Natural Resource Damage Assessment Process Research Articles

Predicting response of migratory fish populations to dam removal

Abstract Dam removal is a potential habitat restoration alternative through which parties responsible for injuries to natural resources can provide compensation for reductions in fish populations. Predicting the potential response of migratory fish populations to candidate dam removal(s) is a critical step in the natural resource damage assessment process to evaluate whether the proposed action provides adequate compensation. There is currently no standard approach to making such predictions, particularly in cases where data on candidate streams with dams are limited. We considered six modeling approaches for addressing this problem and evaluated the features of each approach for this application. We judged that an approach based on habitat suitability indices and weighted usable area provides the best balance between predictive capacity and cost of model implementation. This balancing act evaluating the cost effectiveness of predictive models is worth consideration in a wide range of fisheries modeling applications.

Natural resource damage assessment for the Hebei Spirit oil spill: An application of Habitat Equivalency Analysis

Sixteen oil spills occurred in Korea between 1995 and 2010, including the Hebei Spirit oil spill (HSOS) in 2007, the largest (77,857 barrels) in Korean history. Yet compensation for environmental damages has never been claimed under the International Oil Pollution Compensation Fund for any of these accidents, because there is no adequate natural resource damage assessment (NRDA) procedure and there are no internationally-admissible economic quantification methods established in Korea. The objective of this study is to propose a methodology to overcome these shortcomings. We propose the use of Habitat Equivalency Analysis, which has dominated the US NRDA process for oil spills, and apply it to the HSOS as a case study. A Base Case analysis estimates the compensatory costs of fishery habitat damages (34,703.5ha) with a 10-year recovery rate at $119.4 million. We also conduct sensitivity analyses under several alternative assumptions.

Reprint of: Overview of avian toxicity studies for the Deepwater Horizon Natural Resource Damage Assessment

The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1–20ml of artificially weathered Mississippi Canyon 252 oil kg bw-1 day-1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.

Improving preparedness for marine mammal oil spill response and assessment in the United States

Several recent oil spills in the United States have had the potential to impact large numbers and multiple populations of cetaceans (whales and dolphins) and pinnipeds (seals and sea lions), namely the Macondo-252/Deepwater Horizon oil spill from April 2010, the Texas City Y event in March 2014, and the Refugio Beach oil spill in May 2015. In each of these spills, the National Oceanic and Atmospheric Administration (NOAA) and partners have engaged in significant activities during and following the spills, to both respond effectively to minimize impacts and assess the effects of oil spills on marine mammals. Experience gained during these spills has led to improved preparedness for future events with potential involvement of marine mammals. NOAA's National Marine Fisheries Service (NMFS) has developed the “National Pinniped and Cetacean Oil Spill Response Guidelines,” which are available online. These guidelines provide a broad national overview of response activities, a proposed organizational structure, and considerations to identify, recover, treat, and sample oiled and potentially oiled marine mammals. Further development of a response framework includes regional preparedness plans for marine mammals, based on the national guidelines but with regionally appropriate modifications to reflect local considerations, including species likely to be impacted, geographic concerns, and understanding of local cultural practices. Efforts are underway to improve training opportunities through a national exercise plan and to track trained and qualified individuals for potential deployment. For assessment, NMFS and NOAA's National Ocean Service (NOS) have partnered to develop the “National Marine Mammal Oil Spill Assessment Guidelines” to facilitate early, efficient, and effective assessment of impacts from oil spills on marine mammals as part of the Natural Resource Damage Assessment process. This paper will outline the current status of these products and their role in marine mammal assessment and response in the U.S., raise awareness of marine mammals within oil spills, and identify potential resources for marine mammal response and assessment in other countries.

Publisher's note

The Oil Pollution Act of 1990 establishes liability for injuries to natural resources because of the release or threat of release of oil. Assessment of injury to natural resources resulting from an oil spill and development and implementation of a plan for the restoration, rehabilitation, replacement or acquisition of natural resources to compensate for those injuries is accomplished through the Natural Resource Damage Assessment (NRDA) process. The NRDA process began within a week of the Deepwater Horizon oil spill, which occurred on April 20, 2010. During the spill, more than 8500 dead and impaired birds representing at least 93 avian species were collected. In addition, there were more than 3500 birds observed to be visibly oiled. While information in the literature at the time helped to identify some of the effects of oil on birds, it was not sufficient to fully characterize the nature and extent of the injuries to the thousands of live oiled birds, or to quantify those injuries in terms of effects on bird viability. As a result, the US Fish and Wildlife Service proposed various assessment activities to inform NRDA injury determination and quantification analyses associated with the Deepwater Horizon oil spill, including avian toxicity studies. The goal of these studies was to evaluate the effects of oral exposure to 1-20ml of artificially weathered Mississippi Canyon 252 oil kg bw-1 day-1 from one to 28 days or one to five applications of oil to 20% of the bird's surface area. It was thought that these exposure levels would not result in immediate or short-term mortality but might result in physiological effects that ultimately could affect avian survival, reproduction and health. These studies included oral dosing studies, an external dosing study, metabolic and flight performance studies and field-based flight studies. Results of these studies indicated changes in hematologic endpoints including formation of Heinz bodies and changes in cell counts. There were also effects on multiple organ systems, cardiac function and oxidative status. External oiling affected flight patterns and time spent during flight tasks indicating that migration may be affected by short-term repeated exposure to oil. Feather damage also resulted in increased heat loss and energetic demands. The papers in this special issue indicate that the combined effects of oil toxicity and feather effects in avian species, even in the case of relatively light oiling, can significantly affect the overall health of birds.

Issues Trustees Face in Natural Resource Damage Assessments, Part I

The Natural Resource Damage Assessment (NRDA) process evaluates natural resource injuries arising from hazardous waste or oil spills and determines the appropriate remedies. In this article, the first of a two part series, I address the issues that Natural Resource Trustees regularly face during the NRDA process outlined in numerous environmental statutes. Large scale environmental disasters call for sound science, but also discretionary and informed decision-making specific to the particulars of the scenario faced by the trustee that will make the public whole. If the environmental statutes are read correctly, a NRDA will enable a trustee to make the best decisions regarding restoration plans and damages owed. However, constant challenges to the trustee’s authority by the responsible party during the assessment process are not only inconsistent with the trustee’s statutorily delegated authority and the purpose of the environmental statutes themselves, but add considerable delay and cost to the restoration process. This article outlines the NRDA process a trustee typically follows while addressing common misinterpretations of statutory authority that often hinder the ultimate goal of environmental restoration.

Estimating Upper Bounds for Occupancy and Number of Manatees in Areas Potentially Affected by Oil from the Deepwater Horizon Oil Spill

The explosion of the Deepwater Horizon drilling platform created the largest marine oil spill in U.S. history. As part of the Natural Resource Damage Assessment process, we applied an innovative modeling approach to obtain upper estimates for occupancy and for number of manatees in areas potentially affected by the oil spill. Our data consisted of aerial survey counts in waters of the Florida Panhandle, Alabama and Mississippi. Our method, which uses a Bayesian approach, allows for the propagation of uncertainty associated with estimates from empirical data and from the published literature. We illustrate that it is possible to derive estimates of occupancy rate and upper estimates of the number of manatees present at the time of sampling, even when no manatees were observed in our sampled plots during surveys. We estimated that fewer than 2.4% of potentially affected manatee habitat in our Florida study area may have been occupied by manatees. The upper estimate for the number of manatees present in potentially impacted areas (within our study area) was estimated with our model to be 74 (95%CI 46 to 107). This upper estimate for the number of manatees was conditioned on the upper 95%CI value of the occupancy rate. In other words, based on our estimates, it is highly probable that there were 107 or fewer manatees in our study area during the time of our surveys. Because our analyses apply to habitats considered likely manatee habitats, our inference is restricted to these sites and to the time frame of our surveys. Given that manatees may be hard to see during aerial surveys, it was important to account for imperfect detection. The approach that we described can be useful for determining the best allocation of resources for monitoring and conservation.

Integrating Natural Resource Damage Assessment and Environmental Cleanup Activities at CERCLA and RCRA Sites

AbstractAlthough the release or threatened release of hazardous substances into the environment often creates liability for both cleanup costs and natural resource damages liability, the process of planning and conducting cleanup and the process of assessing natural resource damages are most often conducted separately. However, the substantial similarities between the two processes often present opportunities to integrate significant steps in each. Such integration has the potential to reduce both the cost of measuring and, often, resolving the full range of environmental claims at a given cleanup site and the time it takes to do so. It can also lead to faster restoration of injured natural resources and the services they provide to the public and the environment. One key reason for the lack of integration is the fact that cleanup managers generally know little if anything about the natural resource damage assessment process, while the public officials authorized to assess damages to natural resources know little about the cleanup process. This article identifies the similarities between the cleanup and natural resource damage assessment processes and provides guidance on when and how to integrate the two. © 2013 Wiley Periodicals, Inc.

Oil and Water, Economics and Ecology in the Gulf of Mexico

Some economists and ecologists predict that the Deepwater Horizon oil disaster will sharpen the tools of ecosystem damage valuation in much the same way that war advances emergency medicine. Others fault both the methods and the premises of attempts to price nature. Generally agreed: avoiding future “spills” always beats trying to calculate the losses afterward, and that industrial societies have to rerig the incentives that fail to prevent appalling carelessness. The federal Natural Resource Damage Assessment (NRDA) process for the Gulf of Mexico may absorb federal scientists and economists, as well as dozens of collaborators in academia, for years. “Every damage assessment is different, and this one is really different. I couldn’t put a timeline on it,” says Tom Brosnan, a NOAA (National Oceanic and Atmospheric Administration) environmental scientist and a veteran of several earlier oil spill audits. NOAA and the US Fish and Wildlife Service are the lead agencies for the NRDA. Economic techniques used to calculate direct losses to fishers, boaters, tourists, sunbathers, or scuba divers and the businesses that serve them are complex but comparatively well settled. Trying to tally ecosystem Assessment and restoration Dollars can become the focus if there is litigation, or if the perpetrators want to settle. But the federal NRDA process is intended to look past the difficult question of dollar valuation of nature, at least initially, to calculate the costs of restoration instead. “Our job is to damage that doesn’t immediately affect what humans buy, consume, or earn from directly, however, sends economists and ecologists down a labyrinth. What’s the price tag for a brown pelican, sea turtle, reef, marsh, or mangrove, or for the ecological resilience of the Gulf as a whole?

Translating Ecological Risk to Ecosystem Service Loss

Hazardous site management in the United States includes remediation of contaminated environmental media and restoration of injured natural resources. Site remediation decisions are informed by ecological risk assessment (ERA), whereas restoration and compensation decisions are informed by the natural resource damage assessment (NRDA) process. Despite similarities in many of their data needs and the advantages of more closely linking their analyses, ERA and NRDA have been conducted largely independently of one another. This is the 4th in a series of papers reporting the results of a recent workshop that explored how ERA and NRDA data needs and assessment processes could be more closely linked. Our objective is to evaluate the technical underpinnings of recentmethods used to translate natural resource injuries into ecological service losses and to propose ways to enhance the usefulness of data obtained in ERAs to the NRDA process. Three aspects are addressed: 1) improving the linkage among ERA assessment endpoints and ecological services evaluated in the NRDA process, 2) enhancing ERA data collection and interpretation approaches to improve translation of ERA measurements in damage assessments, and 3) highlighting methods that can be used to aggregate service losses across contaminants and across natural resources. We propose that ERA and NRDA both would benefit by focusing ecological assessment endpoints on the ecosystem services that correspond most directly to restoration and damage compensation decisions, and we encourage development of generic ecosystem service assessment endpoints for application in hazardous site investigations. To facilitate their use in NRDA, ERA measurements should focus on natural resource species that affect the flow of ecosystem services most directly, should encompass levels of biological organization above organisms, and should be made with the use of experimental designs that support description of responses to contaminants as continuous (as opposed to discrete) variables. Application of a data quality objective process, involving input from ERA and NRDA practitioners and site decision makers alike, can facilitate identification of data collection and analysis approaches that will benefit both assessment processes. Because of their demonstrated relationships to a number of important ecosystem services, we recommend that measures of biodiversity be targeted as key measurement endpoints in ERA to support the translation between risk and service losses. Building from case studies of recent successes, suggestions are offered for aggregating service losses at sites involving combinations of chemicals and multiple natural resource groups. Recognizing that ERA and NRDA are conducted for different purposes, we conclude that their values to environmental decision making can be enhanced by more closely linking their data collection and analysis activities.

MODELING THE DYNAMICS OF FISHERY STOCK RECOVERY: IMPLICATIONS FOR THE ASSESSMENT OF NATURAL RESOURCE DAMAGES

ABSTRACT. During the restoration planning phase of the natural resource damage assessment (NRDA) process, potential injuries to natural resources and services are evaluated in terms of the nature, degree and extent of injury so that the need for and scale of restoration actions can be ascertained. Injuries are quantified by comparing the condition of the injured natural resource relative to baseline (pre‐injury) conditions. The “Type A” procedures are used to quantify damages from smaller spills and rely on a standardized methodology and computer model to calculate injury and value of damages. In this model, fishery stock changes from injuries and resulting changes in user participation are not treated as dynamic. If true stock growth and re‐growth are indeed dynamic, then the Type A model is likely underestimating fishery losses. The purpose of this paper is to illustrate the potential for such underestimation by comparing simulated stock and harvest losses under dynamic treatment and a static treatment that more closely represents the way stock and service losses are estimated under the current NRDA process.

The NRDA Process can be Timely and Productive for All

ABSTRACT On August 24, 1998, there was an accidental hose failure at Tesoro Hawaii Corporation's (“Tesoro Hawaii” or “Tesoro”) single-point mooring (SPM) about a half mile off Barbers Point, near Honolulu, Oahu, Hawaii. The incident released approximately 117 barrels of bunker fuel. Immediate containment and clean up efforts were commenced, but on September 5, 1998, tarballs began to come ashore on Kauai. Shoreline impacts were observed between Kilauea Point to Makahuena Point on the eastern shore and between Makaha Point and Mana Point on the western shore of Kauai. To avoid the costs and delays associated with litigating resource damages that may have resulted from the release and any associated civil penalties, the Trustees and Tesoro Hawaii entered into a cooperative Natural Resource Damage Assessment (NRDA) protocol. The Trustees and Tesoro Hawaii conducted a phased approach focusing on injury determination and quantification using technical working groups (TWGs) composed of Trustee and Tesoro Hawaii representatives. Resource injuries considered were for seabirds, marine environment (opihi), marine mammals (Hawaiian monk seal), and human use. To expedite the process, it was agreed that time and money would best be spent identifying and scaling restoration projects. Coordination of effort was key to cost-effectiveness of the assessment and avoiding duplication of studies. The Final Restoration Plan and Environmental Assessment were accomplished within two years, including public participation. Restoration actions were undertaken promptly following execution of the Consent Decree. One of the initiatives developed by this collaborative effort was a derelict net removal project (the “Project”). The Project met the goals of the Trustees by compensating for interim losses to shoreline, intertidal and subtidal habitats and the biota in those habitats and by addressing potential injury to the endangered Hawaiian monk seal.

Quantifying natural resource injuries and ecological service reductions: challenges and opportunities.

The natural resource damage assessment (NRDA) provisions of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Oil Pollution Act (OPA) are complex and have been difficult to implement. The complexity and difficulty in implementation arise both from the assessment procedures specified in agency NRDA guidance and from the limited ability of ecologists to quantify impacts of hazardous substances on natural resources. This paper explores the scientific aspects of NRDA implementation, and discusses conceptual and methodological relationships between NRDA and the much broader field of ecological risk assessment (ERA). We discuss three critical components of the NRDA assessment approach: measuring natural resource injuries and reductions in resource services; evaluating causality; and establishing baseline conditions. We identify (1) specific approaches drawn from ERA practice that could improve each of these components, and (2) research needs and institutional changes that may improve the ability of the NRDA process to achieve its stated objectives. We recommend the acceleration of the ongoing dialogue among NRDA practitioners from the Trustee and PRP communities as a first step toward resolving the procedural and technical deficiencies of the NRDA process.

THE INTRUSION OF CRIMINAL LAW ON THE NRDA PROCESS

ABSTRACT A primary goal of the Oil Pollution Act of 1990 (OPA 90) is to make the environment and public whole for injuries to natural resources that result from the discharge of oil. OPA 90 authorizes state and federal natural resource agencies to serve as trustees for natural resources and provides them with the responsibility, through a natural resource damage assessment (NRDA) process, to ensure that injured natural resources are restored. The National Oceanic and Atmospheric Administration (NOAA) promulgated damage assessment regulations, and in an attempt to correct deficiencies and meet OPA 90 mandates, developed a framework intended to promote expeditious restoration. To lessen the common litigious nature of the NRDA process, the regulations encourage active participation by a responsible party in a cooperative assessment of damages. Natural resource trustee agencies also have authority to enforce criminal aspects of other statutes for impacts resulting from an oil spill. However, when agencies initiate a criminal investigation under these statutes for an oil spill, the goals mandated in OPA 90 and set forth in the NOAA regulations can be substantially undermined. There are potential solutions that could, at least partially, resolve this dilemma for the responsible party to a point where participation in the NRDA process would not unduly prejudice its position in a criminal investigation. Such solutions might include written agreements as to communications and transactional use of immunity agreements, stay of proceedings, and protective orders, which singly, or in combination, could prove invaluable in preserving a progressive NRDA process, fully inclusive of the responsible party.

The Lake Barre Oil Spill Nrda: From Response To Restoration

ABSTRACT A release of approximately 6,561 barrels of crude oil from a Texaco pipeline into Lake Barre in May 1997 injured marsh, birds, and aquatic fauna. Texaco was proactive in dealing with the trustees in the Natural Resource Damage Assessment (NRDA) process and stayed directly involved throughout; resulting in a cooperative assessment. The trustees focused quickly on the key injuries that required assessment. There was early agreement to conduct a cooperative, restoration-based NRDA, and to design field studies for the injured marsh to provide inputs for scaling using habitat equivalency analysis (HEA). It also was agreed that for this incident, field studies to assess bird and aquatic faunal injury would not be cost-effective or likely improve the accuracy of injury estimates. Although agreement on a common quantification approach for faunal injury was not reached, the two sides agreed on how much restoration was appropriate. The parties developed an extensive list of restoration alternatives, and although the trustees retained the final decision making authority, there were no significant disagreements on how various alternatives ranked according to restoration selection criteria. The selected project is planting saltmarsh vegetation on a platform of dredged material placed on East Timbalier Island by the Coastal Wetland Planning, Protection, and Restoration Act (CWPPRA) program. No CWPPRA funds were available for planting. In scaling the restoration, Texaco will only get credit for the ecological services provided by their planting above that which would occur in the absence of planting. Factors such as erosion rates expected with and without planting and the rate of natural colonization of marsh in the absence of planting were considered in the scaling calculations. The trustees and Texaco jointly briefed attorneys for both sides throughout the NRDA process, but were not active participants in meetings regarding technical matters. These briefings ensured a quick transition from the injury assessment and restoration project selection process to settlement negotiations. A consent decree was lodged with the court in September 1999. Texaco will implement the restoration and the monitoring plan, and pay all trustee assessment and restoration oversight costs as part of the settlement.

SOURCE CHARACTERIZATION AND IDENTIFICATION OF NEW CARISSA OIL IN NRDA ENVIRONMENTAL SAMPLES USING A COMBINED STATISTICAL AND FINGERPRINTING APPROACH1

ABSTRACT Source oil characterization and its subsequent identification and quantification in different receiving environments are integral components of a natural resource damage assessment (NRDA) following a spill. When the M/V New Carissa broke up on the Oregon coast in February 1999, it released an estimated 70,000 gallons of two bunker fuels and two diesel fuels. Numerous oil, water, sediment, and tissue samples were subsequently analyzed for the standard suite of aliphatic and polynuclear aromatic hydrocarbon (PAH) fractions, as well as steranes and triterpanes to use in chemical fingerprinting in support of the NRDA process. The fingerprinting task was uniquely complex with this spill because of the four major source oils of highly disparate compositions and additional compositional changes occurring as a result of partial in situ burning and release of residual fuels onboard the vessel during the response effort. Also unique to NRDA process was the segregated sampling of dissolved-phase and dispersed-oil droplet fractions from the water column, information that proved invaluable in the fingerprinting process. To assist with the complex data analysis in identifying New Carissa oil in environmental samples, a combination of multivariate principal-component analyses and hierarchical agglomerative-cluster analyses, conventional double-ratio analyses of selected PAH, and custom computer displays to allow comparison of multiple graphs on a single page was developed. Results show two different mechanisms of hydrocarbon uptake into affected organisms: direct uptake of dissolved-phase PAH from the water column into crab tissues, and accumulation of aliphatic and aromatic constituents from dispersed oil droplets and oiled suspended particulate material (SPM) by filter-feeding organisms. From the combined statistical and fingerprinting process, it was possible to differentiate New Carissa oil from background combustion-derived (and sediment-associated) PAH in selected clam and oyster tissue samples from inside Coos Bay. Also documented was interstitial water contamination of otherwise clean and unoiled sandy beach substrates by offshore dissolved-phase PAH, and the accumulation of hydrocarbons from the surface microlayer by diatoms.

The Use Of Methods For Injury Determination And Quantification From Natural Resource Damage Assessment In Ecological Risk Assessment

Several Federal statutes provide the government the authority to recover natural resource damages including the Clean Water Act Amendments (1977), the Outer Continental Shelf Act Amendments (1978), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, and the Oil Pollution Act of 1990 (OPA 90). CERCLA and OPA 90 are the principle Federal statutes which authorize trustees to assess damages for trust resources which are lost, injured, or destroyed as a result of the discharge of oil or the release of hazardous substances. The Department of the Interior was charged with developing natural resource damage assessment (NRDA) regulations and procedures from CERCLA and the Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) was charged with developing regulations for OPA 90. NRDA is a process for making the public “whole” for direct injury to natural resources and/or the services of natural resources. The primary objectives of the NRDA process are to identify and quantify natural resource injury, determine the damages resulting from the injury, and develop and implement appropriate restoration actions. The goal is to be accomplished by implementing a plan for the restoration, rehabilitation, replacement, or acquisition of equivalent natural resources. NRDA is an after-the-fact process; however, the OPA 90 NRDA rules describe a pre-spill planning process. The models and formulae can be used in this pre-spill planning process to estimate damages (both ecological and economic). Some of those tools, in particular NRDAMCME, have uses in ranking risk from spills of petroleum products and hazardous substances. This information can be used to protect ecological resources and lower NRDA costs through pre spill planning and management of resources during a spill.

NORTH CAPE OIL SPILL NRDA PROCESS UNDER OPA 1990

ABSTRACT On January 19, 1996, the tank borge North Cape and the tug Scandia grounded on Moonstone Beach in southern Rhode Island, spilling 828,000 gallons of no. 2 heating oil into Block Island Sound. Just 2 weeks prior to the grounding, the National Oceanic and Atmospheric Administration (NOAA) had published the final natural resource damage assessment (NRDA) rule for the Oil Pollution Act of 1990 (OPA). The North Cape oil spill became the first opportunity to implement the new NRDA rules. One of the key provisions of the NRDA rule is the requirement that trustees must invite the responsible parties (RP) to participate in a cooperative assessment of damages. If the trustees and the RP can agree to perform the initial phases of an assessment cooperatively, the chances of achieving a fair settlement and avoiding protracted litigation are expected to be enhanced. The cooperative approach should also reduce overall transaction costs, facilitate settlement, and result in a more rapid implementation of restoration projects. This paper presents an overview of the cooperative natural resource damage assessment process being undertaken by the trustees and the RPs following the North Cape oil spill and highlights some of the lessons learned in conducting a cooperative assessment.