title: Persistence of trophic hotspots and relation to human impacts within an upwelling marine ecosystem.
abstract: Human impacts (e.g., fishing, pollution, and shipping) on pelagic ecosystems are increasing, causing concerns about stresses on marine food webs. Maintaining predator-prey relationships through protection of pelagic hotspots is crucial for conservation and management of living marine resources. Biotic components of pelagic, plankton-based, ecosystems exhibit high variability in abundance in time and space (i.e., extreme patchiness), requiring investigation of persistence of abundance across trophic levels to resolve trophic hotspots. Using a 26-yr record of indicators for primary production, secondary (zooplankton and larval fish), and tertiary (seabirds) consumers, we show distributions of trophic hotspots in the southern California Current Ecosystem result from interactions between a strong upwelling center and a productive retention zone with enhanced nutrients, which concentrate prey and predators across multiple trophic levels. Trophic hotspots also overlap with human impacts, including fisheries extraction of coastal pelagic and groundfish species, as well as intense commercial shipping traffic. Spatial overlap of trophic hotspots with fisheries and shipping increases vulnerability of the ecosystem to localized depletion of forage fish, ship strikes on marine mammals, and pollution. This study represents a critical step toward resolving pelagic areas of high conservation interest for planktonic ecosystems and may serve as a model for other ocean regions where ecosystem-based management and marine spatial planning of pelagic ecosystems is warranted.
authors.affiliation: Department of Applied Mathematics and Statistics, Center for Stock Assessment Research, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California, 96060, USA.
authors.forename: Jarrod A
authors.initials: JA
authors.lastname: Santora
authors.affiliation: Farallon Institute for Advanced Ecosystem Research, 101 H Street, Suite Q, Petaluma, California, 94952, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Sydeman
authors.affiliation: Cooperative Institute for Marine Ecosystems and Climate (CIMEC), University of California, Santa Cruz, Santa Cruz, California, 95060, USA.|Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, California, 93940, USA.
authors.forename: Isaac D
authors.initials: ID
authors.lastname: Schroeder
authors.affiliation: Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Field
authors.affiliation: Cooperative Institute for Marine Ecosystems and Climate (CIMEC), University of California, Santa Cruz, Santa Cruz, California, 95060, USA.|Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA.
authors.forename: Rebecca R
authors.initials: RR
authors.lastname: Miller
authors.affiliation: Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA.
authors.forename: Brian K
authors.initials: BK
authors.lastname: Wells
mesh_terms: D000818:Animals; D002140:California; D003132:Commerce; D017753:Ecosystem; D005398:Fisheries; D020387:Food Chain; D006802:Human Activities; D010140:Pacific Ocean; D012767:Ships
keywords: anchovy; fisheries; food web; krill; oil; primary productivity; retention; sardine; seabirds; shipping; spatial management; upwelling