Dataset Information

Phylogenetic clustering and rarity imply risk of local species extinction in prospective deep-sea mining areas of the Clarion-Clipperton Fracture Zone.

ABSTRACT: An understanding of the forces controlling community structure in the deep sea is essential at a time when its pristineness is threatened by polymetallic nodule mining. Because abiotically defined communities are more sensitive to environmental change, we applied occurrence- and phylogeny-based metrics to determine the importance of biotic versus abiotic structuring processes in nematodes, the most abundant invertebrate taxon of the Clarion-Clipperton Fracture Zone (CCFZ), an area targeted for mining. We investigated the prevalence of rarity and the explanatory power of environmental parameters with respect to phylogenetic diversity (PD). We found evidence for aggregation and phylogenetic clustering in nematode amplicon sequence variants (ASVs) and the dominant genus Acantholaimus, indicating the influence of environmental filtering, sympatric speciation, affinity for overlapping habitats and facilitation for community structure. PD was associated with abiotic variables such as total organic carbon, chloroplastic pigments equivalents and/or mud content, explaining up to 57% of the observed variability and providing further support of the prominence of environmental structuring forces. Rarity was high throughout, ranging from 64 to 75% unique ASVs. Communities defined by environmental filtering with a prevalence of rarity in the CCFZ suggest taxa of these nodule-bearing abyssal plains will be especially vulnerable to the risk of extinction brought about by the efforts to extract them.

SUBMITTER: Macheriotou L

PROVIDER: S-EPMC7209057 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Phylogenetic clustering and rarity imply risk of local species extinction in prospective deep-sea mining areas of the Clarion-Clipperton Fracture Zone.

Macheriotou Lara L Rigaux Annelien A Derycke Sofie S Vanreusel Ann A

Proceedings. Biological sciences 20200401 1924

An understanding of the forces controlling community structure in the deep sea is essential at a time when its pristineness is threatened by polymetallic nodule mining. Because abiotically defined communities are more sensitive to environmental change, we applied occurrence- and phylogeny-based metrics to determine the importance of biotic versus abiotic structuring processes in nematodes, the most abundant invertebrate taxon of the Clarion-Clipperton Fracture Zone (CCFZ), an area targeted for m ...[more]

PMID: 32228410

Similar Datasets

Project description:The potential for imminent polymetallic nodule mining in the Clarion Clipperton Fracture Zone (CCZ) has attracted considerable scientific and public attention. This concern stems from both the extremely large seafloor areas that may be impacted by mining, and the very limited knowledge of the fauna and ecology of this region. The environmental factors regulating seafloor ecology are still very poorly understood. In this study, we focus on megafaunal ecology in the proposed conservation zone 'Area of Particular Environmental Interest 6' (study area centred 17°16'N, 122°55'W). We employ bathymetric data to objectively define three landscape types in the area (a level bottom Flat, an elevated Ridge, a depressed Trough; water depth 3950-4250 m) that are characteristic of the wider CCZ. We use direct seabed sampling to characterise the sedimentary environment in each landscape, detecting no statistically significant differences in particle size distributions or organic matter content. Additional seafloor characteristics and data on both the metazoan and xenophyophore components of the megafauna were derived by extensive photographic survey from an autonomous underwater vehicle. Image data revealed that there were statistically significant differences in seafloor cover by nodules and in the occurrence of other hard substrata habitat between landscapes. Statistically significant differences in megafauna standing stock, functional structuring, diversity, and faunal composition were detected between landscapes. The Flat and Ridge areas exhibited a significantly higher standing stock and a distinct assemblage composition compared to the Trough. Geomorphological variations, presumably regulating local bottom water flows and the occurrence of nodule and xenophyophore test substrata, between study areas may be the mechanism driving these assemblage differences. We also used these data to assess the influence of sampling unit size on the estimation of ecological parameters. We discuss these results in the contexts of regional benthic ecology and the appropriate management of potential mining activities in the CCZ and elsewhere in the deep ocean.

Project description:We present DNA taxonomy of abyssal polychaete worms from the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruises 'AB01' and 'AB02' to the UK Seabed Resources Ltd (UKSRL) polymetallic nodule exploration contract area 'UK-1', the Ocean Mineral Singapore exploration contract area 'OMS-1' and an Area of Particular Environmental Interest, 'APEI-6'. This is the fourth paper in a series to provide regional taxonomic data with previous papers reporting on Cnidaria, Echinodermata and Mollusca. Taxonomic data are presented for 23 species from 85 records within four polychaete families: Capitellidae, Opheliidae, Scalibregmatidae and Travisiidae, identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. Two taxa (genetically separated from one another) morphologically matched the same known cosmopolitan species, Ophelina abranchiata that has a type locality in a different ocean basin and depth from where no genetic data was available. These two species were assigned the open nomenclature 'cf.' as a precautionary approach in taxon assignments to avoid over-estimating species ranges. Twelve (12) taxa are here described as new species, Ammotrypanella keenani sp. nov., Ammotrypanella kersteni sp. nov., Ophelina curli sp. nov., Ophelina ganae sp. nov., Ophelina juhazi sp. nov., Ophelina martinezarbizui sp. nov., Ophelina meyerae sp. nov., Ophelina nunnallyi sp. nov., Oligobregma brasierae sp. nov., Oligobregma tani sp. nov., Oligobregma whaleyi sp. nov. and Travisia zieglerae sp. nov. For the remaining nine taxa, we have determined them to be potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. The CCZ is a region undergoing intense exploration for potential deep-sea mineral extraction from polymetallic nodules. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections.

Project description:BackgroundThe Clarion-Clipperton Fracture Zone (CCFZ) in the Northeast Central Pacific Ocean is a region of heightened scientific and public interest because of its wealth in manganese nodules. Due to a poor ecological understanding at the abyssal seafloor and limited knowledge of the organisms inhabiting this area, huge efforts in alpha taxonomy are required. To predict and manage potential hazards associated with future mining, taxonomy is an essential first step to grasp fundamental ecosystem traits, such as biogeographic patterns, connectivity, and the potential for post-impact recolonization. Amongst samples from the Global Sea Mineral Resources NV exploration area (EA) in the CCFZ an undescribed species of the isopod crustacean family Macrostylidae was discovered. Previously, it has been reported from two other nearby regions, the Institut Français de Recherche pour l'Exploitation de la Mer and BGR EAs. There it was one of the more widely distributed and abundant species of the benthic macrofauna and exhibited geographically structured populations. It nevertheless remained taxonomically undescribed so far.MethodsThe new species is described by means of integrative taxonomy. Morphologically, macro photography, confocal microscopy, scanning electron microscopy and light microscopy were used to describe the species and to get first insights on its phylogenetic origin. Additionally, mitochondrial DNA markers were used to test the morphological allocation of the two dimorphic sexes and juvenile stages, to analyze geographic patterns of genetic differentiation, and to study intra-and inter-species relationships, also in light of previously published population genetics on this species.ResultsThe new species, Macrostylis metallicola spec. nov., is a typical representative of Macrostylidae as recognizable from the fossosoma, prognathous cephalothorax, and styliform uropods. It can be morphologically distinguished from congeners by a combination of character states which include the autapomorphic shape of the first pleopod of the copulatory male. A sexual dimorphism, as expressed by a peculiar sequence of article length-width ratios of the male antennula, indicates a relationship with M. marionae Kniesz, Brandt & Riehl (2018) and M. longipes Hansen (1916) amongst other species sharing this dimorphism. Mitochondrial genetic markers point in a similar direction. M. metallicola appears to be amongst the more common and widely distributed components of the benthic macrofauna in this region which may suggest a resilience of this species to future mining activities because of its apparent potential for recolonization of impacted sites from adjacent areas of particular environmental interest. The genetic data, however, show geographic clustering of its genetic variability, pointing towards a limited potential for dispersal. Local extinction of populations could potentially not be compensated quickly and would mean a loss of genetic diversity of this species.

Dataset Information

Phylogenetic clustering and rarity imply risk of local species extinction in prospective deep-sea mining areas of the Clarion-Clipperton Fracture Zone.

Publications

Phylogenetic clustering and rarity imply risk of local species extinction in prospective deep-sea mining areas of the Clarion-Clipperton Fracture Zone.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets