Yet, Barrett reminded his readers, “a scientific expedition has serious work to do.” The shore party, led by Thomas Alan Stephenson, assisted by his wife, Anne, was studying reef animal ecologies. They aimed to isolate “typical areas” within different environmental zones. They’d already mapped out a ten-foot-square “coral garden,” photographed it in sections, and counted its inhabitants. They were also dredging up samples of seabed mud and sand for examination in the lab. Their eventual aim was to work out the breeding habits and seasonal behaviors of sixteen key marine animals, “about which little is known.” These included giant clams, sea urchins, corals, crabs, and bristle worms. Many species appeared to show some strange connection between breeding times and particular tidal and lunar phases—another mystery to be unlocked.19
Working with the shore party was a “physiological group” of Maurice, Mattie, and a young Australian student, Aubrey Nicholls. They aimed to investigate “the family life of corals,” especially how corals feed and grow—what Maurice thought “the most fascinating [problem] marine biology has to offer.” Among other experiments, they used clamshells, drainpipes, and logs to attract coral “settlers,” and constructed bases on which to graft varieties of coral species. After distributing these bases over a range of reef environments, the scientists would monitor the differing growth rates of the new coral. This was vital information because reefs were always competing with the forces that worked toward their destruction, which ranged from burrowing crustaceans to coral-eating fish and torrential rainstorms.20
The Australian Frank Moorhouse was also one of the shore party, and Barrett observed that his work as an economic biologist would have vital significance for the future wealth of Queensland. The marine creatures Moorhouse was investigating included smoked bêche-de-mer for the Chinese market, and the crimson- and red-banded trochus shells whose nacreous interiors were used in the Japanese button industry. Moorhouse had found a little “nook” in the fringing reef from which he could observe the live snails of the trochus, which were also easily gathered by hand at low tide. Andy Dabah would later build Moorhouse separate trochus and oyster pens for his experiments, but prior to that, Barrett reported, Moorhouse worked in the lab with a microscope, “seeing what no one had ever seen before—the very beginning of trochus shell life.”21
Barrett also wrote about going plankton hunting with the “boat party” in the waters surrounding the Low Isles, which he claimed resulted in some of his strangest experiences. Frederick Russell, Gweneth’s husband, stalked zooplankton, the microscopic animals that float almost unseen in every drop of reef seawater, and on which scores of predators feed. Sheina Marshall chased phytoplankton, especially the tiny vegetable diatoms that make up the “pastures of the sea,” and which are the base of a food chain that works up through corals and fish to humans. A. P. Orr, the chemist, was investigating the chemical compositions of plankton environments, testing samples of seawater for salinity, phosphates, nitrates, oxygen, and organic materials. He was also measuring the light densities of seawater—something Barrett joined him in—because phytoplankton, being plants, were dependent on light for energy.
Barrett regarded plankton catching at different water depths as very like big-game hunting, except that it was a “scientific sport … with a definite object [and] its results are of economic value.” In these seawater safaris, “the score is made up of problems solved, secrets of Nature’s ways discovered.” More mysteries lurked unexplored in the waters of the Low Isles, he claimed, than in the jungles of New Guinea. But instead of guns, the researchers’ weapons were fine-meshed trawling nets, insulated water bottles, depth recorders, and tin cylinders painted black so as not to attract sharks. Barrett felt a frisson of anticipation as he peered into the collecting jar, hoping that some new species of pelagic life would be wriggling among the mass of copepods, crab larvae, tiny jellyfish, Sagittoidea (arrow worms), diatoms, and Foraminifera (minute, single-cell protozoans). He was also excited because he’d only seen such bizarre creatures in drawings: “Believe me it is revelation to spend even a day in a tropic sea, with plankton hunters, who hunt for research.”22
Some aspects of Low Isles research also carried the thrill of real danger. The expedition was equipped with a specially built diving helmet modeled on one pioneered by the American biologist Alfred Mayor. Made of galvanized iron and with two glass windows, its air supply depended on continual hand pumping. Frederick Russell, looking like “Ned Kelly preparing for a police offensive,” was the first of the expedition’s scientists to use it, observing the radiant corals below the reef’s edge.
Barrett was envious until he tried a shallow dive himself, to be abruptly reminded of wearing a wartime gas mask. And down there, he couldn’t help thinking about man-eating tiger sharks, groupers with indiscriminate jaws, giant clams (Tridacna) waiting to clamp on the unwary diver’s foot, or the toxic fangs of sea snakes, just like the six-footer he’d seen over near the mangroves. Still, these young scientists seemed as brave as they were clever: “nobody is worrying at all about the perils of the reef,” Barrett wrote. Sensibly, they were more concerned about avoiding everyday annoyances like the sting of jellyfish, the scratch of jagged corals, and the needle-sharp spines of sea urchins.23
But the peril was real enough the day Barrett traveled with the boat party to Batt Reef, on the outer Barrier, where they hoped to view “a section of the submarine structure which ranks as one of the wonders of the world.” A stiff breeze made the boat “curtsy” as they passed beyond the shelter of the mangroves. This turned into “a proper dusting” as they crossed the eight miles of open water to the outer reef. Eventually they sighted a line of breakers and the shadows of “ominous brown and yellow ‘isles’ beneath the surface.” Soon they were caught in a coral maze. Quickly they posted a lookout at the masthead and others at the prow. Despite these and a detailed chart, the helmsman had “an anxious time” as they missed a patch of submerged reef by less than half a boat length.
Barrett was reminded of Cook’s incredible navigating ordeals among these “coral strewn waters,” an empathy that grew as they were battered by “swinging seas” on the return voyage: “one huge wave crashed aboard the Luana, and all the way home to our island she was dodging Pacific rollers large enough to make a coastal steamer shudder.”24
Barrett’s final article ruminated about symbiotic cooperation on the Reef. Despite the ferocity of the struggle among most reef species, some marine creatures chose to become what he called “mess-mates”—not unlike the Low Isles scientists themselves. These mess-mates, however, could display radically different styles and degrees of friendship. Some species, parasite-like, exploited their hosts; others were commensal, with one species prospering from the partnership at no cost to the other; and some were mutually cooperative, with the relationship benefiting both partners. Maurice Yonge’s chief task on the expedition was to find out which of these modes fitted the puzzling association between reef-growing corals and the tiny brown algae living in their tissues.
Yonge had found a range of examples of mutually cooperative relationships among the marine creatures of the Low Isles reefs to use for comparison. Barrett himself had captured a small shrimp—“a lively red-tailed midget”—which lived in the body cavity of a giant anemone. Another, smaller anemone gave refuge to a scarlet-and-white-banded pygmy fish. One species of bêche-de-mer even endured what we might regard as the indignity of having a glass eel take up tenancy in its anus. Gall crabs built a home within the rocky cavities of the reef itself, influencing the madreporic corals around them to form a small living room for the female, complete with a tiny passage to the water. Such was love on the Reef.
As he prepared to leave the Low Isles, Barrett confessed to finding this marine research endlessly fascinating, and he envied the young scientists their future year there. They were happy people, both because they were working “in a fairyland” and because, as Alfred Mayor had written, “love, not logic, impels the naturalist to hi
s work.”25
* * *
Charles Barrett’s newspaper articles constituted a remarkable piece of journalism, much of whose accuracy was confirmed in the details of Maurice Yonge’s prosaic daily notes. Barrett’s syndicated articles generated so much local interest that crowds of curious picnic parties began appearing on the Low Isles, forcing the scientists to fence off their experimental areas and equipment. Still, they couldn’t complain: Barrett had won for the expedition the nationwide enthusiasm of Australia’s public and scientific communities.26
Of course, he’d sometimes idealized or oversimplified the story. Some omissions were a result of his early departure. He never saw, for example, Yonge’s occasional flares of exasperation, such as when the Australian Museum conchologist and ichthyologist Tom Iredale brought his young son and a guest to stay on the island without prior consultation. He didn’t see the irritating amount of time Yonge had to spend managing finances, entertaining visitors, organizing work rosters, and conducting meetings to report on research progress. And the sympathetic journalist didn’t stay with the expedition long enough to observe the sheer physical and mental exhaustion entailed in working long hours in tropical humidity, heat, and rain. “Let no one think that life on a coral island is unending bliss,” Yonge later wrote ruefully.
Our work was never finished. All day, and not infrequently, all or part of the night, it continued. Work of such intensity in such a climate was hard; I felt perpetually tired; every action demanded a tremendous initial effort … It was not until I left the island that I realized fully under what a strain we had been living for many months past. At the same time it was work that made life endurable: without that compelling interest the continuous association of so many people in such an environment would have been impossible.27
Neither was the situation of the Aboriginal workers quite as idyllic as it had initially seemed. Gracie proved to have a quick temper, and she chose to leave the island after four months. Andy, in the meantime, had apparently done little but stand motionless, staring at the water with fish spear raised. Yonge probably didn’t notice that he was unwell—he died within a few months of departing the island.
However, the replacements from Yarrabah mission, Minnie and Claude Connolly, and their children Teresa and Stanley, were a greater success. Minnie did all the cooking and washing without complaint. Claude, though elderly and lame, delighted everyone. A former tracker who’d been wounded in a shoot-out with the Kelly gang in Victoria, he never hesitated to take on any challenge. When not working, he carved gifts for the scientists of firesticks, spears, and model canoes, and he loved polishing pearl shells on a grinding wheel to give to them. Maurice Yonge thought him “an honour to his race” and “a living refutation of the slanders from which the Australian aboriginal has so long suffered.”
Yonge also praised the expert contributions of the two Yarrabah boatmen, Harry Mossman and Paul Sexton—“good servants to the expedition … and to science.” Being paid twenty-two shillings and sixpence a month plus free tobacco, at a time when equivalent white male workers earned twenty pounds a month, they obviously weren’t in it for the money.28
Barrett’s early departure from the Low Isles also meant that he missed Yonge’s coral physiology experiments, which were designed to investigate the feeding, digestion, excretion, and respiration of reef-growing corals, and especially their relationship with symbiotic algae (zooxanthellae). A few coral experts, including Stanley Gardiner, speculated without real proof that the tiny brown algae played an important role in coral nutrition. Others thought that the plants might boost the corals’ energy by supplying oxygen. Yonge was skeptical on both counts. He suspected that the relationship was at best commensal, with the algae the sole beneficiaries, or possibly even parasitic, at the expense of the coral hosts.29
It was obvious how algae benefited from the association. Insinuating themselves into the very cells of the coral polyps, they were thus protected from predators while still afforded access to light through the thin tissues of the coral. Like all plants, the algae needed sunlight to create energy through photosynthesis, and in the process they produced oxygen. Using their light-activated coloring matter chlorophyll, the algae built up their basic organic food of starch and sugars from a mixture of seawater elements produced by the corals. They “obtain from the excretion of the corals valuable food material,” Yonge wrote, listing these nutritional wastes as carbon dioxide, ammonia, and hydrogen. With both protection and their food and energy on tap, the little plants could hardly have found a more perfect place to live.30
It didn’t necessarily follow, though, Yonge thought, that the corals received reciprocal benefits. Such an assumption was sentimental rather than scientific, a throwback to the socialistic beliefs of pioneering biologists like Patrick Geddes and Prince Peter Kropotkin, who’d believed that cooperation and not war was nature’s way. To test this cooperative proposition with proper rigor, Yonge designed a series of elegant and trenchant experiments. He began by showing that corals were wholly carnivorous, and greedily so: they gobbled up zooplankton and shunned all vegetable enticements. And though Yonge thought these coral polyps might indeed derive some energy from oxygen, he didn’t see why they couldn’t supply this themselves by processing seawater. His experiments also showed that during daylight the algae produced far more oxygen than the corals needed: their guests’ supply was thus surplus to requirements.31
Two further experiments appeared to reveal that coral polyps did not rely on their algae tenants for survival but continued to live in the dark, apparently by eating zooplankton. When polyps were deprived of zooplankton they became markedly distressed, but well-fed corals survived whether they were in light or dark environments. Yonge did notice that after five months in the dark, corals lost all their color, but he saw no evidence that this bleaching did them any real harm, for they “were otherwise in perfect condition.” It did not occur to him that bleached corals might no longer be capable of building reefs, or that they would in fact eventually die.
Ultimately, Yonge was prepared to make two partial and tentative concessions to the idea of a cooperative symbiosis between corals and algae: “If we must have a ‘use’ for the plants, then I think that the speed with which they dispose of the waste products of the corals increases the efficiency of the latter, while they [the algae] certainly provide abundant supplies of oxygen, without which it is just possible that such immense aggregations of living matter, which constitute the coral reef … could not originate and flourish.”32
* * *
Maurice Yonge’s half-concessions to the cooperative role of zooxanthellae were later proved correct, but he failed to realize the degree to which reef-growing corals are dependent on their algae partners for the oxygen-based nutrition and energy needed to build reefs. His experiments also seemed so original and persuasive that they went largely unquestioned for the next thirty years. Still, though flawed, his findings would provide the baseline for an explosion of new work on coral symbiosis by scientists in the West Indies, the United States, and Europe during the 1960s and 1970s.33
Today we know that because of their symbiotic relationship with algae, reef-growing corals are autotrophic, meaning they are “predominantly self-sufficient in supplying nutrition from their own biological processes.” Although polyps do graze on small amounts of floating plankton, the available supply doesn’t nearly meet their needs as reef builders. Reef corals rely on the solar panels of their algae tenants to provide the prodigious energy required to produce lime-based skeletons, in the same way that we make bone. Geneticist Steve Jones points out that such algae-assisted corals are three times as efficient in the light as in the dark, and in perfect conditions can have their productivity increased a hundredfold by their tiny helpers. Thanks to the zooxanthellae waste, reef corals are able to lay down carbon at nearly twice the rate of a rain forest, “making shallow water coral reefs the most productive natural places on the planet.”34
There are many c
orals that are not algae-assisted, but all reef-growing corals are. They need the extra energy generated by the algae’s oxygen and sugars to grow fast enough to combat all the forces that work toward reef destruction. Maurice Yonge did not quite get this point, but his work was essential in allowing those who followed to make the discovery.
Maurice Yonge was right, though, not to idealize the relationship of polyp and plant. Their partnership is no cooperative utopia. Each partner pays a price for the contract, which seems to be built on nothing but tough Hobbesian self-interest. Though their symbiosis has survived for something like 240 million years, and has produced the Great Barrier Reef in the process, it can, and probably will, break down one day. As we’ll see in later chapters, if forced to go it alone for the sake of self-interest, corals and algae will part. Each might perhaps survive alone, but they will no longer build reefs. Steve Jones warns us: “In fact the submarine union is always on the edge, with the guest in constant danger of forced expulsion or voluntary exile, and its host of a solitary existence that may be bad for its health. The arrangement thrives when times are good, but may split up when they get nasty.”35
* * *
The Cambridge expedition’s body of scientific findings was presented in seven massive volumes between 1930 and 1968, as well as in scores of papers and books. Its global impact on coral reef science and tropical marine ecology can hardly be exaggerated. There’d been nothing like it before, and there have been few more influential expeditions since. Low Isles data is still admired and used today.
Within Australia, one emblem of the success of the partnership was the decision by the British Reef Committee to donate the Low Isles buildings to the Queensland government for a permanent marine research station. It was to be led by Frank Moorhouse and to focus on economic biology, but sadly it didn’t last long. A cyclone leveled the buildings in 1934 and this, coupled with the indifference of the Queensland government, pushed Moorhouse to resign a year later. After that the station petered out.
The Reef: A Passionate History: The Great Barrier Reef from Captain Cook to Climate Change Page 25