What did the joyous, good-natured Olympic torch-bearing carnival that passed through my local town of Aylesbury this week have to do with saving the planet, or even little parts of it?

I counted a dozen police motorcyclists, half as many police cars, official torch support vehicles  and a convoy of big promotional sponsors’ trucks. And all this as a prelude to a single ecstatic anonymous torchbearer having the time of his life, being cheered by bystanders, mosty of whom didn’t have a clue who he was.

The two Olympic support cars were new, high-mpg BMWs, see here,  and at least one of the sponsors’ vehicles, Samsung I think, proclaimed itself to zero-emission and pollution free. But when the man from McDonald’s walked down the line handing out promotional tokens, offering McChicken sandwich or Filet-o-Fish, with fries, for £1.99, I did not immediately link him to the prospect of eco-salvation.

And yet, there was a branch nearby and they now do free Wi-Fi. So, as convenience food is meant to be convenient, I went in.

I didn’t think it fair to quiz the young man who was serving me about what the fish was, where it came from and whether it was sustainable (it does actually say that on the box, as I would have found out) so I played safe and ordered the McChicken, with fries. (My drink was ethical enough: McDonald’s now serve 100% Rainforest Alliance Certified coffee.)

In the end, I might have been better off with the Filet-o-Fish. Drilling down on the company’s website to see where the chicken was sourced, I found the following under  this:

“We buy our 10% of our chicken from the UK and more than half from Western Europe. We also buy chicken from Thailand and Brazil in varying degrees during the year”. I deduced they were intensively bred, not free range, organically fed birds. And if they were, why did the web site not say so?

There was easier to find background on the ethical provenance of the eggs sold in the Bacon & Egg McMuffin (pictures of some real British egg farmers demonstrating “how free-range egg production can be undertaken with maximum benefit to the well-being of the flock [sic] and providing a diverse and sustainable business in a rural environment”)

There was much on where the beef for the Big Macs and the rest comes from. It comes from various farms in the UK. “We only use whole cuts of 100% British and Irish beef  in our burgers, seasoned with just a pinch of salt and pepper after cooking.” So that seems to answer the “chopping down rainforests for beef cattle”  criticism, at least as it concerns the UK market.

I found out this about the fish I could have had. In June 2011 McDonald’s announced that over 13 million customers every day across Europe would be able to buy Marine Stewardship Council (MSC)-certified sustainable fish in McDonald’s restaurants from that October.

The MSC is an independent global body set up to tackle the problem of overfishing by recognising and rewarding sustainable fisheries through its certification and eco-labelling programme. The web-site states: “ We source all of the fish on our UK menu from Marine Stewardship Council Certified sustainable fisheries.

This demonstrates our ongoing commitment to sustainable sourcing and shows that all fish used by McDonald’s UK is fully traceable from sea to restaurant. We are the first company in our sector to introduce MSC certified white fish throughout Europe.”

It seems to me McDonald’s have quite a positive tale to tell (for example, it recycles its used cooking oil into bio-diesel, to fuel more than half of its delivery trucks) although they weren’t telling it in a conspicuous way in the central Aylesbury branch on my visit. It’s certainly something to be proud of, being one of the biggest providers of sustainable fish in the UK.

I hope they are not telling the story because people would be put off by the names of fish, hoki and Alaskan Pollock, if they were prominently displayed.  According to the Marine conservation Society, Stewardship Council, Alaskan Pollock is “a small relative of the cod….a large-eyed fish, the most important groundfish species in world fisheries, with a soft, white meat, suitable for processed, especially coated, products.”

The hoki has a more heroic alternative name, the blue grenadier. It is an offshore midwater fish, widely distributed but abundant at depths between 200-600 m throughout New Zealand waters.

On its UK website McDonald’s says it uses “Hoki fish for our Filet-O-Fish and Fish Fingers rather than cod, which is at risk from overfishing…The blue logo you will see on our Filet-o-Fish and Fish Fingers packaging shows that our entire supply chain is formally certified against the MSC Chain of Custody standard.”

It would be easy for me to join in the ritual McDonald’s bashing (and hypocritical as I occasionally dine  there), to hold up McDonald’s as a big brash operator, pushing themselves around, along with their fellow sponsors, at this the biggest sporting event in the world. A British doctors’ group says having the fast food outfirt there sends the wrong message in a country with ballooning obesity.

During the London 2012 Olympics the fast-food giant will soon be opening its largest franchise in the world, a two-story restaurant that seats 1,500 customers, at London’s Olympic Park. I do hope they’ll be selling Filet-O-Fish and Fish Fingers, and that large numbers of people order it. It would be good to know that people realised they were buying fish that is sustainable, and not under threat, at a very troubled time for world fisheries.

I would like to think that every piece of fish sold in the Olympic complex comes from sustainable sources, as  McDonald’s say theirs will. McDonald’s, if you look at their chicken, have some way to go yet, but there is less transparency elsewhere.

Next time I go to Wembley Stadium (not for an Olympic event) I would be interested to know the provenance of the coffee, the burgers, the fish, even the bottled water. There’s no reason why the less well-known caterers should be scrutinised less closely than McDonald’s.