News from the UN that, on average, 46,000 pieces of plastic float on every square mile of ocean. Though shocking, it does not surprise me now. There must be a similar amount on the surface of rivers. By a quirk of the current, which eddies round my barge, a good deal of it finds its way between the hull and the bank.

Each morning I discover what has surreptitiously arrived overnight. Plastic soda bottles are frequent visitors. Milk cartons in particular have an extraordinary ability to find their way back, since they fill with less water and get blown by the breeze. The necks of glass beer bottles bob out of the water between a single child’s shoe, crisp packets, corks, objects it doesn’t bear thinking about and a sort of generalized, semi-organic grunge laced with bubbles.

When I first arrived here my instinct was to fish this stuff out of the water and dispose of it in the normal way. But I could spend the better part of most days doing this, only to clear fresh space for new arrivals. The shock I felt when shown a long pole with which to shift the stuff downstream has now largely gone.

Along the length of this river there must be a lot of other people doing much the same thing – just occasionally, with the faintest pang, giving a thought to what may have happened to the child’s other shoe.

Repeat the process along all the rivers everywhere in the world, and within a matter of days you have 1,000 more pieces of plastic floating on every square mile of ocean, where it all ends up.

Still, it’s foolish to be self-righteous. The other day I thought I’d better give my generator some more diesel. It’s called ‘red’ diesel because it’s the same, tinted and less heavily taxed stuff that’s used for farm machinery. By a quirk of legislation – which the European Union is, naturally, attempting to rectify – river boats in England are entitled to use red diesel too, though you have to go to special places to get it.

I’d never before thought of refuelling as tricky. True, on the barge you have to take extreme care to ensure you open the filler cap marked ‘diesel’ not ‘water’. Also, the cap is flush with the deck, so you need to use a funnel to guide the diesel from the heavy container into the hole.

I thought I was doing pretty well. But surges and gurgles splashed the deck. Trickles began to form and head off in all directions. At first I thought of the fire risk, which was real enough, particularly if the stuff got inside the hull or anywhere near the generator. So I fetched the mop, with the idea of swilling it away. Just in time, I remembered that the result of that would be to flush it into the river, where the tiniest drop spreads out to form a large, ugly slick. From time to time the long, wispy, glistening things slide past the barge from somewhere upstream. A bad idea.

So I wiped the deck dry with paper kitchen towels, though these I could not dispose of in the bin inside the boat, for fear – and dislike – of the fumes. A trip to a specialist depot was required. Two hours later I returned to the barge, consoling myself that here was one mistake I would never make again. No doubt there are many more to come.

Speaking of the generator, perhaps I should explain the rather odd ritual I am beginning to adopt on Mondays and Fridays – my barge ‘working’ days. There are some things that only function when the generator runs, including the water pump and water heater. You have to run the generator for about 45 minutes to get hot water, and keep it running to pump the hot water into the bath, then out again afterwards.

To switch the generator on I have to go outside, walk the length of the boat and lower myself into the generator compartment; not something to be done in slippers and pyjamas, perhaps forgetfully smoking a pipe. Riverine residential etiquette suggests that you never switch the thing on much before 8.00am, or leave it running much after 8.00pm.

Since I leave for Oxford before 7.00am on Tuesdays, I have to take a bath on Mondays. But I work on Mondays, so just about the only time I can manage to take a bath is during my lunch break. Throughout my working life I’ve never been very interested in lunch breaks – or, come to that, lunch. Now I find myself taking a lunch break in order to take a bath, and perhaps even a bit of lunch as well.

And since I get back to the barge after 8.00pm on Thursday evenings, when it’s too late to take a bath, the same ritual takes place on Fridays as well. The next bath is unlikely to take place before Monday lunchtime. After all, everyone who lives here is, figuratively speaking, in the same boat.