North Central Coast: Coastal environmental conditions (1990-2010)

• Main Authors: Sarah Ann Thompson, Bill Sydeman
• Format: Dataset
• Language: unknown
• Published: California Ocean Protection Council Data Repository 2013
• Subjects: Farallon Institute for Advanced Ecosystem Research; Physical oceanographic data; Chemical oceanographic data; Water quality; Baseline MPA monitoring; North Central Coast; Arctic; Pacific; Soi; Rani; Phytoplankton
• Online Access: https://doi.org/10.25494/P61P49

Evaluation of management actions requires baseline information on environmental variability that may also affect biological populations and confound interpretations. Here, we develop and explore ocean-climate indicators (“OCI”) of temporal environmental variability known to affect fish and wildlife of the north-central California Current over 21 years, 1990-2010. This analysis supports ongoing efforts to evaluate responses in local coastal ecosystems to recent changes in fishing effort practices within the State’s newly established network of marine protected areas (MPA). To develop multivariate OCI, we selected, compiled and analyzed 16 well-known atmospheric and oceanographic indicators that represent key basin-scale drivers and regional attributes of the coastal environment. These include drivers of ocean-climate variability from the tropics (e.g., SOI/ENSO) and extra-tropics (e.g., PNA/PDO/NPGO), and regional-local driver/response variables such as wind stress, sea surface temperature and salinity, and a novel time series of surface flow from the State of California’s HF radar array. We implemented seasonally-based multivariate OCI using principal component analysis. Over the study period, the ENSO cycle apparently weakened resulting in fewer and less intense El Niño events. Sub-arctic influences increased with a strengthening of the North Pacific Gyre Oscillation (NPGO) and cooling of the Pacific Decadal Oscillation (PDO). Corresponding to these changes, the Northern Oscillation Index (NOI) strengthened leading to enhanced upwelling-favorable wind stress as well as air and ocean surface temperature cooling. Phytoplankton biomass, proxied by satellite remote-sensing of chl-a, increased from 1995-2010. However, this positive trend in lower trophic level productivity was not observed in mid (juvenile Sebastes) or upper trophic level (salmon) biological indicators. Our results support a hypothesis of enhanced sub-arctic influences and upwelling intensification in north-central California over the past two decades that is contributing to greater lower, but not upper, trophic level productivity. Linking these changes to newly obtained biological records within and outside newly established MPA is warranted to separate the effects of climate variability from changes in fishing pressure on coastal ecosystems. This dataset was originally uploaded to Oceanspaces (http://oceanspaces.org/) in 2013 as part of the North Central Coast baseline monitoring program. In 2020 the baseline data and reports were uploaded to the California Ocean Protection Council Data Repository by Mike Esgro ([e-mail]) and Rani Gaddam ([e-mail]). Every attempt has been made to include all of the original data, metadata, and reports submitted in 2013, but please contact the Data Set Contacts with any questions. The long-term California MPA boundary and project info tables referenced in this dataset can be found as a separate dataset here: https://opc.dataone.org/view/doi:10.25494/P64S3W