The dock
The dock is half the system. Fixed benthic infrastructure with its own lifecycle, independent of the fish. It recharges, swaps cartridges, aggregates captured waste, runs the local biology reservoir, and offloads data to shore.
What it does
- Recharges the fish via inductive coupling at the bay
- Offloads data by high-rate optical link in the bay (1–10 Mbps OOK)
- Swaps cartridges via the bay’s cartridge arm — hot-swap, no human required for routine rotation
- Reseeds depleted cartridges in the on-board biology reservoir
- Aggregates waste — microplastics, metal precipitates — in a sealed hopper for periodic human pickup
- Coordinates the fleet via JANUS acoustic modem, surface buoy uplink
Three dock variants
| Dock | Power source | Use case |
|---|---|---|
shoal-dock-A |
Benthic MFC + solar surface buoy | Remote rivers, marine, wetlands. 6+ months autonomous. |
shoal-dock-B |
Shore-tethered (power + fiber) | Harbors, urban stormwater, industrial outfalls. |
shoal-dock-C |
Battery-buffered, ship-deployed | Spill-response missions, temporary deployment. |
Spacing
A function of fish energy budget. With ~50 mW continuous MFC harvest in moderate pollutant load:
- Energy-positive cruise radius: ~500 m round trip
- Battery-buffered survey radius: ~2 km round trip
- Dense deployment: 300–500 m between docks
- Sparse monitoring: 1–2 km between docks
A typical river stretch in dense remediation mode: 5–20 docks per linear km. Sparse monitoring mode: ~1 dock per few km.
The biology reservoir
The novel dock subsystem. A small (~5 L) sealed bioreactor that:
- maintains live cultures of every consortium the local fleet uses
- reseeds spent gut cartridges by flushing and reinoculating
- monitors community composition via genomic markers (low duty cycle)
- runs slow directed-evolution experiments — the fleet gets better at handling local pollutant chemistry over time
- never releases cultures to the environment (UV-treated effluent if water exchange is needed)
This is the part that requires the most novel biology engineering. It’s also the part that makes the system compound.