I really like fish: not to eat, not to keep in an aquarium, but just like other people love dogs, or birds.
Before I go any further, a short warning: once you have studied fish, you enter a confusing, incomprehensible world.
Fish do not exist. At least, not in the biological sense of the word. Most of the animals we call 'fish' do not share any kinship. A tuna and a shark are very similar; they are large predatory fish, with roughly the same shapes, but they have totally different ancestors. There's no such thing as a fish. At first glance, this may seem like a funny fact, but it's more than that: it shows how little we understand about what lives under water - or who.
Fish are, in general, not seen as fully fledged animals. There are plenty of vegetarians who do 'just' eat fish. The fish is not as attractive as a piglet or cow. Fish lack the caressing factor, but also the limbs, the facial expressions, the way of breathing - they look like cold-blooded, silent aliens. Who would expect them to have feelings, enter into relationships, make choices or have different personalities?
And yet all that seems to be going on.
Often the first fish you encounter as a human being is the goldfish, usually on its own, in a small, sparsely decorated bowl. The orange animal bites a little, swims around a bit, and spend an hour... just staring off into space. No wonder we've come to believe that they have a thirty second memory.
However, research has shown that the memory of a goldfish is many times better. Scientists released goldfish in an aquarium with different colored tubes, some of which contain food and some of which do not. A year later they repeated this experiment with a few of the same goldfish, and a few new ones. The veterans swam straight to their former tubes - they remembered the color of the tube they had found food in a year earlier.
As long as we keep goldfish in small bowls on their own, we will never see what they are capable of: that they can live for decades, help each other in case of emergency, and learn to recognize the different animals (and people) in their household. We don't really look, when we look at the fish, and that's why we miss so much.
Take the puffer fish. Most people know it as a comical creature that blows itself up when in danger, or as that life-threatening Japanese delicacy. But who has registered that it is the same puffer fish that makes a mandala in the sand in this viral video from the BBC?
A fish can be an artist, or a farmer. For example, in another episode of Blue Planet II you can see how the Garibaldi damselfish maintains a field of seaweed. The seaweed attracts small creatures that the garibaldi eats, so he maintains the green, and removes grazing sea urchins. There are known cases of fish (such as the choerodon schoenleinii) that use tools to open mussels, and fish that build nests for their eggs from pebbles, water plants and coral remnants.
Fish talk to each other, not only within their own species, but also with other fish species. When the red coral perch preys on a fish in a cramped cavity, where she can't reach it, she fetches a moray eel. By shaking her body in a certain way, the coral perch communicates where the fish is, so that the moray eel, with its thin, snake-like body, can hunt through the small holes to set the prey free. They divide the loot, like people who hunt with dogs or falcons.
And the cleaner lipfish, which you might know from his famous cleaning station, where he eats off the parasites of larger fish, is not only a social entrepreneur, but is also able to recognize himself in the mirror. The mirror test has previously been successfully completed by dolphins and chimpanzees, and is used as proof that a non-human animal has self-confidence.
All this is just the beginning. We have only been doing serious research into the behavior of animals living in water for a few decades now. There are currently about 30,000 known species of fish, of which a few hundred have actually been described. The question is whether we still have time to find out what kind of animals they are, what they do, or how they live. Because we drill in the seabed for fire and raw materials. Because the oceans are acidifying. Because the earth is warming up.
And because people keep eating fish in huge numbers. Imagine walking down the street and suddenly being dragged along by a gigantic net. You're not alone in the net; you're squeezed together with all the strangers you don't know, and a rottweiler, and a couple of rats and crows, and perhaps a stray rhino from the zoo. Flattened in the net, you gasp for air, and try to push the rest aside, when all of a sudden you're pushed underwater, dozens of meters deep. Your eardrums tear, your lungs fill up with water, and so you drown, in a wave of fear and panic.
If we know that fish are animals with a form of (self) consciousness, that experience pain and suffering, that enter into relationships with other fish and maintain those relationships, that some fish work with tools and other fish make art, is it still justifiable to continue catching, torturing and eating these animals en masse?
It is estimated that, if we continue on this footing, the ocean will be empty in 2048. That is to say: perhaps we will still have enormous jellyfish plagues and here and there a shellfish. But the fish, the marine mammals and the octopuses, they will be extinct. In 28 years' time. Most of us will experience that.
The question is whether that process can still be stopped. As with climate destruction, there are too many different, mutually reinforcing factors. But it starts with looking at fish differently. That we throw our short-sighted categories overboard and really learn to look at life under water. There is a world full of extraterrestrials we hardly know anything about, and they are closer than we thought.
