June 7, 2018 - The San Francisco Bay Area Network's Pinniped Monitoring Program recorded the first harbor seal pups of the 2018 breeding season at Drakes Estero and Tomales Bay on March 23rd, which was right on schedule. Pups were seen at all sites by the week of April 8th. The peak of pupping occurred during late April and early May, with a maximum number of approximately 1,000 pups recorded throughout Marin County locations. This peak is similar to the 16-year average of 1,080 pups. Drakes Estero and Bolinas Lagoon were the two top sites with approximately 360 and 260 pups, respectively. Bolinas Lagoon has had increased pup counts over the last six years and is now about 60% greater than its site average.
2018 Harbor Seal Monitoring Updates
The number of surveys at Double Point has been reduced due to safety concerns at the observation spot. Surveys are now concentrated during the peak of pupping and, along with last year, we are seeing very low pup numbers at this site. This year’s peak of 150 pups is about 50% less than the site’s average. It is unknown why this site is declining, but could be due to an increase in coyotes and habitat effects from the large storms in 2017.
Maximum Harbor Seal Count By Site
Maximum Harbor Seal Pup Counts, 2000-2018
The Details: Weekly Maximum Harbor Seal Counts By Site
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