NMML Small Cetacean Aerial Survey 1999

Roderick Hobbs

doi:10.15468/n6qf5x

NMML Small Cetacean Aerial Survey 1999

Citation

Hobbs, R. 2013. NMML Small Cetacean Aerial Survey 1999. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/117) on yyyy-mm-dd. https://doi.org/10.15468/n6qf5x accessed via GBIF.org on 2024-12-15.

Description

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: The National Marine Mammal Laboratory (NMML) conducted an aerial survey for small cetaceans from 5 June to 4 July, 1999 in Bristol Bay and along southwestern Alaska Peninsula (out to the 1,829 m [1,000 fm] depth contour). A total of 8,522 km were surveyed in a Dehavilland Twin Otter at 152.5 m (500 ft) altitude and 185 km/hr (100 kts). Two overlapping sawtooth lines were designed along the coastline of Bristol Bay. Both sides of each sawtooth were approximately 37 km with a 46 km base. Large bays were also included in the survey. Primary observers searched through bubble windows on the left and right sides of the aircraft and reported sightings to a computer operator. To estimate a perception bias correction factor for this study, an independent observer was added at a belly window position to determine the number of animals in the immediate vicinity of the trackline that were missed by the primary observers. There were 215 sightings of harbor porpoise (260 individuals), 12 Dall's porpoise (24 individuals), and 16 Pacific white-sided dolphins (170 individuals) while surveying tracklines. Additional cetacean sightings included 12 gray whales (13 individuals), 18 humpback whales (29 individuals), 8 minke whales (13 individuals), and 3 killer whales (11 individuals). Purpose: The current study (1997-1999) will provide new abundance estimates for each stock of harbor porpoise and Dall's porpoise. 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. However, a concurrent vessel survey in a selected portion of southeastern Alaska and a calibration study with the survey vessel. We report here the results from the third year of surveys (1999). References: Dahlheim, M., A. York, J. Waite, and C. Goebel-Diaz. 1992. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska, Cook Inlet and Bristol Bay. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910. Dahlheim, M., A. York, J. Waite, and R. Towell. 1993. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska, Kodiak Island, and the south side of the Alaska Peninsula, 1992. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910. Dahlheim, M., A. York, J. Waite, and R. Towell. 1994. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska and the offshore waters of Dixon Entrance to Prince William Sound, 1993. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910.

Purpose

The current study (1997-1999) will provide new abundance estimates for each stock of harbor porpoise and Dall's porpoise. 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. However, a concurrent vessel survey in a selected portion of southeastern Alaska and a calibration study with the survey vessel. We report here the results from the third year of surveys (1999). References: Dahlheim, M., A. York, J. Waite, and C. Goebel-Diaz. 1992. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska, Cook Inlet and Bristol Bay. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910. Dahlheim, M., A. York, J. Waite, and R. Towell. 1993. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska, Kodiak Island, and the south side of the Alaska Peninsula, 1992. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910. Dahlheim, M., A. York, J. Waite, and R. Towell. 1994. Abundance and distribution of harbor porpoise (Phocoena phocoena) in southeast Alaska and the offshore waters of Dixon Entrance to Prince William Sound, 1993. Annual report to the MMPA Assessment Program, Office of Protected Resources, NMFS, NOAA, 1335 East-West Highway, Silver Spring, MD 20910.

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 acutorostrata
common name: Minke 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
Odobenus rosmarus
common name: Walrus rank: species
Phocoenoides dalli
common name: Dall's Porpoise rank: species
Phocoena phocoena
common name: Harbor Porpoise rank: species
Phoca vitulina
common name: Harbor Seal rank: species
Cetacea
common name: cetaceans rank: order
Cetacea
common name: cetaceans rank: order

Geographic Coverages

Alaska,Gulf of Alaska,Southeast Alaska,Bristol Bay,Bering Sea

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