Map Layers
Erosion Risk
High (>3 ft/yr)
Medium (1–3 ft/yr)
Low (<1 ft/yr)
Satellite Data
Loading…
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Surface Temp LIVE
Woods Hole gauge
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Sea Level NOAA
above 1993 base
1.8 ft/yr
Avg Erosion
accelerating
42,318 ac
Protected Coast
+1,200 in 2025
Click any highlighted area to explore its data

Ocean & Climate Data

Historical trends from NOAA tide gauges, buoys, and satellite SST sensors

Temperature & Sea Level
Sea Surface Temperature
Annual avg °F — Woods Hole (1990–2024)
Sea Level Rise
Inches above 1993 baseline — Woods Hole gauge
Chemistry & Conditions
Ocean pH
Annual mean — Buzzards Bay buoy (2005–2024)
Salinity
Monthly avg PSU — Vineyard Sound (2019–2024)
Projections
Sea Level Rise Projections (2025–2100)
NOAA Low / Intermediate / High scenarios — inches above 2000 baseline

Ecosystem Health

Habitat status updated quarterly from aerial surveys, satellite NDVI, and field monitoring

Habitat Status
Eelgrass / Seagrass
Concern
Coverage down 34% since 2000. Eutrophication and warming primary causes. Critical habitat for bay scallops.
Shellfish Habitat
Fair
Oyster and quahog populations stable. Ocean acidification threatens larval survival. Active restoration underway.
Salt Marsh
Fair
Approx. 3,400 acres remain on the Cape. Vertical accretion keeping pace in some zones, loss in others.
Shorebird Nesting
Good
Piping Plover population up 18% over 5 years on MV. Tern colonies stable. Predator management effective.
Fish Habitat
Good
Striped bass and bluefish populations stable. Range shifts northward consistent with warming trend.
Coastal Wetlands
Concern
421 acres lost in past decade. Inland migration blocked by roads and infrastructure.
Lobster Population
Fair
Cape Cod Bay populations declining as warming pushes range northward. Significant economic impact.
Dune Vegetation
Good
Beach grass stabilization projects showing success on MV south shore. Storm overwash remains a threat.

Erosion & Risk — All Zones

All 19 monitored zones ranked by erosion severity · click any row to open its detail panel

Sort by:
# Zone Region Survey Rate ▼ Sat Rate (7yr) vs Long-term Risk

Survey rates: USGS CoSMO · Satellite rates: ESA Sentinel-2 via GEE · "vs Long-term" compares 2yr to 7yr satellite average

Generate a Preservation Report

Export a summary of current conditions, key risk areas, and priority parcels — ready for board meetings or grant applications.

Data Sources

All APIs and datasets used in this dashboard are publicly available and free

Federal & State Data
NOAA CO-OPS
Tide gauge data, water levels, sea surface temperature. Station 8447930 (Woods Hole) is primary reference.
tidesandcurrents.noaa.gov
NASA Earthdata
MODIS and Sentinel-2 satellite imagery for SST, NDVI vegetation index, and coastline change detection.
earthdata.nasa.gov
USGS Coastal Change Hazards
National shoreline change database, erosion rates, and coastal hazard risk assessments for the region.
USGS Coastal Hazards Portal
NOAA NDBC Buoys
Real-time buoy data for wave height, water temperature, wind, and ocean conditions in Buzzards Bay and Vineyard Sound.
ndbc.noaa.gov
MassBays NEP
Massachusetts estuarine water quality, eelgrass surveys, and nutrient loading data for Cape Cod Bay.
MassBays Program
MassGIS / OLIVER
Protected land parcels, conservation restrictions, wetlands mapping, and habitat data for the Commonwealth.
MassGIS

Data Methodology

How satellite rates, erosion figures, and risk classifications are calculated

🛰 Satellite Erosion Analysis (Sentinel-2)

Coastal land-change detection uses ESA Sentinel-2 multispectral imagery processed through Google Earth Engine. For each zone, a waterline is extracted using the Normalized Difference Water Index (NDWI) — a spectral index that separates water from land using the Green and Near-Infrared bands.

Land loss is calculated as the area (m²) that transitioned from land to water between the start and end image of each time window. Results are reported as annualized rates.

NDWI = (Green − NIR) / (Green + NIR) 10m resolution Cloud-filtered composites

📅 Time Windows

Four analysis windows are computed per zone, comparing a baseline composite against a 2025 endpoint composite:

2-Year (2023–2025)Recent trend; most sensitive to storm-season variability. Best indicator of current acceleration.
5-Year (2020–2025)Medium-term trend; averages out individual storm years. Good baseline for planning.
7-Year (2018–2025)Primary long-term reference. Used for all ft/yr satellite rate calculations shown in zone panels.
8-Year (2017–2025)Uses the earliest reliable Sentinel-2 imagery. Some tidal-flat zones show artifacts — see note below.

⚠️ 8-Year Artifact Note

Five zones (Bourne, Falmouth, Barnstable, Buzzards Bay, Elizabeth Islands) have their 8-year values suppressed. The 2017 Sentinel-2 baseline for these tidal-flat zones was captured at a different tidal state than the 2025 endpoint composite, causing apparent land loss of 2.6–11× the 7-year rate. This is a data artifact, not a real erosion event. The 7-year rate is the recommended figure for these zones.

📐 Rate Conversion (m² → ft/yr)

Converting satellite area loss to linear shoreline retreat (ft/yr) requires dividing by the effective shoreline length. Each zone uses a calibrated shorelineKm value, tuned so the 7-year satellite rate matches published USGS survey rates for that coastal type.

For tidal-flat zones where a reliable shoreline length cannot be defined (Barnstable, Dennis & Brewster), rates are reported as ac/yr only.

ft/yr = (annual m²/yr ÷ shoreline m) × 3.28084

🔴 Risk Classification

High RiskSurvey erosion rate >3 ft/yr, and/or active barrier breach risk, cliff failure, or culturally significant land loss.
Medium RiskSurvey rate 1–3 ft/yr with measurable trend. Sea level inundation likely by 2050 for low-lying areas.
Low RiskSurvey rate <1 ft/yr with stable or improving habitat. May still face secondary threats (water quality, N-loading).

📡 Live & Reference Data Sources

NOAA CO-OPSLive water temperature and sea level anomaly via Woods Hole tide gauge (Station 8447930). Updated in real time on page load.
ESA Sentinel-210m multispectral imagery via Google Earth Engine. Analysis last run: 2025. Re-run GEE v3 script to update.
USGS CoSMONational Shoreline Change Database. Source of historical survey erosion rates (ft/yr) used in each zone panel.
NOAA SLR Scenarios2022 Interagency Sea Level Rise Technical Report. Low / Intermediate / High projections through 2100.
MassGIS / MassBaysProtected land boundaries, habitat classifications, and ecosystem status data for Cape & Islands.

📋 Citing This Dashboard

Cape and Islands Conservation Dashboard (2025). Coastal erosion and habitat monitoring for Martha's Vineyard, Nantucket, and Cape Cod. Satellite analysis: ESA Sentinel-2 via Google Earth Engine. Live ocean data: NOAA CO-OPS Station 8447930 (Woods Hole, MA). Survey rates: USGS National Shoreline Change Database.