Florida Keys 2026 Coral Thermal Stress & Bleaching Dossier
Scientific Investigation Question: What do authoritative satellite thermal-stress metrics, independent shallow in-situ temperature observations, and documented biological observations establish regarding coral thermal stress and bleaching onset in the Florida Keys during July 2026, and what conclusions remain unsupported?
Assurance Level
SIGNED_AUTHORITY_LOCAL_BOOTSTRAP
R6 Cryptographic Provenance
Supported Facts
4
Fully Verified Claims (C1-C4)
Blocked Overclaims
5
Hostile Overclaims Blocked (H1-H5)
Raw Retained Datasets
5
CRW, KYWF1, VCAF1, AOML x2
Authority Lineage & Sensing Modality Independence
Institutional Commonality: All retained evidence sources in this investigation share common high-level agency provenance within the National Oceanic and Atmospheric Administration (NOAA: Coral Reef Watch, National Ocean Service CO-OPS, and Atlantic Oceanographic and Meteorological Laboratory).
Modality Independence: While institutionally aligned, these datasets represent three physically independent sensing modalities: (1) Satellite Infrared Radiometry (CRW L4 SST), (2) In-Situ Fixed-Depth Harbor/Bay Thermistors (CO-OPS), and (3) In-Situ Diver Visual & Photographic Field Surveys (AOML).
NOAA CRW Operational Precomputed Product
OceanSig consumes the precomputed NOAA CRW operational Regional Virtual Station time series (5-km SST, SSTA, 90th percentile HotSpot, DHW, and BAA). Upstream Level-4 multi-satellite blending is performed by NOAA CRW and is not recomputed from raw orbital granules by OceanSig.
NOAA AOML Institutional Field Reporting
Retained AOML web publications establish that NOAA scientists publicly documented observed signs of bleaching at Cheeca Rocks in early July 2026. This is classified as Institutional Field Reporting; raw benthic diver transects and photo-quadrat spreadsheets are pending formal NCEI accession.
Crucial Spatial & Physical Non-Equivalence Principles
OceanSig strictly forbids conflating regional satellite surface skin temperature with localized benthic reef thermistors or distant coastal harbors. The four observation platforms in this investigation occupy distinct physical environments:
CRW Virtual Station
Regional Polygon (5-km grid average)
Satellite thermal-infrared sea-surface temperature product; representative of ocean surface skin and not a measurement of subsurface or benthic water temperature.
Key West Harbor (KYWF1)
Point Station (8724580, -81.8079, 24.5557)
0.85 m depth in enclosed harbor. ~130 km southwest of Cheeca Rocks.
Vaca Key / Bay (VCAF1)
Point Station (8723970, -81.1065, 24.7110)
1.03 m depth in shallow Florida Bay. ~58 km southwest of Cheeca Rocks.
Cheeca Rocks Patch Reef
Biological Survey Site (-80.617, 24.900)
Inshore patch reef (3-6 m depth). Ground-truth diver biological observation point.
Epistemic Field Classification Matrix
OceanSig strictly distinguishes between directly parsed raw telemetry, deterministic statistical reductions, normalized reports, investigator domain bounds, and unverified client strings:
| Field / Parameter Group | Classification Tier | Epistemic & Provenance Rationale |
|---|---|---|
| CRW SST, SSTA, HotSpot, DHW, BAA | PARSED_FROM_SOURCE | Directly extracted line-for-line from retained CRW ASCII text file on 2026-07-19. |
| KYWF1 & VCAF1 Mean/Min/Max Temps | MACHINE_COMPUTED | Mathematically calculated via deterministic statistical reduction across 240 continuous 6-min CSV readings. |
| AOML Cheeca Bleaching Observation | HUMAN_ASSISTED_NORMALIZED | Structured sentence and metadata normalized from retained raw AOML HTML reporting pages. |
| CRW Skin Depth Domain (Surface Skin) | INVESTIGATOR_CONFIGURED | Configured by OceanSig investigators to reflect satellite infrared radiometer skin depth. |
| Sensor Depth Datum & Spec Accuracy | EXTERNAL_METADATA_ASSERTION | Injected from published NOAA NOS datum and instrument specifications; not in raw time series. |
| Evaluator Identity & Session Feedback | UNVERIFIED_ASSERTED | Self-asserted client string; strictly isolated from scientific evaluation graphs. |
Pillar I: What We Know (Supported Facts)
Regional Bleaching Alert Level 2 Exceeded
On July 19, 2026, the NOAA Coral Reef Watch Florida Keys Regional Virtual Station recorded Degree Heating Weeks (DHW) of 8.0757 °C-weeks and Bleaching Alert Area (BAA) 7-day maximum of 4 (Alert Level 2), with SST@90th_HS reaching 31.18 °C (SSTA = +1.62 °C). Consumed as precomputed operational product.
Key West Harbor Continuous Water Temp
On July 19, 2026, NOAA CO-OPS Station 8724580 (KYWF1) recorded 240 continuous 6-minute water temperature measurements averaging 32.13 °C (min 31.90 °C, max 32.50 °C) at a depth of 0.85 m below MLLW.
Vaca Key / Florida Bay Continuous Water Temp
On July 19, 2026, NOAA CO-OPS Station 8723970 (VCAF1) recorded 240 continuous 6-minute water temperature measurements averaging 32.02 °C (min 31.30 °C, max 32.80 °C) at a depth of 1.03 m below MLLW.
Documented Bleaching Onset at Cheeca Rocks
NOAA AOML scientific divers documented the first field signs of coral bleaching at the Cheeca Rocks inshore patch reef in early July 2026 (photographed July 6, 2026). Normalized from NOAA AOML threats and media institutional reporting pages.
Pillar II: Why We Think We Know It (Provenance Lineage)
Every supported claim is cryptographically linked to retained raw source bytes, immutable SHA-256 digests, and deterministic R6 processing run specifications:
▶ C1 Lineage: NOAA Coral Reef Watch Virtual StationClick to expand cryptographic audit trail
84151CA8EB0F40ED500AD3F5A6F6155DBB71D8D4D473A22D77FCF3943874BF93 (1,265,185 bytes)▶ C2 Lineage: NOAA NOS CO-OPS Station 8724580 (KYWF1)Click to expand cryptographic audit trail
00A55AA18CE5DC3589E8AC49B2C76328F34EEEE2FF27775363DFAAAC8C591214 (134,439 bytes)▶ C3 Lineage: NOAA NOS CO-OPS Station 8723970 (VCAF1)Click to expand cryptographic audit trail
86351E2CE78502F59B3231616F1BF6D061156AA078529A2210F83773C7BECE89 (134,435 bytes)▶ C4 Lineage: NOAA AOML Threats & Media Resources (Normalized Artifact)Click to expand cryptographic audit trail
372763A6832456DD7164CE7DDB762FF3A9EBA9577BEF30B29B6C35FDD7193EFC4629846A609EF7687D397361B57A86199C343E6BE26D1AC67392EC5063AACB95 (206,062 B)E3528BB1328412CB18AF9DEFA2EDAED57969603218FC8D87B1E4C7002350FCCC (80,217 B)Pillar III: What Differs / Conflicts (Physical Distinctions)
Regional Satellite SST (31.18 °C) vs. Coastal Thermistors (~32.1 °C)
On July 19, 2026, regional composite satellite SST@90th_HS was 31.18 °C, whereas Key West Harbor mean water temperature was 32.13 °C and Vaca Key shallow bay water temperature was 32.02 °C.
Spatial & Physical Distinction: On July 19, 2026, the retained KYWF1 and VCAF1 daily means were approximately 0.95 °C and 0.84 °C warmer, respectively, than the CRW SST@90th_HS value. These measurements are spatially and physically non-equivalent and should not be interpreted as establishing a persistent offset.
Surface Skin Radiometer vs. Subsurface Fixed Depth Loggers
NOAA Coral Reef Watch thermal-infrared SST is representative of the ocean surface skin and is not a measurement of subsurface or benthic water temperature, whereas CO-OPS thermistors are mounted at fixed reference datums (0.85 m below MLLW at Key West, 1.03 m at Vaca Key).
Epistemic Boundary: Skin temperatures are susceptible to diurnal wind mixing and evaporative cooling, whereas fixed benthic and subsurface loggers integrate water column heat content.
Pillar IV: What We Cannot Conclude (Blocked Overclaims)
OceanSig's frozen R6 scientific kernel automatically refuted and rejected five hostile extrapolations:
Satellite SST = Cheeca Reef Temp
CRW regional composite SST cannot be claimed as the exact benthic temperature at Cheeca Rocks.
Harbor Temp = Outer Reef Temp
Harbor/bay point temperatures cannot be spatially extrapolated 70-130 km to outer patch reefs.
Cheeca Bleaching = Keys-Wide
Documented onset at one patch reef does not establish regional bleaching percentage across all Keys reefs.
Bleaching Observed = Coral Mortality
Observing bleaching signs does not prove coral mortality without repeated post-stress survival surveys.
Thermal Stress = Exclusive Cause
Satellite thermal metrics alone cannot exclude co-factors (salinity, irradiance, localized disease).
Pillar V: Cryptographic Provenance Walkback Engine
Step backwards from any rendered claim value directly to the immutable upstream byte artifact with verification digests.
End-to-End Cryptographic Provenance Walkback
Step backward from any displayed scientific metric to its verified mathematical transformation, retained raw disk artifact, retrieval event, and canonical institution.
Rendered Value: 8.08 °C-weeks
User-facing scientific metric 'Degree Heating Weeks (DHW)' rendered in chart or dossier view.
Normalized Telemetry Record (rec-crw-fk-20260719)
Structured schema-validated observation record within the OceanSig dataset engine.
Processing Run: 12-Week HotSpot (>= 1.0°C) Half-Sum Accumulation
Mathematical transformation executed by 'packages/shared/src/scientific-kernel.ts'.
Retained Disk Artifact: florida_keys_crw.txt
Primary source file stored in local repository storage with exact SHA-256 byte verification.
Retrieval Event: 2026-09-20
Automated network ingestion event from 'https://coralreefwatch.noaa.gov/product/vs/data/florida_keys.txt'.
Canonical Provider: NOAA NESDIS STAR / Coral Reef Watch
Authoritative scientific publisher/institution responsible for instrument deployment and calibration.
Documented Scientific & Reproducibility Limitations
PRECOMPUTED_OPERATIONAL_PRODUCT
NOAA CRW virtual station represents operational L4 satellite processing. OceanSig consumes precomputed time series without recomputing raw sensor granules.
INSTITUTIONAL_FIELD_REPORTING
AOML documents observed bleaching signs in early July 2026. Raw diver transects and photo-quadrat spreadsheets are pending public NCEI accession.
SHARED_AGENCY_LINEAGE
All data sources originate within NOAA line offices (CRW, NOS CO-OPS, AOML), while utilizing three distinct, physically independent sensing modalities.
HERMETIC_REPRODUCIBILITY_NOT_YET_PROVEN
Execution in linked git worktree environment with shared Node.js runtime; full bare-metal container hermetic isolation is not yet formally verified.
External Evaluator Session Recording
Log your validation evaluation session. Records are stored for review in compliance with operator security controls.