Postcard, c. 1930 – 1945

In 2016, among lonely sea urchins the color of day-old blood and a smattering of feather-soft hydrozoa wafting in the current, a team of scientific divers set out to catalog the physical features and species composition of known pearl-oyster reefs in the waters around Qatar. Between 12 and 25 meters underwater, they took samples of oysters where they found them, recorded the sediments that made up a mostly-empty seafloor, and noted key species. Of the five reefs surveyed, only one was still populated with oysters. One hundred and ten years earlier—long before glitzy skyscrapers filled the Gulf coastlines or artificial islands carved out the shape of the world in its waters, before the invention of scuba diving technology or, for that matter, the inception of “marine biology” as a profession—British colonial officials relying on the expertise of local nakhodas (captains) had listed several dozen pearl banks whose famed “noble” reefs promised hundreds of oysters. Thirty years before that, another bureaucrat had observed that oysters were everywhere: “the whole of the shallows,” he wrote, “[is] more or less fertile.” If, reader, you are still turning the clock back, look perhaps to passages in the Qur’an that list the bounties of coral stone and pearl spilling forth from the seas. History offers us visions of the bounty of oceans past, illustrating worlds entirely different from our own.

Life in the Anthropocene is suffused with environmental destruction, making it critical for societies to determine viable conservation goals for marine and terrestrial environments. But where should we derive these standards from? In a recent piece for Granta, the marine biologist Callum Roberts describes a research trip to the Maldives where he realizes, to his horror, that the depleted fish populations on the coral reefs appear plentiful to the unaccustomed eyes of his students. “We have forgotten the past so completely that few people question whether a different world is even possible, or desirable, today,” he concludes darkly. Fisheries scientist Daniel Pauly dubbed this Shifting Baseline Syndrome (SBS), outlining a kind of professional environmental amnesia where “each generation of fisheries scientists accepts as a baseline the stock size and species composition that occurred at the beginning of their careers and uses this to evaluate changes.” The result is an acceptance of the decline and disappearance of species and the adoption of exceedingly low rehabilitation targets. Meanwhile, as biologist Jeremy Jackson points out, coastal regions are now dotted with cities and towns named for plants and animals that have long since disappeared from there, offering spectral traces of the oyster reefs, kelp forests, sea otter rafts, and whale pods that once thronged the world’s oceans.

If our own subjective perceptions of environmental degradation fail us, history appears to come to the rescue. Given that for most periods before the first decades of the 20th century, modern ecological data does not exist, Pauly argued that anecdotes might point to greater abundance, combating failures of the imagination and lax policymaking. As an example, he described an incident recalled by a fisherman working the waters of Kattegat between the Baltic and the North Sea in the 1920s who, attempting to fish for mackerel, was disturbed by a bluefin tuna fish that kept getting tangled in his nets. Today, the range of bluefin tuna almost entirely excludes the North Sea. A casual aside on a routine disturbance to work became the core of a methodology: this trace of the tuna in history, revealing wildly different habitat and species range, Pauly wrote, was “as factual as a temperature record.” The problem of SBS finds its antidote in the field known as marine historical ecology, which aims to recover these anecdotes.

Within marine historical ecology, subsequent work has extended Pauly’s ideas around shifting baselines, using archival research to calculate conservation targets with the goal of restoring healthier oceans. But the turn to history for environmental solutions is not straightforward. In fact, these approaches, which trawl historical documents for quantitative and reliable facts, often take context-dependent, culturally-loaded descriptions at face value based on the assumption that nature is external to humans and value-free. But 500 years ago, just like today, ecology could not be extracted cleanly from other concerns—capitalism, caste, labor, and colonialism.

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Evidence about past abundance certainly offers powerful tools for environmental activism and management. The narratives are particularly striking in visual form: photographs taken over 50 years show prize catches of groupers longer than the average man and twice as wide dwindle down to pocket size; in a century and a half, beaches once filled end to end with the carcasses of Pacific gray whales are now lucky to have even one live cetacean breach the surface of their waters. But marine historical ecology is more than descriptive. Instead, establishing suitable baselines through historical reconstruction is a critical component of project proposals and research in environmental restoration. These methods have been used in conservation projects including the coral cover in the Florida Keys, sea life in the Gulf of California, rodents in Gabon and Equatorial Guinea, and bird populations in Yorkshire. Public service announcements about Pauly and Jackson’s Shifting Baselines Ocean Media Project have received over $10 million in free airtime, and the two regularly collaborate with Hollywood celebrities to host “Oceans Nights” complete with blue, rather than red, carpets. The recommendations include reducing fishing subsidies, setting up large marine protected areas, cutting the world fishing fleet by a factor of three, and a global fishing ban (“simply stop fishing,” in Jackson’s words).

Marine historical ecology uses archives in the service of ecological modeling. Of course, even apart from uncritically reading historical sources, arriving at baseline estimates is a fraught endeavor. For instance, if we wanted to set the stock population of green turtles in the Caribbean (where the animals currently number less than 200,000), reading historical descriptions or paleoecological data might set the appropriate baseline at anywhere from 33 million to 660 million depending on whether we aimed for a starting time of pre-human or pre-European contact. Baselines, far from being self-evident, are instead determined by ecologists’ judgments. And human judgments haunt archives just as much as they do contemporary ecological models.

Although palaeoecological techniques (such as radiocarbon dating or fossil analysis) can reveal certain trends for periods as far back as 125,000 years, starting about 500 years ago, textual sources offer comparatively detailed and rich accounts of natural history. Historical ecology reads these texts for mentions of large marine vertebrate species (such as whales, dugong, sharks, rays, or giant grouper) and matches them to an “abundance descriptor” like “absent,” “rare,” “present,” “common,” or “plentiful in the ecosystem” based on the description in the passage. For instance, an ecologist reading a line from English explorer and fur trader James Colnett’s 1798 expedition diary mentioning that whales “cover the sea” would interpret it as evidence of a cetacean population several orders of magnitude larger than the population today.

Natural historical texts are not so easily prized apart from their contexts: the colonial travel literature often used for marine historical ecology was written for particular audiences to emphasize the wondrous and the strange, for instance. The sources scientists use are mostly texts authored by European colonists, missionaries, and naturalists about non-European spaces such as the Caribbean, the Gulf of Mexico, or the Persian Gulf. They tend to be places that witnessed extractive, racialized capitalism, which often prompted these descriptions by drawing colonists there in the first place. These texts also often highlight species that were valuable for capitalist enterprise at the time. Orientalist tropes and images of exotic island idylls prevent a straightforward reading of the historical archive for species abundance—a credulous reader of British colonialists’ accounts of the Arabian Peninsula might come away with the impression that the region was wall-to-wall camels or that the island of Ceylon was suffused with jasmine. Neither of these ecological assessments would be accurate, but they certainly reflect popular literary conceits at the time they were written.

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For all the emphasis on recovering forgotten pasts, historical ecology often results in its own assumptions and elisions, particularly of social and political contexts surrounding naturalistic descriptions. Consider an example from the ecological history of the Caribbean. In 1687, the English physician Hans Sloane traveled to Jamaica as part of the household of the newly appointed governor of Jamaica, the Duke of Albermarle. Over the next 15 months, Sloane collected several hundred specimens, took notes on the flora and fauna, and ministered to the sick, both white and enslaved (healthy slaves were essential to keeping British plantations profitable). The resulting text, Natural History of Jamaica, contains a section where Sloane described the

great, long prickled Sea Egg…set about on every hand with prickles, the largest being three or four inches long, with membrane round their setting on to the shell…. The prickles of this Sea Echinus are very rough and considered poisonous. I have found them in great numbers on the reef by Gun-Key, or, Cayos off the Port Royal Harbour [now Kingston Harbour] in great numbers.

The prickly egg Sloane referred to is probably Diadema antillarum, a species of long-spined sea urchin that plays a key role in ecosystem management by grazing on seagrass that would otherwise overrun coral reefs. Ecologists have generally ventured that Diadema’s abundance is due to 20th-century overfishing, which removed predators who might otherwise eat the urchins. Sloane’s comments, however, suggest that in fact Diadema was incredibly abundant on Caribbean reefs long before. In this manner, historical sources can provide detailed ecological understandings of the prior history of Caribbean reefs. So far so good.

As much as baselines recover, they also forget. Sloane (whose collections would eventually form the bedrock of the British Museum) did not just collect objects and specimens; he was also complicit in slavery. As well as writing on the sea urchin, Sloane also described people who were not white Europeans: he contrasted, for instance, “the Negroes from Angola and Gamba, [who] are not troubled with worms” with “those from the Gold Coast very much.” At the end of the 18th century, Jamaica was the jewel in the British Crown, and its white residents were some of the richest people in the empire. To focus on the ecological alone in colonial texts is to write out the human and to uphold ideas of ecology as external both to humans and to human ideas of race, power, and colonialism. Sloane’s own fortune derived largely from his marriage to a Jamaican heiress, and he found African slavery unproblematic. The naturalistic texts from which these species descriptions are drawn also served as a catalogue of the resources of England’s slave colony. Sloane’s ability to observe sea urchins is inextricably linked to slavery, even when we use his scientific writings in the service of modern conservation.

Reading documents for historical ecology uncritically like this can lead to the establishment of faulty ecological baselines. Marine historical ecologists use the archives of pearl fisheries, where Europeans frequently described sharks as the perennial “enemies of pearl divers,” for information on this top predator. Data from the Gulf of California, for instance, shows low prevalence of this predator in the past. But labor historians might read traces of animals in their sources differently. While colonial officials were firm that “not a shark was seen” off the coast of Ceylon, the Times of Ceylon carried an article in April of 1904 claiming that the pearl banks of the island were swarming with large marine predators. “On average one diver a day has fallen prey to sharks,” the paper warned readers. The British, meanwhile, alleged that the paper was making up sensationalist, anti-government stories. In fact, the presence or absence of sharks was a highly contested issue at the pearl fisheries, embroiled with issues of labor, race, and caste. In 1877, for example, a boat of pearl divers had reported “an enormous tiger shark with a white belly and a large head, &c. as long as the boat, and able to carry four men on his back”; other divers reported that there was “a huge monster about 15 feet only and very large in girth who churned up the water.” Eager to get the men back to work, British overseers insisted that the shark was an excuse to stop the harvest of pearls. Divers may indeed have used the shark as a rallying cry to convince hundreds of men not to go to sea; alternatively, there may very well have been sharks in the waters that day, hunting and feeding, impervious to human designs on shore. What is, however, evident is that three groups—divers, colonial officials, and journalists—estimated the presence or absence of sharks differently, and the choice of whom ecologists today should listen to is a deeply political one.

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Marine historical ecology can reveal which way the needle of environmental change is moving. It uses history in creative, unconventional ways. Drastic realignments of public policy to preserve the environment are long overdue, and their urgency grows every minute. This is not a call to restrict archival access to university-affiliated professional historians—environmental activism surely needs every tool in the box, historical and modern. It is, however, a plea to consider that uncritical readings of historical texts can lead to problematic or faulty prescriptions.

Baseline approaches to history need to acknowledge that the oceans are not purely biological spaces but rather cultural, political, and social entities. The parallels in setting aside social and political context in order to rescue ecology or “nature” are hard to ignore. Dramatic proposals such as a global fishing ban take no account of fisher livelihood, and social and economic wellbeing are secondary concerns to preserving “pristine” nature. Perhaps reading historical ecology within social, racial, or geographic concerns might also lead us to models that integrate these concerns more fully within climate justice parameters. Marine historical ecology, in its most daring iteration, demands that when we turn to the past, we resuscitate and reimagine not only the ghosts of marine megafauna but also those of empire, capitalism, and racialized systems of labor—a task that will require much more serious interdisciplinary collaboration.

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