Under the Pacific Ocean, in harbours and ports, lives an unseen world of wood—wharves, jetties, and piers—created by colonial and commercial expansion from the nineteenth century. These new structures facilitated the emergence of urban spaces and transformed submarine environments.Footnote 1 Mangrove-fringed tidal coasts were reclaimed by settlers and remade into ordered, vertical divisions of land and sea. From the mid-nineteenth to the mid-twentieth century, wood-eating bivalve molluscs such as shipworms found new coastal habitats, moving from ships’ timber or ballast water into the immobile timber located below the water line. Shipworms include a number of wood-eating marine borer species adapted to living in and consuming submerged wood in the ocean: mangroves, driftwood, ships, wrecks, wharf piles. These marine borers were dependent on oceanic wood, but also destroyed it. At the heart of this article is the multispecies assemblage of worm and wood and their shifting relationship with the ocean ecosystem and the different communities at coast and sea. How people related to, managed, and understood this assemblage reveals different knowledges of the oceanic world, and the extent to which such knowledge travelled, or not, around the Pacific.
This article examines the flows and disconnections of environmental knowledges as well as the literal disintegration of shipping infrastructure caused by the flourishing and spread of endemic and introduced marine borers such as Teredo navalis (naval shipworm, T. navalis) across Pacific waters from the mid-nineteenth to the mid-twentieth century. These borers existed largely unseen until they had eaten away at the very foundations of the ports that—often forcefully—sought to integrate Pacific species and peoples into wider global networks of energy and capital flows. Shipworms periodically interrupted the movement towards greater interconnection and undermined dominant narratives of imperial mastery over the islands and oceans.
Marine borers and underwater wood in Pacific ports formed a terraqueous assemblage that connected sea and land together in complicated, unexpected ways, revealing the contours of multispecies mobility that emerged alongside human mobility across oceans. While some coastal Indigenous communities around the region valued the shipworm as a source of food and others managed their threat to waka or vessels, the development of colonial ports disrupted existing relationships with littoral ecosystems and reframed endemic and introduced marine borers solely as pests. Marine borers’ spread and increased presence was often intimately tied to technologies of ship and port, and marine scientists and engineers in different harbours had limited success in preventing the continued entanglement of animal and infrastructure. Examples from Suva, Sydney, and Honolulu illustrate the ongoing challenges that these experts faced in understanding and preventing marine borers’ impacts on coastal infrastructure, long after preventative measures were applied to the ships moving between ports. They transported and trialled different timbers for piles, but knowledge did not always travel so easily and solutions that worked in one harbour proved unsuccessful in another, demonstrating the embedded, local, and contingent nature of solutions to the shipworm problem.
The marine borers’ chewpoints thus provide a metaphor for the fragility of globalizing oceanic networks, technologies, and infrastructure in the nineteenth and early twentieth century, and contrast long-standing Indigenous relationships with worm and wood in the region. I use chewpoints to signify those points where species come together temporally and geographically in distinctive and perhaps unexpected ways, fracturing the imperial narrative of increasing global integration through control over the marine environment and the species within it. From this starting point, we can analyse colonial ports and infrastructure as lively, multispecies ecosystems, rather than dead wood, and examine different stories of the transformation of Pacific coastlines and waters.
This article contributes to global oceanic history and animal histories in two ways. First, focusing on the Pacific reveals varied relations between humans and marine borers. Indigenous communities knew of the worm, and in some cases actively cultivated it, in ways that challenge the influential, colonial narrative of marine borers as an invasive or pest species. Such histories demonstrate the significance of shipworms before the colonial ship and the possibilities of different multispecies relationships in the present. These included Papuan and coastal Indigenous Australian peoples’ use of marine borers as food, and boat-building knowledge and practices across Te Moana-nui-a-kiwa (the Pacific) by Māori, iTaukei (Indigenous Fijians), and other groups in what Damon Salesa calls the ‘native seas’ of this oceanic region.Footnote 2 Shipworms were thus not only pests or invasive species, as was the dominant colonial and scholarly narrative. Moreover, managing the threat of shipworms required local solutions and embedded knowledge not only of the ocean but the forest and soil, something that scientists themselves came to realize. The entanglement of land, species, and sea reflects a relational view of the environment embedded in Pacific cultures, where knowledge cannot be separated from place.Footnote 3
Second, tracing the im/mobility of the borers, timber, and scientific and engineering practices between different Pacific ports highlights the interplay of mobility and immobility, integration and disintegration, and connection and disconnection in an era of rapid colonial and capitalist development in the world’s largest ocean. Shipworms troubled colonial control, even though they did not fully halt the expansion of colonial ports: preventing their presence was costly, difficult, and complete eradication proved impossible. Indeed shipworms depended on the timber piles that literally and metaphorically held up maritime empires even as they undermined their structural integrity, reflecting the ways in animals and empires were co-constituted.Footnote 4 Shipworms’ chewpoints thus exemplify the ways in which ‘connective and disconnective processes are deeply interwoven and interreact intensively’ in global histories.Footnote 5
The Pacific world was expansive and oceanic. Here I mean the Pacific of islands, seas, and peoples connected by the ocean, centring on the basin rather than only the Pacific rim. This ‘other one-third of globe’ is often absent in global histories, despite the long history of distance voyaging before and after colonialization.Footnote 6 The region is important to histories of both ocean and imperialism writ large, as a critical space where ‘the push-and-pull dynamic of globalisation’ shaped the modern world.Footnote 7 By the late eighteenth century, Islanders and newcomers engaged across the liminal space of the beach, to use Greg Dening’s influential formulation.Footnote 8 This mutual process of discovery and exchange was shaped by local and global currents, with waves of trading, whaling and marine resource extraction, and missionization intensifying through the nineteenth century—often bringing new species (including shipworms) into the region. Formal colonization followed unevenly. Taking the locations in this article to illustrate the point, the British invaded the Australian continent for penal colonization and later settlement from 1788, while Te Tiriti o Waitangi (Treaty of Waitangi) between signing rangatira (chiefs) and the British crown facilitated the latter’s annexation of Aotearoa New Zealand in 1840. Britain was drawn into Fiji in 1874 following Bauan chief Cakobau’s appeal for support against internal rivals and US claims; New Guinea was divided between the Netherlands, Germany, and Britain after 1884; while Hawai‘i became an American colony following the illegal overthrow of the Hawai‘ian monarchy in 1893. Imperial administration thereafter was also uneven, but was felt most intensively at the coasts.
Pacific ports were generally sites of imperial development, nodes of connection, the material heart of new political and economic connections between Island landscapes and communities and the wider world. In global histories, port cities have been important as sites of intensive cultural, religious, and economic exchange, both before and after colonization.Footnote 9 In contrast to urban centres in the Indian Ocean, Pacific port cities largely developed either out of nineteenth-century resource trading (Honolulu, for example) or planned centres for colonial administration (Suva, for example). In the age of maritime empires, ports could also be entangled in colonial processes of ‘islanding’, as the ‘sea of islands’ was restructured by imperial visions of islands as isolated.Footnote 10 Port infrastructure was thus key to the simultaneous processes of disconnecting during the colonial period, though the environmental side of this story has been under-explored.
This article draws on examples from a range of Pacific port cities, driven largely by following archival sources that drew specific places together through material exchanges or comparison. The ports and coastlines in question nevertheless represent different forms of Anglophone imperialism in the region. Sydney was an exemplar of a settler city of Australian colonies, whereas Suva started as an administrative centre for the Crown Colony of Fiji and Honolulu began as a trading port and then capital of the Hawai‘ian Kingdom.Footnote 11 While each has a specific history, by the late nineteenth century they were connected in new formations by steamship routes moving goods, migrants, and tourists. Suva, Honolulu, and Sydney, alongside Auckland, Pape‘ete, Vancouver, and San Francisco, were all significant nodes in imperial shipping networks, and faced similar environmental challenges.Footnote 12
Focusing on shipworms and their assemblage with oceanic wood in ports illuminates the significance of terraqueous history as an approach to global histories. As Alison Bashford articulates, this approach encompasses ‘not just land and sea, but the transforming matter that constantly connected them: atmospheres, vapours, airs, and waters … coastlines, beaches, islands, ships’.Footnote 13 Jules Skotnes-Brown’s work on shipboard rats highlights the value of bringing terraqueous animals into view.Footnote 14 Below the waves, Tamara Fernando demonstrates how multispecies agencies shaped the shifting pearl fishery in Ceylon.Footnote 15 I argue that the port infrastructure itself is a ‘terraqueous’ space par excellence. The unique combination of people and goods, woods and the soils in which they grew, endemic and introduced marine organisms, and fresh and salt water were all shaped by Indigenous, migrant, colonial, and capitalist engagement with littoral space. This terraqueous assemblage was at once both mobile and rooted, like marine borers themselves. Timber, too, moved from forest to coast, and from port to port, to transform coastlines in ports and harbours. Shipworms’ mobility was largely determined by the movement, or not, of the timber in which they enclosed themselves. The im/mobile nature of this assemblage enables us to trace the connections and disconnections of both environments and knowledges across the ocean, and the difficulties in colonial attempts to create boundaries between species and oceans. Shipworms are thus ‘good to think with’ in global history.Footnote 16
Shipworms and oceanic animals in global histories
Though an adversary that loomed large in the minds of earlier generations of ship- and harbour-builders, shipworms have only recently captured the attention of environmental historians. Earlier scholarship focused predominantly on technological innovations to prevent destruction caused by the molluscs’ rasping on ships, emphasizing the varied solutions that navies and shipbuilders developed to counter the worm: dry-docking and cleaning of hulls, sheathing, or painting.Footnote 17 In public-facing accounts, the borer is described as ‘the clam that sank a thousand ships’, from Columbus to Cook.Footnote 18 More recently, though, historians have reinterpreted the ship as a social microcosm and an ecosystem, where ship, crew, shipworms, and other species are embedded in ‘complex and historically contingent relationships’.Footnote 19 The decline in wooden ships could therefore be read as the decline of the shipworm’s ecosystem, explaining some of the historical amnesia towards this tiny monster.
This is not shipworm’s only story, however. The expansion of port infrastructure to support global shipping networks also created new ecosystems. Recent scholarship examines the borers’ impact on immobile infrastructure, though focused almost exclusively on national contexts. The most prominent examples are the 1730s shipworm epidemic in the Netherlands, and the 1918–1920 San Francisco outbreak resulting in the collapse of buildings into the harbour.Footnote 20 Adam Sundberg highlights the overlapping enviro-technical challenges and systems that Dutch dike- and ship-builders used to manage the threat of the worm, as the ‘unprecedented’ epidemic unexpectedly transferred a known hazard from the sea to much closer to shore.Footnote 21 Furthermore, in his work on shipworms in American history, Derek Lee Nelson suggests the name ‘coastworm’ better encapsulates the species’ littoral entanglements—and economic cost—along ports and harbours.Footnote 22
The shipworm’s impact was most felt along coastal infrastructure in the Pacific. Although other oceans and ports also faced the challenges of shipworm, these phenomena are particularly visible in Oceania. The ‘dense connections’ on and between islands throw the ‘dynamics of power, hierarchy and classification into sharper relief’.Footnote 23 Here, colonial expansion and coastal reclamation occurred when incoming ships were no longer sunk by borers, but coastal infrastructure was still subject to the existential threat of wood-eating species. The shift from the Indigenous ocean to an increasingly colonized one also reshaped the dominant narrative about the assemblage of worm and wood, where its potential as food as well as peril were tipped in favour of the latter.
Environmental historians, debating whether the Pacific has coherence as a region, suggest that one unifying element is the migration of marine species.Footnote 24 For example, Ryan Tucker Jones demonstrates that following whales and migrating species enables us to examine the connected histories of the ocean, islands, coasts, and communities.Footnote 25 Certainly whales have enduring cultural significance for many Indigenous communities. The economic value of whale oil and baleen also drew newcomers across the Pacific from the late eighteenth century with dramatic impacts for marine populations, ecosystems, and Islanders. Moreover the trading ports established to support the hunt frequently evolved into colonial towns and administrative capitals by the late nineteenth century. However, histories that explore the Pacific’s integration through maritime species have paid less attention to the disruptions that such animals also caused to economic, imperial, and environmental connections.
Using the worm to examine the challenges of moving between micro- and macro-histories in a planetary age, Dániel Margócsy highlights how shipworms ‘could multiply, jump ships and jump scales’.Footnote 26 He concludes that global stories across historical scales must include the tools of environmental, scientific, and creative disciplines. I argue that the simultaneous im/mobile life cycle of the shipworm offers further analytic possibilities, embodying the connective and disconnective dimensions of the historic ocean.Footnote 27 Thinking across different ports shows how the shipworm became a chewpoint in oceanic imperialism across the Pacific.
Empire was a multispecies phenomenon. Colonialism, in the words of Jonathan Saha, was ‘materially and ideologically forged by interspecies relations even while it transformed the ways that humans and animals related to one another’.Footnote 28 Moreover, as Antoinette Burton and Renisa Mawani argue, ‘animal life, whether large or small, could and did often work against the grain of imperial control’ and ‘dramatized the reality that claims to imperial sovereignty were porous, unstable, and frequently at the mercy of nature’.Footnote 29 Such scholarship is often terrestrial in focus, while oceanic histories have centred on charismatic marine mammals.Footnote 30 Smaller organisms similarly shaped this story, though their traces and agency are harder to see in the archive. With this in mind, I turn to the ‘worm’ in the wood.
Life along the wood grain
Marine borers’ historical impact is deeply entwined with that of submerged wood, whether mangroves, driftwood, ships, or timber infrastructure. Yet by the opening decades of the twentieth century, borers had received ‘little more than spasmodic individual attention’ from engineers.Footnote 31 Shipworm taxonomy was in ‘a state of the utmost confusion’ and understanding of life cycles and reproduction similarly limited.Footnote 32 As Australian scientists argued in their first systematic study in the early 1930s, the responsibility for dealing with the ‘depredations’ of marine borers in harbours was the most important challenge facing engineers: ‘the obscure and uncertain conditions which surround the damage caused … increasingly demand careful investigation’.Footnote 33 Making sense of shipworm’s histories similarly requires a sense of their biology and ecology.
Shipworms’ life cycle is characterized by stages of mobility and immobility, though the exact nature and length of these periods varies across different species in the Teredinidae family.Footnote 34 Taking the widespread and widely studied T. navalis as an example, after spawning larvae spend a short mobile period in the ocean before settling onto the same or nearby wood using ‘waterborne chemical clues’.Footnote 35 Using abrasive shell valves and aided by symbiotic gut bacteria, the shipworm begins to burrow.Footnote 36 It bores and scrapes a minute hole into the wood, eventually rasping away to create a cylindrical tunnel often up to 40 cm long in parallel with its cohabitants.Footnote 37 Depending on season, temperature, and salinity, Teredinidae species reproduce and grow rapidly—some as large as 185 cm if space permits.Footnote 38
Compared to other bivalves’ protective armour, the shipworm’s shell is but a small helmet that helps it to grind through timber. The resultant creation is a ‘tortuous burrow’ in the words of one biologist.Footnote 39 The wood itself provides home and safety for the long and exposed worm-like body, where the borer spends the remainder of its life. Most of their life is thus unseen, but for two small siphons protruding from a pinhole in the wood and pallets to seal the hole in unfavourable conditions. When undisturbed these siphons enable the shipworm to inhale and expel water and reproduce.Footnote 40 Shipworms thus largely move across the ocean, or not, according to the movement of the submarine wood in which they spend their lives encased. Their destructive work was considered all the more concerning compared to other wood-eating or ship-fouling species, precisely because there was so little sign of their damage visible on the wood’s exterior.Footnote 41
In many situations, however, marine borers form a useful part of coastal marine ecosystems. They were ‘friends as well as foes’.Footnote 42 Few species can turn wood biomass into energy for the marine ecosystem, while borer species digest around 70 per cent of the dead wood in mangroves, for example.Footnote 43 Marine wood borers contribute to global carbon cycling, while also aiding bioerosion and habitat creation.Footnote 44 While the mechanism for consuming wood was yet not understood, the ability to clean up woody detritus was valued.Footnote 45 An 1859 description called the ‘inexhaustible mollusc’ the ‘police of sea’ that ‘sweep and clean’ the ocean. This positive view of the tireless shipworm reflected that borers could clear underwater timber hazards in harbours, thereby aiding shipping as well as damaging it.Footnote 46 Shipworms were themselves ‘ecosystem engineers’, reshaping the oceanic environment alongside as their human equivalents.Footnote 47
As their many names suggest—shipworm, teredo, augerworm, pileworm, mangrove worm, taret, cobra, warragárá, obe, termites of the sea—these bivalves escaped easy definition and classification.Footnote 48 Even within a single species, shell and pallet shape vary widely, depending on the mollusc’s relationship with the species and grain of wood within which they lived.Footnote 49 Such variety posed a challenge for species identification. The unruly and shifting taxonomy of marine borers reflected the difficulties in obtaining suitable specimens, morphologically classifying species across multiple locales, and identifying their origins and global spread. The piecemeal acquisition of scientific knowledge struggled to keep pace with attrition of marine infrastructure worn away between the shipworm’s shells.
Collapse of infrastructure and increasing costs of repair resulted in greater investment in scientific studies of shipworms from the 1920s.Footnote 50 Yet taxonomic work remain regional and disconnected until the mid-twentieth century. In her scholarship to recategorize Teredinidae taxonomy in the 1960s, Ruth Dixon Turner highlighted the proliferation in identified species, often undertaken by isolated scientists, with many identifications failing to move across the ocean:
After World War I the destructive activity of marine borers in widely separated areas of the world brought about the formation of special committees to study the problem … An indirect result of this was a large amount of descriptive systematic work, most of it being done by one or two workers in each country.Footnote 51
For example, Lyrodus pedicallus was identified as a ‘new’ shipworm species twenty-one times in the Pacific and twelve times in the Atlantic.Footnote 52
The taxonomic confusion makes tracing the history of specific shipworm species in the Pacific (and globally) challenging. Many accounts reference the teredo (used generically for a range of marine borers), or sometimes T. navalis specifically, though the accuracy of such identifications is often unclear. T. navalis species’ distribution nevertheless provides a useful illustration of the place of marine borers in port assemblages and their global connections.
T. navalis is a cryptogenic species, whose origins are unknown. Both South East Asia and the Atlantic have been identified as potential origins, but records of shipworm activities date back millennia, making it difficult to trace their initial, and indeed recent, spread.Footnote 53 The species is well adapted to a wider range of salinity and temperature (15–25C) compared to other wood-eating bivalves, including some native Pacific genera such as Bankia, and this adaptability facilitated global spread along shipping routes.Footnote 54 The ability to survive at salinity as low as 5 (and to bore and reproduce in salinity as low as 9) meant that T. navalis could also establish itself in brackish and estuarine waters when fresh water flows were low, often around river mouths that appealed to human residents for their transport and food offerings, and which became the site of ports and cities.Footnote 55
So fast was naval shipworms’ movement along commercial and colonial networks that it is difficult to trace its exact routes into the Pacific, if indeed it was introduced. Nevertheless, by the nineteenth century, naval shipworms flourished in tropical waters globally, notably following the waves of transoceanic globalization such as European expansion into the Atlantic and Pacific. By the nineteenth and early twentieth century, teredo appears to have either arrived or increased in different parts of the Pacific.Footnote 56 The longer nature of these imperial voyages helped shipworms to thrive below deck. From the eighteenth century onwards, European ships spent years at sea through temperate and tropical waters with few opportunities for dry docking and treatment or replacement of any planks ‘honeycombed’ by the shipworm.Footnote 57 Alongside the movement of species like T. navalis via shipping routes around the Pacific, there existed a variety of less widespread, endemic species, with the family’s greatest diversity around Australian and Papuan coasts.Footnote 58
While T. navalis larvae might disperse independently along ocean currents, ongoing ‘oceanographic connectivity’ was key to enabling the species’ continued spread and exchange over distant oceans.Footnote 59 Recent genetic scholarship demonstrates a unified genetic population across European waters from Brittany to the Baltic Sea, beyond the extent that larvae might travel independently along currents. Both the distance involved and lack of distinct genetic populations thus indicates that T. navalis rely upon anthropogenic movement or other timber hosts such as driftwood to travel long-distance.Footnote 60 The exact mechanism by which borers spread to different ports historically is unclear and perhaps unknowable. But, whether in ships’ hulls or ballast water, human and shipworm mobility were closely entwined across oceanic space.
When in ships, the worm lived largely an immobile life in mobile wood. They were not alone, however. Multiple marine borers live in parallel with each other along the grain of timber, growing side by side until they run out of space. To repurpose a method and turn of phrase, we might follow borers along the woodgrain to think about animals that were largely invisible, though not unknown, to other historical actors.Footnote 61 Like the minuscule entry holes they left in planks and piles, often overlooked, so too is the archive of borers’ life around the Pacific. Shipworms enter colonial archives only as a problematic animal, but even then they were not always discussed directly. Their presence is hard to glimpse: correspondence on sourcing materials for a wharf refurbishment might discuss the necessity for certain borer-resistant hardwoods without mentioning the troublesome borers.Footnote 62 As objects of scientific study, they appear in journals and reports with some regularity, particularly after moments of disaster like the San Francisco shipworm epidemic, as research investment followed economic loss.Footnote 63 As historical actors, however, their archival traces are rather dispersed: mentioned haphazardly at moments of infrastructure failure or in requests for colonial funding, their labour occasionally evoked in poetry and art or collected by museums in the form of worm-eaten wood.Footnote 64
Indeed their impact was most often felt in their absence, once the marine borers had eaten away the structural integrity of their wooden homes and the now-honeycombed infrastructure failed. Their material traces are but holes. Rayes, Beattie, and Duggan’s research in digitalized New Zealand newspapers highlights shipworms’ periodic public profile, but this approach is limited by the unevenness of digital sources across the Pacific.Footnote 65 The examples used in this article reflect the limited view we have of the worms in the wood: fragmentary moments that point to a larger story. These histories are further complicated by uncertainties over shipworm species and distribution, and the limited colonial attention given to Indigenous knowledge of marine borers.
Indigenous knowledges of worm and wood across Pacific coasts
Though T. navalis may have only been recently introduced to some areas, a range of molluscan marine borers were well known to coastal Indigenous communities. Marine borers might be collected or even cultivated as food, while the threats to Indigenous vessels were mitigated by the use of resistant woods and coating techniques.
Along the Pacific coast of the Australia continent, various First Nations groups ate the cobra, a point that was reported by early visitors with distaste.Footnote 66 Marine borers were mainly consumed by ‘inland’ groups, as sea and river meet in brackish waters. The cobra were known to be ‘fat and soft’ where salt- and freshwater came together, according to Garby Elder Keith Lardner.Footnote 67 In the area currently known as Sydney, the teredo was a totem for the Gahbrogal or Cabrogal clan in the present-day Liverpool area along the Georges River.Footnote 68 David Collins observed Darug people eating teredo in 1798, noting the origins of the Cabrogal name:
In an excursion to the Hawkesbury, we fell in with a native and his child on the banks of one of the creeks of that noble river. We had Cole-be with us, who endeavoured, but in vain, to bring him to a conference; he launched his canoe, and got away as expeditiously as he could, leaving behind him a specimen of his food and the delicacy of his stomach; a piece of water-soaked wood (part of the branch of a tree) full of holes, the lodgment of a large worm, named by them cah-bro, and which they extract and eat; but nothing could be more offensive than the smell of both the worm and its habitation. There is a tribe of natives dwelling inland, who, from the circumstance of their eating these loathsome worms, are named Cah-bro-gal.Footnote 69
Further north in what is now known as Brisbane and Queensland, Indigenous Australian communities constructed teredo farms, placing logs piles for regular harvesting at base camps located at river junctions. Tom Petrie recorded the practice around Brisbane River, in Yawagara Breakfast Creek, in the North and South Pine Rivers, the Maroochy and Mooloolah Rivers, and several creeks in the early nineteenth century. Young women and older men created piles up to 2 feet high by 6 feet across using swamp oak (Casuarina glauca) cut from trees growing near the shore. The piles were constructed along the banks so they were dry at low tide, but covered at high tide, and left for about a year. Teredo were then harvested by cutting the logs with stone tomahawks and knocking them until the worms fell out. The teredo, known locally as kambi or kan-yi, were taken back to camps, and the piles replaced. Petrie reported the teredo from such logs were considered ‘largest and best’, though others would be harvested from any wood that had fallen into the water.Footnote 70 Early visitors occasionally resorted to eating the ‘abundant’ worm themselves when lost and hungry, and at least one such man found them surprisingly ‘very palatable’ in 1836.Footnote 71 At the end of the century, naturalist Charles Hedley affirmed ‘having ventured to taste, my palate compared it to an oyster’ though by this point most settlers viewed the worm as pest, not food.Footnote 72
Indigenous peoples also transplanted shipworms around the Australian coast, spreading the foodstuff to new areas. An Indigenous interlocutor called Genoa Jack told Norman Taylor about First Nations acclimatization practices during the latter’s geological survey of Gippsland in the 1860s. Taylor reported:
Genoa Jack, an aboriginal, says that formerly there were no Warragárá (a species of Teredo, living in rotten logs lying in the half-saltwater of the Genoa and tributaries) in the Snowy River, till the Dora or Snowy River blacks, who used to come periodically to the Genoa, discovered it, cut up the logs into billets, and carried them along the coast to the Snowy River, where they split them and planted them upright in the mud. He says they are plentiful there now. They eat them raw as they pull them out, some are over a foot long.Footnote 73
Undertaking research at Tree Point in northern Australia over a century later, Ruth Dixon Turner recounted that ‘Cobra are considered “good tucker” by the natives, and they could not understand why we popped the “worms into preservative instead of into our mouths.’Footnote 74
This long-standing Indigenous relationship with the assemblage of wood and worm was not totally displaced by colonial attempts to clarify marine borers as pests. By the mid-nineteenth century colonial dispossession along Australia’s Pacific seaboard arguably impacted marine food sources less than terrestrial ones.Footnote 75 More recently in their research on Gumbaynggirr in northern New South Wales, academic Margaret Somerville and Garby Elder and cultural knowledge holder Tony Perkins describe the continued harvest and consumption of cobra as part of ‘eating place’, shaped by ‘intimate embodied knowledge’ learnt on and from country.Footnote 76 Though cobra now are harder to find as fences and private property cut off access to the rivers and mill pollution stunts borers’ growth, the worms and estuary still contain ancestral memory and cultural significance partly ‘because they are not eaten by white people’.Footnote 77 Though these deep relationships with waterways and coast were frequently disrupted by urban expansion, such accounts highlight both the knowledge and management of marine borer species prior to and after invasion.
Marine borers were sometimes consumed in other Pacific Islands, though the evidence is patchy. For example, Charles Hedley of the Australia Museum reported receiving a new species of shipworm from Fiji in the 1890s. The first specimens were obtained from red gum piles left in the Rewa River in the vicinity of the Nausori sugar mill for two years, and others from the Navua River. Hedley thought the best preserved, 2 feet in length, was ‘probably capable of causing much mischief’. However, Pacific labourers employed at the sugar mill took a different view, as ‘the animals were greedily devoured raw’.Footnote 78 The borers were more widely eaten around Papua and the coral triangle, an area of high marine and mollusc biodiversity. The Kamoro in south-west West Papua, for example, prized tambelo (Bactronophorus thoracites, a species of shipworm), gathered by women and valued as a food with health-giving properties.Footnote 79 Around South-East Asia, teredo are similarly valued as a delicacy among many coastal communities.Footnote 80
The risk of marine borers to vaka/waka/waqa/drua (vessels or canoes) in ocean-going communities was also known and mitigated. In Fiji, for example, teredo were called obe.Footnote 81 Expert carpenters of the mataisau clan from Kabara in Lau were renowned for their skill in constructing large ocean-going vessels, such as drua and camakau, using the sacred vesi (Intsia bijuga). Vesi is a hardwood that grew on abundantly on the island but not widely available elsewhere, and was resistant the ravages of insects and marine borers.Footnote 82 The stands of vesi were of such strategic and political importance in the region that they have been described as ‘the titanium of the Pacific’.Footnote 83 Both the Kabara vesi and the canoe-builders’ abilities were known and valued in and beyond Fiji, and through kinship connections Tongan and Sāmoan chiefs contracted carpenters to build large canoes in the 1700s and 1800s.Footnote 84 The vessels could be as large as, and faster than, European equivalents of the era.
Elsewhere, Indigenous communities also selected specific hardwood species at least partly for their resistance to borers, such as tōtara (Tōtara podocarpus) in Aotearoa New Zealand, koa (Acacia koa) in Hawai‘i, and ‘ati (Calophyllum inophyllum) and mara (Nauclea forsteriana) in Tahiti. Like vesi, these trees were often considered sacred or chiefly. In atolls without hardwood, breadfruit (Artocarpus altilis) could serve a suitable, if not as long-lasting, alternative.Footnote 85 Māori also coated waka (canoes) in shark fin oil, adding an additional layer of protection.Footnote 86 Boat-building practices reflected local environmental knowledge built over generations.
Indigenous knowledge of borer species and their relationship to local woods around the Pacific was rarely valued by newcomers by the turn of the twentieth century, reflecting colonial dismissal of Pacific environmental knowledges. In Aotearoa, for example, Māori knowledge of tōtara ‘did not reach Europeans, or at the very least, was not reported, and certainly not acted upon’.Footnote 87 Similarly, late nineteenth-century New South Wales reports on effective hardwoods drew on local settler knowledge but did not appear to engage with Indigenous knowledge-holders.Footnote 88 Aside from briefly noting cobra as an Aboriginal name for shipworm in New South Wales, a large experimental study of timber in Sydney and comparisons to Brisbane and other Australian harbours made no mention of Indigenous knowledges.Footnote 89 In Fiji, Ragg mentioned local sacau (Palaquium sp.) trees being resistant to teredo though not Limnoria, but does not discuss vesi or other hardwoods.Footnote 90 Occasional mentions of local species provides a glimpse of knowledge gained from unknown Indigenous interlocuters, suggesting at least some connection between Indigenous practices and later hardwood trials. Nevertheless, by the end of the nineteenth century, engineers and scientists in these ports showed little engagement with Indigenous environmental practices, preferring to look across the ocean to other ports and colonies for potential solutions to the shipworms’ chewpoints.
Chewpoints in colonial ports: Shifting relationships to worm and wood
Like their Pacific counterparts, shipbuilders in Europe had long sought to mitigate the damage of worm to wood. By the mid-nineteenth century, solutions such as careening and cleaning, tarring, and wooden or copper sheathing were well-established as mechanisms to extend ships’ lives, even if none were completely effectively in eliminating the mollusc within.Footnote 91 Yet the ability to protect and preserve coastal infrastructure where such ships docked was comparatively underdeveloped. Zoologist, Crustacea expert, and keeper of the British Museum’s zoology section William Thomas Calman wrote in Nature in the mid-1920s, ‘shipworm still remains a constant source of anxiety to harbour engineers in many parts of the world’.Footnote 92 As Martin Dusinberre and Roland Wenzlhuemer argue for ships as sites of knowledge, the ‘practice of science must be situated or “put in its place”’.Footnote 93 Hardwood trials in Pacific ports highlight the local and contingent nature to the shipworm problem, despite attempts to find global solutions. Connected examples from Suva, Sydney, and Honolulu in the late nineteenth and early twentieth century reveal the limits of engineering technologies to counter the engineer in mollusc form.
Ship crews and port workers knew well the reality and risks of living alongside these companions. In a French illustrated journal in 1893, G. C. poked fun at the endless debates over shipworm species among the scientific community. By contrast, a port worker tells an illustrious naturalist to listen to hear the ‘teredo making music’. The author concluded that a simple and unlettered worker knew more than the naturalist.Footnote 94 Oystermen and port workers on both sides of the Pacific similarly evoked the sound of shipworms: ‘On still summer nights I have heard them grinding their way into the wood, and the noise of the grinding would surprise you if you should put your ear to the head of a pile in which they were at work.’Footnote 95 Recent research by a French laboratory has recorded the ‘grincements’ (to use G. C.’s description) of shipworms for the first time, confirming for scientists what sailors had long known.Footnote 96
Though often unseen, shipworms were thus not necessarily unknown. Margócsy and Brazelton argue that because transportation required ‘requires complex skills and knowledge of repair and maintenance … much of the knowledge produced in long-distance networks focuses precisely on these practical concerns. Circulation produces the kinds of natural knowledge that facilitate further circulation.’Footnote 97 Some knowledge of the shipworm moved with the ships and crew traversing the ocean, who could hear the work of the worms. But what about the expertise and skills of repair at the nodes in these global networks? To what extent did this knowledge circulate between ports and wharves, the chewpoints in these imperial networks?
Despite the embodied knowledge of those labouring aboard or at port, colonial engineers and scientists struggled to track, classify, and eliminate the shipworm. By the early twentieth century, shipworms were chewing through new port infrastructure across the Pacific, from Sydney to San Francisco, causing millions of dollars of damage when wharves and buildings collapsed into the ocean.Footnote 98 Despite considerable investment, the animal ‘still defie[d] all the resources of the harbour engineer’.Footnote 99 Wooden piles might last just a few months before being riddled with holes and collapsing. In the most extreme example, rapid wharf construction during the Second World War in New Guinea saw almost equally rapid collapse of these facilities: some built with softwoods and coconut lasted less than two months.Footnote 100 Depending on the wood, location, and oceanic conditions, piles might last anywhere from two to twenty years before requiring extensive repair and replacement. Even where structures did not fail, this represented a considerable expense on top of the high costs of construction.Footnote 101 For example, by 1927 pile maintenance costs for the Port of Sydney reached an ‘alarming’ £16,000 annually.Footnote 102
As the worm moved along shipping routes to new port homes, or from mangroves into wharf piles, biologists and engineers looked across the ocean for hardwoods resistant to the mollusc. For example, in 1934 engineer A. A. Ragg reported on the history and future of Suva’s port. As the British colonial town expanded following its establishment as Fiji’s capital in 1882, and its importance as a node in trans-Pacific shipping grew, the wharf and docks necessarily expanded. The surrounding reef formed a convenient natural breakwater for a deep harbour, the mountains protected it from prevailing winds, and from the 1880s coastal mangroves were quickly cleared and land reclaimed to create larger berths and warehouses around Nubukalou Creek. Despite these seemingly ideal conditions, each wharf’s ‘deterioration was both extensive and rapid’.Footnote 103 The first, built of Fijian hardwood, deteriorated within sixteen years. The second, rebuilt in 1902 using Tasmanian timber, lasted barely twelve. Above the water, the combination of sun and rain meant the timber expanded and moisture entered. Below the water was even more troubling. Marine borers had eaten away at foundations unseen, quickly destroying the structural integrity of the piles until they were so riddled with holes and ‘unable to take the pull necessary for their extraction’.Footnote 104
Below the dry prose of Ragg’s account lurked a multispecies history that he pitched as a struggle between the shipworms and the rotating cast of British engineers. He documented various attempts to protect the submerged timber piles from T. navalis and Limnoria, a genus of crustaceans known as gribbles that attacked the wood from the outside, as the port was built, rebuilt, and rebuilt. Different timbers were used, from both Fiji and Australia, but though some resisted the teredo, they were attacked by Limnoria, or vice versa. Use of concrete sheathing around the wood also proved insufficient to prevent teredo larvae’s entry, and soon the worms rasped away as normal. Creosoting timber (impregnating the wood with an oil from distilled coal tar) was dismissed as impractical due to its cost. Ragg discussed the possibility of using charred wood as a deterrent, as he noted was practiced in Australia, but it proved almost impossible to keep the fragile, charred outer intact during wharf construction. Constant replacement seemed to be the only avenue forward.
Despite these challenges, ports like Suva materially embodied oceanic connections. Rebuilt from Tasmanian timber, the wharf piles both rooted and further enabled the city and colony’s entanglement with global flows of people, goods, and ideas. Throughout the region, engineers sought harder and more resistant woods across the sea. In New Zealand, for example, Australian jarrah (Eucalyptus marginata) was long favoured, even as builders of Sydney Harbour considered turpentine the best of the local timbers.Footnote 105 Yet nowhere and no hardwood seemed immune. Indeed, Suva’s wharf fell again in 1952, where fractured concrete cases and the ‘ravages of marine borers and sea action’ meant the slender piles were ‘an easy victim’ of a hurricane.Footnote 106
Scientific publications and newspaper reporting highlighted the trans-Pacific flow of timber species and studies in the early twentieth century, as the first or second generations of wharf infrastructure fell victim to borers and decay.Footnote 107 Considering South American greenheart (Nectandra rodioei), Australian jarrah and turpentine (Syncarpia laurifolia), and New Zealand tōtara in 1919, Calman noted that shipworms and gribbles seemed ‘indifferent’ to timber hardness, eating away at oaks and conifers alike. He theorized something other than hardness alone might explain the comparative longevity of different woods:
The woods that are most resistant to attack probably owe their comparative immunity to the presence of essential oils (as in the Eucalypts) or alkaloids (as in Greenheart), but this resistance is only temporary, and every kind of wood that is commercially available has been found to be attacked sooner or later.Footnote 108
Similarly, in Western Australia, zoologist William Dakin reported that ‘All kinds of timber seem to be attacked by the shipworm, and, from the fact that hard jarrah is burrowed deeply by the creature, it would appear that the hardness of wood is no deterrent, although naturally, progress would be more rapid in a soft wood.’Footnote 109 He compared the longevity of timbers along the Australian coast with US Forest Service research. Observing that one pile might be destroyed but its neighbour unaffected, he extrapolated that ‘If the wooden jetty piles in any harbour remain free from this ardent burrower, it is either because the conditions in the water are detrimental to the life of the animal or else the composition of the timber chemically is a deterrent.’Footnote 110 Thus, in practice the promise of globalized botanical knowledge and technological innovation was undercut by the seeming inevitable attack of the worm. Timber, originally as ships and then as processed planks or piles, was a site of cross-regional integration that was simultaneously necessitated and obfuscated by shipworms, in a further interplay between disconnections of diverse ports as well as their forest hinterlands across the ocean.
Though Turner lamented scientific isolation and the disconnected duplication of taxonomic work, some scientists collaborated or themselves moved between ports. Australian Museum zoologists like Tom Iredale and Francis A. McNeill started their work in Sydney in 1927, before contributing to studies in Brisbane. Australian scientists led a Council for Scientific and Industrial Research (CSIR)-funded survey in New Guinea, then an Australian mandate.Footnote 111 Bishop Museum zoologist Charles Edmondson in Honolulu sought shipworm specimens from across the region by mobilizing US army and navy networks.Footnote 112 Turner herself later researched Australian shipworms, invited by CSIR.Footnote 113
In another example, engineers and scientists experimented with a similar range of woods and wood treatment to protect piles in Honolulu, Hawai‘i, where untreated timber lasted a maximum of two years and often less.Footnote 114 G. L. Amos, a scientist with CSIR’s Forest Products division, recounted experiments in extending the life of underwater wood in the 1930 and 1940s, revealing a story of failure that connected Australia, Papua New Guinea, and Hawai‘i. The search for resistant hardwoods gradually grew ‘an empirical knowledge of a few woods widely scattered in occurrence, which were relatively immune to shipworms … so that countries could grow the resistant timbers locally rather than import them’. Substantial effort went into new plantations, only to find that the timbers that offered some protection in one Pacific harbour proved ineffective in another. Demerara greenheart (Chlorocardium rodiei, or N. rodioei), a tropical American timber reputed be resistant, did not stand up to trials in Sydney Harbour. Turpentine (S. laurifolia), an Australian timber that had ‘received universal recognition as being very resistant’, stood up well in Sydney experiments. A turpentine plantation was therefore established in Hawai‘i, and the wood tested in Honolulu Harbour, where ‘depredations by shipworms were very severe’. After several months submerged, the locally grown turpentine had been eaten with ‘avidity’.Footnote 115 By contrast Australian-grown timber samples, submerged at the same time, demonstrated their known resistance to the worm. The only difference appeared to be the locality in which the wood was grown.
Further studies of the cross-sections suggested that Australian-grown turpentine contain nodules of silica absent in the Hawai‘ian-grown equivalent. The soil in which the trees grew shaped the silica content of wood and thus its resistant properties. The local environment was as important as the imported species. Scientific solutions, thus rooted in place, were not so easily transferable across the ocean as the borers or the timber that had carried them between ports. Similarly, turpentine effective in Port Jackson was ‘readily destroyed’ in Brisbane waters.Footnote 116 Amos concluded that ‘for a long time [siliceous timbers] have been used by native peoples for boat building’, suggesting the need for further research into suitable local timbers in the Pacific region.Footnote 117 His conclusion highlighted a point frequently ignored by colonial scientists: the importance of ecological knowledge and the relationships that Indigenous communities in coastal Australia and the Pacific had with both worm and wood.Footnote 118
To borrow a phrase from Pacific studies, such knowledge had both routes and roots.Footnote 119 The soil and land—country, vanua, whenua, or ‘āina—in which the different trees were rooted and nurtured could not simply be separated from each other, reflecting how environmental knowledges, like timber, were grounded in place, even when also mobile and global. This was a point scientists themselves came to realize. Despite the increased circulation of both scientific studies and timber, in their work on woodborers in Sydney Harbour, Tom Iredale, R. A. Johnson, and F. A. McNeill emphasized that their findings could not be transported. They stated ‘some writers in the past have confused localities, the identity of borers, and the lives of piles in the most inexplicable manner’. Shipworms’ distribution varied, and, importantly, they ‘react differently to slightly changed conditions’.Footnote 120 The story of marine borers’ resilience in the face of ongoing, and often global, efforts of harbour engineers and marine ecologists to combat their presence highlights how this underwater assemblage was not just a coastal or oceanic one, but also deeply rooted in soil and place.
The shift towards concrete construction and chemically treated timber in the mid-twentieth century, along with increased harbour pollution, eventually reduced the shipworm threat. Aspects of this history are difficult to trace: in Fiji, archival mention of the shipworms seemingly end.Footnote 121 The experience elsewhere provides some clues. Creosote treatment of timber had long been established as a potential measure against shipworms, though it was only effective if applied correctly. Moreover, while it hindered shipworms, it did not prevent gribbles.Footnote 122 These difficulties meant chemical treatments were unevenly used in the Pacific. Subsequently copper-chromate-arsenate (CCA) was patented in 1950s, a method effective against gribbles.Footnote 123 From the mid-twentieth century, creosote or CCA emerged as the treatments of choice. In Sydney, for example, McNeill and Johnson developed a new technique to help protect piles:
A ‘floating collar’ is filled with poison creosote, and this slides up and down each pile with the tide … The poison floats on the sea-water and impregnates the timber of the pile. Then the ‘collar’ is shifted to another pile and the process is repeated.Footnote 124
A local plant to pressure-treat wood with creosote opened in the late 1950s, likely incentivizing greater use.Footnote 125 In Papua New Guinea, scientists similarly advised hardwood or creosoted timber for resistant wharves and boats, though tests from Honolulu (including using Australian creosoted wood) were less optimistic.Footnote 126 Nevertheless, in 1961 McNeill celebrated that piles in Sydney now had an ‘indefinite life’ for just 7 shillings a year per pile (compared to the replacement cost of £100).Footnote 127 Yet the resilience of the shipworm paralleled the resilience of efforts to master nature. In 1970, a borer-riddled Queensland wharf again collapsed after just three years, prompting renew interest in studying both worm and wood.Footnote 128
Epilogue: Let them eat wood?
Part of shipworm’s power was symbolic: an unseen threat and source of anxiety.Footnote 129 Shipworms were thus a productive source of cultural allegory, as Nelson explores in the US context.Footnote 130 As well as their literal littoral disconnections, shipworms offer a metaphor for oceanic imperialism in the Pacific. Shipworms could be the source of their own destruction, through the over-consumption of the wood within which they lived, echoing colonial over-exploitation of oceanic resources. In 1926, ecologist Robert C. Miller observed:
If undisturbed, the molluscan borers fall victims at last of their own rapaciousness, their boring activities coming to an enforced end upon the utilization of all available space in the wood. After this the organisms begin to die off, conditions of putrescence ensue which prove lethal to the occupants of neighboring burrows, and finally the wood falls to pieces, which is fatal to any survivor.Footnote 131
That the borers could be both destructive and self-destructive is a provocative parallel for the history of colonial and capitalist expansion.Footnote 132 Colonial vessels voyaging into the Pacific, and the wharf piles they tied to, often contained the source of their own destruction. Indeed, the most infamous of visitors, Captain James Cook, found his own ship replete with shipworms during his 1769–1771 voyage across Oceania.Footnote 133
The continued presence and impact of shipworms further reflects the difficult legacies of colonialism inherited in the contemporary Pacific, and the globally connected nature of this story. In August 2022, The Guardian reported shipworms were destroying RI 2394, a contested shipwreck off the Rhode Island coast, which the Australian Maritime Museum claimed is the remains of Cook’s Endeavour.Footnote 134 Whether this is a disaster for maritime heritage or perhaps a cause for celebration is a matter of perspective. While some call to preserve the Endeavour shipwreck against the shipworm’s rasps as ‘one of the most important wrecks in human history’, Indigenous scholars such as Alice Te Punga Somerville emphasize that Cook has been given far too much oxygen already. Resting in this US harbour, rather than at the heart of the empire in the Thames as has often been assumed, the Endeavour’s final home suggests the ‘messiness, multivalence and in-the-moment forgetfulness of empire’.Footnote 135 Shipworms, too, embody this messy and often overlooked multispecies history, as they both mobilized and undermined global oceanic networks.
Shipworms served as chewpoints, disrupting both the practical and symbolic extension of empire over oceanic space through their invisible consumption of ships’ timber and the submerged wooden piles of the jetties, wharves, and ports. These chewpoints brought worm and wood together in new configurations, as a multispecies assemblage which simultaneously harnessed and troubled anthropogenic changes in littoral ecosystems around the Pacific during a period of rapid colonial and commercial expansion in the region.
The shipworm and wood thus embody the interplay of inter- and dis-connection in global histories. The proliferation of transoceanic shipping and associated wooden construction around harbours and coasts created new opportunities for endemic and introduced shipworms to flourish in Pacific waters, destroying wharves and flummoxing harbour engineers, marine and forest scientists, and colonial governments. But destruction and decay is not always bad. Focusing on these chewpoints enables us to critique the seeming inevitability and dominance of global systems through a focus on smaller, less visible, species and their wider ecological relationships. The assemblage of worm and wood has a deeper history in the Pacific, as part of a healthy coastal ecosystem, with endemic species managed as part of the earliest aquaculture systems along Australia’s coasts, gathered as food resources in many islands, or contained through sophisticated boat-building expertise. These alternative, enduring understandings of worm and wood highlight the potential for different stories about, and relationships with, a so-called marine pest that dominated colonial imagination of coastal waters around the Pacific.
Acknowledgements
Thank you to Rohan Howitt for his enthusiastic and thoughtful comments on drafts, my writing hui for their insightful suggestions, and the Oceans Dis:connect symposium organizers (David Armitage, Sujit Sivasundaram, and Roland Wenzlhuemer) and participants for helping shape the concepts and argument. Thoughtful and generous suggestions from the reviewers and JGH editor Heidi Tworek have further benefited the article—I thank them for their time and expertise.
Financial support
This research was supported by a Marsden Fund Fast-Start Grant (UOW2012).
Competing interests
The author declares none.
Kate Stevens is a Pākehā historian at the University of Waikato in Aotearoa New Zealand. She researches and teaches histories of cultural, environmental, and legal exchange in the Pacific world. Her first book, Gender, Violence and Criminal Justice in the Colonial Pacific 1880–1920, was published by Bloomsbury in 2023.
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