Coastal upwelling affects filter-feeder stable isotope composition across three continents

• Published in: Marine environmental research 2019-05, Vol.147 (1-2), p.13-23
• Main Authors: Puccinelli, Eleonora, McQuaid, Christopher D., Dobretsov, Sergey, Christofoletti, Ronaldo A.
• Format: Article
• Language: English
• Subjects: Animals; Atmospheric particulates; Benthos; Bioengineers; Brazil; Cascading; Climate change; Climate effects; Coastal environments; Coastal upwelling; Dust storms; Ecosystem; Ecosystems; Environmental changes; Environmental Sciences; Fertilization; Filter feeders; Food Chain; Food webs; Intertidal; Invertebrates; Isotope composition; Isotopes; Marine molluscs; Mussels; Ocean circulation; Oceanographic processes; Oman; Phytoplankton; Population Dynamics; South Africa; Stable isotopes; Subsidies; Trophic levels; Upwelling; δ13C
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2019.03.015

Large-scale nutrient fertilisation by coastal upwelling promotes benthic productivity through energy subsidies from enhanced phytoplankton production, and predictions of alterations to upwelling under climate change have implications for benthic ecosystem functioning. We investigated the stable isotope compositions of two bioengineers of global significance, the mussels Perna perna and Mytilus galloprovincialis, from upwelling and non-upwelling sites in five upwelling systems. Samples from Brazil, South Africa and Oman exhibited lower δ13C values at upwelling sites than at non-upwelling sites, with clearer effects where upwelling is more intense and frequent. North West Africa showed variability, probably linked to Saharan dust input. We highlight the importance of upwelling to sustaining benthic primary consumers and the sensitivity of consumer diet to the intensity and frequency of upwelling within each region. These results have implications in relation to climate change scenario effects on upwelling events, with potential cascading effects on higher trophic levels and ecosystem functioning. •We examined upwelling effects on bioengineer diets in five upwelling systems.•Filter feeder δ15N was not influenced by upwelling.•Mussel δ13C at upwelling sites was lower than at non-upwelling sites in four regions.•Variation in North Africa reflected possible additional effects of Saharan dust input.•The effects of upwelling were nested within system-specific factors.