Pemba Island · Zanzibar · FAO 51
A no-net handline fleet working the Pemba Channel. Each fish is taken on a single hook, iced on the boat, frozen the day it lands, and recorded against the boat and the person who caught it.
The problem with the category
Seafood is the hardest food category in the world to verify. Species get substituted, catch areas get rounded to an ocean, and “sustainably sourced” is a phrase with no legal definition anywhere.
So we stopped making claims and started publishing records. Every number on this site carries the date it was measured, the organisation that measured it, and a link to the source. Where the evidence is weak, we say the evidence is weak. Where a stock we sell is in trouble, we publish that too.
“A claim you cannot check is marketing. A record you can check is a receipt.”
The landings ledger
When a boat lands, each fish is weighed, graded and given a lot number, and the sheet records the vessel and its registration, the skipper, the landing site, the date and the whole weight. That is what we can show a buyer today, for every fish, and it is written down by a person, not measured by an instrument.
We are not going to dress that up. There is no tracker on the boats yet, no probe in the ice bin, no logger on the freezer. The digital lot record — catch position and time from a vessel tracker, minutes to ice from a bin probe, the freeze curve from the tunnel controller, a lookup on this page — is what the facility we are building is designed to produce. When it exists, this section changes. Until then, the ledger below is the honest version.
Catch position and catch time from a vessel tracker. Time to ice from a probe in the slurry bin. The full freeze curve from the tunnel controller. A code on every carton, and a lookup on this page that resolves it to all of the above. Each of these will be marked measured only when an instrument measured it.
Why hook and line
A handline catches one fish at a time, by hand, and anything unwanted goes back in the water alive. There is no net to sort through, no wall of mesh, no fish aggregating device.
This is not a technique we invented. It is how Pemba has fished for generations — and it happens to be the lowest-impact commercial gear there is. Independent research on the closest comparable fishery, the Maldivian pole-and-line tuna fleet, recorded bycatch at 0.65% of the tuna catch, with dead discards at 0.02%. Indian Ocean purse seine runs about 4.7%. Longline runs 28–36%.
Read that carefully. That 0.65% figure is measured in the Maldives, on pole-and-line gear, not on our boats in Pemba. It is the closest published analogue to what we do, and we quote it as an analogue — not as our own result. We have not yet published observer data of our own. When we do, it will be here, with the methodology attached.
Miller et al. (2017), “Bycatch in the Maldivian pole-and-line tuna fishery”, PLOS ONE 12(5): e0177391. Comparator figures for purse seine and longline from the same paper.
Our species
Thunnus albacares · Kiswahili: Jodari
Sleek, metallic blue-black back over yellow flanks. Our principal species and the one our handline fleet is built around — sold to mainland Tanzania today, graded to an export specification for tomorrow.
Coryphaena hippurus · Kiswahili: Fulusi
Mahi-mahi. Iridescent blue-green back, golden flanks. A fast-growing species that reaches maturity in four to five months.
Scomberomorus commerson · Kiswahili: Nguru
Narrow-barred Spanish mackerel. Torpedo-bodied, greenish-blue over silver. Firm, dense flesh that holds a steak cut.
Lutjanus spp. · Kiswahili: Tembo
Reef-associated snapper from the outer shelf slope. Pale rose flesh, clean flavour. Sold to genus, with DNA confirmation on request.
Stock status per IOTC Scientific Committee status summary, 2025 (assessment years vary by species). Dorado and snapper carry no regional assessment — see Sustainability for what that means and how we handle it.
The cold chain
Zanzibar's documented weak point is ice. A 2024 survey of the archipelago's fisheries found that across 235 landing sites, “the use of ice is rare” — with essentially one 2.5-tonne-a-day ice machine and a single freezer truck serving the islands.
That is the gap we exist to close. Not a slogan — an infrastructure problem with a measurable answer.
How blast freezing actually works
JICA, Information Collection Survey on the Fisheries Sector in Zanzibar, final report, January 2024.
Where we are, and where we are going. Today our store runs at −30 °C — legal, and honestly stated. Peer-reviewed work on tuna stored for up to sixteen months found that metmyoglobin browning — the reaction that turns red tuna brown — stops entirely at −45 °C or colder, regardless of the meat's pH. That is why the facility we are building is specified to −45 °C, and why we will not describe our current product as super-frozen until it is.
Nakazawa, Okazaki et al. (2020), International Journal of Refrigeration 112: 270–280. DOI 10.1016/j.ijrefrig.2019.12.012
Next
A sample box, with the landing record for every fish in it — vessel, skipper, landing site, date and weight — and a straight answer about what we do not record yet.
