The benthic boundary layer is the layer of water above the sediment which is important for the biogeochemistry of the oceans as it is the site of significant organic matter cycling. The effect of the deposition of jellyfish carcasses on the seafloor and the benthic boundary layer is unknown however, it is thought that the presence of jellyfalls, particularly large falls, will induce a change in benthic boundary layer flow dynamics.
The Jelly-Farm Project is setting out to test whether the physical presence of jellyfish carcasses will induce "skimming flow" in the benthic boundary layer. Skimming flow is when fluids find it easier to flow over rather than around objects. It is thought that skimming flow over jellyfish carcasses
would result in
a thicker diffusive boundary layer and a reduction in oxygen flux to the
sediments. Such an impact would significantly affect organic matter cycling on the seafloor.
In April flume experiments will be conducted to simulate and provide initial results
to determine the effect of relatively small, medium and large jellyfalls on the
benthic boundary layer.
Today prototypes of artificial jellyfish carcasses were created in the lab at IRIS.
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| Test materials for making artificial jellyfish carcasses. |
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| A disney ball used as a mould for an agar artificial jellyfish. A screw is used as a weight to keep the jellyfish anchored to the sediment during the flume experiments. |
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| A smaller jellyfish mould prototype with washer weight. |
