Lindquist et al. (2025)
Author Information
Kirsten Lindquist: Greater Farallones Association
Jan Roletto: Greater Farallones & Cordell Bank National Marine Sanctuaries
2024 marked the 31st year of Beach Watch, the coastal monitoring program of Greater
Farallones and Cordell Bank National Marine Sanctuaries (GFNMS/CBNMS) and Greater Farallones Association. In 2024, Beach Watch monitored 60 survey sites over 5 counties in Northern California: Mendocino south to San Mateo counties. Volunteers and staff collect data on coastal birds, mammals, human activities, entanglements, oil pollution, and status of streams and lagoons. In 2024, volunteers contributed over 11,753 hours of service to NOAA, equaling over $393,607.97 (hours x $33.49).
In 2024, seabird deposition was higher than our 30-year mean deposition rates (i.e., 1993–2023 baseline deposition rates). This increase was driven by higher rates for three species of seabirds: Cassin’s Auklet (Ptychoramphus aleuticus), Brown Pelican (Pelecanus occidentalis), and Brandt’s Cormorant (Urile penicillatus). Cassin’s Auklets had a 125% increase in mean deposition rates (from a baseline rate of 0.03 birds/km to 0.07 birds/km in 2024). Cassin’s Auklet deposition was driven by January 2024 storms; 72% were adults and 39% were immature. Brown Pelican had a 95% increase in mean annual deposition rate (from a baseline of 0.021 birds/km to 0.041 birds/km in 2024); approximately 33% were adults. Brandt’s Cormorant had a 95% increase in mean annual deposition rate (from a baseline rate of 0.089 birds/km to 0.122 birds/km, in 2024). Approximately 54% of the dead Brandt’s Cormorants were adults, 39% were immature (aged to be second- and third-year birds).
In contrast to the higher deposition rates overall, two of our most common species had average or lower than average deposition rates; Common Murre (Uria aalge) (long-term mean baseline 0.37 birds/km and 0.37 birds/km in 2024) and Northern Fulmar (Fulmarus glacialis) (long-term mean 0.154 birds/km and 0.023 birds/km in 2024). For marine mammals, the California Sea Lion (Zalophus californianus) annual deposition rate was higher, resulting in an 18% increase in mean deposition rate of 0.051 mammals/km to 0.06 mammals/km in 2024.
Beach Watch data are publicly accessible through the GFA data portal: https://bwonline.beachwat.ch/BeachWatchData.php Researchers and managers can contact Kirsten Lindquist, KLindquist@farallones.org, or Jan.Roletto@noaa.gov for raw data.
For more information on data sharing, access to raw data, details of surveys for beach closures, stream and lagoon status, human activities, oil pollution, demographics of beach vertebrates, or relative abundance of beach wrack, please contact Kirsten Lindquist, KLindquist@farallones.org or Jan.Roletto@noaa.gov.
