Decomposition of jellyfish carrion in situ: Short-term impacts on infauna, benthic nutrient fluxes and sediment redox conditions.
Jellyfish often form blooms that persist for weeks to months before they collapse en masse, resulting in the sudden release of large amounts of organic matter to the environment. This study investigated the biogeochemical and ecological effects of the decomposition of jellyfish in a shallow coastal lagoon in New South Wales, Australia. Catostylus mosaicus carrion was added to the surface of shallow sub-tidal sediments and biogeochemical parameters and macrofaunal abundance immediately below the jellyfish carrion were measured over three days. Sediment plots without jellyfish served as controls. Sediment oxygen demand and carbon and nitrogen efflux increased by up to 60-fold in the jellyfish plots, compared to control plots, and dissolved organic nutrient fluxes were more sustained than in previous studies due to the use of fresh rather than frozen biomass. The decomposing jellyfish progressively altered sediment redox conditions, indicated by an increase in porewater iron (II) and sulfide concentrations measured by high-resolution in situ diffusive samplers. Abundance of some macrofaunal taxa in the jellyfish plots decreased relative to controls, however, the abundance of a carnivorous gastropod, which was presumably feeding on the carrion, increased in the jellyfish plots. While jellyfish carrion may be a food source for some macrofauna, low oxygen conditions coupled with the accumulation of toxic dissolved sulfides in the near-surface sediments may explain the overall change in the macroinfaunal community.
Australian Rivers Institute - Coasts and Estuaries, Griffith School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia. Electronic address: ariella.chelsky@griffithuni.edu.au.
Ariella
A
Chelsky
Australian Rivers Institute - Coasts and Estuaries, Griffith School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia.
Kylie A
KA
Pitt
New South Wales Office of Environment and Heritage, Sydney, New South Wales 2000, Australia.
Angus J P
AJP
Ferguson
Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia.
William W
WW
Bennett
Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia.
Peter R
PR
Teasdale
Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast, Queensland 4222, Australia.
David T
DT
Welsh
D000818:Animals; D058448:Biota; D003643:Death; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D007448:Invertebrates / Q000502:physiology*; D009517:New South Wales; D010084:Oxidation-Reduction; D037401:Scyphozoa / Q000502:physiology*; D014876:Water Pollution
Bacterial decomposition; Benthic macrofauna; Diffusive equilibration in thin films (DET); Diffusive gradients in thin films (DGT); Gelatinous zooplankton; Remineralization