- Jan Roletto
Greater Farallones National Marine Sanctuary
- Shannon Lyday
Greater Farallones Association
Beach Watch is a long-term, beach-monitoring project. Forty-one beach segments are surveyed every 2 weeks by trained volunteers. Beaches surveyed stretch from Bodega Head in Sonoma County down to Año Nuevo in San Mateo County. Volunteers survey a designated beach segment counting, identifying, and photo-documenting live and dead birds and marine mammals and human activity on- and immediately offshore. Surveyors are often the first to report oil or tar balls, and are trained to document and collect oil samples as evidence.
Summary to DateFrom October 1993 – September 2008, 283 volunteers have collected data on 53 beach segments. This constitutes 11,179 surveys of over 23,000 kilometers of shoreline.
Beach Watch data establish baseline encounter rates for bird and marine mammal mortality. Examining these data reveal spatial patterns along the coast. Differences in dead animal deposition between beach segments can reflect geographic features and oceanographic patterns. Differences between beaches can also be attributed to proximity to breeding or roosting colonies.
Since 1996, Beach Watch has collected data on the number of tarballs found on each beach segment. The relatively low-level of tarballs on sanctuary beaches can alert resource managers to an oil event. Surveyors collect tarball samples that are analyzed by California’s Office of Spill Prevention and Response. Some tarballs are typed to anthropogenic sources, such as sunken vessels or oil spills, others originate from natural seeps. The baseline encounter rates of tarballs can also be used to determine chronic levels of oil pollution along the coast.
- Habitat association
- Migration/movement patterns
Study MethodsSurvey methods along each beach segment include: live bird and marine mammal enumeration, visitor/dog activity notation, dead vertebrate documentation, general wrack and invertebrate assessment, oil/tarball documentation, and streams and lagoons status.
Data collected on each beached specimen are: species identification, condition (rate of decomposition), sex, age, evidence of scavenging, probable cause of death (when possible), whether oiled and oil extent and location, and if tagged, tag number, color and location. Each dead specimen is photographed for later verification by an ornithologist or a marine mammal expert to confirm species identification, age, and sex.
Figures and Images
Figure 1. Map of beach segments surveyed by Beach Watch. Credit: Tim Reed
Figure 2. Volunteers documenting a dead bird on Rodeo Beach. Credit: GFNMS
Figure 3. Oiled Common Murre found on Beach Watch survey. Credit: GFNMS