2026 Harbor Seal Monitoring Updates

By National Park Service Marine Ecologist Sarah Codde

Each spring, harbor seals gather in large groups on sheltered beaches and sandbars in Golden Gate and Point Reyes for their breeding season. During this time, female harbor seals give birth to single pups. Then in the summer, harbor seals of all ages return to these areas to molt, or shed their fur. The Harbor Seal Monitoring Team—a group of dedicated volunteers, partners, and staff—surveys these breeding and molting seals to learn about when/how/why their population size and breeding success changes over time. After all, these sensitive, curious seals are our parks’ only year-round marine mammal residents. And their population health is a great proxy for the health of our parks’ nearshore ecosystems.

Breeding Season Summary

Harbor seal mother and pup in a tidepool off of Tomales Point. NPS / Dan Russell

In 2026, we wrapped up our breeding season surveys at the end of May. We counted around 690 pups at seven sites throughout the parks. This count is one of the two lowest counts on record during the 27-year monitoring period, along with the count from 2024. We’ve been seeing low pup counts since 2021.

The simple line graphs represent harbor seal pup counts at each site from 2000 to 2026. Their y-axes all range from 0 to 500 pups. In 2026, Bolinas Lagoon had the highest count, with 237 pups. Drakes Estero fell to the number two spot with 172 pups. Sites were not surveyed in 2020. NPS

Double Point, Drakes Estero, and Tomales Point all had pup counts that were far below their respective long-term averages. In fact, they had the lowest counts on record for each of their sites. We continued to see the ongoing presence of coyotes at Drakes Estero and Double Point this year, which possibly led to the large declines at those sites.

Not all sites experienced record low counts though! Point Bonita, Tomales Bay, and Duxbury Reef had counts that were similar to their respective long-term averages, and Bolinas Lagoon had an above-average count. For only the second time in our monitoring program's history, Bolinas Lagoon had the highest count of all Marin County locations with 237 pups. Drakes Estero fell to the number two spot with 172 pups.

Molt Season Summary

Harbor seals resting on a sandbar in Bolinas Lagoon as they shed their fur and grow new coats. NPS / Clair Sapilewski

The line graphs represent maximum harbor seal molt counts at each site from 2000 to 2026. Their y-axes all range from 0 to 2,000 seals. Sites were not surveyed in 2020.

During the 2026 molt season, we recorded a maximum count of 1,605 harbor seals. This is close to our 2025 count, but the lowest count on record since the National Park Service monitoring program began. The 26-year average count is 3,234 molting seals. As with our pup counts, we have seen molting seal counts decline steadily since 2021. It’s promising, though, to see the decline slow this year and nearly match last year's count of 1,645 seals.

Bolinas Lagoon had the largest count of all our monitoring sites with 442 seals, followed by Tomales Point with 314 seals. All sites had lower-than-average maximum molt counts, but they were all very similar to last year's counts. No site experienced a big decrease compared to last year.

We thank the 20 National Park Service volunteers and various Marin County Parks staff for helping conduct 211 surveys across seven sites in or near Point Reyes and Golden Gate in 2026.

Preliminary Data

2026 Maximum Harbor Seal Count By Site

Maximum harbor seal counts by site during the breeding season (adults and pups) and the molting season (all seals). NPS

Maximum Harbor Seal Pup Counts, 2000-2026

Maximum harbor seal pup counts for 2000-2025 at Marin County sites. The black solid line on the graph represents the mean, or average, of the maximum pup counts from 2000-2024 (mean = 1,037), and the dashed lines represent one standard deviation from the mean. Not all sites were surveyed in 2020. NPS

Maximum Harbor Seal Molt Counts, 2000-2026

Maximum harbor seal molt season counts for 2000-2026 across all Marin County sites. The black solid line on the graph represents the mean, or average, of the maximum seal counts from 2000-2025 (mean = 3,234). Dashed lines represent one standard deviation from the mean, or the normal range of variation. Not all sites were surveyed in 2020. NPS

The Details: 2026 Weekly Maximum Harbor Seal Counts By Site

Maximum weekly harbor seal counts by site and survey week between March and July 2026. Bolinas Lagoon has the highest maximum counts of breeding and molting seals with the clearest seasonal peaks. NPS

For More Information

Webpages

San Francisco Bay Area Network - Pinniped Monitoring

Pacific Coast Science and Learning Center - Harbor Seals

Data

Pinniped Monitoring for the San Francisco Bay Area Network: 1983-2025 - Data Package

Contact

Point Reyes National Seashore

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• Golden Gate National Recreation Area
• Point Reyes National Seashore

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