Biosecurity Zoning & Access Control
How physical space maps to containment: the four-tier zoning of the Station, the footbaths and PPE thresholds that condition people, the quarantine discipline that protects the collection from what arrives by hull, and the pressure cascade that protects the restricted core from us — and us from it.
Zoning Principle
The Station is zoned so that biosecurity tier rises monotonically as one moves from the public face inward and downward toward Abyssal Holding. Water always flows from clean systems to treatment, never the reverse; air in the Restricted wing always flows in and is exhausted through filtration. Personnel decontaminate moving out of a higher tier, never carry it back. There is no path from the public Reef galleries to a restricted system that does not cross at least two footbath thresholds, one PPE gateway, and a rising sequence of badge, biometric, and two-person controls. This page is the physical companion to the procedural controls in the Standard Operating Procedures.
Containment Telemetry
The Four-Tier Scheme
Every space in the Station carries one of four biosecurity tiers, BSL-equivalent in discipline. The tier sets the entry requirements, the water-handling rules, and who may pass.
Public / Education
Reef Conservatory galleries, visitor atrium, education theatre. No live-stock contact; viewing only behind sealed glass. Badge-free, escorted beyond the rail.
Husbandry
All production system floors — Cichlid Hall, Livebearer Racks, Inverts, Flora, Water Prep. Closed footwear, footbath in, hand & net hygiene between systems.
Triage & Isolation
Incoming and sick stock under isolated LSS. Dedicated PPE, system-specific nets, no shared equipment; air and water never join the production loop.
Abyssal Holding
Deep/cold/high-value stock under a pressure cascade. Encapsulating PPE option, two-person rule, biometric + log; air flows inward, treated on exhaust.
Zone-to-Tier Mapping
Each physical zone carries a tier and a corresponding air-pressure offset relative to the corridor datum (0 Pa). Negative offsets mean air flows into the zone and is exhausted through filtration — the signature of a containment space; positive offsets keep a clean space clean.
| Zone | Tier | Air vs datum | Water Handling | Boundary Type |
|---|---|---|---|---|
| Visitor Atrium / Reef galleries | Open | +10 Pa (clean) | No contact · sealed display | Glass + rail, escort |
| Cichlid / Livebearer / Flora / Inverts | General | 0 Pa (datum) | Closed-loop per system | Footbath + badge |
| Water Prep & Reservoirs | General | 0 Pa | RO + species mixing, source-of-truth | Footbath + badge |
| Fleet Dock & Dispatch | Open → Quar. | 0 Pa | Sealed transfer, never mixed w/ dock | Decon bay + manifest |
| Quarantine & Triage | Quarantine | −15 Pa | Isolated LSS · UV + ozone polish | Anteroom + PPE gateway |
| Abyssal Holding | Restricted | −55 Pa (cascade) | Pressure-rated, no recirc to production | 2-stage mantrap + 2-person |
Entry Requirements per Tier
People are conditioned at every tier transition. Donning is enforced on entry; doffing and decontamination are enforced on exit. The deeper the tier, the more the threshold demands.
| Tier Entered | PPE / Hygiene Requirement | Footbath / Decon | Access Control | Two-Person Rule |
|---|---|---|---|---|
| Open | Street clothing; no stock contact | None | Ticket / escort | No |
| General | Station uniform, closed wet boots, hand hygiene, system-dedicated nets | Footbath in; net-dip between systems | Badge + zone PIN | No |
| Quarantine | Disposable gown, gloves, lot-dedicated boots & nets, no cross-equipment | Footbath in & out · glove/boot wash · gown drop | Badge + biometric | No (logged solo OK) |
| Restricted | Encapsulating drysuit option, double-glove, dive-cleared for in-water work | Air-shower + 2-stage decon on exit · suit integrity check | Badge + biometric + log | Yes — mandatory |
- Footbath stations: 14 total — one at every General threshold, doubled at each Quarantine and Restricted boundary; charge and date logged by AquaLink.
- Net & equipment discipline: every system has colour-coded, dedicated nets and siphons; cross-system use is a reportable biosecurity breach.
- Decon effluent: all Quarantine and Restricted decon effluent is captured to a bunded kill-tank, chemically neutralized, and assayed before any release to reclaim.
Pathogen & Invasive Control
Two threats drive the whole scheme. Pathogens (ich, velvet, columnaris, viral haemorrhagic agents) move between systems on wet hands, shared nets, and un-quarantined stock — controlled by isolation, dedicated equipment, and UV/ozone polish. Invasives (a non-native fish, a snail, a fragment of nuisance algae, a ballast hitchhiker) threaten the ocean we defend if they ever escape via discharge or a vessel hull — controlled at the dock and at every discharge point.
| Threat | Vector | Primary Control | Backstop |
|---|---|---|---|
| Aquatic pathogens | Un-quarantined stock, shared nets/water | Mandatory Quarantine & Triage clearance before production | System-dedicated equipment · UV + ozone |
| Non-native species escape | Discharge to environment | No untreated discharge — all effluent UV/ozone/filtered, assayed | Bunded kill-tank · discharge permit log |
| Ballast / bilge hitchhikers | Vessel water from foreign waters | Ballast & bilge assay before discharge at dock | Hull-rinse · sealed live-transfer lock |
| Nuisance algae / snails | New plants, frags, wet gear | Flora propagation dip & isolation before display | Gear decon · footbath |
Pressure Cascade — Abyssal Holding
The Restricted Abyssal Holding wing is protected by a staged negative-pressure cascade. A person entering passes through progressively more negative spaces; air leaks from the cleaner side toward the dirtier side at every door, so any momentary seal failure pulls inward, toward containment, not outward. The cascade is held by 2N fan trains on the Essential Bus with a 30-minute reserve, per AE-FAC-0030.
Corridor Datum
Clean-side approach. Badge + biometric to reach the cascade vestibule.
Anteroom / Gown
First mantrap door. Don PPE; dive-cleared check for in-water work. Interlocked — outer door reseals before inner unlocks.
Transfer Lock
Two-person confirmation within a 30 s window. Air-shower on entry, decon on exit.
Holding Floor
Restricted working space. Pressure-rated systems, cold-water stock. Air treated on exhaust, no recirc to production.
Access Matrix — Zone vs Clearance Tier
Access is granted at the lowest clearance that satisfies the zone's tier and the person's role. ● = permitted; ◐ = permitted with escort / two-person rule; ✕ = denied. Tiers are issued and revoked by Human Resources and enforced physically by Security & Access Control (FAC-SEC).
| Zone ↓ / Clearance → | C1 Visitor | C2 Husbandry | C3 Quarantine | C4 Restricted |
|---|---|---|---|---|
| Reef galleries / Atrium (Open) | ● | ● | ● | ● |
| Production systems (General) | ✕ | ● | ● | ● |
| Water Prep & Reservoirs | ✕ | ● | ● | ● |
| Fleet Dock & Dispatch | ✕ | ◐ | ● | ● |
| Quarantine & Triage | ✕ | ✕ | ● | ● |
| Abyssal Holding (Restricted) | ✕ | ✕ | ✕ | ◐ |
Clearance & Credential Tiers
| Clearance | Credential Factors | Typical Holder | Issued By |
|---|---|---|---|
| C1 Visitor | Ticket / escort pass | Public, education groups (escorted) | Front-of-House |
| C2 Husbandry | Badge + zone PIN | Aquarists, plant trades, dock crew | HR + FAC-SEC |
| C3 Quarantine | Badge + biometric + health clearance | Triage vets, quarantine techs | FAC-SEC + HR medical |
| C4 Restricted | Badge + biometric + dive clearance + two-person + Director authorization | Named Abyssal Holding personnel only | Station Director authorization |