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 the south side of the Alaska Peninsula. Employing a Twin Otter as the survey platform, the second of two 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 the south side of the Alaska Peninsula was 1.1 (SE = 0.10) and 2.03 groups/100 km2 (SE = 1.65). 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 September 8, 2005. Those who downloaded them before that date should renew them.
Enregistrements de données
Les données de cette ressource occurrence ont été publiées sous forme d'une Archive Darwin Core (Darwin Core Archive ou DwC-A), le format standard pour partager des données de biodiversité en tant qu'ensemble d'un ou plusieurs tableurs de données. Le tableur de données du cœur de standard (core) contient 41 enregistrements.
Cet IPT archive les données et sert donc de dépôt de données. Les données et métadonnées de la ressource sont disponibles pour téléchargement dans la section téléchargements. Le tableau des versions liste les autres versions de chaque ressource rendues disponibles de façon publique et permet de tracer les modifications apportées à la ressource au fil du temps.
Versions
Le tableau ci-dessous n'affiche que les versions publiées de la ressource accessibles publiquement.
Comment citer
Les chercheurs doivent citer cette ressource comme suit:
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.
Droits
Les chercheurs doivent respecter la déclaration de droits suivante:
L’éditeur et détenteur des droits de cette ressource est OBIS-SEAMAP. Ce travail est sous licence Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0.
Enregistrement GBIF
Cette ressource a été enregistrée sur le portail GBIF, et possède l'UUID GBIF suivante : c15c7913-e0f4-44d6-a246-678ce908a9e5. OBIS-SEAMAP publie cette ressource, et est enregistré dans le GBIF comme éditeur de données avec l'approbation du Ocean Biodiversity Information System.
Mots-clé
Occurrence,Aircraft,Sightings,harbor porpoise,Phocoena phocoena,abundance,aerial survey,marine mammal survey,survey,marine mammal,cetacean; Observation; Occurrence
Données externes
Les données de la ressource sont disponibles dans d'autres formats
OBIS-SEAMAP Dataset Page | http://seamap.env.duke.edu/dataset/136 UTF-8 Interactive map |
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FGDC Metadata | http://seamap.env.duke.edu/dataset/136/xml UTF-8 XML |
Contacts
- Propriétaire ●
- Créateur ●
- Personne De Contact
- Fournisseur Des Métadonnées ●
- Distributeur
Couverture géographique
Alaska Peninsula,Alaska
Enveloppe géographique | Sud Ouest [55,314, -159,936], Nord Est [57,638, -154,732] |
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Couverture taxonomique
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) |
Couverture temporelle
Date de début | 1992-07-31 |
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Données sur le projet
Pas de description disponible
Titre | NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992 |
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Financement | NA |
Les personnes impliquées dans le projet:
- Propriétaire
- Propriétaire
Méthodes d'échantillonnage
NA
Etendue de l'étude | NA |
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Description des étapes de la méthode:
- NA
Données de collection
Nom de la collection | zd_136 |
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Identifiant de collection | zd_136 |
Identifiant de la collection parente | OBIS-SEAMAP |
Métadonnées additionnelles
marine, harvested by iOBIS
Objet | 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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Identifiants alternatifs | http://ipt.env.duke.edu/resource?r=zd_136 |