Tuna graded, loined and vacuum-packed at the harbour for the sashimi market, not sold whole

A first step

Stand at the harbour when the long-line boats unload and record what a whole tuna fetches that morning, by weight and by boat. Then ask a hotel's head chef or a sushi kitchen in the city what they pay per kilo for sashimi-grade loin, and whether they would take a trial order cut and vacuum-packed at the harbour. The difference between those two numbers, and one trial order, is the business case.

Who pays first

A sushi kitchen or hotel chef who pays by the kilo for graded, loined tuna and cannot trust whole fish that sat on a hot quay.

What leaves today

Whole tuna leaves the harbour at a bulk price, and the grading, cutting and cold packing that make it sashimi are paid for somewhere else.

The idea and the mechanism are from the book. The first step was written for this site as a suggestion; if you know a better one, say so.

The test

Does it keep value that now leaves the island, or build the proof that lets somebody else do so?

The only test any idea on this site has to pass. The four rules that go with it are here.

In the book

• Ch. TwoAn Island Nobody Has Counted
  An ocean eight times the size of the land

More from cluster 13

• 251Sailing charters and a yacht marina at Galle or Trincomalee, with the crew trained here
• 252Diving schools at the wrecks of Trincomalee and the reefs of the east, certified to international standard
• 253Sport fishing charters with catch-and-release, sold to the Gulf and Europe
• 254Sea-cucumber and seaweed farming in the northern lagoons, which Japan and Korea buy
• 256Crab and prawn from the lagoons as a branded chilled export, with the lagoon's name
• 257Dried fish and Maldive fish for Sri Lankans abroad, packed to a food-safety standard

All 20 ideas in this cluster