JPI Oceans -Deep Sea Mining- JPIO-cruise participation on cruise leg SO242-1 on the "Ecological Aspects of deep sea mining" cruise for NTNU

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2015

End date

12/31/2018

Budget

62,730 EUR

Fundings

Abstract

The scientific work during SO242/2 (28. August - 01. October 2015) was part of the JPIO Pilot Action ?Ecological Aspects of Deep-Sea Mining?. The main goal was to study the potential long-term ecological impact of anthropogenic disturbances on the deep-sea floor from mining polymetallic Mn-nodules. The expedition SO242 was using the research vessel RV Sonne and built on studies of the former German TUSCH projects (1989-1996) with four RV SONNE cruises to the DISCOL Experimental Area in the Peru Basin, South Pacific (7°S, 88.5° W; 4150 m water depth) between 1989 and 1996 (DISCOL and ATESEPP projects). The main research questions targeted were the effect of disturbances on different ecosystem compartments and processes including: ? Physicochemical habitat characteristics ? Geochemical and biogeochemical processes at the seafloor and in the bottom ? waters ? Composition of benthic assemblages (mainly mega-, meio-, and microfauna) ? Metabolic activity and transfer of energy and matter in benthic communities ? Release, bioaccumulation, and ecotoxicological effects of contaminants The project presents the first hyperspectral image data from the deep seafloor. The Scientific Underwater Hyperspectral Imager (model UHI_SCI_6000) produced by Ecotone A/S was integrated into the ROV system and successfully tested and operated by NTNU. The data were acquired in about 4200 m water depth using the UHI. Data were recorded for spatial resolution (1 mm per image pixel). Combined with supervised classification methods the project shows that UHI represents a promising tool for high- resolution seafloor exploration and characterization for to resource exploration. Identification of benthic megafauna is another promising deep sea application of the UHI. Currently this identification is based on physical samples, video or photo imagery. But, sampling may be difficult and time-consuming, especially in the deep sea, and interpretation of seabed images often only allows characterization into taxonomic classes. The UHI provides a much higher spectral resolution than standard RGB imagery, enabling classification of marine organisms based on spectral signatures. The UHI data provide an increased detection rate for small megafauna difficult to resolve in standard RGB imagery.