How to build and run a kelp strain catalogue: naming, provenance records, gametophyte lineage tracking, outcrossing rotation, and audit-ready hatchery documentation.
Every kelp hatchery accumulates a genetic library whether it means to or not: a shelf of culture tubes, a freezer box of cryopreserved gametophytes, a rack of flasks labelled in marker pen. The difference between a collection and a catalogue is paperwork — full reproductive histories of every lineage, written down in a way that survives staff turnover, audits, breeding decisions in year five, and worst of all, your own memory. At Tidewright's Holdfast nurseries, the strain catalogue is the single document a restoration director reaches for first when we ask "which seed belongs on this reef?" This guide explains how to build one that answers that question confidently.
A hatchery's worst quiet failure is genetic drift through neglect: a strain line repeatedly back-crossed with itself, mislabeled flasks, lost provenance, two strains silently merged after a contamination event. By the time anyone notices — a farm complaining that "this year's seed" underperforms — the genealogy that could diagnose it is gone.
A working catalogue prevents three catastrophes:
Adopt a naming schema before lineage number one, and never improvise. A robust scheme encodes species, region, collection event, and generation. Tidewright's convention (adapted freely — ours is fictional, the logic is real):
<SPECIES>-<REGION>-<SITE>-<YEAR>-<FAMILY>-<SEX>-<ISOLATE>
For example: SLAT-ATLN-BJ07-2024-F12-F-03 reads as sugar kelp, Atlantic North region, collection site BJ07, wild parents collected 2024, family 12 from that collection, female gametophyte, isolate 03. Six fields, each answered from the collection sheet alone, and any flask can be decoded by a new technician with no oral history.
Rules that keep it working:
The provenance record is born on the boat, not in the culture room. For each wild collection that founds a family, record:
The number of parents per founding family matters genetically. Crossing tissue from a single blade produces a family of half- and full-siblings; founding families from fewer than five parent blades sets a low genetic ceiling for everything downstream. Standard practice in our program: no founding family from a single sorus unless the point of the family is the sorus (e.g., a deliberate single-line archive).
Above provenance sits the reproductive ledger. Each culture entry, at minimum:
| Field | Captures |
|---|---|
| Strain code | The object identity |
| Parent codes | Male × female gametophyte codes for every cross that produced it |
| Cross date & batch | When the cross was made and which production batch it fed |
| Generation depth | Crosses since wild collection (F1, F2…) |
| Ploidy/sex | Male, female, or sporophyte |
| Genome notes | Any genotyping results — microsatellite or SNP panel — where performed |
| Status | Active / banked / retired / culled, with date and reason |
With those seven fields you can compute inbreeding coefficients, trace any farm complaint back to a mating pair, and answer a verifier's hardest question: show me the ancestors of the seed that went onto that reef. At Holdfast, lineage records feed directly into the delivery dossier that travels with every Holdfast seed batch — the genetic biography of the seed a reef receives.
Clonal gametophyte lines can live for years, but seed performance decays if each production year draws on the same pair. Rotation rules we recommend, informed by conservation-genetics practice:
For hatcheries doing directed improvement rather than maintenance breeding, the catalogue integrates with the selection pipeline described in Selective Breeding for Kelp; crossing decisions generate future catalogue entries, and the catalogue constrains crossing decisions. The two documents should be one.
The strain catalogue records meaning; the gametophyte bank records locations and conditions. Every banked line's entry should name its physical custody: room, rack transfer dates, cryo tank, cane, and viability-testing history. The twin discipline mirrors the standards in The Seed Vault of the Sea: triplicate custody (two in-house copies plus one at a partner institution), annual viability checks on a rotating sample, and a disaster plan no more than one step from the catalogue itself.
A catalogue line that says a strain exists but can't tell you which tank holds it in under a minute does not, in a flood or freezer failure, contain that strain at all.
Auditors — certification bodies, grant funders, restoration verifiers — don't want your database. They want confidence that five-minute interrogation returns consistent answers. Practical habits:
Our own catalogue underpins the genetic reporting in the impact methodology that Tidewright publishes alongside its (illustrative) restoration statistics — the chain from reef survey to strain code to outplanted seed is part of what makes a restoration claim auditable at all.
A spreadsheet is a fine beginning for under a few hundred lines if the schema above is followed strictly: one row per strain, immutable IDs, controlled vocabulary for status fields, and a read-only change log sheet. At 500+ lines or multiple sites, move to a lightweight relational database or a lab information management system (LIMS) with a custom module; the schema in this article maps directly onto such systems. The tool matters far less than the rule that the catalogue is authoritative and the flasks are copies. When the two disagree, you have a contamination or labeling event — not a spreadsheet problem.
A five-line hobby-scale hatchery needs the schema, not the software. Code every line, record provenance at collection, and log crosses. Genetics doesn't scale its patience to your operation size — a mislabeled flask breeds the same problems in a closet as in a campus.
Enough that no single mating pair dominates production: commonly three to six male and three to six female lines per production strain-family, plus cryopreserved founders. Exact numbers depend on cross-compatibility and breeding goals; the catalogue is what tells you whether your rotation is actually achieving balance.
None is required for basic provenance management — the lineage records carry you a long way. Genotyping (SNP or microsatellite panels) becomes worth its cost when you're doing directed selection, verifying lines after a suspected mix-up, or certifying strains for high-stakes restoration where identity guarantees are contracted.
Clonally perpetuated under clean, low-light, cool conditions, lines can persist years; cryopreserved, decades. The limiting factor is usually not lifespan but performance confidence: refresh production from refreshed or re-collected founders every few generations, and record each refresh as a catalogue event.
Quarantine both sources, re-isolate, and genotype if identity matters. Then record it as an incident in the catalogue change log — mixed and honest beats clean and wrong. An audit that finds an incident log finds a functioning system; one that finds nothing amiss in ten years finds a fiction.
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