Algae and worms
There have been several posts recently on worms, the lifeblood of soil, but this is just as much a question as a statement.
Some years ago in S Wales a chap bred ragworms for fishing using algae, and I wondered if there's anything in algae that might be equally nutritious for earthworms in gardens? He created beds of 'seapeat', the semi-decayed salt water detritus. He then arranged interlinked parallel clear plastic tubes horizontally and filled them in his case with sea water. Over time they became green with algae via the sunlight, at which point he opened a tap and allowed all the algae water to flow into the seapeat beds where the ragworms fed on it.
Do any of the science gurus amongst us know if the nutritional value of algae would be likely to make a freshwater equivalent of his stimulate more worms for those who have apparently so few?