title: Minimal ecosystem uptake of selenium from Westland petrels, a forest-breeding seabird.
abstract: Endemic Westland petrels (Procellaria westlandica) are a remnant of extensive seabird populations that occupied the forested hill country of prehuman New Zealand. Because seabird guano is rich in Se, an often-deficient essential element, we proposed that Westland petrels enhance Se concentrations in ecosystems associated with their breeding grounds. We sampled terrestrial (soil, plants, riparian spiders) and freshwater (benthic invertebrates, fish) components from Westland petrel-enriched and non-seabird forests on the western coast of New Zealand's South Island, an area characterised by highly leached, nutrient-poor soils. Median seabird soil Se was an order of magnitude higher than soil from non-seabird sites (2.2mgkg-1compared to 0.2mgkg-1), but corresponding plant foliage concentrations (0.06mgkg-1; 0.05mgkg-1) showed no difference between seabird and non-seabird sites. In streams, Se ranged from 0.05mgkg-1(riparian foliage) to 3.1mgkg-1(riparian spiders and freshwater mussels). However, there was no difference between seabird and non-seabird streams. Stoichiometric ratios (N:Se, P:Se) showed Se loss across all ecosystem components relative to seabird guano, except in seabird colony soil where N was lost preferentially. Seabirds therefore did not enrich the terrestrial plants and associated stream ecosystems in Se. We conclude that incorporation of trace elements brought ashore by seabirds cannot be assumed, even though seabirds are a significant source of marine-derived nutrients and trace elements to coastal ecosystems world-wide.
authors.affiliation: Department of Applied Sciences & Allied Health, Ara Institute of Canterbury, PO Box 540, Christchurch 8140, New Zealand. Electronic address: david.hawke@ara.ac.nz.
authors.forename: David J
authors.initials: DJ
authors.lastname: Hawke
authors.affiliation: School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Roseanna
authors.initials: R
authors.lastname: Gamlen-Greene
authors.affiliation: School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Jon S
authors.initials: JS
authors.lastname: Harding
authors.affiliation: Department of Applied Sciences & Allied Health, Ara Institute of Canterbury, PO Box 540, Christchurch 8140, New Zealand.
authors.forename: Dana
authors.initials: D
authors.lastname: Leishman
mesh_terms: D000818:Animals; D001717:Birds; D017753:Ecosystem; D004784:Environmental Monitoring; D020387:Food Chain; D065928:Forests; D009520:New Zealand; D012643:Selenium / Q000378:metabolism*
chemical_list: D012643:Selenium
keywords: Guano; Procellariidae; Seabird soil; Stream ecosystem; Trace element