Arroyo Hondo | MARINe

Click here for Long-Term trends

Click here for Biodiversity Survey findings

Arroyo Hondo is located in the South Coast region of California. This site is 0.2 miles west of the Arroyo Hondo Canyon Mouth Mussel Watch site. This gently sloping site consists of moderately uneven terrain, containing few cracks and folds.

Arroyo Hondo biodiversity survey overview

Arroyo Hondo is dominated by a mixture of consolidated sandstone and mudstone bedrock and sandy beach, and the area surrounding the site is comprised of a mixture of consolidated bedrock and sandy beach. The primary coastal orientation of this site is south.

Long-Term Monitoring Surveys at Arroyo Hondo were established in 1992. This site was sampled by the University of California Los Angeles through 2018 and is now monitored by the University of California Santa Barbara. Long-Term MARINe surveys currently target the following species and/or areas: Chthamalus/Balanus (Acorn Barnacles), Mytilus (California Mussel), Rock (Above Barnacles), Phyllospadix (Surfgrass), and Pisaster (Ochre Star). In addition, motile invertebrates, barnacle recruitment, and mussel size structure are monitored at this site. Click here to view Long-Term trends at this site.

Arroyo Hondo long-term monitoring overview

Biodiversity Surveys were done in 2001, 2005, 2016, and 2022. The Biodiversity Survey grid encompasses one section that is approximately 30 meters (along shore) x 20 meters (seaward). Click here to view Biodiversity Survey findings at this site.

Arroyo Hondo was sampled in 2015 as part of a Natural Resource Damage Assessment (NRDA). Biodiversity Linked Vertical Photoplot (BLVP) and motile invertebrate surveys were done as part of the NRDA.

For more information about Arroyo Hondo, please contact Jenn Caselle (

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