Gray Whale Mortality and Identity in San Francisco Bay from 2018 to 2025

114 individual gray whales were identified in San Francisco Bay from 2018 to 2025 using photo-identification data from vessel surveys and community submissions. The dataset, authored by Josephine M. Slaathaug and last updated in April 2026, includes matches to known foraging subgroups and carcasses, with a minimum mortality rate of 18% determined. Vessel strike was identified as the leading cause of death for matched animals.

Use Cases

• Modeling vessel strike mortality risk based on whale subgroup identity and residency length.
• Analyzing range shifts and habitat use by gray whale subgroups in response to climate change.
• Evaluating the effectiveness of photo-identification for individual matching and mortality tracking.

Strengths

• Includes 114 individually identified whales with 21 matched to carcasses.
• Covers a 7-year time range from 2018 to 2025.
• Cause of death was determined for 30 of 70 carcasses, with vessel strike identified for 9 of 11 matched animals.

Limitations

• Row count is unknown, which may limit suitability assessment.
• Column-level documentation is absent; field semantics must be inferred after download.
• Data may reflect geographic and temporal bias inherent to opportunistic and community-submitted observations.

Provenance

Source

figshare

Collection Method

Data collected through vessel-based surveys, opportunistic effort, and community submissions.

Time Range

2018–2025

Freshness

Last updated 2026-04-13 04:30:41; freshness should be verified.

Geography

San Francisco Bay, California