MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 604:99-120 (2018) - DOI: https://doi.org/10.3354/meps12742 Changes in zooplankton assemblages in northern Monterey Bay, California, during a fall transition Julio B. J. Harvey1,*, Jennifer L. Fisher2, John P. Ryan1, Shannon B. Johnson1, William T. Peterson3,†, Robert C. Vrijenhoek1 1Monterey Bay Aquarium Research Institute, Moss Landing, California 95062, USA 2Cooperative Institute for Marine Resources Studies, Newport, Oregon 97365, USA 3National Oceanic and Atmospheric Administration, Northwest Fisheries Science Center, Seattle, Washington 98112, USA *Corresponding author: jbjharvey@gmail.com†Deceased ABSTRACT: Accurately assessing the diversity and abundance of marine zooplankton is greatly confounded by the interactions of biological and physical processes that vary in space and time. This study simultaneously assessed biological and physical sources of zooplankton assemblage variation with multidisciplinary methods. Autonomous underwater vehicles (AUVs) and shipboard plankton net sampling were used to document a seasonal shift that occurred during a typical fall transition period in northern Monterey Bay, California. Intrusion of low salinity offshore waters into our study region was associated with decreased stratification of the water column. Morphological taxonomy and high-throughput DNA sequencing (HTS), involving mitochondrial cytochrome oxidase subunit-I (COI) and large subunit (28S) nuclear ribosomal RNA, were used to document zooplankton communities in 36 vertical plankton tows collected during the fall transition. Increased copepod diversity and delivery of species associated with warmer southern waters corresponded with the intrusion of offshore waters. Echinoderms and barnacles also increased in abundance. Conversely, species of polychaetes and gastropods decreased in diversity and abundance. Onshore-offshore spatial shifts also occurred between August and October sampling periods. Primary insights contributed by newer methods included high resolution documentation of environmental variation (i.e. AUV data) and increased taxonomic resolution for some zooplankton groups (e.g. polychaetes and gastropods; HTS data) compared to the morphological assessment. Together, the AUV environmental data, morphological assessments and HTS zooplankton identifications provided a compelling picture of how water mass variation typical of the fall season can affect zooplankton assemblages in northern Monterey Bay, California. KEY WORDS: Marine zooplankton · Biological oceanography · Plankton ecology · Upwelling shadow · Monterey Bay · California Current Full text in pdf format Supplementary material PreviousNextCite this article as: Harvey JBJ, Fisher JL, Ryan JP, Johnson SB, Peterson WT, Vrijenhoek RC (2018) Changes in zooplankton assemblages in northern Monterey Bay, California, during a fall transition. Mar Ecol Prog Ser 604:99-120. https://doi.org/10.3354/meps12742 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 604. Online publication date: October 04, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.