Feeding

Little information was available on food sources in 2004 according to Freiwald et al. One educated guess was that corals feed on plankton and suspended particulate matter (SPM) that is captured by polyp tentacles. As food is a scarce resource in the deep-ocean L.pertusa (figure 8 ) has large polyps to achieve greater surface area.

Lophelia pertusa filter feeding on SPM and detritus using its large tenticles

Fig.8. Lophelia pertusa showing tenticles, feeding at 450m (courtesy of NOAA)

It was also suggested by Hovland et al. (1997) that L.pertusa may acquire nutrients from bacteria associated with hydrocarbon seeps although there seems to be no evidence to back up this theory (Kiriakoulakis et al. in press).

More recently Davies et al. (2009) resolved two distinct feeding mechanisms; rapid downwelling of surface water caused by hydraulic control that seems to transport food from the surface to the CWCs in under an hour. The second involves advection of deep bottom water with high SPM load during peak tides.

Finally Theim et al. 2006 has done studies involving numerical modelling. The results showed that encounter rates between SPM and the water layer near the seabed was particularly high close to shelf breaks. This could explain why Lophelia reefs are found in high densities along shelf breaks.

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