Palmer's Pages

An intense blue presses all around as light fractures into wavering ribbons. The hue deepens and shapes begin to emerge, some tall and spindly reaching skywards like leafless trees, others squat and boulder-like nestled into place, and still more rippling and swaying gently, as if in a breeze. The vivid mosaic of deep purples, rich browns, pinks and yellows come into focus.  Closer now the texture resolves into intricate patterns, repeating in honeycomb grids or winding in maze-like ridges. Run your finger along it and it will feel rough like stone, inert and unyielding, but this is a deception, because what you’re touching is alive.   

We were diving on the Belize Barrier Reef. The array of wildlife that call the reef home is nothing short of spectacular. With slow, deliberate strokes of its powerful flipper, the loggerhead turtle dissolves into the deep blue. The cold lifeless eyes of the nurse shark track us as it patrols the reef, no less unnerving for the reassurances that they are harmless. Disturbed from their hiding places on the seabed, rays lift and glide away, their wings undulating in slow, rhythmic waves, clouds of sand trailing behind them.

 These big and beautiful creatures of the ocean cannot help but inspire awe in those lucky enough to see them. But the true magic of diving is in studying the smaller unassuming lives, the shy beings sheltering within the nooks and crevices of the coral, lurking in the rippling strands of seagrass or buried beneath the seabed.  It is these creatures that make you feel as though you have entered an alien world. Worms resembling feather dusters that, when disturbed, will shoot back into the tube from which their plumage protrudes; jawfish hover above their burrows, mouths full of sand, darting down in a flash, spitting it out to seal the entrance; and sea cucumbers, oddly poised on end, periodically expel clouds of white matter into the water. The importance of animals in the ecosystem is not proportionate to their size; they all play a role in this interconnected underwater world. It is here amongst these strange and wonderful creatures, that you begin to appreciate the true vastness and variety of the natural world, and how much of it will always remain beyond our understanding.

As I drift over the coral below, I notice a patch where its colour seems dulled beneath a scummy film, algae clinging to its form and shifting in the current, softening the coral’s edge. Surrounded by such abundance and vitality it is easy to pass over, to mistake it for something natural, like lichen clinging to a tree trunk or moss covering a rock – another sign of profuse life even. But this is not harmless coexistence, this apparent growth masks decay beneath. The coral is no longer able to sustain itself, and in its weakened state, the algae begin to thrive and dominate. This blemish is the wound scarring an animal, the visible symptom of an unseen disease. All over the reef, the delicate balance of life is slipping, and it’s the corals themselves that are first to fall.

Earlier this year I joined a team of marine biologists to travel out to the Port Honduras Marine Reserve, off the coast of Punta Gorda, to monitor coral health. As the boat skims over the glassy morning sea, the water intermittently emits a golden glow as sunlight reflects from the dazzlingly pale sand below, before the boat passes over the dark shadow of a seagrass bed. Even this far out from the coast, the water is so shallow you can often see the seabed, especially in the channels connecting the mangrove-covered cayes. The water is wonderfully warm, the suns powerful rays penetrate easily to its depths. It is these warm, light-filled conditions that have allowed the reef to flourish. Yet, in recent years these waters have become slightly too warm, and the conditions that sustain such abundance are beginning to shift.  

Corals are animals, and each reef is formed by vast colonies of these organisms living together. The individual coral animals, known as polyps, like all animals require energy. Rather than taking the conventional route of feeding on plants or other animals, corals host microscopic organisms that absorb energy from the sun, while painting the corals in their rich colours.  The health of the coral depends on this symbiotic relationship. But all over the reef this relationship is deteriorating, rising sea temperatures triggers a stress response in coral, causing them to expel the microscopic algae living within its tissues. When they are expelled, the coral’s tissue becomes translucent; revealing the ghostly white calcium-carbonate skeleton beneath, a stark and visible indicator that the reef is under stress.

As we dive amid the vibrant colours of the reef, a few corals catch my eye, their normally rich browns, pinks, and golds dulled to a pale, milky hue. The effect drains the scene of some of its opulence, but coral is not just scenery; for the many lives that inhabit it, it is survival. Tiny reef fish live inside the spindly branches of staghorn corals or dart into the crevices of maze corals when the shadow of a predator passes overhead. Parrotfish and surgeonfish graze across algae-covered boulder corals, while butterflyfish pick at the tiny polyps within. The influence of the reef extends to less visible processes. Corals recycle nutrients in the reef, transforming sunlight into organic energy that underpins the surrounding food web and reefs produce rich, complex soundscapes that resonate through the water and help orientate fish as they navigate the open ocean.

The reef is not  a population of single organisms but a deeply interconnected system embedded in the flows of light, nutrients, and energy that wash through it. In this jumble of life, each organism depends on another—sometimes directly, sometimes through chains of connection that stretch across the ecosystem—but all are bound into the same web, one that ultimately traces back to the coral itself. As the coral fades, the reef doesn’t just lose colour it loses complexity, and with it, the intricate web of relationships begins to unravel and the life that it supports begins to dwindle.

One such life, is the sea turtle.  Belize’s, warm waters are home to four species of endangered turtle: loggerhead, hawkbill, green and leatherback. Their lives, like those of all Belize’s marine life, intimately entwined with the coral reef. Turtles move slowly and deliberately through the water, their front flippers sweeping in broad powerful arcs, giving them a surprising grace despite their bulk. Their shells catch the light in shades of green and brown, patterned like stained wood, or mottled glass. Their large calm eyes give them a world-weary character.   They pause to graze on seagrass, and algae or to pick sponges of the coral, gently adjusting position with small movements of their flippers. In so doing they help maintain the reef, keeping these prolific populations from overwhelming it.  Without constant grazing, algae can spread unchecked across the coral, and sponges can begin to smother its living structure. In their passing, turtles leave behind small openings in the surface of the reef, spaces where coral larvae may one day settle and grow.

Coral repays this favour in an unexpected way. Belize’s palm-strewn cayes provide safe places for turtles to lay their eggs. But these cayes are fragile, little more than low piles of sand and coral fragments held in place by a balance of waves, currents and vegetation, their edges never entirely fixed against the movement of the sea. Already they are eroding, beaches retreating, trees collapsing into the water and some cayes disappearing altogether.  Last year Nicholas Caye, which I visited at the start of this year’s nesting season, supported around eighty nesting mothers. On the surrounding cayes the tell-tale signs are there too, the drag of flippers and the scatter of freshly turned sand if you walk the beaches in first light. Watching from these beaches, you can see the waves breaking apparently in the middle of the ocean, as if they’ve met an invisible shore. The reef is absorbing the oceans force breaking the waves before they reach the low-lying cayes where turtles nest, helping to hold these narrow fragile stretches of sand in place. And once they hatch, it is the reef that will shelter these turtles through their earliest and most vulnerable years.

When I asked one of the marine biologists what would happen to the data on coral bleaching that we had collected, he told me it would be combined with the work of other organisations across Mesoamerica to build a fuller picture of the reef’s health. When I asked what would be done with that picture, he shrugged, a hint of resignation in his voice: “What can be done?” It is a fair question, if a defeatist one. Across Belize’s waters, the harvesting of parrotfish has also been banned in recognition of their role in controlling algal growth and maintaining the balance of the reef. along the southern coastline, where stretches of beach are protected during turtle nesting seasons to safeguard emerging hatchlings, and nesting females are monitored by local teams and conservation groups. Most excitingly, in the sea off the coast of Placencia, close to Punta Gorda, coral nurseries have been established, where fragments of broken coral are collected and fixed to underwater frames, left to grow in calmer water before being returned to degraded sections of reef. Local guides, fishers and divers are trained to plant the coral and monitor its development. Admirable work and often effective at addressing a singular issue, safeguarding one species, restoring one patch of coral. But the reef is not a collection of isolated problems, it is a complex adaptive system whose recovery depends on interactions operating across scales far beyond any single intervention. To treat the symptoms is not to restore the system itself.