Story Factory: Bubble

[An original draft of this article was written as part of the 2019 Pen to Paper Challenge, supporting Story Factory, in which the 2019 theme was ‘bubble’. Audrey Daybook editor Carly Saillard raised $845 as part of the challenge, which Lovatts Media matched, to donate $1,766 in total. To support ongoing literacy programs for marginalised and underprivileged children, visit Story Factory]

Bubble

I love learning extraordinary things about the natural world. I tend to think that the more you find out about animals, insects, and ecosystems, the more you appreciate how infinite life can be. I’ve been fascinated by Glass-Wing Butterflies (with delicate wings you can literally see through), Great White Sharks off the coast of South Africa who leap out of the water at their prey, Golden Eagles that can soar on thermals high above the ground and see their prey when it’s just a speck in the distance. Consider bubbles for a moment. They are brief, fragile and destined to burst, so it might come as a surprise to learn that around the world, bubbles are used to sustain life, to expand horizons, and to make the world bigger instead of smaller.

HUMPBACK WHALE (Megaptera novaeangliae)

Humpback whales only feed during half of the year and, as a general rule, are solitary in their habits. But off the coast of Alaska, groups of humpback whales perform an extraordinary act of coordination: bubble-net feeding. Curiously, it seems to be a learned behaviour, uncommon and complex.

So how is this cooperative hunt performed? Circling a school of fish like herring, krill or salmon, the whales use vocal communication to coordinate their attack. One begins to exhale bubbles from its blowhole, signalling to the others do so as well while continuing to circle. Seen from above, a spiral of bubbles bursts through the surface, announcing the unleashing of the whales’ net. The bubble net shrinks as it rises, confining the school to a narrowing cylinder. A feeding call is sounded, driving the fish towards the surface. Together the whales rise and, taking in 15,000 gallons of water filtered through their baleen plates, they feed on the trapped fish, hundreds or thousands at a time.

Some scientists theorise that it’s not the bubbles themselves but the acoustics of this manoeuvre that leads to success. They suggest that it’s a wall of sound within the net of bubbles that traps the fish. While inside the net is relatively quiet, the bubbles themselves are a whirling maelstrom of noise that the fish won’t cross.

PEACOCK MANTIS SHRIMP (Odontodactylus scyllarus)

From giants of the ocean to tiny shrimp that punch well above their weight – observe the peacock mantis shrimp. This little stomatopod is a crustacean that grows up to 10cm in length and has a stunning iridescent carapace, a beautiful exterior that hides its predatorial nature. The mantis shrimp has several weapons at its disposal including incredible eyesight and a shell so hard it’s being studied by engineers, but perhaps most spectacular are its claws.

After all, the beautiful peacock mantis shrimp is a Smasher. This means it has two raptorial claws that it uses as clubs. Smashers can use these clubs at incredible speeds and acceleration to bludgeon their prey (which, incidentally, is often larger than the shrimp). In fact, they accelerate so fast that it’s the same velocity as a gunshot from a 22 caliber rifle and they strike their prey with 1,500 Newtons of force. The beautiful rainbow shrimp has been known to use this ability to break the glass of aquariums.

The speed of this attack creates cavitation bubbles – vapour-filled bubbles in the water. When these bubbles collapse, they cause a shock wave that adds to the strength of the attack, as well as an effect called sonoluminescence: tiny bursts of light undetectable to the human eye.

DIVING BELL SPIDER (Argyroneta aquatica)

While other spider species are semi-aquatic or capable of diving below the surface of water, only the Diving Bell spider use bubbles to live almost constantly underwater. Constructing a diving bell web spun between underwater plants using their silk and a hydrogel, these spiders transfer oxygen from the surface above using air carried from the surface on their abdomens and legs. From there the diving bell acts as a gill, extracting oxygen from the surrounding water.

When prey touches the silk threads anchoring the bell or the bell itself, this scuba spider strikes. Safe within its little bubble it can live below the surface for more than a day before surfacing to replenish its air supply.

VIOLET SEA-SNAIL (Janthina janthina)

One of the most well-travelled gastropods, the violet sea-snail sails the oceans of the world on a raft made of bubbles. Only 3 or 4cm long, this brilliantly hued sailor creates its little ship using mucous and air bubbles either released from within its shell or from agitating the water itself with its foot. The combined mucous and bubbles harden into a floating raft – the violet snail then attaches itself and begins its lifelong journey.

These little beauties protect themselves using countershading camouflage; which is to say, the underside of their shell which when seen from above the surface is much darker than the colour seen from below. As a result, predators below see only the sky above while predators overhead see the dark colours of the water. Meanwhile the violet snail effortlessly floats on, wherever the currents of the open oceans take it.

HUMANS (Homo sapiens)

As people we tend to live within our bubbles. Social circles, suburbs, economic and business scenes – they’re all limiting things. But our bubble, as it turns out, isn’t housing growth or inner-city suburbs or political parties. Our bubble is biodiversity. Our bubble is knowledge, understanding, and empathy. Our bubble is taking responsibility. Our bubble is our planet.

Every day it seems like another glacier has razed off the edge of an ice pack. Tundra is disappearing. Weather events are increasing. Water is rising. The temperature is rising. The carbon dioxide levels in our atmosphere are rising. We’re creating a bubble that seems ready to burst – a self-fulfilling prophecy if you think of bubbles as destined to pop.

Meanwhile humpbacks send out fishing nets made of bubbles. Rainbow shrimp unleash bubble shockwaves that can shatter glass. Somewhere out there a sea snail is creating a raft to cross an ocean. A spider is anchoring its diving bell to reeds using silken threads.

Our bubble is in trouble. While bubbles are fragile, they can also be strong enough to feed whales thousands of fish, weightless enough to send snails across the ocean, and powerful enough to create light. A bubble can be infinite if you just let it be.