Bacteria

Bacteria are both the largely unseen basis of life in the ocean and a possible part of the chain of events threatening continental slopes. Their importance in the novel lies in this double perspective: they are ordinary organisms essential to planetary cycles, yet their abundance and activity can matter at geological scales. The account also draws a careful boundary between bacterial processes science can describe and the extraordinary collective behavior attributed to the Yrr, which are identified as amoebas rather than bacteria.

The hidden scale of ocean life

The novel shifts attention away from the large animals that commonly stand for ocean life. A single drop of seawater contains a crowded microbial world: the account estimates tens of billions of viruses, a billion bacteria, five million protozoa, and a million algae in each litre of surface water. Samples collected more than 6,000 metres down still contain millions of viruses and bacteria. The ocean’s apparent emptiness, then, is partly an effect of human scale and perception; much of its life is too small to register without instruments.

The water itself is described as more than a simple liquid. Under a fluorescence microscope, seawater appears gel-like, threaded by interconnected macromolecules and transparent fibres that provide surfaces for bacteria. The quantities embedded in even a small sample are striking: untangling the contents of a millilitre would yield two kilometres of DNA molecules, 310 kilometres of proteins, and 5,600 kilometres of polysaccharides. This intricate material environment helps explain why the novel treats the microscopic ocean not as an empty setting between visible creatures, but as a dense habitat whose activity is difficult to map or monitor.

That distinction also limits what can be concluded about the mysterious jelly examined in the story. Its remarkable appearance initially encourages speculation about an exotic organism, but the material is ultimately described as ordinary deep-sea amoebas mixed with seawater and other life. The possibility that intelligence might be hidden among the microbes is raised without turning bacteria into the answer: bacterial abundance establishes the scale and complexity of the microbial world, while the identified cellular collective belongs to a different organism.

Chemical signaling and collective behavior

Bacteria provide a known biological comparison for the question of how individual microscopic cells might coordinate. One example discussed is Myxococcus xanthus, a soil-dwelling bacterium that moves in loose swarms. When an individual cannot find enough nutrients, it releases a chemical starvation signal. As more cells experience starvation, the signal intensifies; once it reaches a threshold, the swarm draws together and forms a multicellular structure called a fruiting body, visible to the naked eye. The example gives the research team a grounded model of how chemical messages can turn many separate cells into coordinated activity.

The comparison matters because it separates a demonstrated mechanism from a much larger hypothesis. Chemical signals and aggregation are not, by themselves, proof of intelligence. They do show how cells can change their behavior in response to information produced by other cells, without relying on sight or hearing. The novel uses that established possibility to make collective microscopic action imaginable, while leaving the Yrr’s capacities beyond what the bacterial example can establish.

The proposed Yrr signaling system is described specifically in terms of amoebas. The team isolates a chemical pheromone that causes cells to aggregate and can synthesize it, although they remain uncertain about what initiates aggregation and how communication continues after cells have joined. Their model gives the cells paired receptors: one identifies a cell as Yrr, while the other identifies it as healthy and capable of joining the collective. In that account, the pheromone has a second, more destructive role: when a defective cell is excluded, it can act as a toxin and trigger programmed cell death. These findings are part of the novel’s explanation of the Yrr, not a claim that bacteria use the same system.

Essential work and evolutionary endurance

Bacteria are also described through their ordinary ecological work. The novel attributes the oxygen in the atmosphere to bacterial activity and places microbes among the organisms that keep essential chemical elements circulating. Bacteria, fungi, protozoa, microscopic scavengers, insects, and worms break down plant and animal matter and return its components to the cycle of life. This makes bacteria indispensable to complex organisms without making that dependence reciprocal: the argument is that humans could not survive without bacteria, whereas bacteria would have no comparable need for humans.

Their resilience sharpens that contrast. Highly specialized organisms may be vulnerable when their environments change; the example given is the koala’s dependence on eucalyptus. Many single-celled organisms, by comparison, can survive ice ages, volcanic eruptions, and changes in oxygen and methane concentrations. Some can remain in a death-like state for thousands of years before resuming activity. Bacteria are found in boiling springs, glaciers, and kilometres beneath the ground. They are not presented as invulnerable, but as life forms whose small scale and varied habitats make them capable of persisting through conditions that threaten larger, more specialized species.

This account challenges the assumption that size or complexity confers evolutionary supremacy. In periods of environmental change or mass extinction, the organisms most dependent on narrow conditions may disappear, while simpler life continues. The argument is not that bacteria are morally superior or consciously dominant; it is that the continuity of life depends on processes that human attention, focused on visible animals and human interests, easily overlooks.

Hydrates, the seabed, and the limits of intervention

The possibility that bacteria may contribute to geological danger becomes concrete during an operation to remove worms from the seabed near La Palma. After the suction tube has operated for sixteen hours, the disturbed sediment settles and the monitors reveal marbled lava, with isolated strings of bubbles rising from the rock. Closer images show that the marbling consists of bacterial mats. Beneath them, grey lines identify the hydrate. The scene does not establish how far the bacteria have penetrated; the research team cannot tell whether they have colonized only the surface or worked through the sediment.

That uncertainty gives the bacterial mats their narrative force. Removing the visible worms does not guarantee that the underlying threat has been removed, because bacteria may already have been deposited in the ice. Gerhard Bohrmann worries that it could be too late to prevent the collapse of Cumbre Vieja, even as he continues to hope that the operation will work. The effort to intervene therefore encounters a mismatch of scale: machinery can extract organisms by the tonne, but it cannot immediately reveal the extent of microbial activity within the seabed.

Bacteria consequently occupy two linked positions in the story. They are essential participants in the cycles that sustain life, and their abundance makes the ocean a world beyond straightforward human observation. At the same time, bacterial mats and the possibility of activity within hydrate-bearing material turn the microbial into a potential factor in slope instability. The novel does not collapse these roles into a simple claim that bacteria are the enemy. Instead, it uses them to unsettle the boundary between the ordinary processes on which life depends and the ecological changes that human technology may be unable to control.