago and nation captures the accomplishment of the islanders, who quarried coral limestone, built the megalithic marvel known as the Ha’among a’ Maui in the 13^th century, and curated through time.  It also shows the reception of the islanders’ culture by the western European missionizing enterprise in the 19^th century.  The image is part of the Father Edward Leo Hayes Collection, UQFL2, Album H5 at the Fryer Library of the University of Queensland Library and in the public domain.

The structures that coral polyps built, humans living along coral shores have taken advantage of for their own building construction needs, from the islands of the Pacific to the Caribbean and the shores of Florida.  The East African littoral and the Red Sea, the focus of this piece, offer excellent examples of building construction practices utilizing coral blocks. 

At the site of Shanga, Mark Horton uncovered the stratigraphy of a mosque that displayed a transition between post and daub architecture to “stone” built structures utilizing coral blocks by the 10^th century.  Image of the 10^th-century mosque remains by Mark Horton, accessed through Oxford Research Encyclopaedia online

In a landmark publication of a Swahili East African archaeological site, Mark Horton described in detail the two different modes of quarrying the coral used in building construction at Shanga, an early Islamic Swahili port town in the Lamu Archipelago.  A mosque at the site dates to as far back as the 8^th century. From the 10^th century it was rebuilt with a new building technique, one that featured blocks made of coral.  In Shanga, Horton explains, coral was extracted either in its fossilized form on dry land—the term for this material is coral rag—or from the live colonies of the porites solida species in shallow coastal waters.  The resulting material has different properties.  Coral rag is denser more durable but harder to shape whereas blocks quarried from live coral are more maliable but also more porous. The Swahili tradition of building entire towns of this material lives on in the traditional “stone towns” in Kenya and Tanzania. “Stone” here refers to coral blocks.  The Lamu archipelago and Zanzibar being the most celebrated examples of such coral-built towns.

Coral blocks ready to be loaded on a small boat at Lamu, the main island of the homonymous archipelago in 2011.  Image by Eric Lafforgue, Alamy.

Further north, in the Red Sea, the use of coral blocks is a basic characteristic of what scholars have called a “Red Sea style” of architecture.  In addition to Suakin, the port city of Massawa offers a spectacular example of this Red Sea practice.  Coral blocks make up the most distinctive feature of the town’s physical urban fabric.  A palimpsest of late medieval, Ottoman, and 19^th century development, Massawa has unfortunately suffered terribly during and since the Eritrean war of independence.  The need for conservation is dire, but the splendor of this city built by the sea with the gifts of the sea still shines through.

A panorama of the port of Massawa, Eritrea, located on the coastal island of Ras al-Midr, as seen from the causeway that connected the harbor to the mainland side of the city.  The image was created by Italian photographer Luigi Naretti (1859-1922) during the Italian rule of Eritrea, when the city became a prized colonial possession. The Italian occupiers developed the city utilizing the centuries’ old local practice of coral block construction. Image courtesy of Jonathan Miran.

Coral block structure of uncertain date on Dahlak Kebir, the main island of the homonymous archipelago across from Massawa, which boasts over a hundred coralline islands.  Island geology ensures that the main building material is coral. Photo from https://shabait.com/2022/09/08/a-glimpse-into-the-history-of-the-dahlak-archipelago-2/

Why build with coral?  An obvious answer is the geology of the seaboards of the tropical and subtropical waters where this practice has taken root.  In the case of the Red Sea and the East African coast, island-building coral banks fringe shores, and have, with time, become partly exposed and fossilized.  While sheltering sea-life and protecting shores from erosion, these formations also result in easily accessible live and fossilized coral, quarries within easy reach.

Furthermore, coral blocks are a good material to build with. A professor of architecture writing about the conservation of the city of Suakin, Abdel Rahim Salim describes the virtues of coral blocks as “excellent” construction material thus: “Being porous, they were light in weight, had low heat conductivity, and were easy to cut.” Salim is probably referring primarily to porites or live quarried coral.  Obviously the porousness of this kind of material had to be mitigated by applying lime plaster on surfaces, adding both extra labor and a particular “look” to the result.  We should also add the versatility of the material. In a study of the town of Lamu in the homonymous archipelago, Usam Ghaidan describes how walls and floors were built with coral blocks set in lime mortar, while roofs were constructed with layers of coral lumps sealed with with lime plaster and set over wooden, often mangrove, beams.

We featured this image in our previous installments on corals: a building in Massawa made of coral blocks, which are clearly visible especially where the stucco surface has eroded.  Massawa March 2019, photo by REM.

How far back in time can we trace this practice?  A medieval traveler whom we have encountered in previous posts, Ibn al-Mujawir testifies to the prevalence in his time, the 13^th-century, of coral block construction in the Arabian Red Sea ports of Jeddah and Ghulafiqa.   In his entertaining and incredibly informative travel narrative, Ibn al-Mujawir describes that the early settlers of the medieval port of Jeddah reinforced an original circuit wall with an extra layer made of hewn coral blocks and covered with stucco.  In his description of the more southerly Red Sea port of Ghulafiqa in Yemen he notes that the inhabitants of that town “built fine houses and mosques with courtyards, made from kāshūr stone, which is stone extracted from the bottom of the sea.”  The underwater quarrying and subsequent shaping of coral blocks that went into the construction of the medieval ports of the Red Sea thus stood out to outside observers in the past as it does today.

Jeddah’s old city center (the balad) was built primary of coral and a seashell limestone locally called manqabi.  Few buildings of this kind survive, most of which go back to the 19^th century.  Their conservation is an ongoing effort and the recent inscription in UNESCO’s world heritage list is part of it. Photographs © Kingdom of Saudi Arabia, from the Permanent Delegation of the Kingdom of Saudi Arabia to UNESCO.

As Guy Standing states in his bold examination of the economy of the sea and the threats of greedy exploitation of marine resources, “reefs, seashores, beaches and estuaries are also part of the blue commons, and all are in trouble” in our days (The Blue Commons: Rescuing the Economy of the Sea, 39).  The use of coral blocks and mangrove timber for land-based activities in the past does not offer a blueprint for future development because environmental conditions have changed, coastal ecosystems are degrading alarmingly fast, and development pressures create gargantuan demands that cannot be met with sustainable small-scale exploitation. Along the western seaboard of the Indian Ocean a variety of conservation efforts have focused on documentation of practices in coral block building construction, preservation of historic buildings and coral “stone towns” as in Jeddah, Suakin, Lamu, and Zanzibar, and stewardship of mangrove forests from the Red Sea to the Rufiji Delta in Mozambique.  Local knowledge and collaboration with local communities are the only way to secure meaningful intangible heritage of past craftsmanship and to ensure the survival of these incredibly rich marine environments between land and sea.

Let’s end with this somewhat hopeful image of building not from the sea, but in and for the sea: a regeneration tower made of concrete breezeblocks, sunk in the sea around the Caribbean island of Granada, and offering both a shelter to fish, urchins and other marine creatures and a potential nursery for young coral.  A ten-year scientific assessment of the results for the health of degraded reefs in the region appears to be cautiously positive.  I first encountered the image in and learned about the project from a report by Richard Aspinall in The Guardian, accompanied by his marvelous photographs.  We thank him for sending us high resolution copies to use on our blog.  Image courtesy of Richard Aspinall www.richardaspinall.com

Do you want to know more? We have suggestions!

Do you want to cite this work?  Here is how: Margariti, R. 2025. Built from the sea: marine building materials and Indian Ocean cultures, Archives of the Sea, https://www.archivesofthesea.com/en/post/****, accessed on --****