News from the sea floor: Report on the 18th GEOHAB Conference
Santa Barbara, California, 14 °C and foggy, many participants made a mistake in the choice of their clothing. About 200 people met in not-so-sunny California already on Monday to be able to participate in the paid workshop offered by ESRI and QPS for the first day.
‘GEOHAB’ means „Marine Geological and Biological Habitat Mapping“ and unites marine biologists, acousticians, geoscientists, statisticians, und environmental managers from all over the world. This conference lasting several days was founded 20 years ago by Gary Greene and has been well established internationally. From Tuesday to Thursday, 14 sessions were offered to the audience with broadband topics from e.g. deep water corals to coastal and marine management.
Similar to the strategic principle of the HYDRO conference, the GEOHAB community is tightly linked with manufacturers of e.g. multibeam echosounders and software. Renowned manufacturers from the hard- and software business focussing on sea floor mapping were present in the exhibition hall. Several public authorities are also very active in the GEOHAB community, like the ‘Geological Survey of Norway’, or NOAA, or the Bureau of Ocean Energy Management (BOEM) from USA.
Besides the well-balanced programme focussing on the subjects marine habitat mapping, classification and habitat exploration, another highlight this year, no doubt, was the award ceremony of the Multispectral Challenge launched by R2SONIC. The participants had almost a year to analyze a given multifrequency multibeam echosounder dataset (100, 200, und 400 kHz) in the best way possible. The winner can look forward to a 300.000 Dollar package including a brand new 2026 multibeam echosounder. After his talk and the award ceremony, the winner Timo Gaida, Kiel University alumnus and now TU Delft PhD student, seemed astonished. The TU Delft method of data analysis is based on the fact that backscatter data can be described statistically. Averaged over many data points, it is assumed that backscatter data appears locally Gaussian distributed. This assumption again can be used to build different sea floor classes.
Another motivation of our group to participate in the conference was to join the Backscatter Working Group (BSWG). This group formed several years ago under the umbrella of GEOHAB and the lead of Xavier Lurton (Ifremer, Frankreich), who is a well-known author and expert in the field of hydroacoustics.
In the BSWG Session on Tuesday evening moderated by Xavier Lurton und Geoffroy Lamarche, it was agreed on the need for a catalogue listing the multispectral behaviour of individual habitates. In this respect, terrestrial research is decades ahead of marine research. Most of the users are satisfied with the quality of bathymetric measurements, whereas they are not with backscatter measurements, which was plausibly termed „end-user-frustration“ by Marc Roche. It is our impression that in moments like these hard- and software manufacturers and end users find a common language and identify common problems, which is also experienced at the HYDRO conference.
It is very motivating to follow the activities of this open group in its efforts to improve backscatter data. In our current project, we also work intensively on the subjects of multifrequency analysis and habitat mapping. Knowing this, Xavier Lurton asked us to moderate this subject, and to take the lead to feed it into a new issue of the BSWG reports. A challenging task.
Another announcement of Peter Harris pricked our ears: a new issue of the ‘GeoHab Atlas of seafloor geomorphic features and benthic habitats’ is in preparation. For anyone who is fast enough, there might be the opportunity for a contribution.
Until the end of the year it is also possible to submit contributions to the special volume “Geological Seafloor Mapping” (guest editors: Markus Diesing, Peter Feldens; ECOMAP) of the journal Geosciences.
Our thanks go to the organizers, who made it possible that we could participate in this highly interesting event. With the final excursion to the Channel-Islands situated off the coast, they put a cherry on the cake. Next year, the GEOHAB crowd migrates east to St. Petersburg. We are looking forward to meet again there!
Jens Schneider von Deimling
Harris, P. T., & Baker, E. K. (Eds.). (2011). Seafloor Geomorphology as Benthic Habitat: GeoHab Atlas of seafloor geomorphic features and benthic habitats. Elsevier.
Lamarche, G., & Lurton, X. (2017). Recommendations for improved and coherent acquisition and processing of backscatter data from seafloor-mapping sonars. Marine Geophysical Research, 1-18.