Regular readers will know that I am oddly interested in fish farming. I’ve written here before about the resurgence of the salmon trade.

The business had a horrible few years in the early part of the decade as demand fell just as supply peaked. Bankruptcies and consolidation followed.

However, business is booming again: rising demand (partly kicked off by the bird flu scare, which cut demand for chicken) has once again pushed up prices and global production should rise 8 per cent to 10 per cent this year.

Huge numbers of other fish are also farmed around the world, and as wild stocks of the most popular varieties fall, farmers are beginning to experiment with evermore species: in the Shetlands, for example, the first cod farm is up and running.

But the more fish farms there are, the more fish food is required and that is where the system runs into something of a problem. What do you feed your caged fish on? Farmed fish need protein and in particular marine protein, but given the concerns about wild fish stocks, giving them mashed up wild fishmeal just doesn’t seem quite right.

A better solution, and one that more farmers appear to be coming round to, might be to feed them krill meal (krill are the tiny crustaceans at the bottom of the ocean’s food chain).

Krill are high in protein and antioxidants and, I am told, particularly good for feeding to larvae when distilled into an oil: more krill-oil fed larvae make it to adulthood than those fed on other foods. Another plus is that krill oil comes in a bright shade of red, which means it can be used in organic farms to colour salmon the pink colour that consumers appear to like.

However, it isn’t just baby salmon that thrive on krill oil. It is humans too. A variety of perfectly reputable studies back up the idea that krill oil is a good thing: it has been shown to reduce cholesterol, cut blood-sugar levels, alleviate the symptoms of Alzheimer’s, reduce the pain of rheumatoid arthritis and banish the symptoms of PMS. Its most enthusiastic fans even claim it can slow down the ageing process (see krill-oil.biz for more on the science — it’s all to do with antioxidants and Omega 3s and phospholipids).

Look up krill oil on the internet and you’ll find that the Americans are already downing pints of the stuff and, as word of its benefits spreads, I imagine we’ll soon be doing the same, particularly as krill thrive best in deep water and they’re considered to be free of contaminants such as heavy metals and PCBs.

If we drink green tea to protect ourselves from cancer and cinnamon tablets to regulate our blood sugar, why not distilled mini shrimp for everything else?

The final piece of good news in krill’s favour is that, despite the fact that it does all these good things, there is an awful lot of it about. Krill is mainly trawled for in Antarctica where the conservation authority conservatively estimates the total resource to be around 400m-500m tonnes (which makes it the single-largest biomass reserve on the planet) of which it will not allow more than 5m to be picked up in any one year. That’s not a limit the krill fishermen are going to be hitting any time soon: currently not much more than 100,000 tonnes are caught every year.

So why am I telling you all this? Because there is now a way you can buy into the booming popularity of krill. A small Norwegian company called Aker Biomarine has spent the past three years researching a better way to both catch and process the crustaceans. Instead of trawling for krill (a destructive process that is no good for the Antarctic’s seals and penguins) they use vacuum technology to suck them straight into their on-board processing plant.

This makes sense not only for environmental reasons but because it ups the yield from each trip substantially (krill are so little they are hard to keep in traditional trawling nets) and because as the krill arrive in the plant alive, their antioxidant qualities have no time to decay.

Other krill processors such as Neptune Technologies & Bio-ressources [sic] (which is listed in Canada) get their krill frozen and work from there, something that apparently reduces the efficacy of the final product.

Aker had sales of 430m Norwegian kroner (£36m) last year, but Viktor Jakobsen of SEB Enskilda tells me he sees the company generating sales of more like 2 billion kroner in the next four years as it catches, processes and sells more.

Note that its new Antarctic vessel will be capable of dealing with 200,000 tonnes of krill a year, double the current total global catch. Aker doesn’t make a profit (it is spending too much on development for that) and it is very small. However, it is also growing very fast in a fascinating area and seems to be the only way (outside Neptune, which is only a processor) to get exposure to the next big thing in supplements, pharmaceuticals and, less excitingly but just as importantly, fish food.

I think that makes it worth looking at. The shares are listed only on the OTC market in Norway, but you should be able to get hold of them via a stockbroker, and Jakobsen tells me the firm should have a full listing by the summer.

Merryn Somerset Webb is a former stockbroker and now editor of Money Week. Her views are personal and investors should always seek professional advice.