osures from Oil Mist During the Exxon Vuldez Spi11Occupational ExpCleanupCarl Relier

Alaska Health Project

313 ~

Crude oil deanup during the ExxonValdez spill relied heavily on high pres-sure water and steam{Exxon,1989! whichgenerated anoilmist, Monitoring recordsdocument an average oil mist exposure12 times in excess of permissible expo-sure limits.

The National Institute for Occupa-tional Safety and Health NIOSH! re-ported 1,811 worker's compensationdaims in 1989 related to the Exxon Valdezoil spill Gorman et al,, 1991!. The lead-ing non-physical injury reported was res-piratory system damage. Inhalation ofoil mist is well recognized as a cause ofoccupational respiratory damage Lan-cet, 1990; Robertson et al., 1988!.

Prior evaluations of the 15,000 Exxon

Vatdez cleanup workers occupationalexposure to airborne contaminates statedthat, in general, exposures were a frac-tion of permissible exposure limits PEL!, Gorman et al., 1991; Wade, 1990!. How-ever, oil mist measurements were notmentioned by Wade and NIOSH con-ducted limited oil mist testing, This isthe first independent review of ExxonValdez oil spill cleanup worker exposurerecords,

The objectiveof this study is anevalu-ation of the health and safety implica-tions of using hot water and steam athigh pressure and elevated temperatureto clean crude-oil-contaminated beaches.

Under contract to Exxon, Med-ToxAssociates collected over 6,000 air

samples in 1989 from Exxon Vatdez oilspill cleanup workers. The Alaska Health

Exxon Valdez Oil Spill Symposium Abstracts

Project obtained Exxon and Med-Toxexposure data, health and safety records,and laboratory procedure manuals. Thisinformation was then compared to theliterature.

The data collected from workers re-

vealed that the average exposure ex-ceeded the NIOSH limit by 12-fold. Themaximum overexposure of 400 times thePEL was found on a "hot wash beach."

Average exposures for other chemicalswere below NIOSH recommended PKL.

However, maximum exposures were sig-nificantly greater than NIOSH limits; thatis, total PNAs 170 times greater than thelimit, benzene 160 times greater, hydro-gen sulfide 40 times greater, butoxy-ethanol eight times greater, and carbonmonoxide six times greater. NIOSHlimits were adjusted for the increasedlength of working day, as recommendedby Exxon publications see "ExtendedWork Days" below!, but were not ad-hered to.

Another issue of parhcular concern isthe fact PEL are developed on a chemi-cal-by-chemical basis and Exxon did nottake into account multiple simultaneousexposures with synergistic potential.Finally, the upper 5% of exposures, inevery case listed below, exceeded NIOSHlimits.

Three serious problems are evidentwith Exxon's laboratory procedures anddata interpretation regarding oil mistmonitoring records: standard referencematerial, applicability of PEL, and ex-tended work days.

~ 314

Poster: Occupational Exposures from Oil Mist

Standard Reference MaterialThe standard reference material for

oil mist PEL is "mineral oil" NIOSHa,1990!. Mineral oil is a highly purifiedproduct designed for non toxicity andfreedom of irritation to humans and use

in the preparation of pharmaceuticals ASTM, 1989!. Oil spill cleanup workerswere exposed to Prudhoe Bay crude oil PBCO!. PBCO consists mostly of ali-phatic and aromatic components andsmaller amounts of heterocycles andasphaltenes. The aliphatic fraction isdominated by n-alkanes containing 11 to40 carbon atoms and isoprenoid hydro-carbons. The aromatic components con-sist of a series of parent and alky1atednaphthalenes, phenanthrenes, fluorenes,biphenyls, chrysenes, and benzan-thracenes Rahimtula, 1987!.

In addition to hydrocarbons crude oilcontains sulfur compounds such as thi-ols, sulfides, disulfides, and thiophenes.The higher boiling point sulfur com-pounds are thiocyclo-, thiobicyclo-,thiotricycioalkanes, complex thiophenes,and benzothiophenes. Basic nitrogencompounds found are pyridines andquinolines while nonbasic nitrogen com-pounds include pyrroles, indoles, andcarbazoles. Oxygen compounds foundinclude ketones and phenols with alkaneand cycloalkane acids in the higher boil-ing point fraction Costantinides andArich, 1967!.

Nickel and vanadium occur prima-rily as complexes such as porphyrinsand over 30 metals commonly occur incrude oil. Other substances are intro-

duced into crude oil during the processof drilling, pumping, preparing andtransportation IARC, 1989!. Althoughmineral oil may be derived from crudeoil, the refining process selectively re-moves a specific hydrocarbon fraction

leaving most of the components men-tioned above in other residues.

Based on the differences between

mineral oil and PBCO two things shouldhave been done regarding calibrationstandards and PEL, Laboratory equip-ment should have been calibrated usingPBCO as the standard. A review of labo-

ratory procedures and quality controldocumentation did not find evidence thatPBCO was used as the standard for whichto measure PBCO derived oil mist

Pristas, 1989!. Substantial bias likelyexists in the data because of inappropri-ate use of standard reference materials.

The problem of inappropriate standardsand infrared spectrophotometric quanti-fication of crude oil is well documented

Baugh and Lovegreen, 1989!,

Applicability of PELNo corrections were applied to PEL

for the elevated toxicity of crude oil com-pared to mineral oil. Crude oil is a car-cinogen, neoplastigen and tumorigenwhen applied to the skin. Inhalation ofvapor or particulates can cause aspira-tion pneumonia Sax, 1989!. A materialsafety data sheet for crude oil recom-mends a PEL of 0.2 mg/m Lyondell,1990!; 25 times lower than the 5.0 mg/mPEL selected as relevant by Exxon.NIOSH recommends a PEI. of 0.1 mg/m~ NIOSHb, 1990!; 50 times lower thanExxon's,

Extended Work DaysFinally, the working conditions dur-

ing the Exxon Vatdez cleanup were not 8hour days with weekends off. Moretypically, workers were on the job inexcess of 12 hours a day, seven days aweek and some for months without a

break, Exxon recognized more than tenyears ago that the PEL for airborne toxi-cants were probably inappropriate with-

315 ~

out modification for unusual work shifts.

A simple linear equation was proposedby Exxon as a first step toward healthand safety concerns Exxon,1986!, How-ever these considerations were not taken

into account for the extremely long shiftsof Exxon Valdez spill cleanup workers, 6we apply Exxon's model to NIOSH oilmist PEL, the acceptable limit should bereduced by a factor of at least 2.1 84 vs.40 hour week!. Using the PEL of 0,1mg/m3 and a factor of 2,1 yields a PEL of0.05 mg/m'.

The average worker was exposed to12 times more oil mist than what NIOSH

standards permit. Some exposures were400 times higher than PEL, Whether ornot an individual worker's health prob-lem was caused by over exposures dur-ing the Exxon Valdez cleanup can only bedetermined on a case-by-case basis.Based on the information summarized

above, further research is needed regard-ing medical histories of exposed workersto protect future generations when se-lecting cleanup technologies at otherspills,

ReferencesAmerican Society for Testing Materials. 1989.

White mineral oils in Manual on the signifi-cance of tests for petroleum products p 158

Baugh, A. and J. Lovegreen. 1989. "Differentia-tion of crude oil and refined petroleum prod-ucts in soil". Kostecki, P and Calabrese, Eeds. Petroleum Contaminated Soils, Lewis,p 142

Costantinides, G. and G, Arich. 1967. Non-hydrocarbon compounds in petroleum. In:

Exxon Valdez Oil Spill Symposium Abstracts

Nagy, B. k Colombo, U., eds. Fundamentalaspects of petroleum geochemistry,Amsterdam, Elsevier, pp.109-175

Exxon. 1989. Shoreline Clean-Up ExecutionPlan. April 15, 1989.

Exxon. 1986. Occupational health aspects ofunusual work schedules: A review of Exxon'sexperiences. American Industrial HygieneAssociation Journal v,47, no.4:199-202

Gorman, R., S. Berardinelle, T Bender. 1991.Health Hazard Evaluation Report. NationalInstitute of Occupational Safety and Health.HETA 89-200 k 89-273-2111

International Agency for Research on Cancer.1989. Occupational exposures in petroleumrefining; crude oil and mapr petroleum fu-els, v.5

Lancet. 1990. Health Risks of Oil Mist. 17NOV90 1246

Lyondell Petrochemical Co. 1990. Material SafetyData Sheet for Crude Oil. MSDS No.

HCR00001Med-Tox. Statistical summary of industrial hy-

giene monitoring. enclosed!NIOSHa. 'I990. Guide to chemical hazards. CAS

8012-95-1. p 170NIOSHb. 1990, Guide to chemical hazards, p 72Pristas, R. of Exxon to McAllister, J. of Med-Tox.

November 16, 1989. let ter regarding analyti-cal procedures, <endosed!

Rahimtula, A., Y. Lee, J. Silva. 1987. Induction ofepidermal and hepatic ornithine decarboxy-lase by a Prudhoe Bay crude oil. Fundamen-tal and Applied Toxicology v.8, no.3:408-414

Robertson, A., D. Weir, and P. Burge. 1988.Occupational asthma due to oil mists, Tho-rax, 42:200-205

Sax, I. and R. Lewis. 1989. Mineral oils andpetroleum in Dangerous properties of in-dustrial materials 7th ed. v.2:2418, 2698

Wade, R. 1990. The Exxon Valdez Oil Spill: Theenvironmental health response to man-madedisasters. Journal of Environmental Healthv. 52, no.4:213-215.

Poster: Boat-Based Surveys of Sea Otters

gBoat-Based Surveys of Sea OttersSound, Alaska.Douglas M, BurnU.S. Fish and Wi7dlife Service

When the TfV Exxon Valdez ranaground on Bligh Reef on March 24,1989,the resulting spill of 11 million gallons ofcrude oil into Prince William Sound re-

sulted in the death and injury of morethan a thousand of sea otters EnhydraI@tris!. As part of the Natural ResourcesDamage Assessment effort, the U.S. Fishand Wildlife Service conducted boat-

based population surveys of marine birdsand sea otters in Prince William Sound

between June, 1989 and July 199'1. Basedin part on similar surveys conductedduring the summers of 1984 and 1985,the purpose of this work was to estimatepost-spill sea otter abundance in order todetermine initial injury to the popula-tion, and monitor continuing injury orrecovery,

The study area consisted primarily ofthe waters of Prince William Sound,Alaska. The study area was divided intothree distinct strata: shoreline, coastal,and pelagic. The shoreline stratum wasbased on shoreline transects surveyedby Irons, Nysewander and Trapp �988!during the summers of 1984 and 1985,and was defined as the 200 m-wide stripimmediately adjacent to the coastline.Within the Prince William Sound studyarea, 742 shoreline transects were de-fined with a total area of 822.3 km'.

Waters outside the shoreline stratum

were divided into sampling "blocks"based on a 5-minute latitude /longitudegrid system, These blocks were thenstratified into two categories. coastal andpelagic, The coastal stratum was com-

Enhydra lutris! in Prince William

prised of those blocks that are immedi-ately adjacent to 1 km or more of shore-line, while the pelagic stratum was com-prised of those blocks that are adjacent toless than 1 km of shoreline. This dassifi-

cation scheme resulted in the creation of

207 coastal and 86 pelagic blocks, withtotal areas of 4,524 km~ and 3,637 km',respectively. Within each block, a num-ber of 200 m-wide strip transects usu-ally two! were systematicaUy placed andsampled.

Watercraft used in this survey were25'Boston Whalers,with three crew mem-bers serving equally as operator and ob-servers, Shoreline transects were sur-

veyed from 100 m offshore at a cruisingspeed of 5-10 knots. One observerscanned the water from the vessel up toand including the shoreline, while an-other observer scanned the water from

the vessel seaward an additional 100 m,

Coastal and pelagic transects were sur-veyed at a slightly faster cruising speedof 10-15 knots, with each observer scan-ning the water from the trackline of theboat outward 100 m. In addition, thewatercraft operator assisted with obser-vations of animals directly ahead of thevessel. While the vessel was in motion,all marine mammals and birds sightedwere recorded on standardized data

sheets,

As stated earlier, the shoreline stra-tum was based on a set of transects origi-nally surveyed during the summers of1984 and 1985 Irons et al. 1988!. Over the

course of two field seasons, virtually all

Exxon Valdez Oil Spill Syrnposiurn Abstracts

of the available shoreline habitats were

surveyed �08 out of the possible 742transects!. These data served as thebaseline for comparison with post-spillsurveys,

Post-spill surveys were conducted inJune, July, and August of 1989, March,June, July, and Augustof 1990, and Marchand July of 1991, Approximately threeweeks were needed to complete eachreplicate of the survey. Post-spill sur-veys were initially conducted during thesummer of 1989 as a random sample ofapproximately 25% of available shore-line transects and the original coastaland pelagic blocks. Only the shorelinestratum was sampled during June 1989.All three strata were sampled in each ofthe remaining surveys. Once the initialrandom sample of transects and blockswas chosen, each successive survey rep-licated the same sampling units.

Classification of sampling units asoiled or unoiled was based on Alaska

Department of Environmental Conser-vation overflight data collected at thetime of the spill ADEC 1989!. Aerialobservations were used to create a GIS

coverage depicting the movement of oilover the surface of the water, Since sea

otters are highly mobile animals, ottersinhabiting areas adjacent to the path ofthe oil could have encountered the slick

during their normal movement patterns.Given this fact, coupled with an inherentuncertainty as to the exact geographicalextent of the surface oiling, a buffer zoneof 5 km was added to the ADEC over-

flight data coverage to represent an areawithin which otters might have been af-fected by oil. Shoreline transects, andcoastal and pelagic and offshore blockswith any area located within 5 km ofsurface oil were classifie as oiled.

Sea otter density and abundance esti-

mates for each survey strata were calcu-lated using ratio estimator techniques Cochran 1977!.

In the unoiled area, otter densities inthe shoreline stratum increased 13,5%

between the pre-spill surveys of Irons etal, �988! and the summer 1989 surveys.Otter densities in the oiled shoreline stra-

turn declined approximately 34,6% dur-ing the same period, Surveys conductedin the summer of 1990 show further de-

fines in shoreline sea otter density withinthe oiled area, However, otter density inunoiled areas also exhibited a decline

during the same period. Otter densitywithin the oiled area did not appear tohave changed between July 1990 andJuly 1991. With the exception of the July1990 survey, otter densities in the oiledarea were consistently lower than thosein the unoiled area, which is in contrast

to the pre-spill pattern.In the unoiled area, there was consid-

erable overlap between pre- and post-spill shoreline population estimates.There was no overlap between pre- andpost-spill estimates in the oiled area forthis stratum. This lack of overlap be-tween estimates within the oiled area

suggests that the post-spill populationwas significantly lower that the pre-spilllevel.

Although sea otter densities werelower in coastal and pelagic strata, giventheir larger total areas, these strata con-tained a considerable number of otters,

In some mstances, these strata accountedfor over 50% of the total estimated popu-lation, Post-spill population estimatesfrom this study range from a high of8,242 + 2,280! in July 1989 to a low of4,399 k 948! in March 1991.

In July 1990, it was the decision of theManagement Team that data from thevarious damage assessment studies

~ 318

Poster. Boat-Based Surveys of Sea Otters

should bebrought together in an attemptto quantify initial injury to the PrinceWilliam Sound sea otter population. In acooperative effort, results of studies onsighting probability, carcass recoveryrates, and the age structure of the recov-ered carcasses were synthesized withthese survey data to calculate an esti-mate of the initial first-year injury Garrott, Eberhardt, and Burn 1992!. TNsexercise produced a loss estimate of ap-proximately 2,800 sea otters for PrinceWilliam Sound Garrottetal. 1992!. Popu-lation trends in the oiled area suggestthat additional losses may have occurredbeyond the first year, but have not beenquantified at this time.

Although estimates of shoreline seaotter density within the oiled area fellwell below their pre-spill values, it isimportant to note that a substantial frac-tion of the population survived the spilland its aftermath. One reason for this

may have been the presence of smallbays and coves that remained relativelyoil-free Garrott et al, 1992!. In the south-west portion of the Sound for example,Bainbridge Passage was heavily oiled.Yet during each of the three surveys con-ducted in June, July, and August 1989,we observed 3&40 otters concentrated in

an apparently unoiled coveon the south-ern side of the Passage. These unoiledrefuges were scattered throughout thespill zone, and may have provided ahaven for otters.

The long-term effects of the spill onsea otters in the western portion of PrinceWilliam Sound are unknown. Two keyfactors that will determine those long-term effects on sea otters will be the

impact of the spill on the populations ofsea otter prey items primarily musselsand clams!, and continued exposure ofsea otters to hydrocarbons through their

prey. Either one or both of these factorscould have an impact on the recovery ofthe sea otter population within the oiledarea of the Sound.

As a means of estimating the PrinceWilliam Sound sea otter population, thissurvey suffered from a lack of precision,Most of this variability in the estimatescame from the coastal and pelagic strata,Although 25% of the blocks within thesestrata were sampled, only 10% of thearea within the blocks themselves were

surveyed. The net result of this designwas that every otter sighted in the coastaland pelagic strata equated to roughly 50otters in the final estimate.

In order to monitor population trendswith respect to recovery, I believe thatthe shoreline stratum is thebest means of

judging the status of the population. Themajority of otters sighted during thissurvey were observed on shorelinetrans-acts, making this stratum a good index ofpopulation size. It is also the only areafor which pre-spill data exist, One po-tential criterion for estimating when thesea otter population is fully recovered, isthat point when sea otter densities withinthe shoreline stratum increase to pre-spill levels.ReferencesAlaska Department of EnvironmentalConserva-

tion. 1989. Unpublished preliminarydigitalmaps of oil-impacted shore based on aerialand boat surveys during early ADEC re-sponse activities. ARC/INFQ Data Files.

Cochran, W.G. 197l. Sampling Techniques. JohnWiley and Sons,

Inc., New York, N.Y. 428pp.Garrot, R. A., L. L. Eberhardt, and D, M, Bum.

1992. Some impacts of T/V Exxon Veldt oilspill on the Prince William Sound sea otterpopulation. Manuscript in preparation,

Irons, D. B., D. R. Nysewander, and J. L. Trapp.1988. Prince William Sound sea otter distri-bution in relation to population growth andhabitat type. U.S. Fish and Wildlife Service.Unpubl. report. 31pp,

Hydrocarbons in Mussels and Subtidal Sediments: GraphicalPresentation of Hydrocarbon Analysis Data With Geographic MapData

Jeffrey W. Short, Ronald A. Heintz, and Scott FeldhausenNational Oceanic and Atmospheric Administration

319 ~

Oil movements on the surface were

tracked during the spill, but there werelarge unknowns as to what the subsur-face faunawereexposed to, Severalstud-ies sampled mussels and subtidal sedi-ments for hydrocarbon analysis in anattempt to characterize the oil exposureat sites and habitats appropriate to indi-vidual projects. This project attempts tomap oil exposures geographically andtemporally, using samples collected bymany projects.

Maps displaying the distribution andpersistence of Exxon Vatdez crude oilthrough presentation of sediment and of

Exxon Valdez Oil Spill Symposium Abstracts

mussel tissue hydrocarbon analysis dataon shoreline oiling maps will be pre-sented, together with an interpretationof the hydrocarbon data symbols used.

A map for each project that had sedi-ments or mussel tissues analyzed will beavailable for public inspection, with atleast one map for each project containingall the hydrocarbon data generated foreach year of the project. This postersession will focus on the data manipula-tion and quality assurance steps from theraw data generated by the chemistry labo-ratories through the GIS mapping soft-ware.

Poster: Management of Damage Assessment Samples

Management of Natural Resource Damage Assessment Samples andAnalytical DataC. A. Manen' E. Robinson-Wilson' S, Korn' and R. L. Britten~'National Oceanic and Atnrospheric Administration'U. S. Fish and Wildlife Service

~ 320

Within 48 hours after the groundingof the Exxon Vatdez, samples were beingcollected by State of Alaska and FederalTrustee Agencies Alaska Departmentsof Fish and Game, Environmental Con-servation and Natural Resources; U.S.Department of Agriculture, Forest Ser-vice; U, S. Department of Commerce,National Oceanic and Atmospheric Ad-ministration; and U. S. Department ofInterior, Fish and Wildlife Service! todocument the exposure of natural re-sources to the spilled oil and to provide abasis for the determination of the effectsof the oil, During the course of the Natu-ral Resource Damage Assessment, over36,000 samples of water, biota and sedi-ment were collected from Prince WilliamSound and the Gulf of Alaska to meet

these objectives. An additional 1+00experimental samples were generated invarious laboratory experiments.

A cooperative project between theU.S, Fish and Wildlife Services F&WS!and the National Oceanic and Atmo-

spheric Administration NOAA!, Natu-ral Resources Damage Assessment NRDA! Project Technical Services ¹1,was responsible for �! archiving andtracking of these samples; �! analysis ofthe samples, including selection ofsamples for analysis, and the develop-ment and implementation of an analyti-cal quality assurance plan which definedcriteria for the quality and acceptabilityof the data; and �! management of theanalytical data. A relational database PWSOIL! was used to carry out these

tasks, i.e. to maintain and manipulate alldata and information related to the col-

lection and analysis of samples for petro-leum hydrocarbons.

PWSOIL is based on the design usedby NOAA's National Status and TrendsProgram, modified for similarity to otherdatabases either already in use or beingplanned by F&WS and the U.S. Environ-mental Protection Agency at the time ofthe grounding of the Exxon Vatdez . Theoriginal design was then modified in aniterative fashion, however, to meet newlydefined needsand objectives. All changesto the design of PWSOIL and to the dataand information maintained by this da-tabase were preceded - and often initi-ated - by discussion with the users, theProject Leaders. PWSOIL is supportedby hard copies of all chain-of-custodyrecords and aH developed. analytical data,which themselves are kept under chain-of-custody procedures. A complete de-scription of the design, induding defini-tions of the variables and instructions forusers, and implementation of PWSOIL isdocumented in Manen et al.

PWSOIL is focused on the uniqueidentification number assigned to eachsample by the database manager. Asso-ciated with this number are the data and

information which describe and identifythe sample, e.g. where the sample wascollected place name and latitude/lon-gitude!; who collected it; when it wascollected;how it was collected; thesampleidentification number assigned by thecollector; what kind of sample it is sedi-

32l ~

ment, water or tissue!; if a tissue sample,what kind of tissue and from what plantor animal; if a sediment or water sample,the depth at which it was collected; andwhether or not it has been analyzed. Allof these variables are provided by thecollector or Project Leader as part of thechain-of-custody record. The mainte-nance of these variables in PWSOIL al-

lows the sorting of samples by location,project, species, etc.

Over 12,000 of the NRDA sampleshave been analyzed. The majority of thesamples were analyzed for petroleumhydrocarbons �3 parameters! by GC/MS at Texas A~ University; smaller,specialized sample sets were analyzed atNOAA's Auke Bay Laboratory ABL!and NOAA's Northwest Fisheries Cen-

ter NWFC!. Semi-qualitative, non-com-pound specific information was devel-oped for some sediment samples as wellas the concentrations of petroleum me-tabolites in the bile of fish, birds, terres-trial and marine mammals by UVF, atechnique to determine the presence ofpetroleum hydrocarbons. These analy-ses were performed by Texas ARM Uni-versity and NOAA's NWFC. All dataresulting from these analyses, as well as�! calculated indices and parameters;pristane/phytane ratio, carbon prefer-ence index, saturated hydrocarbonweathering ratio, and sums of the al-kanes, aromatics and hydrocarbons; �!supporting data; grain size, total organic

Exron Valdez Oil Spill Symposium Abstracts

carbon, percent moisture and surrogaterecoveries and �! quality control data;the results of the analysis of blanks, stan-dard reference materials and in-house

control materials are maintained byPWSOIL in a batch fashion associated

with the sample identification numbers.The use of PWSOIL to maintain and

manipulate the analytical data in pro-gram-defined reporting formats and filestructures allows the use of data across

projects and analytical laboratories.PWSOIL has supported data analysis forall individual NRDA Projects which col-lected samples for hydrocarbon analy-sis; forms the basis of the secondary da-tabase developed by NRDA Project Sub-tidal ¹8, and has been used by NRDAProject Technical Services ¹3 to developGIS mapping! products and by Exxon incontinuing litigation. To facilitate accessto this database and these data; the data-base PWSOIL!, Users' Manual, and sup-porting analytical and quality assurancedocumentation have been made avail-able as a stand-alone CD-ROM Com-pact Disc-Read Only Memory!. This CDuses non-proprietary softwaredevelopedby U.S. Geological Survey and is theresult of a cooperative project betweenNOAA and the Geological Survey.

References

Manen, C.A.,J.R. Price, S. Korn and M.G. Carls.l993 Natural resource damage assessment:Databasedesign and structure. NOAA Tech.Memo,, in review.

Poster Concentrations of Hydrocarbons in Sediments and Mussels

Pre-spill and Post-spill Concentrations of Hydrocarbons in Sedimentsand Mussels in Prince William SoundMalin M. Babcock, John F, Karinen, Jeffrey W. Short and Christine C. BrodersenNafionat Oceanic aef Atmospheric AdministraHon

~ 322

This study provides comparison ofpetroleum hydrocarbon concentrationsin mussels and sediments before andafter the Exxon Valdez oil spill. Withinseveral days of the spill in 1989, mussels Mytilus trossulus! and sediments at sixhistorically �977-1981! established in-tertidal baseline sites in Prince WilliamSound were resampled. Additionally,six sites were established along the spilltrajectory beforeoiling, and sampled bothbeforeand after oiling to measure changesin petroleum hydrocarbon levels in sedi-ments and rnussels. Sampling continuedin 1990 and 1991.

Both mussel and sediment transects

were 30m long and usually set parallel tothe water line. The sediment transect

was generally down slope from the mus-sel bed in finer grain material. Triplicate�0 each! samples of mussels were takenalong the transect line; and triplicatesamples each a composite of 10subsamples! were collected of sediment.All samples were placed in hydrocar-bon-free jars and frozen according toestablished protocol.

There were no detectable polynucleararomatic hydrocarbons PAHs! in mus-sels sampled prior to the Exxon Valdez oilspill �977-1980! and levels in sedimentsat 4 of these sites were low, generallyunder 20 ng/g dry weight. The patternof low hydrocarbon levels in both mus-sels and sediments continued after 1989at sites not impacted by the spill,

Sleepy Bay, a heavily oiled site, hadPAH concentrations in sediments nearly

100 times historical levels establishedfor other sites in the Sound! in May, '1989 93&404standarderrorng/g dry weight� an amount approximating 6% ExxonValdez crude oil!. Sediment PAH's at thissite declined to 16&17 ng/g in 1990 and4&4 in 1991. Two other oiled sites Bayof Isles and Elrington Island! showedincreases �0-20 fold! of aromatic hydro-carbons in sediments in 1989, d.ecreasesin August, 1989, and increases in April,1990. By August 1990, PAHs in sedi-ments from Elrington Island had de-creased to values similar to unoiled sites,but Bay of Isles sediments remained el-evated over unimpacted sites. Differ-ences in exposure to wave action prob-ably accounts for these variations in re-covery, Both Sleepy Bay and theElrington Island site are quite exposed towind and wave a.ction while the Bay ofIsles site at the southern tip of the SouthArm is quite protected from indementweather.

PAH's in sediments from most of theother sites, Bligh Island, Naked Island,Olsen Bay, Siwash Bay, and Perry Island,were detected at levels not elevated from

historical concentrations.Mussels from Sleepy Bay, the South

Arm of the Bay of Isles, and the Fox Farmon Elrington Island all showed high PAHconcentrations in 1989 up to143,000+13,900 ng/g dry weight!. Theselevels had decreased to 174%27.0-21,700+1,500 ng/ g in 1990 and 166+16.0-5,960+1,100 ng/g in 1991. Mussels fromNaked Island and Crab Bay in Sawmill

323 ~

Bay showed elevated PAH concentra-tions �,95&135 - 6,99~47 ng/g! inApril and Mayof 1989, PAH'sin musselsfromOlsen Bay, Bligh Island, Barnes Coveand Siwash Bay were usually detectedonly sporadically at concentrations neardetection limits about 10 ng/g dryweight for individual PAH's!; naphtha-lene and substituted naphthalenes werethe most frequently detected PAH's atthese sites. Mussels from the latter 5 sites

Exxon Valdex Oil Spill Syxnposiurrt Abstracts

had between 60. R5.00 and 243M7,0 ng/g during 1990 and 1991.

Maps created by GIS systems detail-ing extent and concentrations of PAHswill be displayed.ReferencesKarinen,J.F., M, M, Babcock, D. W, Brown, W, D.

MacLeod, Jr., L.S. Ramos, and J.W. Short. InPreparation. Hydrocarbonsin intertidal sedi-ments and mussels from Prince William

Sound, Alaska, 1977-1980: Characterizationand Probable Sources, NOAA Tech, Memo.

Surface Modeling of Floating Oil, The 1989 Exxon Valdez Oil Spill,Prince William Sound, AlaskaDorothy Mortenson, Hans Buchholdt, Richard McMahon, Randall HallAlaska Department of Natural Resources

~ 324

Poster: Surface Modeling of Hoating Oil

Shortly after the Exxon Valdez ranaground on Bligh Reef in the early morn-ing of March 24, 1989, response teamswere formed to collect information onoiling, to protect the priority areas, andto begin clean up. Due to adverseweather, difficult logistics, and the sizeof the spill, observational informationcollected during this time on surface oil-ing was limited. Unlike shoreline oiling,surface oiling cannot be surveyed at alater time.

Through a series of modeling effortsby National Oceanic & AtmosphericAdministration � Hazardous Materials

Response Branch NOAA! and the Natu-ral Resource Damage Assessment�Technical Services 3 TS3!, surface oilingcould be estimated for general purposes.NOAA has designed a trajectory hindcastmodel, called the On-Scene Spill Model OSSM!, which estimates the flow of oilbased on wind and current patterns.

Technical Services 3 is an inter-agencygroup composed of geographic informa-tion systems GIS!, and technical staff

from the Alaska Department of NaturalResources and the U.S. Fish and WildlifeService. TS3 used the OSSM results in ageographic surface model, called Trian-gular Irregular Network TIN!. As aresult of the OSSM and TIN models, aseries of maps were produced illustrat-ing the general flow over time and therelative concentration of the oil.

This poster explains and illustrateswhat information and advanced tech-

niques were used to create a modeledsurface oiling map. In addition, the first2 weeks of the spill will be representedfor Prince William Sound.

References:Gait, J. A., G.Y. Watabayachi, D. L, Payton and J.

C. Peterson, 1991. Trajectory Analysis for theExxon Vatdez: A Hindcast Study. Proceed-ings of the 1991 International Oil Spill Con-ference. San Diego, California. March 4-7,1991. pp 629-634.

Gait, J, A. and D. L. Payton. Movement of OilSpilled From the T/V Exxon Valdez. Biologi-cal Report 90 �2! � Sea Otter Symposiumproceedings. April 17-19, 1990. U. S. Fishand Wildlife Service.

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Poster: Integration of Shoreline Oiling Data Sets

ond, adjacent polygon boundaries werecreated to delineate the changes in theoriginal shoreline data set. Polygon labelpoints were also created to match theoriginal line data set. When the shorelineattributes are transferred to the polygonlabel points, the polygon data set is spa-tially equal to the shoreline data set fromwhich it was made McMahon, et al 1991!.

Third, once the polygon data set wascompleted, attributes were integrated,or transferred, onto a common shorelineusing polygonal integration algorithms ESRI 1990!. The transferred attributesspatially match the original shoreline dataset.

Final VerificationPlots were used for a spatial check by

visually comparing both the originalshoreline data set and the new integrateddata set for accuracy. A quantitativeanalysis between the original data setand. the integrated data set showed anaverage difference shoreline oiling totalsof less than 1%. Spacial analysis showedmaximum shoreline deviation ofbetween2 and 3 meters in less than 3% of theshoreline, Maps of integrated data setswere also reviewed for accuracy by fieldinvestigators, At the standard scale thatthese maps were produced, these differ-ences would not be seen.

This process started with the integra-tion of two major coastal themes: shore-line oiling and environmental sensitiv-ity, Many of the NRDA investigatorsneeded to focus specifically on areas ofhigh environmental sensitivity. Mapsand statistical summaries were producedof specific sites where habitat protectionand analysis was of concern. These re-sults were also used to provide NRDAinvestigators and peer reviewers withestimates of total oiled shorelineby shore-line sensitivity.

Because some government agenciesfocused primarily on oiling to federal orstate lands only, we combined land sta-tus into the integrated data set to provideownership damage assessment.

One of the more interesting views ofthe combined data set was in the form ofshoreline oiling change. By looking atthe difference in shoreline oiling betweenvarious survey years, changes in shore-line oiling become apparent. Some areasindicate less oiling from year to year,possibly due to mechanical and/or natu-ral cleaning. While other beach segmentsshow an increased amount of shorelineoiling, possibly due to the re-floatingand beaching of oil between surveys,This is a very interesting look into beachdynamics.

Data Sources

The 1989 oiling data was deliveredfrom the oil spill response staff of theAlaska Department of EnvironmentalConservation ADEC 1989; 1990a; 1990b;1990c!. The spring 1990 shoreline survey SSAT! was digitized by Exxon frommulti-agency field reports. Environmen-tal sensitivity index maps were producedby Research Planning Institute RPI, 1979,1983a, 1983b, 1985, 1986! for the NationalOceanic and Atmospheric Administra-tion and digitized by Environmental Ser-vices Research Institute.

ReferencesAlaska Department of Environmental Conserva-

tion ADEC!. 1989. Impact maps and sum-mary reports of shoreline surveys of the ExxonValdex spill site, Seward Area; 3 September-19 October 1989. Alaska Department of En-vironmental Conservation, Anchorage,Alaska. approx. 350pp

Alaska Department of Environmental Conserva-tion ADEC!. 1990a. Impact maps and sum-mary reports of shoreline surveys of the ExxonValdex spill site, Homer Area; 24 August - 20November 1989, Alaska Department of En-

327 ~

vironmental Conservation, Anchorage,Alaska. approx. 120pp

Alaska Department of Envirorunental Conserva-tion ADEC!. 1990b. Impact maps and sum-mary reportsof shoreline surveys of the ExxonValdez spill site, Kodiak Area; 11 September� 11 December 1989. Alaska Department ofEnvironmental Conservation, Anchorage,Alaska, approx. 250pp

Alaska Department of Environmental Conserva-tion ADEC!. 1990c. Impact maps and sum-maryreportsof shoreline surveys of the ExxonVatdez spill site, Prince William Sound; 11September - 11 December 1989. Alaska De-partment of Environmental Conservation,Anchorage, Alaska. approx. 1100pp

Environmental ServicesResearch Institute� ESRI!.

1987, 1988, 1989, 1990. Arc/INFO softwareand manuals. Environmental Services Re-

search Institute, Redlands, CAMcMahon, R. E., R. J. Hall. 1991. Line on line

Exxon Valdez Oil Spill Symposium Abstracts

integration using Arc/Info: Yes, The impos-sible is possible. Proceedings of the EleventhAnnual ESRI Users Conference; volume 2;pp 73-83,

Research Planning Institute, Inc. RPI!. 1983a.Sensitivity ofcoastal environments and wild-life to spilled oil, Prince William Sound,Alaska. RPI/ESI Columbia, SC, 42 maps.

Research Planning Institute, Inc. RPI!. 1983b.Sensi tivityof coastal environments and wild-life to spilledoil,Shelikof Strait, Alaska. RPI/ESI Columbia, SC, 40 maps.

Research Planning Institute, Inc. RPI!. 1985.Sensitivity of coastal environments and wild-life to spilled oil, Cook Inlet/Kenai Penin-sula, Alaska. RPI/ESIColumbia,SC,57maps.

Research Planning Institute, Inc. QPI!. 1986.Sensitivity of coastal environmentsand wild-life to spilled oil, Southern Alaska Peninsula,Alaska. RPI/ESI Columbia, SC, 60 maps.

Poster: Reconstruction of Pink Salxnon Wild Stock Runs

A Reconstruction of Pink Salmon Wild Stock Runs in Prince WilliamSoundWilliam D. Templin, Jeremy S. Collie, and Terrance J. Quinn IIUniversity of Ataska Fairbardcs

~ 328

Assessing the effects of the ExxonValdez oil spill on the Prince WilliamSound wild pink salmon Oncorhynchusgorbuscha! fishery requires knowledge ofthe spatial and temporal distributions ofthe individual salmon stocks. This knowl-edge is important because geographicand economic factors dictate that theharvest occur in mixed-stock areas. Theincidence of large hatchery runs co-oc-curring with the wild stocks in the fish-ery and the lack of information on indi-vidual stock contributions to the catch inthese areas make the management taskmore difficult. Estimates of stock-spe-cific catches are required to determinethe abundance of individual stocks. Runreconstruction, known as the "poor man'sstock ID," builds a history of a stock'smovement through a fishery, providingstock-specific information with few datarequirements.

We develop a multi-stock/multi-dis-trict run reconstruction of wild pinksalmon stocks using catch, effort, tag-ging and escapement data to estimatestock-specific run characteristics. Thereconstruction works backward begin-ning with the fish in their spawningstreams and projecting them backwardthrough the Bshery to the time whenthey enter the sound. This method ispreferable to a forward projection be-cause itrequires fewer assumptions aboutthe distribution of entry to the fishery.The completed reconstruction providesa seasonal history of each stock by esti-mating daily stock abundances in each

district, stock-specific contributions tothe catch in each district, district-specificcatchabilities, movement rates betweendistricts and initial abundances of eachstock.

A continuous database of daily catchand effort and weekly escapementrecords in Prince William Sound existsfor the years between 1968 and thepresent. It is necessary to identify andremove hatchery contributions from thecatch records. This can be accomplishedfor recent years with coded wire tag in-formatio~. Effort is dehned as one seineboat fishing for one day. Purse seinefishing gear is used to harvest pinksalmon in the sound except in District223 where a gillnet fishery co-occurs withthe seine fishery. In this case the gillneteffort is standardized to seine effort units.Information from coded wire and radiotagging experiments is used to establishsalmon movement and rates. To avoidundue complexity, a stock is defined asall the pink salmon spawning in thestreams of a management district. Forthe purposes of damage assessment andbecause the data are more accurate, wereconstruct the 1990 and 1991 pinksalmon runs.

We begin the reconstruction with thedaily entry of fish into the streams as-suming that a fish enters only one streamand remains there until it dies. In PrinceWilliam Sound,salmon hold at the streammouth for a number of days before as-cending. During this time they are notsubject to harvest. Accordingly, the

329 ~

stream entry for stock is delayed beforebeing backed into the fishery as escape-ment.

We model the migration of stock us-ing a transition matrix, assuming thatsalmon movement in Prince William

Sound is directed, stock-specific and con-stant over the season.

The sum of the daily stock-specificcatches is the daily catch in that district.Because of the backward nature of the

reconstruction, catches are modeled asan inverse survival, becoming additionsto the stock abundances. This conve-

niently avoids the possibility of remov-ing more 6sh than are available. Weaccumulate the salmon in pools in eachdistrict as we back them out to the Gulf of

Alaska. The magnitude of these pools isa function of input from escapement,catch and movement between districtsand output to the gulf. The daily move-ment of salmon to the fishery from thegulf is modeled as a fraction of the pool of

Exxon Valdez Oil Spill Symposium Abstracts

fish in their district of entry gateway!.A stock's initial abundance is the sum

of its total escapement and its stock-spe-cific catc contributions. The initial abun-

dance of all wild pink salmon stocks isthe sum of the stock abundances.

The parameters of the model are: d.is-trict-specific catchabilities, gateway-resi-dence times and stock-specific migrationmatrices. The lack of stock identificationinformation prevents us from distin-guishing between removals due to catchand removals due to migration. Thus thecatchabilities and the movement ratescannot be estimated simultaneously. Forthis reason, the migration matrices areassumed to be known and the model

estimates the catchabilities and the gate-way-residence times which are con-strained by total run size. The model isprogrammed in Fortran and parametervalues are estimated by miNmizing thesum of squared residuals using a non-linear least squares routine in lMSL.

Intertidal/Supratidal Site Selection Utilizing A GeographicInformation SystemKimbal Sundberg', Lawrence Deysher' and Lyman McDonalds'Alaska Department of Fish and Garne'Coastal Resources Associates, Inc.'western EcoSysferns Technology, Inc

~ 330

Poster: Intertidal/Supratidal Site Selection

A goal of the Coastal Habitat InjuryAssessment CHIA! is to quantify inju-ries to biological resources inhabitingthe intertidal zone throughout the ExxortValdez oil spill area. The CHIA wasdesigned to provide information for theNatural Resources Damage Assessmentprogram, A Geographic InformationSystem GIS! was employedby the CHIAto identify candidate study sites. A GISwas used for the following reasons: �!the large amount of shoreline poten-tially in excess of 1,244 miles; 2,002 kilo-meters! contaminated by the spill, �! theextreme heterogeneity of shoreline typesand degrees of ailing in the spill-affectedarea, �! the need to embody the variousshoreline habitats and degrees of oilingin the study, and �! to allow for extrapo-lation of injury determinations to theuniverse of all sites in the spill-affectedarea,

Candidate sites were stratified into

15 habitat/oiling categories and ran-domly drawn from the GEO GEO 1989!Arc/Info ESRI! data base with probabil-ity proportional to size. Shorelinelengthsof sites ranged fram 100-600 meters;longer sites had a higher probability ofcandidate selection. Sites less than 100 m

were not selected because they werejudged to be too small ta allow repeatedannual visits with new sample plots overthe period of the study. The GIS datalayers utilized in GEO for site selectionincluded; �! the mean high water shore-line digitized from U.S. Geological Sur-

vey I:63~0 quadrangles in the spill-affected area, �! the Environmental Sen-sitivity Index ESI! maps Hayes k Ruby1979;RPI1983a,1983b,1985,1986!whichclassified the shoreline into 19 geomor-phologic types, and �! the Oil Spill Im-pact OSI! maps ADEC 1989! which das-sified the shoreline into five degrees ofoiling.

From a universe of 21,362 potentialsites encompassing 4,950 miles 9,173kilometers! of shoreline, 424 candidatesites were drawn and 240 sites wereground-truthed in 1989 to validate GIS-depicted geomorphologic and shorelineoiling information and to determine ifthey were accessible by the supratidal/intertidal survey crews. Candidate sitesrepresented both oiled treated! andunoiled control! conditions.

Ground-truthing revealed 119 sitesthat did not fit the GIS assigned habitat/oiling categories. Discrepancies betweenthe GIS classifications and ground-truthed classifications can be attributedto: �! the strong dependence on aerialoverflight information in the ESI and OSIdata bases which was not always consis-tent with characteristics we observed inthe intertidal zone, �! the lag time of 2 to4 months between the shoreline oilingdata in the OSI data base and aur site

selection surveys, and �! a digitizingerror which misclassified 20 candidatesites in the fine-textured category. As-sessable sites that did not fit the GIS

assigned categories were reclassÃed into

331 ~

the observed category. The end numberof sites varied for each of the categories.When the number of sites was over thetarget sample size for a category, thedesired number was drawn at randomwithout replacement. In the case of thesheltered estuarine category, the num-ber of sites was under the target value.

This methodology maintained theprobability based sample; however, ex-treme variation existed in the strata. For

example, the control strata in Prince Wil-liam Sound induded many sites on themainland with low salinity while oiledstrata contained mostly sites on the is-lands with higher salinity. This problemwas rectified during the winter of 1989-1990 by retaining all sites redassifiedinto the moderately-heavily oiled strataand pairing each with a control sitebasedon physical characteristics and proxim-ity to the oiled site.

Ultimately, a total of 97 study sites�0 treated and 47controls! were selectedfor intensive sampling of intertidal biotaby the CHIA. Sites were distributedthroughout the spill-affected area, con-sisting of 37 sites in the Prince WilliamSound area, 27 sites in the Cook In1et/Kenai Peninsula area, and 33 sites in theKodiak/Alaska Peninsula area. Thisstudy design maintained the probabilitybased inferences to the effects of oil onthe intertidal biota in the "adjusted uni-verse" of accessible, moderately-heavilyoiled sites greater than 100 m subject tothe protocol by which paired control siteswere selected.

Exxon Valdex Oil Spill Spnposimn Abstracts

ReferencesAlaska Department of Environmental Conserva-

tion ADEC!, 1989. Oil spill impact maps.Unpublished preliminary data developedunder Air/Water Study Number l. Anchor-age, Alaska,

Environmental Systems Research Institute ESRI!.Arc/Info geographic information systemsoftware. Version 5,0. Redland, California.

Hayes, M. 0 and C. H. Ruby. 1979. OiI spillvulnerabihty index maps, Kodiak Archi-pelago. Unpublished maps. 47 leaves.

RPI Research Planning Institute, Inc.!. 1983a.Sensitivityof coastal environmentsand wild-life to spilled oil, Prince William Sound,Alaska, an atlas of coastal resources, Pre-pared for National Oceanic and AtmosphericAdministration, Office of Oceanography andMarine Services. Seattle, Washington. 48leaves.

1983b. Sensitivity of coastal environ-ments and wildlife to spilled oil, ShelikofStrait Region, Alaska, an atlas of coastal re-sources. P repared for National Oceanic andAtmospheric Administration, Office ofOceanography and Marine Services. Seattle,Washington. 43 leaves.

, 1985. Sensitivity of coastal environmentsand wildlife to spilled oil, Cook Inlet/KenaiPeninsula, Alaska, an atlas of coastal re-sources. Prepared for National Oceanic andAtmospheric Administration, Office ofOceanography and Marine Assessment. Se-attle, Washington. 64 leaves.

1986. Sensitivity of coastal environmentsand wildlife to spilled oil, Southern AlaskaPeninsula, an atlas of coastal resources. Pre-pared for National Oceanic and AtmosphericAdministration, National Ocean Service,Alaska Office and U.S. Department of Inte-rior, Minerals Management Service, AlaskaOCS Region, Anchorage, Alaska. 69 leaves.

Valdez Oil Spill Damage AssessmentGeoprocessing Group GEO!. 1989. Com-bined habitat types and oil impacts. Unpub-Iished maps. 65 leaves.

Poster: Identification of Marbled Murrelet Nesting Habitat

Identification of Marbled Murrelet Nesting Habitat inSouthcentral Alaska to Guide Restoration Efforts Following theExxon Valdez Oil SpillK. J. Kuletz, N. L. Naslund, and D. K. MarksU.S. Fish am/ Wildlife Service

332

The Exxon Valdez oil spill zone is animportant population center for themarbled murrelet Brachyramphusmarmorafus!, a small diving seabird. Themarbled murrelet suffered substantial

injury from the spill Kuletz, in prep!,and its population in Prince WilliamSound has declined by 67% since sur-veys in the early 1970s Laing andKlosiewski in prep!,

In Washington, Orego~ and Califor-nia, the marbled murrelet is listed asthreatened under the Endangered Spe-cies Act. In these states, marbled murreletnests haveonlybeen found in old-growthconifers, and the only remaining popula-tions of marbled murrelets are in watersadjacent to remnant coastal old-growthforests Marshall 1988!.

Because there is evidence that the loss

of critical nesting habitat contributed tothe decline of marbled murrelets at lower

latitudes, protection of nesting habitathas been proposed to assist natural re-covery of the murrelet population in thespill zone, However, little is known aboutthe murrelet in Alaska, and until 1990,there had been no effort to study breed-ing biology of the marbled murrelet insouthcentral Alaska, The only knownnests at that time were six ground neststhat had been found opportunistically Day et al. 19S3! and one tree nest insoutheast Alaska Quinlan and Hughes1990!.

The goal of this project was to de-scribe upland habitat used by murrelets

in the spill zone to guide acquisition oftimber rights and for the development ofmanagement guidelines to assist murreletrecovery.

The objectives were to: 1! Determinemarbled murrelet habitat requirementsand develop criteria for documentingoccupied nesting habitat within forestedportions of the spil1 zone, and 2! Surveyportions of the spill zone to investigateupland murrelet use in the full spectrumof available habitat. During 1991 and1992, in cooperation with the U.S. ForestService, we studied murrelet activityduring the breeding season throughoutwestern Prince William Sound and de-

scribed nesting habitat at Naked Island,located in the center of Prince William

Sound.

The basic method used to surveymurrelets has been the 'dawn watch',whereby observers record murrelet vo-calizations and flight patterns arounddawn, when murrelets fly to their inlandnests Paton et al. 1990!. Because thisprotocol had not been used in Alaska, w' econducted a pilot study in 1990 Kuletz1991! and determined that the 'intensivedawn watch' was best suited to our field

situation.

We also tested for weather effects

and diel daily! and seasonal variabilityby conducting intensive dawn watchesat three sites above Cabin Bay, NakedIsland at bi-monthly intervals from lateMay to mid August in1991 and1992. Tolocate nests, we used a modified dawn

333 ~

watch Naslund et al. 1990!, wherebymultiple observers are used to pinpointthe suspected nesting site over severalmornings, Nest or landing trees wereclimbed at the end of the season for mea-surements and collectionof nestsamples.During all dawn watches we recordedflight behavior and vocalizations to ana-lyze a posteriori murrelet activity at siteswith known nests, no known nests andflight corridors.

We tested murrelet activity amonghabitat types in two stages. In 1991,timber type data for Naked, Storey andPeak islands, available in a geographicinformation system ARC INFO! fromthe U.S. Forest Service, were used todescribe four forest types based on vol-ume class and stand class, ranging froma low volume, small/young age class toa high volume, large/older age class. Werandomly selected 80 sites among thethree islands, and a single dawn watchwas conducted at 73 of these sites be-

tween June and early August, 1991. For-est characteristics were alsorecorded foreach site, and included the diameter atbreast height DBH!, height and condi-tion of the10 nearest overstory trees. Thenumber and type of murrelet detectionswere used to test for differences in

murrelet activity among forest types.In 1992, dawn watches were con-

ducted at 68 randomly selected sites inwestern Prince William Sound to deter-

mine if there was a non-random distri-

bution of murreletactivity at inland sites.Because timber type coverage was notavailable, these analyses will be done aposteriori among habitat types. The po-tential for murrelet occupation of non-forested sites will be evaluated with the1992 data from western Prince William

Sound.At the regularly monitored Cabin Bay

Exxon Valdex Oil Spill Symposium Abstracts

sites, peak murrelet activity occurred 1hour before official dawn; at lower lati-tudes, peak activity is at official dawn.On dear days, murrelet activity beganearlier, and on mornings with low cloudsand fog murrelet activity continued for alonger period after dawn. A peak inmurrelet detections occurred between

mid and late July, and detections de-dined abruptly after early August. Thus,in southcentral Alaska dawn watchesshould begin at least 90 minutes beforeofficial dawn and surveys should be con-ducted from early May to early August.Because of the increase in murrelet activ-

ity in late July, survey effort should bedistributed evenly throughout the sum-mer among sampling strata, or a weight-ing factor appliecL

On Naked Island in 1991 and 1992,we located seven activemarbled murreletnests, three trees with nest cups, andeleven trees where murrelets landed

during the dawn activity period. Basedon the characteristics of these 21 trees,marbled murrelets in Prince William

Sound appear to nest in old-growth,moss-covered conifers. Analysis of be-havioral data among occupied and un-occupied sites will refine the interpreta-tion of behaviors observed at other loca-

tions.

Among the 1991 randomly chosensites on Naked, Peak and Storey islands,we found a positiverelationshipbetweenhigh volume, larger age-class forest andmurrelet nesting activity. On-site mea-surements of overstorytree DBH for thesesites was also positively correlated withthe number of murrelet detections. How-

ever, not all high volume forests hadmurrelet activity. Factors such as slope,aspect, elevation, canopy closure, num-ber and size of moss platforms and othertree and stand characteristics may prove

Poster: Identification of Marbled Murrelet Nesting Habitat

to be important criteria. Thus, althoughwe can now define potential murreletnesting habitat, the value of a specificland parcel as murrelet nesting habitatcan only be determined by a site-specificsurvey.

ReferencesDay, R. H., K.L. Oakley and D. R. Barnard, 1983.

Nest sites and eggs of Kittlitz's and marbledmurrelets. Condor 85: 265-273.

Laing, K.K. and S.P. Klosiewski. In prep. Marinebird populations of Prince William Sound,Alaska, before and after the Exxon Valdez OilSpill. NRDA Bird Study No, 2. U.S. Fish andWildlife Service, Anchorage, Alaska.

Kuletz, K. J. 1991. Restoration feasibility studynumber 4- Identification of upland habitatsused by wildlife affected by the EVOS:marbled murrelets. U.S, Fish and WildlifeService, Anchorage, Alaska.

Kuletz, K. J. In prep. Assessment of injury tomarbled and Kittlitz's murrelets from theExxorr Valdez Oil Spill. NRDA Bird StudyNo. 6. U.S. Fish and Wildlife Service, An-chorage, Alaska.

Marshall, D.B. 1988, The Marbled Murrelet joinsthe old-growth forest conflict. AmericanBtrds: 42�!: 202-212.

Naslund, N. L., S. W, Singer and S. A. Singer.1990. A proposed ground search techniquefor finding tree nests of the Marbled Murreletin open canopy forest. Abstract, Pacific Sea-bird Group Bulletin 17: 28.

Paton, P.W.C., C.J. Ralph, H.R. Carter and S.K.Nelson. 1990. Surveying ma&led murreletsat inland forested sites: a guide. Gen. Tech,Rep. PSW-120. Berkeley, CA. Pacific South-west Research Station, Forest Service, U.S.Department of Agriculture.

Quinlan, S. E. and J. H. Hughes. 1990. Locationand description of a Marbled Murrelet treenest site in Alaska. Condor 92: 1068-1073.