So it turns out that there’s billions of Coca Colas’ worth of sugar released into the rhizosphere beneath sea grasses.
I have a race of humans/superhumans/merfolk that live exclusively in the sea and other aquatic habitats. They very, VERY rarely leave the sea/water unless they absolutely have to. They're very humanlike in appearance with only some visual quirks like webbed hands, long flexible feet, somewhat fatty foreheads to behave as melons, etc. and other internal traits like cetacean-like blood, collapsible ribs, etc.
At best they live in houseboats (of varying types) and make temporary living spaces on makeshift rafts, diving bells, etc. Being an amphibious species, their palette is limited (from a land-lubber’s point of view) outside of sea creatures and kelp/algae/seaweed. So I was looking into other foods and seasonings (besides salt) there could be and came across the sugar under the sea meadows. I wanted to know if there was a way for them to harvest the sugar there to add onto their cuisine.
Their technology is mostly with primitive materials at this stage. They make due with what they can with: seaweed/kelp, shells, bones, rocks, driftwood, sea glass, things salvaged from shipwrecks, reefs, coral, and whatever other things they can get in the ocean. They have also of course achieved very sophisticated free-range farms for their “vegetation”, numerous methods of fishing/hunting, and rearing of numerous sea creatures from krill to small whales. Some races advanced to where they could make primitive paddleboats as expensive as they may be.
With this info, how can they harvest sugar under the sea meadows with what they currently have?
If it helps, I’m looking at the sea grass meadows surrounding Australia in particular, but feel free to use other examples if it improves an answer.
(got approval from the Sandbox this time)