Environmental Sensitivity Index Guidelines Version 4.0

U.S. Department of Commerce National Oceanic and Atmospheric Administration (NOAA) National Ocean Service - Office of Response and Restoration Emergency Response Division Technical Memorandum NOS OR&R 52 April 2019

Environmental Sensitivity Index Guidelines Version 4.0

April 2019

Jill Petersen1, David (Moe) Nelson2, Tim Marcella3, Jacqueline Michel4, Meagan Atkinson3, Mark White4, Chris Boring4, Lauren Szathmary4, Jennifer Horsman4, Jennifer Weaver4

1 National Oceanic and Atmospheric Administration, Office of Response and Restoration, Emergency Response Division, Seattle, WA

2 National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Marine Spatial Ecology Division, Silver Spring, MD

3 Quantum Spatial, Inc., Corvallis, OR 4 Research Planning, Inc., Columbia SC

The suggested citation for this document is:

Petersen, J., et al. 2019. Environmental Sensitivity Index Guidelines, Version 4.0. NOAA Technical Memorandum NOS OR&R 52.

NOAA’s Office of Response and Restoration

NOAA’s Office of Response and Restoration (OR&R) is a center of expertise in preparing for, evaluating, and responding to threats to coastal environments, including oil and chemical spills, releases from hazardous waste sites, and marine debris. To fulfill its mission of protecting and restoring NOAA trust resources, the Office of Response and Restoration:

• Provides scientific and technical support to prepare for and respond to oil and chemical releases.

• Determines damage to natural resources from these releases.

• Protects and restores marine and coastal ecosystems, including coral reefs.

• Works with communities to address critical local regional coastal challenges.

• OR&R is comprised of four divisions: Emergency Response, Assessment and Restoration, Marine Debris

Program, and the Disaster Preparedness Program.

• Collectively, the Office of Response and Restoration provides comprehensive solutions to environmental hazards caused by oil, chemicals, and marine debris.

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Chapter 1 – Introduction to Environmental Sensitivity Index Mapping

1.1 Introduction to Environmental Sensitivity Index (ESI) Maps and Data

1.2 Background

1.3 The need for Standardization

1.4 Guide Outline

Chapter 2 - Fundamentals of the ESI Shoreline Classification System

2.1 Shoreline Classification

Chapter 3 – ESI Shoreline Classification Methodology

3.1 ESI Shoreline Classification

3.1.1 What to Map

3.1.2 ESI Shoreline Data Components

3.1.3 Mapping Projection

3.2 Creating ESI Shoreline Feature Classes

3.2.1 Determining the Regional ESI Area Boundary (AOI)

3.2.2 Creating the ESIL Dataset

3.2.3 Creating the ESIP Dataset

3.2.4 Topology rules for ESIL/ESIP

3.3 Shoreline Classification

3.3.1 Identifying Datasets for Use in Classification

3.3.2 Mapping and Classification Concepts

3.3.3 Common Issues and QA/QC

Chapter 4 – The ESI Biology Component

4.1 Introduction to ESI Biological Resources

4.1.1 Purpose of Biological Resource Mapping in the ESI

4.1.2 Biology Data Components

4.1.3 Biological Attributes and the ESI Data Tables

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4.2 Creating ESI Biological Content

4.2.1 Create a Working Species List

4.2.2 Identifying Partners, Resource Experts, and Relevant Data Sets

4.2.3 Contacting, Engaging, and Meeting with Resource Experts

4.2.4 Data Compilation

4.2.5 Creating ESI Feature Classes

4.2.6 Data Tables – Capturing the When and Why

4.2.7 Data Creation Considerations

Chapter 5 – The ESI Socio-Economic (Human-Use) Component

5.1 Introduction to ESI Socioeconomic Resources

5.1.1 What to map

5.1.2 Human-Use Data Components

5.1.3 Human-Use Attributes and the ESI Data Tables

5.2 Creating ESI Socioeconomic Content

5.2.1 Identifying Relevant Datasets and Resource Experts

5.2.2 Steps to Data Collection

5.2.3 Data Compilation

5.5.4 A Note on Invasive Species

Chapter 6 – Database Compilation & Quality Control Procedures

6.1 Database Compilation & Quality Control Procedures for ESI Data Deliverables to NOAA

6.1.1 Introduction

6.1.2 ESI Database Structure

6.2 Feature Dataset Compilation

6.2.1 Shoreline Compilation

6.2.2 SOCECON Compilation

6.2.3 Biology Compilation

6.3 Minimum Mapping Unit – application to Biological and Human-Use features iii

6.4 Quality Assurance and Quality Control Procedures

6.4.1 Assessing Feature Geometry

6.4.2 Evaluation of Tabular Data Attribution

6.4.3 Generating the Regional ESI Geodatabase and Finalizing Data for Delivery

Chapter 7 – Creating ESI Metadata

7.1 CREATING ESI METADATA

7.1.1 Background

7.1.2 Metadata Standards

7.1.3 Metadata Tools

7.1.4 ESI Metadata Process and NOAA Requirements

7.1.5 ESI Metadata Templates

7.1.6 Metadata References

Appendix A – ESI Biological Elements and Subelements

Appendix B – ESI Data Dictionary

Base Layers ........................................................................................................................ B-3

Biology .............................................................................................................................. B-6

Human-Use ........................................................................................................................ B-8

Political ...................................................................................................................... B-8

Managed .................................................................................................................... B-9

Resource .................................................................................................................. B-10

Natural Hazard ......................................................................................................... B-11

Navigation/Marine ................................................................................................... B-12

Socecon ................................................................................................................... B-13

Data Tables ...................................................................................................................... B-14

Biores ...................................................................................................................... B-14

Sources .................................................................................................................... B-16

Status ...................................................................................................................... B-17

Seasonal .................................................................................................................. B-18

Breed ....................................................................................................................... B-19 iv

Species ..................................................................................................................... B-20

Soc_Dat .................................................................................................................... B-21

Bio_LUT ................................................................................................................... B-23

Soc_LUT ................................................................................................................... B-23

ESI Values, Classification Descriptions, & Crosswalk to Generalized ESI Codes and Descriptions B-24

Qualitative Concentration Attribute Values ............................................................................ B-26

Mapping Qualifiers and Guidelines ......................................................................................... B-27

Human-Use Features – Grouping of Types .............................................................................. B-33

Human-Use Type Explanations ............................................................................................... B-34

Geodatabase Delivery Format ................................................................................................ B-40

Appendix C – Diagram of ESI Data Table Structure

Appendix D – Commonly Referenced Sources For ESI Data

Appendix E – Taxonomic Sources

Appendix F – Previously Published ESI Data

Appendix G – Hard Copy Map Production

ESI Map Production Process and Cartographic Considerations ................................................... G-3

Biological Resources: Filtering and Map Presentation ............................................................... G-6

Explanation of Filter Criteria ..................................................................................................... G-7

Human-use Data: Filtering and Map Presentation ................................................................... G-10

ESI Symbology ....................................................................................................................... G-14

Appendix H – Step by Step Metadata Guide

CHAPTER 1

Introduction to Environmental Sensitivity Index Mapping

1.1 Introduction to Environmental Sensitivity Index (ESI) Maps and Data

Environmental Sensitivity Index (ESI) maps and data provide a concise summary of coastal resources at risk if an oil spill occurs nearby (Figure 1.1). ESI maps are comprised of three types of information:

1. Shoreline Classification – ranked according to a scale relating to sensitivity, natural persistence of oil, and ease of cleanup.

2. Biological Resources – including oil-sensitive animals and rare plants, as well as habitats used by oil-sensitive species or that are themselves sensitive to oil spills, such as submersed aquatic vegetation and coral reefs.

3. Human-Use Resources – specific areas that have added sensitivity and value because of their use (such as beaches, parks and marine sanctuaries, water intakes, and archaeological sites), areas that may be useful in the event of a response (such as boat ramps and access points), jurisdictional boundaries, and resources that may themselves pose a risk.

Figure 1.1: ESI maps and data help responders and planners determine protection priorities

When an oil spill occurs, ESI data can help responders meet one of the main response objectives:

reducing the environmental consequences of the spill and the cleanup efforts. Additionally, ESI data can be used by planners—before a spill happens—to identify vulnerable locations, establish protection priorities, and identify response strategies.

Although the primary audience for ESI maps and data are oil spill planners and responders, the information they contain provides excellent baseline information for a variety of coastal management and planning applications.

1.2 Background

Environmental Sensitivity Index (ESI) maps have been an integral component of oil spill contingency planning and response since 1979, when the first ESI maps were prepared days in advance of the arrival of the oil slicks from the IXTOC 1 well blowout in the Gulf of Mexico. Since that time, ESI data have been compiled for most of the U.S. coast, including Alaska, the Great Lakes, and the U.S.

territories. Appendix F provides a list of ESI atlases and their publication dates.

Before 1989, the typical ESI product was a collection (atlas) of color paper maps, covering a coastal state or region. Because of reproduction costs, these had a limited distribution and were also challenging to update. Since 1989, the ESI data have been compiled using a Geographic Information System (GIS). The digital ESI data serve a broad audience, as they lend themselves well to targeted queries, integration with other regional data sets, and customized products. Despite this, there is still a high demand for the printed and PDF ESI maps, and NOAA continues to support that user community.

The objectives of this guide are to outline the basic elements of a sensitivity mapping system and provide guidance on what and how various components are mapped. Key topics include:

• the role shoreline type plays in the persistence and cleanup of spilled oil

• the ties between shoreline habitats and biological occurrences

• the ESI shoreline classification scheme and how it is applied

• collecting and synthesizing biological resource data

• collecting and synthesizing socio-economic data

• potential sources for biological and socio-economic data

• the data structure for a digital ESI product

• guidance on QA/QC of the ESI data

• standard output formats and symbology to be shown on soft and hard copy maps

• metadata requirements and standards

1.3 The need for Standardization

The spill contingency planning requirements of the Oil Pollution Act of 1990 (OPA 90), and similar legislation passed by many states, require information on the location of sensitive resources to be used as the basis for establishing protection priorities. Digital databases developed to support oil-spill planning and response functions are a subset of those needed for a wide range of natural resource management applications. Standardizing the basic elements for a spill application speeds the development of systems and facilitates their use by national response teams and organizations, such as the U.S. Coast Guard, industry response staff, and spill cooperatives. Data sharing and updates are greatly facilitated by a uniform data structure.

1.4 Guide Outline

This guide is intended primarily for developers of ESI data, whether as a contractor to NOAA, or independently for a state, region, country, or industry. It is divided into seven chapters, with several supporting appendices as listed below.

• Chapter 1 - Introduction to Environmental Sensitivity Index mapping

• Chapter 2 – Fundamentals of the ESI Shoreline Classification System

• Chapter 3 – ESI Shoreline Classification Methodology

• Chapter 4 – The ESI Biology Component: Steps to Collecting, Creating, and Compiling Biological Data and the ESI Biological Data Table Structure and Content

• Chapter 5 – The ESI Socioeconomic (Human-Use) Component: Steps to Collecting, Creating, and Compiling Socioeconomic Data and the ESI Socioeconomic Data Table Structure and Content

• Chapter 6 – Database Compilation & Quality Control Procedures for ESI Data Deliverables to

NOAA

• Chapter 7 – Creating ESI Metadata

• Appendices:

- A: ESI Biological Elements and Subelements

- B: The ESI Data Dictionary: ESI Data Tables, Field Names, Descriptions, and Attribute Values

- C: Diagram of ESI Data Table Structure and Associated Relationships

- D: Commonly Referenced Sources for ESI Data

- E: Taxonomic Sources for Common and Scientific Species Names

- F: Previously Published ESI Data with Publication Date(s) and Atlas Numbers

- G: Hard Copy Map Production: Data Filtering, Presentation, and Symbology

- H: Step by Step Metadata Guide

CHAPTER 2

Fundamentals of the ESI Shoreline Classification System

2.1 Shoreline Classification

Shoreline habitats are at risk during spills because of the high likelihood of being directly oiled when floating slicks impact the shoreline. Oil fate and effects vary significantly by shoreline type, and many cleanup methods are shoreline-specific. The concept of mapping coastal environments and ranking them on a scale of relative sensitivity was originated in 1976 for Lower Cook Inlet (Michel et al. 1978).

Since that time, the ranking system has been refined and expanded to cover shoreline types throughout the world. The classification scheme has also been modified to include lacustrine and riverine shoreline types (NOAA 1995). The complete list of standard ESI shoreline rankings is composed of categories for four environmental settings: estuarine, lacustrine, riverine, and palustrine. To facilitate data use and exchange, these shoreline types and associated ranks should be used on all sensitivity mapping projects (See Figure 2.1). The environmental settings are applied as follows:

• Estuarine: Shorelines adjacent to marine and coastal waters affected by tides

• Lacustrine: Shorelines along large lakes

• Riverine: Shorelines along large freshwater rivers

• Palustrine: Shorelines along small freshwater lakes (only applied to wetlands, ESI = 10)

The classification scheme is based on an understanding of the physical and biological character of the shoreline environment, not just the substrate type and grain size. Relationships among physical processes, substrate type, and associated biota produce specific geomorphic/ecologic shoreline types, sediment transport patterns, and predictable patterns in oil behavior and biological impact. The concepts relating natural factors to the relative sensitivity of coastline, mostly developed in the estuarine setting, were slightly modified for lakes and rivers. The sensitivity ranking is controlled by the following factors:

1. Relative exposure to wave and tidal energy

2. Shoreline slope

3. Substrate type (grain size, mobility, penetration and/or burial, and trafficability)

4. Biological productivity and sensitivity

All of these factors and first-hand observations from spills were considered when developing the relative ESI rankings for shoreline types. Each of the natural factors is discussed in detail below.

2.1.1 Relative Degree of Exposure to Wave and Tidal Energy

Biologists have long recognized that the makeup of intertidal biological communities is closely correlated with relative degree of exposure. In Between Pacific Tides, Rickets et al. (1968) classified the coastal habitats of the central California coast as exposed and sheltered, differentiating between settings subject to intense pounding by the large waves on that coast and those sheltered by offshore rocks, barrier beaches, and other protective features. Early geomorphology studies at the Metula, Urquiola, and Amoco Cadiz oil spills showed that the level of impacts of oil spills is closely related to the relative degree of exposure of the impacted habitat (Hayes and Gundlach 1975; Gundlach and Hayes 1978; Gundlach et al. 1978; Michel et al. 1978).

ESI Code Environment Code Shoreline Classification Description 1A E/L 1A: Exposed, Rocky Shores 1A R 1A: Exposed, Rocky Banks 1B E/L/R 1B: Exposed, Solid Man-Made Structures 1C E/L/R 1C: Exposed, Rocky Cliffs w/Boulder Talus Base 2A E 2A: Exposed, Wave-Cut Platforms (Bedrock/Mud/Clay) 2A L 2A: Shelving Bedrock Shores 2A R 2A: Rocky Shoals and Bedrock Ledges 2B E 2B: Exposed Scarps and Steep Slopes (Clay) 3A E 3A: Fine to Medium Grained Sand Beaches 3B E 3B: Scarps and Steep Slopes (Sand) 3B L 3B: Eroding Scarps (Unconsolidated Sediment) 3B R 3B: Exposed, Eroding Banks (Unconsolidated Sediment) 3C E 3C: Tundra Cliffs 4 E 4: Coarse Grained Sand Beaches 4 L 4: Sand Beaches 4 R 4: Sand Bars and Gently Sloping Banks 5 E/L 5: Mixed Sand and Gravel Beaches 5 R 5: Mixed Sand and Gravel Bars and Gently Sloping Banks

6A E/L 6A: Gravel Beaches 6A E 6A: Gravel Beaches (Granules/Pebbles) – used in Alaska 6A R 6A: Gravel Bars and Gently Sloping Banks 6B E/L/R 6B: Riprap 6B E 6B: Gravel Beaches (Cobbles/Boulders) – used in Alaska 6D E 6D: Boulder Rubble 7 E/L 7: Exposed Tidal Flats

8A E/L 8A: Sheltered Scarps (Bedrock/Mud/Clay) 8A E 8A: Sheltered, Impermeable, Rocky Shores 8B E/L/R 8B: Sheltered, Solid Man-Made Structures 8B E 8B: Sheltered, Permeable, Rocky Shores 8C E/L/R 8C: Sheltered Riprap 8D E 8D: Sheltered, Rocky Rubble Shores 8E E 8E: Peat Shorelines 8F R 8F: Vegetated, Steeply Sloping Bluffs 9A E 9A: Sheltered Tidal Flats 9A L 9A: Sheltered Sand and Mud Flats 9B E/L/R 9B: Vegetated Low Banks 9C E 9C: Hyper-Saline Tidal Flats

10A E 10A: Salt and Brackish Water Marshes 10B E/L/P/R 10B: Freshwater Marshes 10C E/L/P/R 10C: Swamps 10D E/L/P/R 10D: Scrub and Shrub Wetlands 10E E 10E: Inundated Low Lying Tundra 10F E 10F: Mangroves

Figure 2.1: ESI Shoreline Classification

Environment code: E = estuarine, L = lacustrine, R = riverine, P = palustrine

Two physical factors, wave-energy flux and tidal-energy flux, primarily determine the degree of exposure, also referred to as the hydrodynamic energy level, at the coastline. Wave-energy flux is basically a function of the average wave height, measured over at least one year. Where waves are typically large (e.g., heights more than one meter [m] occur frequently), the impact of oil spills on the exposed habitats is reduced because: 1) offshore-directed currents generated by waves reflecting off hard surfaces push the oil away from the shore; 2) wave-generated currents mix and rework coastal sediments, which are typically coarse-grained in these settings, rapidly removing stranded oil; and 3) organisms adapted to living in such a setting are accustomed to short-term perturbations in the environment.

Tidal-energy flux is also important in determining the potential of oil-spill impacts on coastal habitats, although not as pervasive as wave-energy flux. The most important considerations are the potential for strong tidal currents to remove stranded oil and to build and move intertidal sand and/or gravel bars that can bury oil. The effect of the currents on biological communities can also be pronounced. For example, highly mobile substrates set in motion by strong tidal currents typically harbor considerably fewer infauna than stable substrates. Tidal currents generally increase as tidal range increases.

Wave and tidal energy combine to produce a continuum of energy along a coastline. For the sake of portrayal on a map, this continuum must be broken into classes, clear-cut divisions of high, mixed, or low energy. Within a mapping region, the degree of energy present on one shoreline segment is assessed relative to the overall energy levels in the region. High-energy shorelines (1A-2B) are regularly exposed to large waves or strong tidal currents during all seasons. They most commonly occur along the outermost coastline of a region or where dominant winds cause waves to strike the shoreline directly or by wave refraction. Mixed-energy shorelines (3A-7) often have seasonal patterns in storm frequency and wave size. Low-energy shorelines (8A-10F) are sheltered from wave and tidal energy, except during unusual or infrequent events. As a general rule, high- and mixed-energy shorelines should not be mapped adjacent to low-energy shorelines unless there is a significant change in shoreline orientation or there is some offshore obstruction to wave energy.

Inherent in these energy classes are inferences to the persistence of stranded oil. High energy means rapid natural removal, usually within days to weeks. Low energy means slow, natural removal, usually within years. Mixed energy means that stranded oil will be removed when the next high-energy event occurs, which could be days or months after the spill. The removal of oil on a mixed-energy coast is an event-driven process. Shorelines that do not have predictable, seasonal storms that generate waves of a significant size or from a particular direction are even more difficult to characterize. Along these shorelines, high-energy events usually happen more than once each year but their timing is generally unknown. A shoreline of this type has the potential for longer-than-usual oil persistence. This type of shoreline has storm berms with one to three years of vegetation growth and greater macroalgae coverage on the larger boulders in the intertidal zone than would be seen on a beach exposed to more frequent storms. Efforts should be made to differentiate beaches with irregular patterns in sediment mobility, particularly for gravel beaches.

Rank of 1: Exposed, Impermeable Vertical Substrates

The essential elements are:

- Regular exposure to high wave energy or tidal currents.

- Strong wave-reflection patterns are common.

- Slope of the intertidal zone is 30 degrees or greater, resulting in a narrow intertidal zone.

- By the nature of the high-energy setting, attached organisms are hardy and accustomed to high hydraulic impacts and pressures.

Shoreline types that meet these elements include:

1A = Exposed, Rocky Shores; (estuarine and lacustrine: Figure 2.2)

1A = Exposed, Rocky Banks; (riverine)

1B = Exposed, Solid Man-Made Structures; (estuarine, lacustrine, and riverine: Figure 2.3)

Exposed, Rocky Cliffs with Boulder Talus Base; (estuarine, lacustrine, and riverine:

Figure 2.4)

1C =

These shoreline types are exposed to large waves, which tend to keep oil offshore by reflecting waves.

The substrate is impermeable so oil remains on the surface where natural processes will quickly remove any oil that does strand within a few weeks. Also, any stranded oil tends to form a band along the high-tide line or splash zone, above the elevation of the greatest biological value. No cleanup is generally required or recommended.

Figure 2.2: Exposed, Rocky Shores with ESI rank of 1A.

- Substrate is impermeable (usually bedrock or cement) with no potential for subsurface penetration.

Figure 2.3: Exposed, Solid Man-Made Structures with ESI rank of 1B.

Figure 2.4: Exposed, Rocky Cliffs with Boulder Talus Base with ESI rank of 1C.

Rank of 2: Exposed, Impermeable Substrates, Non-Vertical

The essential elements are:

- Regular exposure to high wave energy or tidal currents.

- Regular strong wave-reflection patterns.

- Substrate is impermeable with no potential for subsurface penetration over much of the intertidal zone, although there can be a thin, mobile veneer of sediment in patches on the surface.

- Slope of the intertidal zone is usually less than 30 degrees, resulting in a wider intertidal zone;

it can be less than five degrees and the intertidal zone can be up to hundreds of meters wide.

- Sediments can accumulate at the base of bedrock cliffs, but are regularly mobilized by storm waves.

- By the nature of the setting, attached organisms are hardy and used to high hydraulic impacts and pressures.

Shoreline types that meet these elements include:

2A = Exposed, Wave-Cut Platforms (Bedrock/Mud/Clay); (estuarine: Figure 2.5)

2A = Shelving Bedrock Shores; (lacustrine: Figure 2.6)

2A = Rocky Shoals and Bedrock Ledges; (riverine)

2B = Exposed Scarps and Steep Slopes (Clay); (estuarine)

As with ESI = 1, these shorelines rank low because they are exposed to high wave energy. However, they have a flatter intertidal zone, sometimes with small accumulations of sediment at the high-tide line, where oil could persist for several weeks to months. When the sediments have been formed into a beach on a rocky platform that has multiple wave-built berms, the ESI classification designates the beach as an additional shoreline type, for example 6A/2A.

Along coastal plain areas, the equivalent shoreline type consists of scarps in relict marsh clay. Biological impacts can be immediate and severe, particularly if fresh oil slicks cover tidal pool communities on rocky platforms. However, the oil is usually removed quickly from the platform by wave action. Cleanup is not necessary except for removing oiled debris and oil deposits at the high-tide line, in areas of high recreational use, or to protect a nearshore resource, such as bird nesting or concentration areas.

Figure 2.5: Exposed, Wave-Cut Platforms (Bedrock/Mud/Clay) with ESI rank of 2A.

Figure 2.6: Shelving Bedrock Shores associated with lake environments with ESI rank of 2A.

Rank of 3: Semi-Permeable Substrate, Lower Potential for Oil Penetration and Burial;

infauna present but not usually abundant

The essential elements are:

- The substrate is semi-permeable (fine- to medium-grained sand) with oil penetration usually less than ten cm.

- Sediments are well-sorted and compacted (hard).

- On beaches, the slope is very low, less than five degrees.

- The rate of sediment mobility is low, so the potential for rapid burial is lower.

- Surface sediments are subject to regular reworking by waves and currents.

- There are relatively low densities of infauna.

Shoreline types that meet these elements include:

3A = Fine- to Medium-Grained Sand Beaches; (estuarine: Figure 2.7)

3B = Scarps and Steep Slopes (Sand); (estuarine: Figure 2.8)

3B = Eroding Scarps (Unconsolidated Sediment); (lacustrine: Figure 2.9)

3B = Exposed, Eroding Banks (Unconsolidated Sediment); (riverine: Figure 2.10)

3C = Tundra Cliffs; (estuarine: Figure 2.11)

This shoreline rank includes exposed sand beaches on outer shores, sheltered sand beaches along bays and lagoons, and sandy scarps and banks along lake and river shores. Compact, fine-grained sand substrates minimize oil penetration, reducing the amount of oiled sediments to be removed.

Furthermore, fine-grained sand beaches generally accrete slowly between storms, reducing the potential for burial of oil by clean sand. On sheltered sand beaches, burial is seldom of concern because of the low wave energy. On exposed beaches, oil may be buried deeply if the oil stranded right after an erosional storm or at the beginning of a seasonal accretionary period. Cleanup on fine-grained sand beaches is simplified by the hard substrate that can support vehicular and foot traffic. Infaunal densities vary significantly both spatially and temporally.

Figure 2.7: Fine- to Medium-Grained Sand Beach with ESI rank of 3A.

Figure 2.8: Scarps and Steep Slopes (Sand) with ESI rank of 3B.

Figure 2.9: Eroding Scarps (Unconsolidated Sediment) associated with lacustrine environments with ESI rank of

3B.

Figure 2.10: Exposed, Eroding Banks (Unconsolidated Sediment) in riverine environments with ESI rank of 3B.

Figure 2.11: Tundra Cliffs with ESI rank of 3C.

Rank of 4: Medium Permeability, Moderate Potential for Oil Penetration and Burial;

infauna present but not usually abundant

The essential elements are:

- The substrate is permeable (coarse-grained sand), with oil penetration up to 25 cm possible.

- The slope is intermediate, between 5 and 15 degrees.

- Rate of sediment mobility is relatively high, with accumulation of up to 20 cm of sediments within a single tidal cycle possible; there is a potential for rapid burial and erosion of oil.

- Sediments are soft, with low trafficability.

- There are relatively low densities of infauna.

Shoreline types that meet these elements include:

4 = Coarse-Grained Sand Beaches; (estuarine: Figure 2.12)

4 = Sand Beaches; (lacustrine)

4 = Sand Bars and Gently Sloping Banks; (riverine: Figure 2.13)

Figure 2.12: Coarse-Grained Sand Beaches with ESI rank of 4.

Coarse-grained sand beaches are ranked separately and higher than fine- to medium- grained sand beaches because of the potential for higher oil penetration and burial, which can be as great as 1 m.

These beaches can undergo very rapid erosional and depositional cycles, with the potential for rapid burial of oil, even after only one tidal cycle. Cleanup is more difficult, as equipment tends to grind oil into the substrate because of the loosely packed sediment. Also, cleanup techniques often have to deal with multiple layers of oiled and clean sediments, increasing the amount of sediments to be handled and disposed of. These more mobile sediments usually have low infaunal populations, which also vary greatly over time and space. In some areas, there is no clear distinction between sand beach types because they cannot be readily differentiated by grain size. Under these conditions, such as along the Great Lakes, all sand beaches are ranked as ESI = 4.

Figure 2.13: Sand Bars and Gently Sloping Banks in riverine environment with ESI rank of 4.

Rank of 5: Medium-to-High Permeability, High Potential for Oil Penetration and Burial;

infauna present but not usually abundant

The essential elements are:

- Medium-to-high permeability of the substrate (mixed sand and gravel) allows oil penetration up to 50 cm.

- Spatial variations in the distribution of grain sizes are significant, with finer-grained sediments (sand to pebbles) at the high-tide line and coarser sediments (cobbles to boulders) in the storm berm and at the toe of the beach.

- The gravel component should comprise at least 20 percent of the sediments.

- The slope is intermediate, between 8 and 15 degrees.

- Sediment mobility is very high only during storms, thus there is a potential for rapid burial and erosion of oil during storms.

- Sediments are soft, with low trafficability.

- Infauna and epifauna populations are low, except at the lowest intertidal levels.

Shoreline types that meet these elements include:

5 = Mixed Sand and Gravel Beaches; (estuarine and lacustrine: Figure 2.14)

5 = Mixed Sand and Gravel Bars and Gently Sloping Banks; (riverine: Figure 2.15)

The gravel-sized component can be composed of bedrock, shell fragments, or coral rubble. Because of higher permeability, oil tends to penetrate deeply into sand and gravel beaches, making it difficult to remove contaminated sediment without causing erosion and waste disposal problems. These beaches may undergo seasonal variations in wave energy and sediment reworking, so natural removal of deeply penetrated oil may only occur during storms that occur just once or twice per year. Biological use is low, because of high sediment mobility and rapid drying during low tide.

These types of beaches range widely in relative degree of exposure. Sediment mobility can be inferred by the extent of attached fauna and macroalgae. Indicator species or assemblage coverages can be used to reflect the potential rate of sediment reworking. For example, in southeastern Alaska, the presence of greater than 20 percent attached algae, mussels, and barnacles indicates beaches that are relatively sheltered, with the more stable substrate supporting a richer biota. Pocket beaches, in particular, can have microenvironments that are more protected from wave energy (called wave shadows) where natural removal may be much slower than the adjacent beach.

Figure 2.14: Mixed Sand and Gravel Beaches with ESI rank of 5.

Figure 2.15: Mixed Sand and Gravel Bars and Gently Sloping Banks in riverine environment with ESI rank of 5.

Rank of 6: High Permeability, High Potential for Oil Penetration and Burial

The essential elements are:

- The substrate is highly permeable (gravel-sized sediments), with penetration possible up to 100 cm.

- The slope is intermediate to steep, between 10 and 20 degrees.

- Rapid burial and erosion of shallow oil can occur during storms.

- There is high annual variability in degree of exposure, and thus in the frequency of mobilization by waves.

- Penetration can extend to depths below those of annual reworking.

- Sediments have lowest trafficability of all beaches.

- Natural replenishment rate of sediments is the slowest of all beaches.

- Infauna and epifauna populations are low, except at the lowest intertidal levels.

Shoreline types that meet these elements include:

6A = Gravel Beaches; (estuarine and lacustrine: Figure 2.16)

6A = Gravel Bars and Gently Sloping Banks; (riverine: Figure 2.17)

6A = Gravel Beaches (Granules/Pebbles); (estuarine; Southeast Alaska only)

6B = Riprap; (estuarine, lacustrine, and riverine: Figure 2.18)

6B = Gravel Beaches (Cobbles/Boulders); (estuarine; Southeast Alaska only)

6D = Boulder Rubble; (estuarine)

Gravel beaches are ranked the highest of all beaches primarily because of the potential for very deep oil penetration and slow natural removal rates of subsurface oil. The slow replenishment rate of gravel makes removal of oiled sediment highly undesirable, thus cleanup of heavily oiled gravel beaches is particularly difficult. For many gravel beaches, significant wave action (meaning waves large enough to rework the sediments to the depth of oil penetration) occurs only every few years, leading to long-term persistence of subsurface oil. Shell fragments can be the equivalent of gravel along Gulf of Mexico and South Atlantic beaches.

Fine-grained gravel beaches are composed primarily of pebbles and cobbles (from 4 to 256 mm), with boulders as a minor fraction. Little sand is evident on the surface, and there is less than 20 percent sand in the subsurface. There can be zones of pure pebbles or cobbles, with the pebbles forming berms at the high-tide line and the cobbles and boulders dominating the lower beach face. Sediment mobility limits the amounts of attached algae, barnacles, and mussels to low levels. The distinction can also be made on the basis of grain size and extent of rounding of the sediments on a shoreline. The gravel is rounded or well-rounded only on those beaches regularly mobilized during storms.

Coarse-grained gravel beaches have boulders dominating the lower intertidal zone. The amounts of attached algae and epifauna are much higher, reflecting the stability of the large sediments. A boulder-and-cobble armoring of the surface of the middle to lower intertidal zone is common on these beaches. Armor may have a very important effect on oil persistence in gravel beaches. Oil beneath an armored surface would tend to remain longer than would subsurface oil on an unarmored beach with similar grain size and wave conditions because of the higher velocities required to mobilize the armor (Hayes et al. 2010). Sub-rounded to sub-angular gravel is a very good indicator of these less mobile beaches.

Riprap is a man-made equivalent of this ESI class, with added problems because it is usually placed at the high-tide line where the highest oil concentrations are found and the riprap boulders are sized so that they are not reworked by storm waves. Flushing can be effective for removing mobile oil, but large amounts of residue can remain after flushing, particularly for heavy oils. Sometimes, the only way to clean riprap completely is to remove and replace it.

Figure 2.16: Gravel Beaches with ESI rank of 6A.

Figure 2.17: Gravel Bars and Gently Sloping Banks in riverine environment with ESI rank of 6A.

Figure 2.18: Riprap with ESI rank of 6B.

Rank of 7: High Permeability, High Potential for Oil Penetration and Burial

The essential elements are:

- They are flat (less than three degrees) accumulations of sediment.

- The highly permeable substrate is dominated by sand, although there may be silt and gravel components.

- Sediments are water-saturated so oil penetration is very limited.

- Exposure to wave or tidal-current energy is evidenced by ripples in sand, scour marks around gravel, or presence of sand ridges or bars.

- Width can vary from a few meters to nearly one kilometer.

- Sediments are soft, with low trafficability.

- Infaunal densities are usually very high.

Shoreline types that meet these elements include:

7 = Exposed tidal flats; (estuarine and lacustrine: Figure 2.19)

Exposed tidal flats commonly occur with other shoreline types, usually marshes, on the landward edge of the flat. They can occur as offshore tidal flats separate from the shoreline, particularly at tidal inlets and in tidal rivers.

Oil does not readily adhere to or penetrate the compact, water-saturated sediments of exposed sand flats. Instead, the oil is pushed across the surface and accumulates at the high-tide line. Even when large slicks spread over the tidal flat at low tide, the tidal currents associated with the next rising tide pick up the oil and move it alongshore. However, oil can penetrate the tops of sand bars and burrows if they dry out at low tide. Because of the high biological use, impacts can be significant to benthic invertebrates exposed to the water-accommodated fraction or smothered. Cleanup is always difficult because of the potential for mixing the oil deeper into the sediment, especially with foot traffic.

Figure 2.19: Exposed Tidal Flats with ESI rank of 7.

Rank of 8: Sheltered Impermeable Substrate, Epibiota Usually Abundant

The essential elements are:

- They are sheltered from wave energy or strong tidal currents.

- Substrate is hard, composed of bedrock, man-made materials, or stiff clay; also includes peat shorelines.

- The type of bedrock can be highly variable, from smooth, vertical bedrock, to rubble slopes, which vary in permeability to oil.

- Slope in bedrock is generally steep (greater than 15 degrees), resulting in a narrow intertidal zone.

- There is usually a very high coverage of attached algae and organisms on hard substrates.

Shoreline types that meet these elements include:

8A = Sheltered Scarps (Bedrock/Mud/Clay); (estuarine and lacustrine: Figures 2.20, 2.21)

8A = Sheltered, Impermeable, Rocky Shores; (estuarine; Southeast Alaska only)

8B = Sheltered, Solid Man-Made Structures; (estuarine, lacustrine, and riverine:

Figure 2.22)

8B = Sheltered, Permeable, Rocky Shores; (estuarine; Southeast Alaska only)

8C = Sheltered Riprap; (estuarine, lacustrine, and riverine: Figure 2.23)

8D = Sheltered, Rocky Rubble Shores; (estuarine: Figure 2.24)

8E = Peat Shorelines; (estuarine: Figure 2.25)

8F = Vegetated, Steeply Sloping Bluffs; (riverine: Figure 2.26)

Oil tends to coat rough rock surfaces in sheltered settings, and oil persists long-term because of the low-energy setting. Where appropriate, mapping should differentiate between solid rock surfaces, which are impermeable to oil, and rocky rubble slopes, which tend to trap oil beneath a veneer of coarse material. Both types can have large amounts of attached organisms, supporting a rich and diverse community. Cleanup is often required because natural removal rates are slow, yet cleanup is often difficult and intrusive. Sheltered seawalls and riprap are the man-made equivalents, with similar oil behavior and persistence patterns. Usually, more intrusive cleanup is necessary for aesthetic reasons. In riverine settings, terrestrial vegetation along the river bluff indicates low energy and thus slow natural removal rates. Peat shorelines include peat scarps, eroded peat, and peat slurries; this shoreline type is most common along the Bering Sea.

Figure 2.20: Sheltered Scarps (Bedrock/Mud/Clay) with ESI rank of 8A.

Figure 2.21: Sheltered Scarps (Bedrock/Mud/Clay) in lacustrine environment with ESI rank of 8A.

Figure 2.22: Sheltered, Solid Man-Made Structures with ESI rank of 8B.

Figure 2.23: Sheltered Riprap with ESI rank of 8C.

Figure 2.24: Sheltered, Rocky Rubble Shores with ESI rank of 8D.

Figure 2.25: Peat Shorelines with ESI rank of 8E.

Figure 2.26: Vegetated, Steeply Sloping Bluffs in riverine environment with ESI rank of 8F.

Rank of 9: Sheltered, Flat, Semi-Permeable Substrate, Soft; infauna usually abundant

The essential elements are:

- They are sheltered from exposure to wave energy or strong tidal currents.

- The substrate is flat (less than three degrees) and dominated by mud.

- The sediments are water-saturated, so permeability is very low, except where animal burrows are present.

- Width can vary from a few meters to nearly one kilometer.

- Sediments are soft, with low trafficability.

- Infaunal densities are usually very high.

Shoreline types that meet these elements include:

9A = Sheltered Tidal Flats; (estuarine: Figure 2.27)

9A = Sheltered Sand and Mud Flats; (lacustrine: Figure 2.28)

9B = Vegetated Low Banks; (estuarine, lacustrine, and riverine: Figure 2.29)

9C = Hyper-Saline Tidal Flats; (estuarine: Figure 2.30)

The soft substrate and limited access makes sheltered tidal flats almost impossible to clean. Usually, any cleanup efforts mix oil deeper into the sediments, prolonging recovery. Once oil reaches these habitats, natural removal rates are very slow. They can be important feeding areas for birds and rearing areas for fish, making them highly sensitive to oil-spill impacts. In areas without a significant tidal range, such as the Great Lakes, sheltered flats are created by less-frequent variations in water level. These flats are unique in that low-water conditions can persist for weeks to months, providing a mechanism for sediment contamination in areas that can be subsequently flooded. Low riverine banks are often muddy, soft, and vegetated, making them extremely difficult to clean. Natural removal rates could be very slow, and depend on flooding frequency.

Figure 2.27: Sheltered Tidal Flats with ESI rank of 9A.

Figure 2.28: Sheltered Sand and Mud Flats in lacustrine environment with ESI rank of 9A.

Figure 2.29: Vegetated Low Banks with ESI rank of 9B.

Figure 2.30: Hyper-Saline Tidal Flats with ESI rank of 9C.

Rank of 10: Vegetated Emergent Wetlands

The essential elements are:

- The substrate is flat and can vary from mud to sand, though high organic, muddy soils are most common.

- Various types of wetland vegetation, including herbaceous grasses and woody vegetation cover the substrate. Floating aquatic vegetation (FAV) and submersed aquatic vegetation (SAV) are treated separately from the ESI classification and are mapped as HABITAT (FAV) or BENTHIC (SAV) biological resources, respectively.

- The break between salt- and brackish-water marshes and freshwater marshes occurs at the inland extent of 0.5 parts per thousand salinity under average yearly low-flow conditions (Cowardin et al.

1979).

- The difference between scrub-shrub wetlands (<6 m) and swamps (>=6 m) is plant height (Cowardin et al. 1979). When present, mangroves are considered a specific habitat type and are not grouped with scrub-shrub vegetation.

Shoreline types that meet these elements include:

10A = Salt and Brackish Water Marshes; (estuarine: Figure 2.31)

10B = Freshwater Marshes; (estuarine, lacustrine, riverine, and palustrine: Figure 2.32)

10C = Swamps; (estuarine, lacustrine, riverine, and palustrine: Figure 2.33)

10D = Scrub and Shrub Wetlands; (estuarine, lacustrine, riverine, and palustrine: Figure 2.34) 10E = Inundated Low Lying Tundra; (estuarine: Figure 2.35)

10F = Mangroves; (estuarine: Figure 2.36)

Marshes, mangroves, and other vegetated wetlands are the most sensitive habitats because of their high biological use and value, difficulty of cleanup, and potential for long-term impacts to many organisms. They occur along the high-water line, where oil also often strands. Many factors influence how oil affects wetlands: oil type, extent of vegetation contamination, degree of sediment contamination, exposure to natural removal processes, time of year of the spill, and species types. Oil readily adheres to the vegetation. Medium to heavy oils do not readily adhere to or penetrate into the fine-grained soils, but can pool on the surface or in animal burrows and root cavities, and soak into accumulated organic matter, such as wrack. Oil persistence under these conditions can be very long term, and cleanup activities can damage the vegetation or mix the oil deeper into the soils. Therefore, natural removal is often the preferred response, particularly if the oiling is light or only on the vegetation.

Refer to the joint NOAA/American Petroleum Institute job-aid “Oil Spills in Marshes: Planning and Response Considerations” (Michel and Rutherford 2013).

Figure 2.31: Salt and Brackish Water Marshes with ESI rank of 10A.

Figure 2.32: Freshwater Marshes with ESI rank of 10BA.

Figure 2.33: Swamps with ESI rank of 10C.

Figure 2.34: Scrub and Shrub Wetlands with ESI rank of 10D.

Figure 2.35: Inundated Low Lying Tundra with ESI rank of 10E.

Figure 2.36: Mangroves with ESI rank of 10F.

CHAPTER 3

ESI Shoreline Classification Methodology

3.1 ESI Shoreline Classification

3.1.1 What to Map

The Environmental Sensitivity Index (ESI) scale, as described in Chapter 2, categorizes coastal shorelines and habitats in terms of their sensitivity to spilled oil, taking into consideration a number of natural physical and biological factors. The most sensitive habitats - vegetated wetlands and sand and mud flats - are especially important to capture when mapping the shoreline. For this reason, the ESI shoreline dataset is composed of both the linear shoreline and polygonal datasets representing important habitats, as follows:

• Vegetated wetlands

• Sand and mud flats

• Classified estuarine, riverine, lacustrine, and/or palustrine shorelines within the boundary of the area being mapped

• Shoreline structures such as piers, groins, jetties, etc.

In order to accurately apply the ESI scale during classification of shoreline wetland habitats, the best available, highest resolution data sources for the area of interest (AOI) must be identified. Each feature mapped as a polygon will, in most cases, share a coincident line typically referred to as the land/water interface. Most shoreline sources will have the land/water interface mapped at mean high tide, which is the target tidal datum for the ESI HYDRO layer. However, there may be times when the best available shoreline data was acquired without tidal control. When tidal elevation of the land/water interface varies based on the source data, the sources table should link to the original metadata that includes acquisition considerations. Likewise, the ESI metadata for the HYDRO layer should clarify the tidal datum of each data source used. Regardless of the tidal elevation used for creating these datasets, the shoreline classification is always classified out to mean low water.

3.1.2 ESI Shoreline Data Components

The ESI shoreline feature dataset includes five feature classes – ESIL, ESIP, HYDROL, HYDROP, and AOI (area of interest). The required attributes for each feature class are listed in the Base Layers section of the Data Dictionary (Appendix B). More detailed descriptions of each feature class and its attributes are provided here.

Classified Shoreline Polylines (ESIL)

The shoreline used for a particular ESI project is often dictated by the shoreline the State and/or Federal agencies are using for other regional mapping efforts. It is not unusual to use more than one source to create the final shoreline within the AOI. Regardless of the source, any changes in shoreline position noted during the classification phase (i.e., eroded shorelines, new man-made features, inlets that have migrated, etc.) are incorporated into the final product. It is key that the shoreline be finalized prior to proceeding with mapping of other data layers, as it will frequently be used as a coincident boundary. For example, polygons for shorebirds are created as a buffer around the shoreline and sea turtle nesting beaches are often represented by buffers around certain sand beaches. The ESIL classified shoreline will also be used to delineate the shoreward side of the HYDROP data layer.

Some man-made structures, for example major piers, breakwaters, groins, and jetties, may be mapped as noncontiguous lines in the ESIL dataset. These features are often oriented perpendicular to the predominant shoreline. As such, they are not included in the polygonal shoreline feature class (HYDROP), but rather captured and stored in both the ESIL and the HYDROL feature classes.