On 1 to 26 June 1993, as part of a larger study, Alaska harbor porpoise (<i>Phocoena phocoena</i>) abundance was investigated during an aerial survey from Prince William Sound to Dixon Entrance. Employing a Twin Otter as the survey platform, the second of three identical sawtooth tracklines was flown at an altitude of 152.2 m (500 ft) and at an airspeed of 185 km/h. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Density of harbor porpoises was calculated using line transect estimates based on perpendicular distances of sightings to the cruise track of the airplane. On average, porpoise group size and density from Prince William Sound to Dixon Entrance was 1.22 (SE = 0.04) and 4.02 groups/100 km2 (SE = 7.42). Although harbor porpoises, <i>Phocoena phocoena</i>, are known to occur throughout Alaska waters, few estimates of abundance exist. In 1991, the National Marine Mammal Laboratory initiated a 3 year study on Alaska harbor porpoises. The objectives of this program were to: <br> 1) Obtain minimum population estimates in coastal waters using line transect methodology with a coefficient of variation for density estimates of less than 30% for each survey area, and <br> 2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. <br><br> During the present study, it was not fiscally possible to survey all areas of the state in any one year. Accordingly, we selected sections of the state to survey in consecutive years to maximize the likelihood of including all of the animals for a particular area surveyed while minimizing the likelihood of significant movement between areas among survey years. This dataset and associated effort data were updated on September 8, 2005. Those who downloaded them before that date should renew them. Dahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick2000Marine Mammal Science16(1):28-45http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepub ground condition 19930602 19930626 Complete None planned -147.17217-132.3273360.3396754.40383-147.17217-132.3273360.3396754.40383Southeast Alaska NoneAircraftSightingsharbor porpoisePhocoena phocoenaabundanceaerial surveymarine mammal surveysurveymarine mammalcetaceanNoneSoutheast Alaska Open public unless otherwise noted. See Use Constraints for details. 1. Not to use data obtained from OBIS-SEAMAP in any publication, product, or commercial application without proper attribution to the original data provider(s) and OBIS-SEAMAP unless the datasets are explicitly shown under the CC0 policy. Citations or credits are suggested as attribution. If the data you downloaded come from multiple datasets, a citation or credit to each of the datasets is required. Suggested citation for this dataset: Suggested citation for OBIS-SEAMAP: Halpin, P.N., A.J. Read, E. Fujioka, B.D. Best, B. Donnelly, L.J. Hazen, C. Kot, K. Urian, E. LaBrecque, A. Dimatteo, J. Cleary, C. Good, L.B. Crowder, and K.D. Hyrenbach. 2009. OBIS-SEAMAP: The world data center for marine mammal, sea bird, and sea turtle distributions. Oceanography 22(2):104-115 2. To forward the citation of any publication / report that made use of the data / tools provided by OBIS-SEAMAP for inclusion in our list of references. 3. Not to hold OBIS-SEAMAP or the original data providers liable for errors in the data. While we have made every effort to ensure the quality of the database, we cannot guarantee the accuracy of these datasets. 4. The burden for determining fitness for use of the downloaded data for any analyses lies entirely with the user. OBIS-SEAMAP or the original data providers do not support outcomes of your analyses that used the data you downloaded from OBIS-SEAMAP. 5. To consider inclusion of the accompanying transect (effort) dataset if available into the methodology of your analyses. 6. Not to redistribute the data you downloaded from OBIS-SEAMAP through any media without contect from OBIS-SEAMAP and the original data providers unless the datasets are explicitly shown under the CC0 policy. Shapefile Janice Waite National Marine Mammal Laboratory mailing and physical address

7600 Sand Point Way N.E.

Seattle WA 98115-6349 USA 206-526-6554 Janice.Waite@noaa.gov National Marine Mammal Laboratory Integrated Taxonomic Information Systemhttp://www.itis.usda.gov/Downloaded April, 2004Refer to the contact information of the datasetKingdomAnimalia202423PhylumChordata158852SubphylumVertebrata331030ClassMammalia179913SubclassTheria179916InfraclassEutheria179925OrderCetacea180403SuborderMysticeti552298FamilyBalaenopteridae180522GenusBalaenoptera180523SpeciesBalaenoptera physalus180527GenusMegaptera180529SpeciesMegaptera novaeangliae180530SuborderOdontoceti180404FamilyDelphinidae180415GenusOrcinus180468SpeciesOrcinus orca180469FamilyPhocoenidae552307GenusPhocoena180472SpeciesPhocoena phocoena180473GenusPhocoenoides180479SpeciesPhocoenoides dalli180480 Relational databaseDahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick2000vector digital dataMarine Mammal Science16(1):28-45http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepubWaite, J2025Version 1.7.0vector digital dataOBIS-SEAMAP140https://seamap.env.duke.edu/dataset/140OBIS-SEAMAPhttps://doi.org/10.82144/6e251322Halpin, P.N., A.J. Read, E. Fujioka, B.D. Best, B. Donnelly, L.J. Hazen, C. Kot, K. Urian, E. LaBrecque, A. Dimatteo, J. Cleary, C. Good, L.B. Crowder, and K.D. Hyrenbach2009Oceanography22(2):104-115 Ei FujiokaDuke Universitymailing and physical address

LSRC A328

DurhamNCUSA27708efujioka@duke.edu919-613-8021 http://www.nbii.gov/ Biological Data Profile 2025091120250911 All observation records are included.Permissible values for date and time and coordinates were validated by the data provider and the OBIS-SEAMAP data manager. Species identification by the data provider was matched with Integrated Taxonomic Information System.Data were put through the OBIS-SEAMAP data registration steps.20250417 OBIS-SEAMAPNicholas School of Environment, Duke Univ.mailing and physical address

A328, LSRC

DurhamNC27708USA919-613-8021seamap-contact@duke.eduNot to hold OBIS-SEAMAP liable for errors in the data. While we have made every effort to ensure the quality of the database, we cannot guarantee the accuracy of these datasets. Also please refer to Use Constraints.FreeGo to the OBIS-SEAMAP web sitezipzipped shapefilehttp://seamap.env.duke.edu/dataset/140OBIS-SEAMAP Dataset ID 140GCS_WGS_1984Decimal degrees1e-051e-05D_WGS_1984WGS_19846378137.000000298.257224National Marine Mammal LaboratoryBiogeographic dataBiogeographic dataNot applicabledatasetData providerlinenoData providerduplData providerlineData providerllegData providerdateData providereventData providertimeData providerdtimeData providerbeaufortData providercloudcovData providerportvisData providerstarvisData providerpglarData providersglarData providerairspdData provideraltData providerlatdegData providerlatminData providerdlatData providerlondegData providerlonminData providerdlongData providerpobsData providerrecorderData providersobsData providerpilotData providerlinenumData providerbegwptData providerendwptData providerherdsizeData providerspcodeData providercommonData providertsnSpecies ITIS TSNData providerSpecies ITIS TSNscientificData providergroupData providerangleData providerperpdisData providerobservData providergrpsizData providercommentsData providerexcludedData providergeomData provideroidUnique ID number (generated by SEAMAP)Data providerUnique ID number (generated by SEAMAP)