Checklist of newly-vouchered annelid taxa from the Clarion-Clipperton Zone, central Pacific Ocean, based on morphology and genetic delimitation.

Background: We present a checklist of annelids from recent United Kingdom Seabed Resources (UKSR) expeditions (Abyssal Baseline - ABYSSLINE project) to the eastern abyssal Pacific Clarion-Clipperton Zone (CCZ) polymetallic nodule fields, based on DNA species delimitation, including imagery of voucher specimens, Darwin Core (DwC) data and links to vouchered specimen material and new GenBank sequence records. This paper includes genetic and imagery data for 129 species of annelids from 339 records and is restricted to material that is, in general, in too poor a condition to describe formally at this time, but likely contains many species new to science. We make these data available both to aid future taxonomic studies in the CCZ that will be able to link back to these genetic data and specimens and to better underpin ongoing ecological studies of potential deep-sea mining impacts using the principles of FAIR (Findable, Accessible, Interoperable, Reusuable) data and specimens that will be available for all.

Taxonomy, phylogeny, and biodiversity of Lumbrineridae (Annelida, Polychaeta) from the Central Pacific Clarion-Clipperton Zone.

The DNA taxonomy of six species of the annelid family Lumbrineridae collected from the Clarion-Clipperton Zone (CCZ) in the Central Pacific, an area of potential mining interest for polymetallic nodules, is presented. Lumbrinerids are an ecologically important and understudied annelid family within the deep sea, with many species still undescribed. This study aims to document the taxonomy and biodiversity of the CCZ using specimens collected from the UK-1, OMS, and NORI-D exploration contract areas and Areas of Particular Environmental Interest.

Carbonate compensation depth drives abyssal biogeography in the northeast Pacific.

Abyssal seafloor communities cover more than 60% of Earth's surface. Despite their great size, abyssal plains extend across modest environmental gradients compared to other marine ecosystems. However, little is known about the patterns and processes regulating biodiversity or potentially delimiting biogeographical boundaries at regional scales in the abyss.

How many metazoan species live in the world's largest mineral exploration region?

The global surge in demand for metals such as cobalt and nickel has created unprecedented interest in deep-sea habitats with mineral resources. The largest area of activity is a 6 million km region known as the Clarion-Clipperton Zone (CCZ) in the central and eastern Pacific, regulated by the International Seabed Authority (ISA). Baseline biodiversity knowledge of the region is crucial to effective management of environmental impact from potential deep-sea mining activities, but until recently this has been almost completely lacking.

Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean.

There is a growing interest in the exploitation of deep-sea mineral deposits, particularly on the abyssal seafloor of the central Pacific Clarion-Clipperton Zone (CCZ), which is rich in polymetallic nodules. In order to effectively manage potential exploitation activities, a thorough understanding of the biodiversity, community structure, species ranges, connectivity, and ecosystem functions across a range of scales is needed. The benthic megafauna plays an important role in the functioning of deep-sea ecosystems and represents an important component of the biodiversity.

Abyssal fauna of polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean: Amphinomidae and Euphrosinidae (Annelida, Amphinomida).

This is a contribution in a series of taxonomic publications on benthic fauna of polymetallic nodule fields in the eastern abyssal Clarion-Clipperton Zone (CCZ). The material was collected during environmental surveys targeting exploration contract areas 'UK-1', 'OMS' and 'NORI-D', as well as an Area of Particular Environmental Interest, 'APEI-6'. The annelid families Amphinomidae and Euphrosinidae are investigated here.

The bone-degrading enzyme machinery: From multi-component understanding to the treatment of residues from the meat industry.

Many microorganisms feed on the tissue and recalcitrant bone materials from dead animals, however little is known about the collaborative effort and characteristics of their enzymes. In this study, microbial metagenomes from symbionts of the marine bone-dwelling worm , and from microbial biofilms growing on experimentally deployed bone surfaces were screened for specialized bone-degrading enzymes. A total of 2,043 taxonomically (closest match within 40 phyla) and functionally (1 proteolytic and 9 glycohydrolytic activities) diverse and non-redundant sequences (median pairwise identity of 23.

Grab what you can-an evaluation of spatial replication to decrease heterogeneity in sediment eDNA metabarcoding.

Environmental DNA methods such as metabarcoding have been suggested as possible alternatives or complements to the current practice of morphology-based diversity assessment for characterizing benthic communities in marine sediment. However, the source volume used in sediment eDNA studies is several magnitudes lower than that used in morphological identification. Here, we used data from a North Sea benthic sampling station to investigate to what extent metabarcoding data is affected by sampling bias and spatial heterogeneity.

Deciphering a Marine Bone-Degrading Microbiome Reveals a Complex Community Effort.

The marine bone biome is a complex assemblage of macro- and microorganisms; however, the enzymatic repertoire to access bone-derived nutrients remains unknown. The bone matrix is a composite material made up mainly of organic collagen and inorganic hydroxyapatite. We conducted field experiments to study microbial assemblages that can use organic bone components as nutrient source.

Abyssal fauna of polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean: Annelida: Capitellidae, Opheliidae, Scalibregmatidae, and Travisiidae.

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.

Mixed-habitat assimilation of organic waste in coastal environments - It's all about synergy!

Fish farms are increasingly situated in strong current sites above or near to mixed-bottom habitats that include organisms not normally considered in the context of organic enrichment. This study takes a holistic view of the benthic enrichment process by combining different survey techniques on complimentary spatial scales: conventional macrofaunal cores, larger-scale visual quantification of epibiota and environmental-DNA metabarcoding of microbial communities. A large tube forming polychaete (Arenicola marina), normally found intertidally and living too deep for conventional sampling, was observed occupying an opportunistic niche in areas of high deposition and in very close association with Capitellid worm complexes.

The highly toxic and cryptogenic clinging jellyfish sp. (Hydrozoa, Limnomedusae) on the Swedish west coast.

The clinging jellyfish sp. is a small hydromedusa species known historically from the Swedish west coast but not reported in recent times. This species is thought to be native to the northwest Pacific where it is notorious for causing severe stings in humans and is considered invasive or cryptogenic elsewhere.

Managing a sustainable deep-sea 'blue economy' requires knowledge of what actually lives there.

Ensuring that the wealth of resources contained in our oceans are managed and developed in a sustainable manner is a priority for the emerging 'blue economy'. However, modern ecosystem-based management approaches do not translate well to regions where we know almost nothing about the individual species found in the ecosystem. Here, we propose a new taxon-focused approach to deep-sea conservation that includes regulatory oversight to set targets for the delivery of taxonomic data.

Implications of population connectivity studies for the design of marine protected areas in the deep sea: An example of a demosponge from the Clarion-Clipperton Zone.

The abyssal demosponge Plenaster craigi inhabits the Clarion-Clipperton Zone (CCZ) in the northeast Pacific, a region with abundant seafloor polymetallic nodules with potential mining interest. Since P. craigi is a very abundant encrusting sponge on nodules, understanding its genetic diversity and connectivity could provide important insights into extinction risks and design of marine protected areas.

Temporal changes in benthic macrofauna on the west coast of Norway resulting from human activities.

Quantitative analyses of soft bottom invertebrate fauna from four Norwegian sill fjords show increased macrofaunal abundance, species richness, and a considerably changed benthic deep water macrofaunal composition in the inner parts of the fjord system. In retrospect, the analyses show significantly altered benthic macrofaunal community structure that was not reflected by the changes in the Shannon-Wiener diversity indices during regular monitoring. The observed changes are mainly due to an increased abundance of opportunistic species, especially of the polychaete Polydora sp.

Mitochondrial genome and polymorphic microsatellite markers from the abyssal sponge Lim & Wiklund, 2017: tools for understanding the impact of deep-sea mining.

The abyssal demosponge is endemic to the Clarion - Clipperton Zone (CCZ) in the NE Pacific, a region with abundant seafloor polymetallic nodules and of potential interest for mining. encrusts on these nodules and is an abundant component of the ecosystem. To assess the impact of mining operations, it is crucial to understand the genetics of this species, because its genetic diversity and connectivity across the area may be representative of other nodule-encrusting invertebrate epifauna.

Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca.

We present the first DNA taxonomy publication on abyssal Mollusca from the Clarion-Clipperton Zone (CCZ), central Pacific ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area 'UK-1' in the eastern CCZ. This is the third paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Taxonomic data are presented for 21 species from 42 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses.

Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Cnidaria.

Background: We present data from a DNA taxonomy register of the abyssal Cnidaria collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area 'UK-1' in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. This is the second paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Data were collected from the UK-1 exploration area following the methods described in Glover et al.

Insights into the abundance and diversity of abyssal megafauna in a polymetallic-nodule region in the eastern Clarion-Clipperton Zone.

There is growing interest in mining polymetallic nodules in the abyssal Clarion-Clipperton Zone (CCZ) in the Pacific. Nonetheless, benthic communities in this region remain poorly known. The ABYSSLINE Project is conducting benthic biological baseline surveys for the UK Seabed Resources Ltd.

Abyssal fauna of the UK-1 polymetallic nodule exploration claim, Clarion-Clipperton Zone, central Pacific Ocean: Echinodermata.

We present data from a DNA taxonomy register of the abyssal benthic Echinodermata collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration claim 'UK-1' in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. Morphological and genetic data are presented for 17 species (4 Asteroidea, 4 Crinoidea, 2 Holothuroidea and 7 Ophiuroidea) identified by a combination of morphological and genetic data. No taxa matched previously published genetic sequences, but 8 taxa could be assigned to previously-described species based on morphology, although here we have used a precautionary approach in taxon assignments to avoid over-estimating species ranges.

Bone-eating worms from the Antarctic: the contrasting fate of whale and wood remains on the Southern Ocean seafloor.

We report the results from the first experimental study of the fate of whale and wood remains on the Antarctic seafloor. Using a baited free-vehicle lander design, we show that whale-falls in the Antarctic are heavily infested by at least two new species of bone-eating worm, Osedax antarcticus sp. nov.

The potent respiratory system of Osedax mucofloris (Siboglinidae, Annelida)--a prerequisite for the origin of bone-eating Osedax?

Members of the conspicuous bone-eating genus, Osedax, are widely distributed on whale falls in the Pacific and Atlantic Oceans. These gutless annelids contain endosymbiotic heterotrophic bacteria in a branching root system embedded in the bones of vertebrates, whereas a trunk and anterior palps extend into the surrounding water. The unique life style within a bone environment is challenged by the high bacterial activity on, and within, the bone matrix possibly causing O(2) depletion, and build-up of potentially toxic sulphide.

Bone-boring worms: characterizing the morphology, rate, and method of bioerosion by Osedax mucofloris (Annelida, Siboglinidae).

Osedax worms possess unique "root" tissues that they use to bore into bones on the seafloor, but details of the boring pattern and processes are poorly understood. Here we use X-ray micro-computed tomography to investigate the borings of Osedax mucofloris in bones of the minke whale (Balaenoptera acutorostrata), quantitatively detailing their morphological characteristics for the first time. Comparative thin-sections of the borings reveal how the bone is eroded at the sub-millimeter level.

High symbiont diversity in the bone-eating worm Osedax mucofloris from shallow whale-falls in the North Atlantic.

Osedax worms are whale-fall specialists that infiltrate whale bones with their root tissues. These are filled with endosymbiotic bacteria hypothesized to provide their hosts with nutrition by extracting organic compounds from the whale bones. We investigated the diversity and distribution of symbiotic bacteria in Osedax mucofloris from shallow-water whale-falls in the North Atlantic using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization (FISH).