title: Spatial dynamics of the bearded goby and its key fish predators off Namibia vary with climate and oxygen availability.
abstract: Hypoxia [O2< 2.0 mL L-1(87μmol kg-1)] and severely hypoxic water masses [O2< 0.5 mL L-1(21.8μmol kg-1)] are increasing in coastal marine ecosystems due to eutrophication and warming. Here, we investigate the response of the suboxic-tolerant endemic fish,Sufflogobius bibarbatus, to variations in the thermal and oxygen environment, as well as to predation pressure, using 22 yr worth of satellite andin situdata. We show that environmental variation and predation pressure affect the goby population, which has expanded over the last decade while that of horse mackerel has contracted. These changes co-occurred with a general warming in the north and central shelf areas (north of 24.5°S). Spring warming positively affected both goby and hake abundances, but not the horse mackerel, suggesting different responses to surface temperature. The goby habitat contracted when predators were abundant, particularly in the north, which is the fringe of its distributional area. The implications of the differential tolerance of gobies and their predators for climate variations are discussed.
authors.affiliation: Department of Biology and Hjort Centre for Marine Ecosystem Dynamics, University of Bergen Bergen, Norway.
authors.forename: Anne Gro V
authors.initials: AG
authors.lastname: Salvanes
authors.affiliation: National Marine Information and Research Centre Swakopmund, Namibia.
authors.forename: Chris
authors.initials: C
authors.lastname: Bartholomae
authors.affiliation: Department of Agriculture, Forestry and Fisheries, Fisheries Branch Cape Town, South Africa ; Department of Oceanography, Marine Research Institute, University of Cape Town Cape Town, South Africa.
authors.forename: Dawit
authors.initials: D
authors.lastname: Yemane
authors.affiliation: University of the Western Cape Bellville, South Africa.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Gibbons
authors.affiliation: National Marine Information and Research Centre Swakopmund, Namibia.
authors.forename: Paul
authors.initials: P
authors.lastname: Kainge
authors.affiliation: Institute of Marine Research and Hjort Centre for Marine Ecosystem Dynamics Bergen, Norway.
authors.forename: Jens-Otto
authors.initials: JO
authors.lastname: Krakstad
authors.affiliation: Nansen-Tutu Center for Marine Environmental Research, University of Cape Town Cape Town, South Africa ; Department of Oceanography, Marine Research Institute, University of Cape Town Cape Town, South Africa.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Rouault
authors.affiliation: Department of Biology and Hjort Centre for Marine Ecosystem Dynamics, University of Bergen Bergen, Norway ; Institute of Marine Research and Hjort Centre for Marine Ecosystem Dynamics Bergen, Norway.
authors.forename: Arved
authors.initials: A
authors.lastname: Staby
authors.affiliation: Institute of Marine Research and Hjort Centre for Marine Ecosystem Dynamics Bergen, Norway.
authors.forename: Svein
authors.initials: S
authors.lastname: Sundby
keywords: Benguela Niño; Sufflogobius bibarbatus; abundance; bearded goby; distribution; hake; horse mackerel; hypoxia; predator–prey environmental dynamics; remote forcing; suboxia