California Coast · Tar & Beach Conditions
About Tarline
Tarline is a crowdsourced record of tar and beach conditions along the California coast, built first for Santa Barbara's South Coast. Every report is a timestamped, geolocated observation in an open dataset that anyone can read, add to, or download.
Start Here
What Tarline Is
A Tarline report is one person's observation of one beach at one moment: how much tar is on the sand, how sticky or weathered it is, whether there is any sign of oil in the water, and a photo if there is one. The site turns those reports into a per-beach score, keeps every underlying observation readable, and publishes the whole set for download. Around them it shows the conditions that help explain what a beach looked like that day, from public buoy, tide, model and agency feeds.
What The Numbers Can Tell You
Tar / oil scores summarize recent crowd observations, not laboratory toxicity measurements or official beach closures. Higher scores mean less reported contamination. No recent reports means unknown, never clean; unobserved water stays unknown even when the sand was reported clean.
Offshore buoy significant wave height, CDIP modeled height at the water depth CDIP publishes for that specific model pointModel point depth CDIP publishes each MOP alongshore point at its own water depth, roughly 10 to 15 m depending on the point, rather than one 10 m contour statewide. Two beaches can therefore carry modeled heights that are not directly comparable. , and estimated breaking-wave face height are different quantities. The surf estimate is not yet validated against a held-out beach-observation dataset. Island shadowing, local wind seas, tide and bathymetry can produce large spot-level errors. Reading The Surf covers how that estimate is built, what it cannot see, and where it is going.
Current surf heights prioritize fresh multi-buoy spectral estimates, with short-period land screening where a verified coastal origin exists. CDIP MOP and the exposure-window model remain fallbacks and provide future guidance; present buoy observations are not extrapolated into a forecast.
Surf quality is a 0–100 modeled index of wind, period and usable wave size, not a probability, water-quality test or safety rating. Surf below 2 ft loses credit, especially below 1 ft; stronger winds reduce quality and longer periods earn progressively more credit through 18 seconds. Missing required inputs mean Unrated. The map's single quality dot is red through 35%, orange above 35% through 65%, yellow above 65% but below 75%, and green at 75% and above. Five-dot ratings summarize the same score in half-dot steps, with four dots and above green. Tar and water contamination remain separate.
Weather is model guidance, water temperature is a nearby buoy reading rather than a thermometer at your feet, and tides are astronomical predictions referenced to MLLW. Interpolated tide curves are labeled. Check valid times and source labels before relying on any value.
Live ingestion never falls back to sample fixtures. Feed receipts retain response digests or source snapshots as polling provenance; they are not a complete raw-payload archive. Earlier environmental history predating September 6, 2026 needs provenance review. Sample reports have been removed from the public site and retained only locally. Anonymous reporting works without an account; email sign-in is available for account and research-group participationQuality grades A report's grade sets how heavily it weighs into a beach's score: A for a verified research-group member, B for a signed-in user, C for anonymous. Attaching a photo lifts an anonymous report to B, because a photo is stronger evidence than a bare claim. Signing in or creating a group does not by itself confer verified research-group status. . See Research for timestamped environmental exports and feed health.
Why This Record Exists
The gap Tarline aims at is a real one: the last published multi-beach tar time series for this coast that we have been able to find is the 2001–2003 monthly transect program USGS ran with Santa Barbara County (USGS Open-File Report 2009-1225, Chapter 4). We have not located a public, continuously updated one since. That is a statement about what we could find, not proof that nothing exists.
The state is moving on part of the same gap from the other end: the California State Lands Commission has authorized seep studies in the Santa Barbara Channel, budgeted at $600,000 for February 2026 through January 2029, to inventory offshore natural tar, oil and gas seeps and determine locations, rates and fingerprints in state waters (2025 SB 44 progress report, pages 12–13). That work measures sources. Tarline measures shorelines.
Either way, attribution is time-critical, and how critical depends on the source. In the USGS chemometric study, seep oil near Coal Oil Point and produced oil from Platform Holly or Platform A are so similar that they “cannot be definitively distinguished after a period of a few days of weathering,” while oils from the Point Conception platforms stay separable on fingerprinting alone, and oils from Platforms Harmony, Heritage and Hondo take on the order of two weeks to a month to converge on the local tar signature. A dense, dated record of when and where tar showed up is one of the few things that can still narrow the question after that window closes. The Tar Story walks through the chemistry and the caveats.
Scoring Engine v5
How Scoring Works
Tarline scores every report with a two-factor model (scoring engine v5): how much tar degrades the beach visit, and how much the evidence says to be cautious about. The two are kept separate on purpose — a field of bone-dry, weathered tar balls is a big nuisance but a small health signal; a thin sheen in the water is barely visible but the single biggest caution flag Tarline tracks. Coverage class, tar-ball size/consistency, and oil form still borrow their vocabulary from NOAA's Shoreline Cleanup Assessment Technique (SCAT), so a Tarline report and a professional shoreline survey describe tar the same way.
The Formula
Score = 10 − Experience − Toxicity
Every report starts at a perfect 10. Two penalties pull it down: Experience (0–4) is how much tar ruins the visit — driven by how much coverage there is and how sticky or liquid it is underfoot. Toxicity (0–5) is how cautious the evidence says to be — driven by freshness, oil form, and — above all — whether there's any sign of oil actually in the water, where it can be swallowed or coat skin head to toe. Because each penalty is capped on its own (4 and 5), the score can never drop below 1, and a report with nothing to flag scores exactly 10 — not a special case, just both penalties legitimately at zero. One more observation sits outside this arithmetic: the whole-visit petroleum smell is scored as its own channel and the worst channel sets the final number (see below).
Score Scale
The same 10-to-1 range as a single strip: flag-band colors underneath, the calibration anchors marked on top.
Score Ladder
Where a report lands on the 10-to-1 scale, anchored to the owner's calibration points (bold) and the public flag-band boundaries (thin dividers).
- 10.0 No tar Clean sand, clear water -- nothing to penalize.
- 8.6 Petroleum smell, nothing else observed Clean sand, ocean never looked at, but the air smelled of petroleum -- the smell is its own channel and moves the overall score without inventing water evidence.
- 8.3 Hard, sporadic tar balls Weathered tar balls scattered underfoot, water clean. Owner anchor -- “hard, sporadic tar balls ≈ 8, easy to enjoy the beach.”
- 7.0 Green / yellow line Below 7, Tarline starts calling the water “posted.”
- 6.2 Soft, sticky tar, widespread Sticks to your feet across most of the beach, water still clean. Owner anchor -- “softer, widespread ≈ 6–7, still a normal beach day.”
- 4.4 Sheen alone in the water Sand looks fine; a sheen on the water pulls the score down on its own -- toxicity and experience are separate axes.
- 4.0 Yellow / red line Nuisance is no longer the whole story -- toxicity signal is climbing.
- 2.5 Red / black line Tarline treats the water as effectively closed at this point.
- 1.3 Widespread sheen on sand and in the water Fresh, greasy oiling on the beach and a sheen with a petroleum smell in the water. Owner anchor -- “widespread oily sheen on the beach and in the water ≈ 1–3.”
Experience vs. Toxicity
Because the two penalties are independent axes, the same tar can land in very different places depending on which one it drives. Widespread hard tar (top-right) is a high-nuisance, low-toxicity read; a lone sheen in the water (bottom-left) is the opposite — barely a nuisance, but the highest-toxicity signal Tarline has.
Score Matrix (Experience × Toxicity)
The formula itself, gridded: every whole-number Experience/Toxicity combination and the score it produces (10 − E − T, clamped 1–10), colored by flag band. Real reports rarely land on every cell — each sand form has its own achievable ceiling on E and T — but the arithmetic is identical everywhere in the grid.
| E ↓ / T → | 0 | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|---|
| 0 | 10 | 9 | 8 | 7 | 6 | 5 |
| 1 | 9 | 8 | 7 | 6 | 5 | 4 |
| 2 | 8 | 7 | 6 | 5 | 4 | 3 |
| 3 | 7 | 6 | 5 | 4 | 3 | 2 |
| 4 | 6 | 5 | 4 | 3 | 2 | 1 |
Experience Penalty Factors (E, 0–4)
Nuisance points, added together and capped at 4.
| Factor | Read | Points | Why |
|---|---|---|---|
| Coverage | None | 0.0 | More sand covered means a worse visit and higher odds of stepping in it — a pure nuisance dial, SCAT's own coverage bands. |
| Trace (<1%) | 0.9 | ||
| Scattered (1–10%) | 1.35 | ||
| Patchy (11–50%) | 1.8 | ||
| Broken/widespread (51–100%) | 2.1 | ||
| Material weight | None | × 0 | Multiply the material's stickiness, freshness and form terms by this coverage-dependent weight. These are editorial score weights, not measured area fractions or exposure doses. Tideline, water and smell terms remain independent. Tar on feet is recorded separately, not charged a second time. |
| Trace (<1%) | × 0.3 | ||
| Scattered (1–10%) | × 0.5 | ||
| Patchy (11–50%) | × 0.75 | ||
| Broken/widespread (51–100%) | × 1 | ||
| Stickiness | Hard | 0.3 | Even hard tar isn't literally harmless underfoot; liquid oil is the messiest to avoid tracking onto towels, gear, and car seats. |
| Firm | 0.5 | ||
| Sticky | 0.8 | ||
| Liquid | 1.2 | ||
| Form bonus | Tar balls/patties | 0.0 | Sheet-like oiling (a film or a greasy coat) is harder to avoid than discrete balls you can step around; a hardened crust adds nothing extra. |
| Stain/film | 0.3 | ||
| Greasy coat | 0.8 | ||
| Asphalt pavement | 0.0 | ||
| Tideline | None | 0.0 | The wrack line is often the only visible sign of tar even when the rest of the beach looks clean. |
| Black line | 0.3 | ||
| Sheen line | 0.5 |
Toxicity Signal Factors (T, 0–5)
Sand-material terms use the coverage-dependent material weight above; tideline sheen does not. Sand caution points are capped at 5. Water-column signs are scored independently and weighted well above dry-sand material — see the evidence for why.
| Factor | Read | Points | Why |
|---|---|---|---|
| Freshness | Hard | 0.5 | Weathering strips off the volatile, more bioavailable fractions first (NOAA: brief contact with weathered tar "will do no harm" for most people) — but weathered PAHs are still persistent carcinogens, so even "hard" isn't zero. |
| Firm | 0.6 | ||
| Sticky | 0.9 | ||
| Liquid | 1.6 | ||
| Form bonus | Tar balls/patties | 0.0 | A film or greasy coat transfers to skin far more readily than a pick-up-able ball; a hardened crust is the least bioavailable form there is. |
| Stain/film | 1.0 | ||
| Greasy coat | 1.5 | ||
| Asphalt pavement | 0.0 | ||
| Tideline sheen | Sheen line only | 0.5 | An iridescent wrack line is a freshness/toxicity signal, not just a coverage one — a plain black line isn't (it doesn't add here). |
| Water signs | Sheen in the water | 5.6 | Oil actually in the water opens ingestion and whole-body dermal routes a dry-sand tar ball never has — this is the single biggest lever in the model. Odor is a rough proxy for volatile/fresh compounds (ATSDR: TPH inhalation → CNS symptoms). |
| Tar balls in the water | 2.2 | ||
| Odor | 1.4 | ||
| Extent multiplier | Widespread (vs. isolated) | ×1.25 | Applies only to the water-signs sum above — a widespread water read is scaled up, isolated stays at face value. |
The petroleum smell is its own channel
Every reporter is asked one question about the air: did it smell of petroleum? That is not a water sign and it is not scored as one — someone standing on the sand who never looked at the ocean can answer it. A “yes” scores 8.6 on its own (10 − 1.4, the same weight an odor noticed in the water carries), an explicit “no” scores a flat 10.0, and a report that was never asked is left out of that average rather than counted as a clean answer. The beach's overall score takes the worst of the sand, water and smell channels, so a smell can pull the top-line number down on its own — but it never moves the water sub-score, and it never invents a water reading where nobody looked. The evidence is counted once: a report that logged an odor in the water and answered yes here is charged the worse of the two channels, never both.
Worked Examples
The three owner-calibrated anchors, with the full arithmetic. Sand, water and the whole-visit smell are scored separately, then the worst of the answered channels wins — the same "min-ish blend" the beach-level aggregate has always used. None of these three reporters was asked about the smell, so their scores come down to sand versus water.
Hard tar balls, sporadic coverage, clean water
Owner anchor -- “hard, sporadic tar balls ≈ 8, easy to enjoy the beach.”
Experience
- Coverage (sporadic)1.35
- Stickiness (hard) × 0.50.15
- Form (tar balls/patties) × 0.50
- Tideline (none)0
E = 1.35 + 0.15 + 0 + 0 = 1.5 = 1.5
Toxicity — sand
- Freshness (hard) × 0.50.25
- Form (tar balls/patties) × 0.50
- Tideline sheen (none)0
T(sand) = 0.25 + 0 + 0 = 0.25
Sand score = 10 − 1.5 − 0.25 ≈ 8.3
Score = 10 − 1.5 − 0.25 ≈ 8.3
Soft, sticky tar, broken/widespread coverage, clean water
Owner anchor -- “softer, widespread ≈ 6–7, still a normal beach day.”
Experience
- Coverage (broken/widespread)2.1
- Stickiness (sticky) × 10.8
- Form (tar balls/patties) × 10
- Tideline (none)0
E = 2.1 + 0.8 + 0 + 0 = 2.9 = 2.9
Toxicity — sand
- Freshness (sticky) × 10.9
- Form (tar balls/patties) × 10
- Tideline sheen (none)0
T(sand) = 0.9 + 0 + 0 = 0.9
Sand score = 10 − 2.9 − 0.9 ≈ 6.2
Score = 10 − 2.9 − 0.9 ≈ 6.2
Widespread greasy sheen on the sand, sheen + odor in the water, widespread
Owner anchor -- “widespread oily sheen on the beach and in the water ≈ 1–3.”
Experience
- Coverage (broken/widespread)2.1
- Stickiness (liquid) × 11.2
- Form (greasy coat) × 10.8
- Tideline (sheen line)0.5
E = 2.1 + 1.2 + 0.8 + 0.5 = 4.6 → clamped to 4
Toxicity — sand
- Freshness (liquid) × 11.6
- Form (greasy coat) × 11.5
- Tideline sheen (sheen line)0.5
T(sand) = 1.6 + 1.5 + 0.5 = 3.6
Sand score = 10 − 4 − 3.6 ≈ 2.4
Toxicity — water (widespread)
- Sheen in the water5.6
- Odor in the water1.4
- Widespread extent multiplier×1.25
T(water) = (5.6 + 1.4) × 1.25 = 8.75
Water score = 10 − 8.75 ≈ 1.3
Score = min(2.4, 1.3) ≈ 1.3 — the water side wins: any sign of oil in the water pulls the score down further than the sand alone would.
The Evidence Behind the Score
Full sourcing, confidence ratings, and open questions live in Tarline's internal evidence brief; this is the summary. Three findings from the toxicology literature shape every constant above:
- Weathered tar is a low-acute-risk nuisance, not harmless. NOAA's public guidance on tar balls is direct: weathered tar is "hard and crusty on the outside and soft and gooey on the inside," and "occasional brief contact with a small amount of oil, while not recommended, will do no harm" for most people (some get rashes). That's the evidence basis for scoring hard/dry tar as mostly a nuisance — NOAA Office of Response & Restoration — Tarballs.
- Weathering changes exposure, not just appearance. Volatile compounds such as benzene are lost as oil weathers, while less volatile petroleum constituents can remain. This supports a relative distinction between fresh oil and weathered tar, not a claim of zero inhalation risk. Some polycyclic aromatic hydrocarbons (PAHs) are carcinogenic; the sources reviewed here do not establish a safe dose for casual beach contact or let us infer exposure from a photograph. Sources: ATSDR ToxFAQs for Total Petroleum Hydrocarbons, Polycyclic Aromatic Hydrocarbons, and Benzene.
- Water contact opens routes a dry tar ball doesn't have. Oil or sheen in swimmable water adds incidental ingestion and whole-body dermal contact — routes a beach tar ball sitting on dry sand simply doesn't have. Standard spill-response practice converges on the same precaution regardless of a fixed numeric threshold: avoid contact, and don't enter water where oil or sheen is visible. That's why the Toxicity Signal table above weights water signs so far above everything else.
- Appearance is not a measurement. Nothing about the color, size or stickiness of tar on a beach reveals what is in it. Composition is established by gas chromatography and mass spectrometry on a collected sample, which is how the USGS survey of this coastline worked, and even then the report is careful to say that produced platform oil and nearby seep oil are often too similar to separate. Tarline's factors describe what an observer can see, so the score is a condition read. It is never a toxicity result, and it is never a source attribution.
This is a condition score, not a health advisory. Recreational dose-response to petroleum exposure is genuinely unquantified in the literature — hazard identification for PAHs and benzene is solid, but what a specific beach exposure does to a specific person isn't. When in doubt, follow official closures and postings, not this number.
No Statewide Petroleum Standard
California's only standing beach-posting law, AB411, covers bacterial water quality (fecal indicator bacteria) at Health & Safety Code §§115875–115915; there is no equivalent standard for petroleum. Beach closures during an active spill are called case-by-case by local health officers and Unified Command based on visible oiling, riding on general emergency authority such as Health & Safety Code §101040 rather than any numeric oiling index. Outside a declared spill, oil and tar go unposted, whatever the sand and water look like. That gap is what Tarline's score addresses: not a legal advisory, but a continuously updated, sourced read on conditions AB411 was never built to cover.
Geology And Industry
A Brief History
Tar on Santa Barbara's beaches is partly a story of geology and partly a story of industry — the two are hard to fully untangle, which is exactly why records matter. This is the short version; read the full story for the long one.
- 1896 Oil development at Summerland begins along the beach and pushes seaward, “the wells being drilled from wharves built out over the water.” These are the first offshore oil wells in California. Arnold, USGS Bulletin 321 (1907)
- 1900s Summerland production ceases in the early 1900s, leaving hundreds of wells drilled and plugged without regulation and “virtually no records” of how. The State Lands Commission today ranks 200 of them high-priority for potential leakage into the marine environment. CA State Lands Commission
- 1920s–30s The Ellwood field, just west of Coal Oil Point, is drilled below shallow water from more than sixteen oil piers. USGS OFR 2009-1225, ch. 1
- 1967 Production from the South Ellwood field begins with the construction of Platform Holly. USGS OFR 2009-1225, ch. 1
- 1969 On January 28, well A-21 under Union Oil's Platform A blows out 5.5 miles southeast of Santa Barbara. The well is capped February 7, but seafloor faults keep venting: about 100,000 barrels (4.2 million gallons) through December 1969. The federal National Pollution Contingency Plan is activated for the first time on February 2. NOAA IncidentNews case 6206
- 2015 Plains All American's 24-inch Line 901 ruptures near Refugio State Beach on May 19. NOAA's day-one record describes an estimated 500-barrel release (21,000 gallons), with oil flowing to the ocean. Its later damage-assessment page gives a total release over 100,000 gallons. These are records from different assessment stages, not competing final totals. NOAA IncidentNews case 8934
- 2018 The Becker #1 well, drilled in the 1890s, sitting in the surf zone, and for years the notorious source of visible oil on Summerland Beach, is permanently re-abandoned inside a driven pipe pile and cement. Remediation complete. CA State Lands Commission
- 2025 On February 28 the Commission completes re-abandonment of wells A and B at Summerland: eight wells since the SB 44 program's inception, plus the 2018 Becker pilot. Plugging is not always final, though. On October 10 oil was reported leaking near the Duquesne-910 well, four years after it was plugged; a contractor found and repaired the source on November 6. Wells C and D are planned for 2026, along with a $600,000 Santa Barbara Channel seep study. 2025 SB 44 progress report
- 2026 On January 22 the Commission issues a Notice of Preparation for an environmental impact report on decommissioning Platform Holly, with the comment period extended to March 6. CA State Lands Commission
- 2026 In July, elevated tar reports along the South Coast, concentrated around Carpinteria, prompt a public advisory. The source is unconfirmed as of publication; natural seepage is suspected but not established. Santa Barbara Independent, Jul 16, 2026
Feeds, Layers And Archives
Where The Data Comes From
Tarline layers live feeds, static reference layers, and archival datasets, each credited and linked back to its publisher below.
Live Conditions 6 sources
Cadences describe Tarline's polling schedule, not data freshness. Source details distinguish observation time, forecast validity and successful fetch time. A fetch does not prove values changed, and unknown upstream issue times remain unknown.
| Source | What it provides | Cadence | License |
|---|---|---|---|
| NOAA National Data Buoy Center (NDBC) | Wave height/period, wind, air & water temperature from offshore buoys | Polled every 10 min | Public domain (U.S. govt) |
| Scripps Coastal Data Information Program (CDIP) | Directional buoy observations and spectra, with provider identity and quality-control status preserved | Polled every 30 min | Open (DOI cited) |
| CDIP Monitoring and Prediction (MOP) System | Nearshore wave model: Hs/Tp/Dp nowcast + 10-day forecast at ~100m alongshore spacing, at each model point's own published water depth, for 45 of Tarline's 89 California beaches | Nowcast hourly; forecast every 6 hours | Nearshore wave model: CDIP MOP (Scripps), DOI 10.18437/C7WC72 |
| NOAA Tides & Currents (CO-OPS) | Regional high/low tide predictions relative to MLLW; not live water-level or current observations | Polled every 6 hours | Public domain (U.S. govt) |
| Open-Meteo Weather | Weather model guidance: air temperature, sustained wind, gusts, cloud, precipitation, pressure, humidity and UV | Polled hourly | CC BY 4.0; API terms apply |
| Open-Meteo Marine | Offshore wave and swell forecasts used by the beach exposure model and station outlooks | Polled every 3 hours | CC BY 4.0; API terms apply |
Calculated Astronomy 1 source
Calculated here, not measurements at a beach. Rise/set times use beach coordinates and the Pacific calendar day; moon phase uses date and time. Terrain and atmospheric conditions affect visible rise/set times.
| Source | What it provides | Cadence | License |
|---|---|---|---|
| SunCalc — Volodymyr Agafonkin | Sunrise, sunset, moonrise, moonset and moon phase; approximate next-full-moon date | Calculated when page data is assembled | BSD-2-Clause |
Oil & Spill Monitoring 4 sources
| Source | What it provides | Cadence | License |
|---|---|---|---|
| NOAA Incident News | Case pages for spill and pollution incidents NOAA has responded to | Polled daily | Public domain (U.S. govt) |
| U.S. Coast Guard National Response Center | Nationwide pollution-report intake — raw, caller-submitted reports, unvalidated; shown labeled as such and never merged into scored data | FOIA export checked weekly; not a real-time alert feed | Public domain (U.S. govt) |
| CDFW Office of Spill Prevention and Response — Cal Spill Watch | Active spill response status and public notices for California waters | Polled every 90 min | CA state public data |
| NOAA OSPO Marine Pollution Surveillance Reports (MPSR) | Satellite analyst assessments of possible surface oil, carrying a stated confidence level. An instrument-based inference about a slick, never a confirmed attribution to an operator | Polled daily | Public domain (U.S. govt) |
Static GIS Layers 3 sources
Static map context and coastline geometry — not live feeds. Agency publication dates and source resolution differ.
| Source | What it provides | Cadence | License |
|---|---|---|---|
| USGS National Hydrography Dataset coastline | Known-land geometry for short-period surf screening at verified wet-point origins; not bathymetry or long-period refraction | Retained source snapshot | Public domain (U.S. govt) |
| CalGEM (CA Geologic Energy Management Division) GIS | Oil & gas well locations and status statewide | Static | CA state public data |
| BOEM (Bureau of Ocean Energy Management) GIS | Offshore platform, lease, and pipeline layers | Static | Public domain (U.S. govt) |
Historical Datasets 3 sources
Fixed, archival sources used for background context and the site's history writing — not updated on any schedule.
| Source | What it provides | Cadence | License |
|---|---|---|---|
| USGS Open-File Report 2009-1225 | Natural oil seep locations and rates, Santa Barbara Channel, plus data appendices | Archival | Public domain (U.S. govt) |
| NOAA DIVER — Refugio Beach project | Trustee sampling, response and monitoring data from the 2015 Refugio pipeline spill | Archival | Public domain (U.S. govt) |
| CA State Lands Commission — Coastal Hazards & Legacy Wells | Summerland legacy-well inventory and re-abandonment record, plus annual SB 44 progress reports (source of the 200 high-priority well count) | Annual report + project updates | CA state public data |
Beach Metadata 4 sources
Where each beach's own name and coordinates come from: the California Coastal Commission's public access inventory (26 of 89 beaches), USGS GNIS named places (46), OpenStreetMap features (4), and public Surfline spot pages for named surf breaks (12). Geography only: no commercial forecast data is imported, and every wave, weather and tide number on the site comes from the public feeds listed above.
| Source | What it provides | Cadence | License |
|---|---|---|---|
| California Coastal Commission API | Beach access points, facilities, and jurisdiction metadata | Static | CA state public data |
| USGS Geographic Names Information System (GNIS) | Federally recognized beach names and coordinates (GNIS "Beach"-class features), the naming and position cross-reference behind 46 of the catalog's beaches | Static (cached snapshot) | Public domain (U.S. govt) |
| OpenStreetMap | Basemap tiles, coastline geometry, parking and access paths | Live | ODbL, © OSM contributors |
| Surfline public spot pages | Public spot taxonomy (surf-break names, subregions and spot coordinates), used to identify and de-duplicate 12 named breaks in the catalog. Geography only: no Surfline forecast, rating, or cam data is imported or displayed | Static | Public spot pages, cited for geography |
Open Dataset
For Researchers
The research portal exports the underlying dataset as CSV, GeoJSON, or JSON,
filterable by cohort and quality grade, in a schema compatible with SCAT field records. Reports carry a
quality grade (A for a verified research-group member, B for a
signed-in user, C for anonymous) which sets how heavily a report is weighted into
a beach's score. Attaching at least one photo upgrades an anonymous (C) report to B, the same bump as
signing in, since a photo is stronger evidence than a bare claim. Exports include a
photo_count column alongside the (photo-adjusted) qualityGrade so researchers
can see both.
Email sign-in is available through the Account page. Signed-in users can create and join research groups; grade A remains reserved for verified research-group members, not every account or newly created group. Anonymous reports remain welcome, and a photo can raise an anonymous report from grade C to grade B. Use the actual grade and cohort fields in each export rather than assuming that any particular grade is populated.
Citation
Tarline Community & Research Network (2026). Tarline beach tar observations [Data set]. tarline.org
Primary Sources
Further Reading
Reports & Data 11 entries
- Open-File Report 2009-1225: natural offshore oil seepage and related tarball accumulation, Santa Barbara Channel (report + data appendices) — USGS / MMS
- The same report as a PDF: chapter 3 is the chemometric fingerprinting method, chapter 4 the 2001–2003 beach tar monitoring (52 MB) — USGS
- The world's most spectacular marine hydrocarbon seeps (Coal Oil Point): quantification of emissions (Hornafius, Quigley & Luyendyk, 1999) — J. Geophysical Research: Oceans
- Decrease in natural marine hydrocarbon seepage near Coal Oil Point associated with offshore oil production (Quigley et al., 1999) — Geology
- Beach tar accumulation, transport mechanisms, and sources of variability at Coal Oil Point (Del Sontro et al., 2007) — Marine Pollution Bulletin
- Weathering and the fallout plume of heavy oil from strong petroleum seeps near Coal Oil Point (Farwell et al., 2009) — Environmental Science & Technology
- How oil harms animals and plants in marine environments — NOAA Office of Response and Restoration
- Shoreline Assessment Manual, 4th ed. (PDF): the coverage, thickness and oil-type vocabulary Tarline borrows — NOAA Office of Response and Restoration
- Refugio Beach oil spill: damage assessment, settlement and restoration record — NOAA DARRP
- Coastal Hazards and Legacy Wells program: Summerland well inventory, re-abandonment record, annual SB 44 reports — CA State Lands Commission
- Platform Holly Decommissioning Project: CEQA notice of preparation and scoping record — CA State Lands Commission
Historical Images Used On This Site 3 entries
- “Pumping oil out of the Pacific Ocean at Summerland, California,” ca. 1920. Rights advisory: no known restrictions on publication — Library of Congress, Prints & Photographs Division (item 2012647900)
- “Pumping oil from the sea - oil wells in the surf at Summerland, California,” stereograph, H. C. White Co., LOC-dated 1906. Rights advisory: no known restrictions on publication — Library of Congress, Prints & Photographs Division (item 2018645586)
- USGS copyright and credit policy: why the 2003 Coal Oil Point tar photograph on the Tar Story page is reusable — U.S. Geological Survey
News Coverage 4 entries
- Unusual Amount of Oil and Tar Reported on Beaches Across South Coast — Santa Barbara Independent, Jul 16, 2026
- Tar, Oil From Possible Natural Seepage Spotted on South Coast Beaches — Noozhawk
- Higher-Than-Normal Amounts of Black Tar Covers Parts of Carpinteria Beaches, Officials Say Natural Seeps Are to Blame — edhat
- Leaks or Seeps? Big Tar Balls Abundant on Santa Barbara Beaches — Santa Barbara Independent, Sep 17, 2023
Attribution
Credits & Licenses
Data
Data: NOAA (NDBC, CO-OPS, NWS, OR&R, OSPO) · Scripps CDIP (DOI 10.18437/C7WC72) · USGS · USCG National Response Center · CDFW-OSPR · CalGEM · BOEM · CA State Lands Commission · California Coastal Commission · CA Water Board (ODC-By).
Maps & Typefaces
Maps: © OpenStreetMap contributors (ODbL), served via OpenFreeMap; terrain from AWS Open Data. Typeface: Roboto, self-hosted — no external font requests.
Historical Images
Historical images: “Pumping oil out of the Pacific Ocean at Summerland, California,” ca. 1920, Library of Congress Prints and Photographs Division, item 2012647900, rights advisory “No known restrictions on publication.” Fresh tar at Coal Oil Point, June 10, 2003, Figure I-4 of USGS Open-File Report 2009-1225; USGS-produced material is public domain. Both appear on the Tar Story page with dated captions. Rights were checked at item level; neither is reused on the strength of its age or of who hosts it.
Tarline is in beta. Report data on the public site is real user submissions; the seeded sample reports used during development have been removed from it.