Geographic distribution of free-living marine nematodes in the Clarion–Clipperton Zone: implications for future deep-sea mining scenarios

Autor: Freija Hauquier, Lara Macheriotou, Tania N. Bezerra, Great Egho, Pedro Martínez Arbizu, Ann Vanreusel
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: BIOGEOSCIENCES DISCUSSIONS
ISSN: 1726-4189
1810-6285
1810-6277
Popis: Mining of polymetallic nodules in abyssal seafloor sediments promises to address the growing worldwide demand for metallic minerals. Given that prospective mining operations are likely to have profound impacts on deep seafloor communities, industrial investment has been accompanied by scientific involvement for the assessment of baseline conditions and provision of guidelines for environmentally sustainable mining practices. Benthic meiofaunal communities were studied in four prospective mining areas of the Clarion–Clipperton Zone (CCZ) in the east Pacific Ocean, arranged in a southeast-northwest fashion coinciding with the productivity gradient in the area. Additionally, samples were collected from an Area of Particular Environmental Interest (APEI-3) in the northwest of the CCZ where mining will be prohibited and which should serve as a source area for the biota within the larger CCZ. Total densities in the 0–5 upper cm layer of the sediment were influenced by sedimentary characteristics, water depth and nodule density at the various sampling locations, indicating the importance of nodules for meiofaunal standing stock. Nematodes were the most abundant meiobenthic taxon and displayed a relatively similar community composition for the different areas. Assemblages were typically dominated by a few genera (generally 2–6), accounting for 40–70 % of all individuals, as well as a large number of rare genera each contributing less than 5 % to the overall abundances. Dominant genera were widely spread within the CCZ and shared among all sampled license areas, whereas rare genera were usually limited to one. The same trend was present when looking at the species level of one of the dominant genera, Halalaimus, implying that it might be mainly these rare genera and species that will be affected by changes in their habitat due to mining activities.
Databáze: OpenAIRE
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