A reader notified me of a mass sex-change taking place in his country. Half the male fish in some British lowland rivers have female characteristics, and many can now lay eggs, research indicates.

This must be causing extremely awkward underwater conversations. Female Fish: “I have news, Stanley: I’m pregnant!” Male Fish: “Wonderful, darling, me too!”

Grandparent fish are surely delighted at the double portions of grandchildren, although the market for underwater league football TV specials must have collapsed.

The reader, who wanted only to be known as Concerned Teacher, said he only bought it up because many young males in his class seem to be taking the same journey. I told him it was probably just a sign of the times, but he should call me if any of his boys actually lay eggs so I can make a viral video, I mean, express my heartfelt concern.

The news clipping said scientists blame the problem on contamination by estrogen, a chemical known for causing mammals to purchase shoes and care what colour curtains are. But why is there no corresponding contamination from testosterone, a chemical that causes massive growth in the human male’s most prominent organ, the ego?

“It’s apparently estrogen from contraceptive pills which leaks into nature and creates feminisation,” Concerned Teacher said. Feminisation was originally detected in fish, whales and dolphins but has been found in land animals, including seals, otters, polar bears, frogs, alligators and, yes, humans.

The good news is that contraceptive-swamped Western civilisation is by far the most likely to be wiped out, which may actually be worth it when you consider that the world would be rid of the Kardashians, British “food”, reality TV shows, etc., and even my Western friends agreed with that.

But further reflection suggests that a world in which the only music, movies and culture were Eastern would be pretty sad. There’s only so much Gangnam Style a person can take.

On the plus side, females are less affected by estrogen; so we may end up with a female-dominated world, which might be a good thing. There’d be fewer wars, since geopolitical summits would end up with one leader saying “Fine” and the others trying to work out whether this was good or bad.

My colleagues were less inclined to panic over the gender-blender trend. One told me about a kindergarten parent he encountered who initially refused to identify the sex of her child, but its two initial acts — the gleeful emission of astonishing amounts of sound from the end of its colon, and the use of toys to commit mindless acts of violence on other toys — were biggish clues that it may not be female. But these days you never know, do you?

While writing this column, a newspaper arrived reporting that train announcers in London have been told to stop opening their statements with “Ladies and gentlemen”. Presumably this is to show respect for the many lowland river fish who travel by train these days.

Not sure what a politically correct columnist should say about that. Maybe: “Fine.”