from hub partner Geoscience Australia

The Marine Hub’s visit to the shelf that surrounds Lord Howe Island aboard Australia’s National research vessel, the ”Southern Surveyor”, was the first survey to sample infauna from this remote World Heritage area.

Infauna, the organisms living in marine sediments, make up a large part of the species richness of benthic systems and play an important role in marine chemical cycles and food webs.

A multi-disciplinary team of researchers collected marine sediment samples from depths of 20 – 80 m around Lord Howe Island, as well as multi-beam sonar bathymetry data and underwater video footage to test the utility of a range of physical seabed parameters as surrogates for patterns of biodiversity on mid-ocean shallow-shelf environments. The sediment samples contain many strange and interesting species, many of which are new to science. Dr Buz Wilson, a crustacean taxonomist at the Australian Museum, is taking on the task of describing and naming the isopods never before seen by humans.  Isopods, familiar to most as garden slaters, are a group of crustaceans found in almost every marine habitat in a wide variety of shapes and sizes.

There are around three hundred thousand species of benthic organisms already described and at least as many yet to receive attention, so collecting undescribed species around Lord Howe Island was not unexpected, especially given the island’s isolation and the high degree of endemism of its reef biota.  “The more samples you take and the closer you look at them, the more likely you are to see something no-one’s ever come across before,” stated Marine Hub benthic ecologist, Matt McArthur.  “Identifying organisms to species rather than “morphotypes” provides considerably more analytical power” added Buz Wilson. This sort of discovery is also important because it helps indicate how many species, both known and as yet unknown, exist in Australia’s marine systems.  One of the specimens from a shallow sample is from a family normally only seen in deep systems, so in addition to discovering new species this work is also enhancing our understanding of species’ ranges and environmental tolerances.  As Matt McArthur notes “This work demonstrates how Marine Hub research is improving our understanding of what lives within Australia’s marine systems and why its located in a particular habitat, and then supplying that information to the agencies making decisions about what habitats require protection.

Photo caption:  A new species of Tanzanapseudes Bacescu, 1975 (family Tanzanapseudidae) from Lord Howe Island (Photo by B. Wilson).