NMML Small Cetacean Aerial Survey 1997

Roderick Hobbs

doi:10.15468/44vz4g

NMML Small Cetacean Aerial Survey 1997

Citation

Hobbs R, OBIS-SEAMAP (2021). NMML Small Cetacean Aerial Survey 1997. OBIS-SEAMAP. Occurrence dataset https://doi.org/10.15468/44vz4g accessed via GBIF.org on 2024-12-13.

Description

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: Aerial surveys was conducted in 1997 progressing from east to west, to estimate abundance of the Southeast Alaska (SEA, 9,844 km survey effort), Gulf of Alaska (GOA, 10,127 km survey effort), and Bering Sea (BS, 7849 km survey effort) harbor porpoise stocks. In addition, 1355 km of survey effort during a Cook Inlet beluga survey were analyzed to add to the coverage for the GOA stock. Data from an independent observer concentrating on the trackline was used to estimate perception bias. Significant differences in g(0) and effective strip width (ESW) were found between the survey conducted in 1997 and the 1998 and 1999 surveys, therefore 1997 was treated separately. In both analyses, g(0) was dependent on visibility reported by observers, and in the 1997 data ESW was dependent as well. The 1997 survey included the inland waters of southeastern Alaska and the eastern Gulf of Alaska from Dixon Entrance to Cape Suckling Purpose: A 3-year survey began in 1997 to complete a new abundance estimate by 1999. This survey will also include an abundance estimate for Dalls porpoise (Phocoenoides dalli). Once the 3 years of surveys are completed, the data will be used to estimate annual abundance of harbor porpoise and Dalls porpoise, which is one of the key pieces of information needed to manage marine mammal-fishery interactions, as required under the Marine Mammal Protection Act. Supplemental information: Although the previous harbor porpoise surveys (1991- 1993) used a vessel platform for the inside waters of Southeast Alaska (Dahlheim et al. 1992, 1993, 1994), the current survey was conducted entirely from aircraft.

Purpose

A 3-year survey began in 1997 to complete a new abundance estimate by 1999. This survey will also include an abundance estimate for Dalls porpoise (Phocoenoides dalli). Once the 3 years of surveys are completed, the data will be used to estimate annual abundance of harbor porpoise and Dalls porpoise, which is one of the key pieces of information needed to manage marine mammal-fishery interactions, as required under the Marine Mammal Protection Act.

Sampling Description

Study Extent

NA

Sampling

NA

Method steps

NA

Additional info

marine, harvested by iOBIS

Taxonomic Coverages

Scientific names are based on the Integrated Taxonomic Information System (ITIS).

Balaenoptera physalus
common name: Fin Whale rank: species
Eumetopias jubatus
common name: Steller Sea Lion rank: species
Eschrichtius robustus
common name: Gray Whale rank: species
Lagenorhynchus obliquidens
common name: Pacific White-sided Dolphin rank: species
Megaptera novaeangliae
common name: Humpback Whale rank: species
Orcinus orca
common name: Killer Whale rank: species
Phocoenoides dalli
common name: Dall's Porpoise rank: species
Physeter macrocephalus
common name: Sperm Whale rank: species
Phocoena phocoena
common name: Harbor Porpoise rank: species
Phoca vitulina
common name: Harbor Seal rank: species
Mesoplodon
common name: beaked whales rank: genus
Cetacea
common name: cetaceans rank: order
Cetacea
common name: cetaceans rank: order

Geographic Coverages

Alaska,Eastern Alaska,Gulf of Alaska,Dixon Entrance,Cape Suckling

Bibliographic Citations

Contacts

Roderick Hobbs
originator
position: Primary contact
National Marine Mammal Laboratory
email: Rod.Hobbs@noaa.gov

OBIS-SEAMAP
metadata author
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

OBIS-SEAMAP
distributor
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

Roderick Hobbs
owner
position: Primary contact
National Marine Mammal Laboratory
email: Rod.Hobbs@noaa.gov

Roderick Hobbs
administrative point of contact
position: Primary contact
National Marine Mammal Laboratory
email: Rod.Hobbs@noaa.gov