Cetacean Sightings in the Northern California Current During 2000 Upwelling Season

Two line-transect surveys recorded cetacean distributions during the 2000 upwelling season in the northern California Current system. The surveys were conducted by the GLOBEC-Northeast Pacific project aboard the R/V New Horizon on cruises in May-June and July-August 2000. Data collection involved multiple observers using specialized binoculars and GPS-linked logging.

Use Cases

• Model cetacean density and distribution using geospatial sighting locations and survey effort data.
• Analyze seasonal differences in species presence between the May-June and July-August survey periods.
• Correlate cetacean sightings with concurrent oceanographic data from the GLOBEC project using timestamps and GPS coordinates.
• Validate line-transect survey methodologies by examining observer roles and equipment specifications documented in the collection.

Strengths

• Data includes precise geospatial positions corrected from ship GPS to actual animal locations.
• Standardized observation protocols with multiple observers and specific equipment (25x150 binoculars, 7x50 binoculars).
• Surveys conducted during daylight hours with defined visibility and weather criteria (Beaufort <6, visibility >2 nm).

Limitations

• Sample size is limited to two cruises within a single upwelling season, restricting temporal generalizability.
• Observations are confined to daylight hours and fair weather, introducing potential detection bias.
• The dataset is over 20 years old, and species distributions may have shifted due to environmental changes.

Provenance

Source

GLOBEC-Northeast Pacific project, organization SCIOPS.

Collection Method

Line-transect surveys from shipboard platforms using visual observers with binoculars and GPS-linked data entry.

Time Range

28 May - 13 June 2000 and 27 July - 12 August 2000.

Freshness

null

Geography

Northern California Current System, coastal Oregon and Northern California.