The basalt shelf contracts at dawn.
Four calcareous plates lock hard
Against the drying heat of stone,
A sealed vault in the blistered guard.
Then, sudden weight: the green advance
Smashes the dry air into spray.
The internal muscle feels the chill,
The hydraulic valves give way.
Out snap the feathery cirri, blind,
To comb the rushing wall of brine,
Filtering motion into meat
Along the intertidal line.
Before the backwash strips the ledge,
The four plates slam their bolted door,
Leaving the sudden vacuum dry,
A silent pyramid once more.

Encased in lignin, blind to sun,
The dual valves rasp the sodden pine.
A slow, calcic extrusion reams
A tunnel through the weighted brine.
No current reaches this damp dark,
Only the shudder of the pier,
The dull vibration of the punt,
The salt-load shifting in the gear.
To bore is to consume the grain,
To line the shaft with seamless lime,
A winding labyrinth of bone
Sealed safe against the sliding time.
Here pressure is the only wall,
And timber is the single shore—
A life dissolved in brackish wood,
Until the rotten pilings roar.

The grey axis stands upon the ridge.
Two score of woody follicles lock hard,
Untouched by salt-spray from the ledge,
A fused and fire-resistant guard.
The vulcanised and corky skin
Resists the weathering of the trade;
The dual valves keep the twins within,
Behind a resin-welded blade.
Until the front: the thermal spike
Triggers the deep mechanical crack.
The baked lips part, precise, alike,
Across the charcoal-dusted track.
Out spin the winged samaras, dry,
To rotate through the thermal drift,
Dropping beneath a smoke-veiled sky
Into the charred and open rift.
The empty capsule keeps the line,
A hollowed cone upon the hill—
Stripped of its seed-stocks by the brine,
A silent apparatus, still.

The grey disc skims across the tidal flat,
Where sunlit shallows warm the river mud;
It leaves no footprint where its shadow passed,
No wake to mark the gliding of the flood.
Blind to the world above the mirrored skin,
It reads the bottom through a denser sense,
Detecting every pulse that stirs within
The silent channels of the confluence.
No heavy armor guards its gliding bone,
Nor shell to turn the current from its path;
It maps the submerged floor and goes alone,
Untouched by human ledger or by wrath.

The hook-billed silhouette aligns the post,
A water-logged and heavy iron frame;
It holds its stationed watch along the coast,
Indifferent to the wind or to a name.
The primitive and oil-less feathers take
The weight of entry when the muscles plunge;
No buoyant air remains to mar the wake,
A sinking arrow cutting like a sponge.
Down in the turbid gut it drives its path,
Propelled by webbed and backward-striking feet,
Blind to the surface sky or human wrath,
Converting silver motion into meat.
Then, up to dry: the carbon wings extend,
A stationary solar-panel spread,
To vent the heavy dampness to the wind
Above the stone-work of the riverbed.

The receding tide exposes thousands more,
A swirling legion on the wet expanse,
That sweep the surface of the sandy floor
In synchronized, concentric circumstance.
No solitary creature claims this space,
But packed battalions rolling like a wheel,
Consuming surface detritus apace
With sorting mouthparts made of stony steel.
When shadow falls or heavy footsteps near,
The collective drill turns downward in a ring,
Corkscrewing backward without panic or fear
Into the sand-bed, leaving not a thing.

The jagged valve cements into the stone,
A lime encrustation on the timber post;
It grows by cold accretion, fixed and lone,
Along the intertidal working coast.
Within the sharp, calcified casing deep,
The sightless mantle gills pump out the silt;
The microscopic cilia never sleep,
Straining the currents where the marsh was built.
It extracts the micron from the tidal track,
Concentrating carbonate to seal the room,
Unmoved by southerly or buster-crack,
Feeding in silence through the brackish gloom.
The tide runs out, the flanged edges lock,
A compressed vacuum holding fast the wet,
A dense, lithic node upon the dock,
Where mechanical hours are unspent yet.

The black-and-white surveyor claims the wire,
A strict proprietor of fence and post;
He measures out his square of dry attire,
And sounds his iron warble down the coast.
No casual passer-by escapes his sight,
For every meter of the air is mapped;
He sweeps the paddock in a sliding flight,
Where structural boundaries are strictly capped.
With beak of bone and amber-burnished eye,
He patrols the air-space with an engine’s grace,
Defending every quarter of the sky
Against intrusion in his gated space.