From 4 to 13 August 1991, as part of a larger study, Alaska harbor porpoise (<i>Phocoena phocoena</i>) abundance was investigated during an aerial survey throughout the coastal waters of Bristol Bay. A Twin Otter was used as the survey platform and was flown at an altitude of 152.2 m (500 ft) and at an airspeed of 185 km/h. The third of three identical sawtooth track lines was flown along the south side of Bristol Bay. 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 for Bristol Bay was 1.17 (SE = 0.35) and 4.48 groups/100 km2 (SE = 1.38).
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. Breiwick2000Harbor porpoise (Phocoena phocoena) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepubMarine Mammal Science16(1): 28-45
ground condition
1991-08-06
1991-08-12
None planned
-164.93833-159.2086756.9538355.01267-164.93833-159.2086756.9538355.01267
PlatformAircraftSightingsUser definedharbor porpoisePhocoena phocoenaabundanceaerial surveymarine mammal surveysurveymarine mammalcetaceanUser definedBristol BayAlaska
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
<a href='http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepub' target='reference'>Dahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick. 2000. Harbor porpoise (<i>Phocoena phocoena</i>) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993. Marine Mammal Science. 16(1): 28-45</a>
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 SystemIntegrated Taxonomic Information Systemhttp://www.itis.usda.gov/Downloaded April, 2004Refer to the contact information of the datasetKingdomAnimalia202423PhylumChordata158852SubphylumVertebrata331030ClassMammalia179913SubclassTheria179916InfraclassEutheria179925OrderCetacea180403SuborderMysticeti552298FamilyEschrichtiidae180519GenusEschrichtius180520SpeciesEschrichtius robustus180521SuborderOdontoceti180404FamilyDelphinidae180415GenusLagenorhynchus180441SpeciesLagenorhynchus obliquidens180444FamilyPhocoenidae552307GenusPhocoena180472SpeciesPhocoena phocoena180473GenusPhocoenoides180479SpeciesPhocoenoides dalli180480
Dahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick2000Harbor porpoise (<i>Phocoena phocoena</i>) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepubMarine Mammal Science16(1): 28-45Halpin, 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. Hyrenbach2009OBIS-SEAMAP: The world data center for marine mammal, sea bird, and sea turtle distributionsOceanography22(2):104-115http://www.tos.org/oceanography/article/obis-seamap-the-world-data-center-for-marine-mammal-sea-bird-and-sea-turtle
Ei FujiokaDuke Universitymailing and physical addressLSRC A328DurhamNCUSA27708efujioka@duke.edu919-613-8021
http://www.nbii.gov/
Biological Data Profile
2009-05-282012-08-15
OBIS-SEAMAPNicholas School of Environment, Duke Univ.mailing and physical addressA328, LSRCDurhamNC27708USA919-613-8021seamap-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/130GCS_WGS_1984Decimal degrees0.0001670.000167D_WGS_1984WGS_19846378137.000000298.257224National Marine Mammal LaboratorydatasetlinenodupllinellegdateeventtimedtimebeaufortcloudcovportvisstarvispglarsglarairspdaltlatdeglatmindlatlondeglonmindlongpobsrecordersobspilotlinenumbegwptendwptherdsizespcodecommontsnSpecies ITIS TSNscientificgroupangleperpdisobservgrpsizcommentsexcludedoidUnique ID number (generated by SEAMAP)