Mining Impact 2 is a project within the framework of the European initiative JPIOceans. It focuses on environmental impacts and risks of deep-sea mining of polymetallic nodules in the Clarion Clipperton Fracture Zone (CCZ), north-eastern equatorial Pacific.
The Belgian company DEME-GSR is planning a nodule collector test at two sites in this area and the Mining Impact 2 project was initiated to independently monitor and investigate its impacts on the deep-sea environment and the benthic fauna. These investigations are carried out by an international and multidisciplinary team.
Originally, the collector test was scheduled for spring 2019 and monitoring was supposed to be conducted by the participants of the scientific cruise SO-268 on the research vessel SONNE. But due to cable damage, the collector test had to be postponed and, hence, the cruise was used for an expanded baseline and a small scale experiment to test the monitoring strategies. We, from Senckenberg, could successfully apply our new 20-core multicorer for the first time during the cruise and obtained many samples of meiofauna and megafauna from the seafloor.
Our task within Mining Impact 2 is the development and testing of rapid assessment methods to monitor the deep-sea fauna. Biodiversity is extremely high in the deep sea and especially in the CCZ, although most species remain scientifically undescribed. Hence, fast and definite identification of many organisms is a key feature in any monitoring approach. We focus mainly on two techniques, meta-barcoding and MALDI-TOF MS.
In the meta-barcoding approach, a DNA-barcode of all organisms in a sample is sequenced in parallel, revealing all taxa or species that occur at this position. A DNA-barcode is a small piece of DNA, usually with a length of several hundred base-pairs, which varies between species. To link these sequences to real, existing species or taxa, we are also establishing reference libraries with the DNA-barcodes of different taxa. This method is especially useful for a fast, qualitative investigation of all species present at a position.
MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) is also a molecular method. Here, the composition of differently sized proteins and amino-acids, the so called “proteomic fingerprint”, is used to differentiate between species. It is especially fast and cost-effective for specimen-by-specimen investigations for a quantitative assessment of abundances.