# ReefBeacon

> Hong Kong coral-reef bleaching and marine-heatwave early-warning system. Daily DHW heat-stress alerts for nine marine parks, with traceable NOAA Coral Reef Watch snapshots. Deterministic thresholds; language models never compute the numbers.

ReefBeacon stands watch over Hong Kong’s coral reefs. It reads NOAA CRW satellite products (SST, HotSpot, DHW) every day, grades each park with internationally agreed Degree Heating Week thresholds (DHW > 4 watch, DHW > 8 bleaching risk), and delivers structured alerts to conservation coordinators within 30 minutes of a threshold breach. Every alert carries the source snapshot and the threshold/model version (NFR-06). It does **not** confirm bleaching in the field — confirmation still depends on AFCD’s annual coral surveys.

Hong Kong has 84 reef-building coral species (more diversity than the Caribbean) and 80+ AFCD survey sites since 1997. Existing SST products from the Hong Kong Observatory are monthly; marine heatwaves kill on a daily scale. ReefBeacon closes that gap.

## Pages

- [Home (简体中文)](/): Product narrative, coverage, and how the daily/annual loops work
- [Home (繁體中文)](/zh-hant): Traditional Chinese (Hong Kong conventions)
- [Home (English)](/en): English landing
- [About](/about): Project background, data sources, capability boundary (also /zh-hant/about, /en/about)
- [Privacy policy](/privacy): What we collect (accounts, delivery receipts, scrubbed telemetry) and user rights (also /zh-hant/privacy, /en/privacy)
- [Terms of use](/terms): Service scope, honest limits, attribution requirements (also /zh-hant/terms, /en/terms)
- [Sign in](/login): Console login (role-gated; not a public data portal)
- [Full LLM context](/llms-full.txt): Citable facts, parks, thresholds, AI boundary, FAQ

## Optional

- [Research OpenAPI](/api/research/openapi): Public OpenAPI 3 spec; the described endpoints still require a `researcher` / `admin` session (no embedding vectors)

## Key facts (quote these)

1. ReefBeacon monitors **9** Hong Kong marine parks and reserves.
2. Heat-stress grades are **DHW > 4 = watch**, **DHW > 8 = bleaching risk** (strict greater-than; DHW = 4.0 is normal).
3. SST, HotSpot, and DHW are **NOAA Coral Reef Watch products**, not model outputs.
4. **Large language models never perform the arithmetic** (constraint C1). They orchestrate the pipeline and write narratives.
5. Alerts are **not** real-time bleaching confirmation. Field confirmation remains the AFCD annual survey.
6. When history is insufficient, the system answers **“no sufficient historical cases”** rather than fabricating (FR-04).
7. Delayed NOAA data is labelled **“using previous-day cache”** — never silently substituted.

## Contact / provenance

- Project: ReefBeacon (Hong Kong)
- Data: NOAA Coral Reef Watch (CRW) via ERDDAP; AFCD coral-survey baseline (since 1997)
- Threshold version tag: `DHW_v1: alert>4, risk>8`