Description
Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: On 6 July to 9 August 1992, as part of a larger study, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during an aerial survey off Kodiak Island. 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 off Kodiak Island was 1.41 (SE = 0.13) and 1.85 groups/100 km2 (SE = 6.03). Purpose: Although harbor porpoises, Phocoena phocoena, 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: 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 2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. 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. Supplemental information: This dataset and associated effort data were updated on Sept 8, 2005. Those who downloaded them before that date should renew them.
Data Records
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 77 records.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
Versions
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Dahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick. 2000. Harbor porpoise (Phocoena phocoena) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993. Marine Mammal Science. 16(1): 28-45.
Rights
Researchers should respect the following rights statement:
The publisher and rights holder of this work is OBIS-SEAMAP. This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC 4.0) License.
GBIF Registration
This resource has been registered with GBIF, and assigned the following GBIF UUID: f4cc557b-1c28-4a3e-a0b6-16c511005193. OBIS-SEAMAP publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Ocean Biodiversity Information System.
Keywords
Occurrence,Aircraft,Sightings,harbor porpoise,Phocoena phocoena,abundance,aerial survey,marine mammal survey,survey,marine mammal,cetacean; Observation; Occurrence
External data
The resource data is also available in other formats
OBIS-SEAMAP Dataset Page | http://seamap.env.duke.edu/dataset/133 UTF-8 Interactive map |
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FGDC Metadata | http://seamap.env.duke.edu/dataset/133/xml UTF-8 XML |
Contacts
- Owner ●
- Originator ●
- Point Of Contact
- Metadata Provider ●
- Distributor
Geographic Coverage
Kodiak Island,Alaska
Bounding Coordinates | South West [55.416, -159.973], North East [58.74, -151.768] |
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Taxonomic Coverage
Scientific names are based on the Integrated Taxonomic Information System (ITIS).
Order | Cetacea (cetaceans), Cetacea (cetaceans) |
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Species | Phocoenoides dalli (Dall's Porpoise), Balaenoptera physalus (Fin Whale), Phocoena phocoena (Harbor Porpoise), Megaptera novaeangliae (Humpback Whale) |
Temporal Coverage
Start Date / End Date | 1992-07-06 / 1992-07-31 |
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Project Data
No Description available
Title | NMML Harbor Porpoise Aerial Survey, Kodiak Island, Replicate 2, 1992 |
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Funding | NA |
The personnel involved in the project:
- Owner
- Owner
Sampling Methods
NA
Study Extent | NA |
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Method step description:
- NA
Collection Data
Collection Name | zd_133 |
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Collection Identifier | zd_133 |
Parent Collection Identifier | OBIS-SEAMAP |
Additional Metadata
marine, harvested by iOBIS
Purpose | Although harbor porpoises, Phocoena phocoena, 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: 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 2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. 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. |
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Alternative Identifiers | http://ipt.env.duke.edu/resource?r=zd_133 |