The official website of the Gulf Coast Ecosystem Restoration Council

OSAT-2: Fate and effects of oil on beaches

The OSAT-2 report provides a Net Environmental Benefit Analysis comparing environmental and human health risks of this remnant oil compared to the environmental risks of pursuing further, more aggressive, cleanup efforts.

The purpose of this report is to provide the Federal On-Scene Coordinator (FOSC) for the Deepwater Horizon MC252 Spill of National Significance with a risk-based Net Environmental Benefits Analysis (NEBA) associated with removing remnant oil from the near shore, surf zone, and shoreline sandy beach areas. 

This report was produced by primarily relying on data collected along the shoreline prior to the OSAT-2 effort. These data, however, were supplemented with laboratory and modeling information and certain supplemental data acquired during the course of the study. While no single source of information used by OSAT is conclusive, the multiple lines of evidence obtained informed the conclusions.

Click here to download the Final OSAT-2 Report (PDF)

The annexes are the informational background and data that support the OSAT-2 Report.  Annexes were prepared by members of the OSAT-2 Team.

Click here to download OSAT-2 Annex A - Charter 

Click here to download OSAT-2 Annex B - Spatial Oil Distribution

Click here to download OSAT-2 Annex C - Weathering and Depletion

Click here to download OSAT-2 Annex D - SEAM3D

Click here to download OSAT-2 Annex E - BIOMARUN

Click here to download OSAT-2 Annex F -  Human Health

Click here to download OSAT-2 Annex G - Ecological Framework

Click here to download OSAT-2 Annex H - Sea Turtles

Click here to download OSAT-2 Annex I - Water Birds

Click here to download OSAT-2 Annex J - Terrestrial Mammals

Click here to download OSAT-2 Annex K - Aquatic Toxicity

Click here to download OSAT-2 Annex L - Miscellaneous Receptors

Click here to download OSAT-2 Annex M- NEBA

BIOMARUN Oil Degredation Study Data

Contains Supratidal Buried Oil sample results that were used to support the modeling.  Please refer to the BIOMARUN Annex for assumptions made and a full description of environmental variables that were used in the model. Contains chemistry results including PAH, SHC and biomarker concentrations, Method Detection Limits (MDL), Reporting Limits (RL).

Click here for Oil Degradation Study Sites

PAH In Nearshore Sediment

Contains sediment sample results that were used to evaluate the potential risks to plant resources.  The simple sums for alkyl PAHs detected in nearshore sediment was used to depict the  total PAH concentrations above thresholds for plants in relation to where tar mats or re-oiled beaches were observed.  This dataset was used to support the Miscellaneous Annex.

Sums PAHS Sed Scribe

Water Accommodated Fraction (WAF) Data

Contains sampling analysis results for Small Surface Residue Balls (SSRB), Surf Zone Subsurface Oil Mats (SOM), Supratidal Buried Oil (SBO) that were partitioned and analyzed using the Water Attenuated Fraction (WAF) analysis method. This data set also contains the parent material sampling results that were analyzed using chemical analysis methods.  This data was used to support the section entitled “Aquatic Invertebrates and Fish” and the associated Aquatic Toxicity analyses. The data attached contains chemistry results including PAH, SHC and biomarker concentrations, Method Detection Limits (MDL), Reporting Limits (RL).

 The parent material results included in this dataset have been separated out and a description of how this data was used is in other analyses is explained in the description below.

Water Accomodated Fraction Sample Results

Click here for WAF Collection Plan

Parent Material Data

Contains Small Surface Residue Balls (SSRB), Surf Zone Subsurface Oil Mats (SOM), Supratidal Buried Oil (SBO) sample results.  This data represents the parent material that was used in the WAF analysis, to support the sections entitled Oil Remaining on Sandy Beaches, Weathering and Depletion of Oil, Ecological Framework and Terrestrial Mammals.  Contains chemistry results including PAH, SHC and biomarker concentrations, Method Detection Limits (MDL), Reporting Limits (RL).

Click here for Parent Material Data

Weathered Oil Data

Contains sampling for Surf Zone Subsurface Oil Mats (SOM) and Supratidal Buried Oil (SBO) used to support the Human Health and Sea Turtle analysis in the OSAT 2 report.  The data attached contains chemistry results including polycyclic aromatic hydrocarbon (PAH), saturated hydrocarbon (SHC), and biomarker (sterane and triterpane) concentrations, Method Detection Limits (MDL), Reporting Limits (RL).

Click for Weathered Oil Data Sheet

Geoplatform - Mapping

Geoplatform provides a geospatial representation of the data used in the OSAT-2 report.  Along with the mapping, attached to the layer are other types of media including photos, report maps and spreadsheets for chemistry data used to support the analyses.  The name of the links below correspond to the analyses and the data sets that were used for each.

OSAT 2 - Aquatic Invertebrates and Fish 

OSAT 2 - Areas of Interest 

OSAT 2 - BIOMARUN Degradation Model

OSAT 2 - Chemistry Data

OSAT 2 - Habitat: Bon Secour

OSAT 2 - Habitat: Fort Pickens

OSAT 2 - Habitat: Grand Isle

OSAT 2 - Habitat: Petit Bois

OSAT 2 - Human Health – Exposure

OSAT 2 - Human Health - Risk Assessment

OSAT 2 - Human Health – Swimming

OSAT 2 - Mammals (Beach Mouse) – Consumption

 OSAT 2 - Mammals (Beach Mouse) - Exposure

 OSAT 2 - Sea Turtles

 OSAT 2 - Water Birds

Click here to view the OSAT-2 press release

Go to Subsurface Oil Monitoring Overview