A few years ago YouTube recommended I watch a video with the word “carpocalypse” in its title. I clicked the link — of course I did — and stared in awe at what resembled a mash-up of a video game, nature documentary and war movie. I saw a river full of fish leaping from the water like chaotic piscine fireworks and men in speedboats yelling and holding out nets to catch them as if they were wet and weighty butterflies. Fish hitting people in the face, fish landing in boats, fish flapping between people’s feet in a mess of slime