"Time is short, young warriors. The battle draws near. We have to fight!"

Hundreds of catfish fell into ranks obeying their leader's strident voice.

"Bluecap Bay is ours! Never again will the pterois be allowed to cross the line."

"Er, Commander... cross the line, sir?" queried one troublesome catfish. He'd injured a fin breaking free of a discarded net, and his respect for authority had taken a knock.

"The line, yes."

"What line is that, Commander?"

"What... why... that one!"

"The fishing line?"

"No... yes... Look, just... Prepare for battle!"

Ranks of catfish formed up, outnumbered by squadrons of enemy pterois. It had been a long time since the last battle in Bluecap Bay, at least as long as any fish present could remember.

"Ready..."

"Er, Commander..."

"Yes?"

"You do realise those are pterois?"

"Of course."

"Also known as lionfish. Aggressive little b—"

"What's your point?"

"We could do with some weapons. And some allies."

"Right. Yes... Cavalry!"

The ranks divided as seahorses darted forward to take up the front line. Well trained and heavily armed, they were a formidable army. The best there was.

"Er, Commander..."

"What is it?"

"Why are they carrying blue and pink lances?"

"It doesn't matter what colour they are."

"Right. But why are the pointy ends... not pointy? They appear to be soft and fluffy. Earbuds, in fact. Yes, soft and fluffy earbuds."

"They're just fine... Cavalry, charge!"

In a rush of bubbles as the seahorses charged towards the enemy.

"Er, Commander..."

"What now?"

"You see that rank of seadragons protecting the lionfish? Well, they seem to have longer weapons. Many of them pink too, granted, but without fluffy tips. Straws, if I'm not mistaken. I suspect were going to need new allies soon."

"Ah... Right," agreed the commander reluctantly. "Bombers!"

A flock of gannets broke through the surface, adding to the already unpleasant sight before them. The bubbles did little to obscure the battle, yet the catfish couldn't quite tell if they were winning.

In the chaos, another gannet dived into the fight ahead of them.

"Er, Commander..."

"What?"

"Why is that one wearing a wetsuit?"

"To swim under water, of course."

"Right. But it looks like it's... drowning. Perhaps it's just a shopping bag?"

The gannet sank below the battle-line, and the catfish could see the lionfish ranks still prepared to fight.

"Er, Comman—"

"WHAT?"

"We seem to be outnumbered again."

"We have no choice. Ready..."

"What is it we're fighting for again?"

"For Bluecap Bay! Look around you, there is barely any clean water remaining! We have to fight!"

The catfish took a moment to glance at his surroundings. Through the hazy water, a discarded food packet floated past. Above, the light was obscured by refuse, countless objects with different shapes and faded colours. Below, the very seabed was spoilt, with rubbish gathering amongst the rocks. And blue bottle-caps littered the sands.

Time is short, young warriors.

We have to fight.