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The 2010 Deepwater Horizon blowout off the coast of Louisiana caused the largest marine oil spill on record. Samples were collected 2–3 months after the Macondo well was capped to assess damage to macrofauna and meiofauna communities. An earlier analysis of 58 stations demonstrated severe and moderate damage to an area of 148 km2. An additional 58 archived stations have been analyzed to enhance the resolution of that assessment and determine if impacts occurred further afield. Impacts included high levels of total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) in the sediment, low diversity, low evenness, and low taxonomic richness of the infauna communities. High nematode to copepod ratios corroborated the severe disturbance of meiofauna communities. Additionally, barium levels near the wellhead were very high because of drilling activities prior to the accident. A principal component analysis (PCA) was used to summarize oil spill impacts at stations near the Macondo well, and the benthic footprint of the DWH oil spill was estimated using Empirical Bayesian Kriging (EBK) interpolation. An area of approximately 263 km2 around the wellhead was affected, which is 78% higher than the original estimate. Particularly severe damages to benthic communities were found in an area of 58 km2, which is 142% higher than the original estimate. The addition of the new stations extended the area of the benthic footprint map to about twice as large as originally thought and improved the resolution of the spatial interpolation. In the future, increasing the spatial extent of sampling should be a top priority for designing assessment studies. [ABSTRACT FROM AUTHOR]

The Deepwater Horizon oil spill occurred in spring and summer 2010 in the northern Gulf of Mexico. Research cruises in 2010 (approximately 2–3 months after the well had been capped), 2011, and 2014 were conducted to determine the initial and subsequent effects of the oil spill on deep-sea soft-bottom infauna. A total of 34 stations were sampled from two zones: 20 stations in the “impact” zone versus 14 stations in the “non-impact” zone. Chemical contaminants were significantly different between the two zones. Polycyclic aromatic hydrocarbons averaged 218 ppb in the impact zone compared to 14 ppb in the non-impact zone. Total petroleum hydrocarbons averaged 1166 ppm in the impact zone compared to 102 ppm in the non-impact zone. While there was no difference between zones for meiofauna and macrofauna abundance, community diversity was significantly lower in the impact zone. Meiofauna taxa richness over the three sampling periods averaged 8 taxa/sample in the impact zone, compared to 10 taxa/sample in the non-impact zone; and macrofauna richness averaged 25 taxa/sample in the impact zone compared to 30 taxa/sample in the non-impact zone. Oil originating from the Deepwater Horizon oil spill reached the seafloor and had a persistent negative impact on diversity of soft-bottom, deep-sea benthic communities. While there are signs of recovery for some benthic community variables, full recovery has not yet occurred four years after the spill. [ABSTRACT FROM AUTHOR]

A new species of Ampharetidae, Amphicteis fiegei sp. nov., is described from the Red Sea reef Al Fahal off Thuwal, Saudi Arabia. It is characterized by the possession of prominent nuchal ridges that are elevated from the prostomium, relatively short paleae, which are few in numbers (five on each side), and transverse rows of cilia in one of its branchial pairs. Furthermore, Samytha storchi Reuscher & Wehe in Wehe, 2009 is recorded for the first time since its original description. [ABSTRACT FROM PUBLISHER]

Sampling methods for benthic meiofauna and macrofauna assessments on the northern Gulf of Mexico continental slope and deep sea were compared. For meiofauna, a core with an inner diameter of 5.1 cm is recommended for yielding an appropriate sample size. Meiofauna are concentrated in the uppermost 2 cm sediment layer, so the top 3 cm are sufficient to sample. Macrofauna penetrate deeper and the top 10 cm are sufficient. Smaller sieves capture more organisms so 45 μm for meiofauna, and 300 μm for macrofauna, is recommended. On average, 88% of meiofauna were extracted in the Ludox fraction compared to the total of both Ludox and the sediment pellet. Box corers and multiple corers were compared for estimating macrofauna and meiofauna metrics. Multicorers are recommended for quantitative assessments, but box corers are useful for qualitative studies that require capturing more diversity. Box cores underestimate macrofauna abundance by 2.9 times. While the larger box core captures more species resulting in higher diversity estimates, it is low relative to the 24 times larger area sampled. The multicorer preserves vertical distribution. Because meiofauna are sampled from subcores, there is little difference between the two devices for estimating meiofauna metrics. Replicate multicore samples (i.e., deployments) do not add substantially to our understanding of the variance of species richness or abundance, thus to describe the spatial footprint of macrofauna community structure, it is recommended that resources should be used to sample more stations over a larger area rather than multiple replicates at fewer stations. [ABSTRACT FROM AUTHOR]

In the third paper about Ampharetidae from Japan, we describe six species that belong to the ‘Amphicteis genus complex’. We divide this complex into the genera Amphicteis Grube, 1850, Paramphicteis Caullery, 1944, Phyllamphicteis Augener, 1918 and Watatsumi gen. nov. Paramphicteis is considered senior synonym of Pseudoamphicteis Hutchings, 1977 and is characterized by pinnate buccal tentacles. Watatsumi gen. nov. with its type species Watatsumi grubei sp. nov. is characterized by the lack of prostomial glandular ridges, the presence of pinnate buccal tentacles, and inconspicuous nuchal ridges. Two of the Amphicteis species are new to science, including A. spinosa sp. nov. and A. taurus sp. nov. Paramphicteis weberi (Caullery, 1944) comb. nov. was transferred from Amphicteis because we found pinnate buccal tentacles in addition to four pairs of foliose branchiae. Paramphicteis foliata (Haswell, 1883) comb. nov. was transferred from Phyllamphicteis because it has pinnate buccal tentacles. Amphicteis uncopalea Chamberlin, 1919 and Paramphicteis angustifolia (Grube, 1878) are newly recorded from Japanese waters. Amphicteis orphnius Chamberlin, 1919 is considered senior synonym of A. obscurior Chamberlin, 1919. A comprehensive table with diagnostic characters of all species of the Amphicteis complex with pinnate buccal tentacles is provided. [ABSTRACT FROM PUBLISHER]

The description of Aricidea (Acmira) flava sp. nov., from coastal waters of the Bohai Sea, the Yellow Sea (China), and the Changjiang River Estuary is presented. Type material of A. (A.) elongata, A. (A.) eximia, A. (A.) finitima, A. (A.) horikoshii, and A. (A.) laubieri was examined. Aricidea (A.) flava is characterized by the presence of a moderately long cirriform prostomial antenna, elongated and cirriform posterior branchiae, neuropodial chaetae arranged in four rows in the posterior branchial region, and acicular chaetae with hirsute tips in posterior neuropodia. Aricidea (A.) flava seems to be restricted to shallow waters of the northern Chinese coast, with the Changjiang River Estuary as the southern boundary. [ABSTRACT FROM AUTHOR]

The new ampharetid species Eclysippe yonaguniensis sp. nov. and Glyphanostomum bilabiatum sp. nov. from the Yonaguni Knoll IV hydrothermal field off the coast of Taiwan and Pavelius makranensis sp. nov. from the cold seeps in the Makran accretionary prism off the coast of Pakistan are described. Amage cf. ehlersi Reuscher, Fiege & Imajima, 2015 and Anobothrus dayi Imajima, Reuscher & Fiege, 2013 are newly recorded from the Yonaguni Knoll IV hydrothermal field.

The second paper of the series about Ampharetidae from Japan includes twelve species of four genera with elevated and modified notopodia, Anobothrus Levinsen, 1884, Sosane Malmgren, 1866 (including species of the synonymized genera Muggoides Hartman, 1965, Sosanopsis Hessle, 1917, and Genus A sensu Uebelacker 1984), Tanseimaruana gen. nov., and Zatsepinia Jirkov, 1986. Tanseimaruana gen. nov. is related to Amphicteis Grube, 1850, but lacks prostomial glandular ridges and has a velum-like dermal outgrowth with two pairs of lobes across the dorsum of the first abdominal unciniger. The new genus comprises Tanseimaruana vestis comb. nov. (Hartman, 1965) (formerly Amphicteis vestis) and T. boninensis sp. nov. Seven additional new species, Anobothrus dayi sp. nov., A. fimbriatus sp. nov., A. flabelligerulus sp. nov., Sosane brevibranchiata sp. nov., Sosane trigintaduo sp. nov., S. uebelackerae sp. nov. (formerly Genus A sensu Uebelacker), and Zatsepinia jirkovi sp. nov., are described. Sosane cf. cinctus (Hartman, 1965), Sosane wireni (Hessle, 1917), and Zatsepinia rittichae Jirkov, 1986, all species previously known from the North Atlantic, are recorded from the North Pacific for the first time. A phylogenetic analysis of Sosane (including the synonymized genera Mugga Eliason, 1955, Muggoides, Sosanopsis, and Genus A sensu Uebelacker) suggests monophyly of the genus with Lysippe Malmgren, 1866 as sister taxon, and a monophyletic clade [Sosane cinctus, Sosane uebelackerae sp. nov., Mugga spp.] within Sosane. The monotypic genus Melinnata Hartman, 1965 has been found indeterminable.