This article was taken from our archives. It first appeared in the August 2004 issue of The Bermudian. It appears here exactly as it did originally.
Charles Darwin and HM Beagle never visited Bermuda. But Darwin wondered about Bermuda. What did the island’s coral have to say about evolution? Like other nineteenth-century naturalists, Darwin concluded that “Bermuda differs much.”
In this era of eco-tourism, the Galapagos Islands have emerged as the ne plus ultra destination. People go there because Charles Darwin visited these islands more than a century and a half ago. They go because the islands furnished the English naturalist with flora, fauna and geological formations that provoked him into believing that the world we live in was not a fixed entity, but instead a system in constant change.
This process of natural selection became the central, and revolutionary, tenet of Darwin’s 1859 treatise On the Origin of the Species. Thus, when eco-tourists stare at the Galapagos finches, lizards and tortoises, they are reminded that Darwin changed the way we see this planet. In its own quiet way, the geology of Bermuda would provoke Darwin and other nineteenth-century naturalists to ask similar questions.
From the outset, Bermuda struck newcomers as an odd piece of real estate. Spanish Captain Diego Ramirez noted in 1603 that the island was “not all solid land, but divided into different islets close together with shallow water between.” William Strachey found Bermuda a place of “broken islands … sundered and torn” by the elements.
In 1827, the Royal Engineers posted young Lieutenant Richard John Nelson to Bermuda. After training at the Royal Military Academy, this was Nelson’s first colonial assignment. Nelson applied his engineering expertise to the fortification of the colony. Military engineering would prove to be an early handmaiden of geological knowledge in Bermuda. Bermuda soft stone was useless for fortification, but Bermuda hard stone-the deeper coral rock that had been hardened by the constant percolation of water through it-was appropriate for ramparts.
In his leisure hours, Nelson addressed the question of what made Bermuda a coral island. Seeking “a clue to the origin and nature of those formations,” Nelson prowled the island’s cave, reporting, for instance, that a “perfect bijou” of a cavern lay beneath Tucker’s Island in the Great Sound. After his return to England in 1833, Nelson placed his observations before the Geological Society of London. “I can see no proof,” he concluded, “that the islands, though once formed beneath the surface of the sea, were suddenly and subsequently elevated.”
Nelson’s point was that Bermuda was an “organic formation” made of a “mass of animal remains, in various stages of communication [pulverisation] and disintegration.” He noted the special role played by reefs offshore and caverns below in the formation of Bermuda. That these caves on occasion collapsed Nelson took to be another sign that Bermuda was in constant growth. Above ground, he noted that the colony was covered in “dry, red earth, containing vegetable matter” but no minerals. Nelson’s intrepid rambling indicated that Bermuda had not been created in some big, Biblical event, but instead had evolved over time.
These were the years in which men “read the rocks” in an attempt to probe the mysteries of life. At the forefront of this exploration was Charles Lyell (1797-1875), a professor at King’s College in London and president of the Geological Society in the years when Nelson was reporting his findings. Lyell’s prominence derived from the 1830 publication of his Principles of Geology or The Modem Changes of the Earth and Its Inhabitants. In this magnum opus, Lyell dethroned the so-called catastrophic school of geology-the notion that the earth had been formed in sudden, dramatic fashion-and suggested a more evolutionary theory. Coral reefs, he wrote, offered persuasive evidence. “The powers of the organic creation in modifying the form and structure of the earth’s crust, are most conspicuously displayed in the labors of the coral animals…” Lyell never visited Bermuda, but he showed his debt to Nelson.
The natives of the Bermuda Islands point out certain corals now growing in the sea, which, according to tradition, have been living in the same spots for centuries. It is supposed that some of them may vie in age with the most ancient tress of Europe.
Lyell’s interest in “reef-building polypifers” soon caught the eye of other pioneering naturalists, most notably Charles Darwin, who was circumnavigating in the Beagle in the same years that Nelson and Lyell had speculated about Bermuda.
Almost two decades before he published Origin, Darwin published The Structure and Distribution of Coral Reefs in 1842. From the decks of the Beagle, Darwin had been fascinated by the coral atolls of the Pacific.
“… for every one must be struck with astonishment, when he first beholds one of these vast rings of coral rock, often many leagues in diameter, here and there surrounded by a low verdant island with dazzling white shore s bathed on the outside by the foaming breakers of the ocean, and on the inside surrounding a calm expanse of water … [and made up of] … the soft and gelatinous bodies of these apparently insignificant creatures.”
HMS Beagle never dropped anchor off Bermuda. The island nonetheless attracted Darwin’s curiosity. Bermuda perplexed Darwin because it did not nearly conform to what he had seen in the Pacific. Bermuda bore “a close general resemblance to an atoll,” but “differs much from any other island I am acquainted with.” Bermuda did not have a perfect fringe reef that was exposed at low water, nor did it have a complete, encircling “border of gradually shoaling water.” Indeed, part of the island’s ring seemed to have tilted below the sea while the other rim was now permanently out of the water. Last, Bermuda’s “size, height, and extraordinary form did not parallel that of the low-lying, circular atolls Darwin had seen on his travels.
Nelson had noted Bermuda’s hills, most notably 260-foot-high Sears’ Hill in Smith’s and 240-foot-high Gibbs Hill in Southampton. It seemed unlikely that such elevations could have been produced by simple coral growth and wind action. The presence of layer of red earth too heavy to have been shifted by wind in the coral strata indicated that other forces must have been at work in the island’s creation. (High on the slopes of the Andes in Chile, Darwin had found embedded seashells, evidence that mountains had once been under the sea). Bermuda was thus a different kind of coral island. Indeed, it was in fact the northernmost coral island in the world. Throughout the rest of the century, geologists would debate just where Bermuda fit in the geological lexicon. Was Darwin right? Was Bermuda the product of subsidence or had the wind and waves alone shaped it?
Bermuda played another role for late nineteenth-century scientists. It offered them a unique base for research, different from North America and Europe in its geology, flora and fauna. The geologists among them invariably returned to the subsidence debate. In the early 1870s, for instance, James Dana of Yale University concluded that the “lonely Bermuda atoll” was the produce of subsidence and “the tongue of warm water due to the Gulf Stream.” Dana dramatically suggested that a “rate of sinking exceeding five feet in a thousand years … would have buried islands and reefs together in the ocean: while, with a lower rate, the reefs might have kept themselves at the water’s surface.” Bermuda, in effect, was in a slow race to stay afloat.
In 1884, William North Rice, a professor of geology at Wesleyan University, asked the now-familiar question “Is Bermuda an atoll?” in a Smithsonian Institution publication. In the late 1870s, Rice spent two winters in Bermuda studying its geology. For Rice, Bermuda was closer to the norm of a coral atoll-the product of age-old, gradual subsidence, constant coral buildup and abrasive erosion. The principal characteristic of Bermuda was “the immense erosion which has taken place…Many of the most picturesque features of Bermudian scenery are due to this erosion.” The cave at Paynter’s Vale was, for instance, full of “pygmy” stalagmites and stalactites.
Other eminent geologists followed in Rice’s footsteps. In 1888, Professor Angelo Heilprin from the Academy of Natural Science in Philadelphia arrived “to satisfy my mind on certain points connected with the structure and physiognomy of coral reefs, to the study of which the Bermudas offer special advantage.” Was Bermuda the result of a contest between low subsidence and compensating coral growth shaved by erosion? Or was it simply the outcome of “simple coral upgrowth”? As impressed as he was by erosion’s “annihilating” power, Heilprin noted that coral accumulation always exceeded erosion and that the relative stability of the island must, therefore, be explained by subtle subsidence. Darwin had another ally.
Darwin still had his naysayers. The spring of 1894 brought another distinguished geologist to Bermuda. Swiss-born Alexander Agassiz was the curator of the Museum of Comparative Zoology at Harvard University and came from a family famous for scientific investigation. Agassiz agreed with Darwin that subsidence had “brought about the existing condition of the islands and sounds” of Bermuda, but differed in believing that “the corals have not added any material part to the reefs.” “It seems to me,” he wrote, “more natural to suppose that the Bermudas were formed during a period of rest, when the level of the reef was stationary …. ” This would explain why Bermuda’s present shape bore little resemblance “to the ring of an atoll.”
Thus, for almost a century, a debate had raged-raged, at least, in polite academic tones-over the fundamental question of where Bermuda had come from. The debate had implications far beyond simply understanding the lay of the land in Bermuda and far beyond the colony’s perimeter reef. Big questions were being asked of a small place, questions of profound importance for people struggling to find a new balance between God and nature. Darwin’s fascination with coral atolls had led him to speculate how landmasses were shaped over time-how they evolved. Other geologists sensed the same potential.
Some closure on the issue of Bermuda’s geological origins came in the 1930s when another Harvard geologist, Robert Wilcox Sayles, reported the findings of his sifting of the Bermuda sands under the melodramatic title of “Bermuda during the Ice Age.” He was “puzzled to understand how such great dunes could develop on such a small island.” The key, he concluded, was glaciation and its effects on global water levels, climatic conditions and ultimately Bermuda’ formation. Sayles carefully examined the stratifications of Bermuda quarries. Contrary to the notion that Bermuda was the produce of an ancient volcano gradually sinking below the wave and a coral platform growing upward to the sea’s surface, Sayles suggested that it was in fact the level of the ocean itself that had been in motion. He explained that an ice age stole water from the sea, drew down its levels and brought on colder climatic conditions in which Bermuda was “heavily wooded and quite free of drifting sand.” When the ice age retreated and water levels and temperatures again rose, this hard layer provided a platform for coral-dune formation.
Echoes of this interest in Bermuda’s geology reverberated through the rest of the twentieth century. Popularisers took the debate over subsidence and placed it before a broader audience. The American naturalist William Beebe walked Bermuda’s beaches, probed its depths in the 1930s and reported his findings in snappily written books or magazine articles. Beebe sided with Darwin on subsidence, with Agassiz on the action of wind and wave and with Sayles on glaciation.
Perhaps the most striking aspect of Bermuda’s geology in the twentieth century was not man’s interpretation of Bermuda’s geology, but instead man’s remaking of Bermuda geology. Two themes stand out: the creation of new landmass in wartime Bermuda and the slow degradation of the Bermuda landscape by its increasingly intrusive society. In World War II, Bermuda became one of the few places in the world to actually expand its landmass. Military engineers dredged coral from the floor of Castle Harbour and created 750 acres to build an airport. More land was added by the consolidation of Morgan’s and Tucker’s Islands in the Great Sound. The imperatives of war blinded the engineers to the geological consequences of their actions. The coral they were using to realise their dreams was, of course, largely living coral. The removal of twenty-thousand cubic yards of such coral not only destroyed living coral but it also disturbed the process of sedimentation by which Bermuda inexorably built itself up.
This became apparent in the 1970s when two Yale geologists Richard Dodge and Rimas Vaisnys-compared coral-growth patterns and populations in dredge- scarred Castle Harbour with those of the island’s unsullied perimeter reefs. The result: “the density of living corals in Castle Harbour is less than for external sites (the reefs), and also that the proportion of living to dead corals in the harbour is much less than those same external reefs.” Dredging was “the most likely event” to explain this discrepancy. Here was the irony of the 1941-43 base creation: In extending the island with its own coral, World War II engineers were tampering with Bermuda’s coral structure. Alter the reefs, and you are in fact jeopardising Bermuda’s fragile mid-Atlantic perch. Man could thus reverse the process that had so fascinated and perplexed Lyell, Darwin and their ilk for over a century.
The late twentieth century brought further evidence that Bermuda’s coral underpinning was being taken for granted. Most spectacularly, the exponential growth of ocean-borne trade brought ecological danger right to the edge of Bermuda’s reefs. Although the island is fortunately not situated on a major sea lane, the presence of ever-larger vessels on the seas carried potential disaster for Bermuda. Several near disasters involving tankers stranded on Bermuda reefs:-like the Mari Boeing stranding of 1979-underlined the sinister threat that spilled oil posed for a living coral reef. In the 1970s and 1980s, the presence of globules of oil-tar-on beaches hinted at the problem. Oceanborne trash also snagged on Bermuda’s reefs, potentially stifling their vitality.
On shore, Bermuda’s geological structure came under other slow but nonetheless worrisome threats. The island’s inexorable growth has made it one of the world’s most densely populated environments. Housing has come at the expense of natural space and, with fewer trees to anchor the soil, questions have arisen about the process by which the island’s dunes-the initial rage of coral sedimentation-will in future be built up. These challenges are almost imperceptible, often creeping into the ecosystem and going unnoticed until some dysfunction emerges.
So what would Nelson or Darwin make of Bermuda’s geology today? Subsidence, Darwin might point out, was undoubtedly continuing. But what about global warming? Would it push up ocean levels and tilt the odds in Bermuda’s race to survive as a land mass? Or would man’s degradation of the coral landscape worry him more? As they did in the nineteenth century, Darwin and fellow geologists might be inclined to squabble over the nuances of reading Bermuda’s rocks. But Darwin and his ilk would want us to be aware that “Bermuda’s delicate balance” was now not just the outcome of the inexorable rhythms of nature but also of man’s stewardship.