Showing papers by "Andrew J. Gooday published in 2016"

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

Abstract: 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. exploration contract area (UK-1) in the CCZ. Using a Remotely Operated Vehicle, we surveyed megafauna at four sites within a 900 km2 stratum in the UK-1 contract area, and at a site ~250 km east of the UK-1 area, allowing us to make the first estimates of abundance and diversity. We distinguished 170 morphotypes within the UK-1 contract area but species-richness estimators suggest this could be as high as 229. Megafaunal abundance averaged 1.48 ind. m−2. Seven of 12 collected metazoan species were new to science, and four belonged to new genera. Approximately half of the morphotypes occurred only on polymetallic nodules. There were weak, but statistically significant, positive correlations between megafaunal and nodule abundance. Eastern-CCZ megafaunal diversity is high relative to two abyssal datasets from other regions, however comparisons with CCZ and DISCOL datasets are problematic given the lack of standardised methods and taxonomy. We postulate that CCZ megafaunal diversity is driven in part by habitat heterogeneity.

Worldwide Analysis of Sedimentary DNA Reveals Major Gaps in Taxonomic Knowledge of Deep-Sea Benthos

Abstract: Deep-sea sediments represent the largest but least known ecosystem on earth. With increasing anthropogenic pressure, it is now a matter of urgency to improve our understanding of deep-sea biodiversity. Traditional morpho-taxonomic studies suggest that the ocean floor hosts extraordinarily diverse benthic communities. However, due to both its remoteness and a lack of expert taxonomists, assessing deep-sea diversity is a very challenging task. Environmental DNA (eDNA) metabarcoding offers a powerful tool to complement morpho-taxonomic studies. Here we use eDNA to assess benthic metazoan diversity in 39 deep-sea sediment samples from bathyal and abyssal depths worldwide. The eDNA dataset was dominated by meiobenthic taxa and we identified all animal phyla commonly found in the deep-sea benthos; yet, the diversity within these phyla remains largely unknown. The large numbers of taxonomically unassigned molecular operational taxonomic units (OTUs) were not equally distributed among phyla, with nematodes and platyhelminthes being the most poorly characterized from a taxonomic perspective. While the data obtained here reveal pronounced heterogeneity and vast amounts of unknown biodiversity in the deep sea, they also expose the difficulties in exploiting metabarcoding datasets resulting from the lack of taxonomic knowledge and appropriate reference databases. Overall, our study demonstrates the promising potential of eDNA metabarcoding to accelerate the assessment of deep-sea biodiversity for pure and applied deep-sea environmental research but also emphasises the necessity to integrate such new approaches with traditional morphology-based examination of deep-sea organisms.

The London Workshop on the Biogeography and Connectivity of the Clarion-Clipperton Zone

Abstract: publisher: Pensoft Publishers articletitle: The London Workshop on the Biogeography and Connectivity of the Clarion-Clipperton Zone journaltitle: Research Ideas and Outcomes copyright: http://creativecommons.org/licenses/by/4.0/ received: 2016-09-16 published: 2016-09-16

Formation of agglutinated cysts by the foraminiferan Sphaeroidina bulloides on the Porcupine Abyssal Plain (NE Atlantic)

Abstract: Benthic foraminiferal species sometimes produce a covering made of sediment and detrital material around their tests (shells). These sedimentary envelopes, termed ‘cysts’, have been observed in a number of species, from organic-walled and agglutinated to calcareous (e.g., Linke and Lutze 1993; Cedhagen 1996; Gross 2000, 2002; Gooday and Hughes 2002; Heinz et al. 2005). However, almost all published records of this phenomenon originate from coastal or bathyal settings, and there are very few examples from abyssal depths, i.e. deeper than 3500 m. During the analysis of Megacorer samples (25.5 cm2 surface area, formalin-buffered, 0–1 cm sediment horizon, >150 ?m fraction) collected in the area of the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) in the northeast Atlantic (49°N 16.5°W, 4850 m water depth), we observed benthic foraminifera that had created partial or complete muddy coatings. Most belonged to Sphaeroidina bulloides d’Orbigny, 1826 (Fig. 1), and a few to Melonis barleeanus (Williamson, 1858). The S. bulloides cysts occasionally incorporated juvenile planktonic foraminiferal tests (<50 ?m), and always included one or more flexible agglutinated tubes (20–35 ?m wide, 140–400 ?m long) that extended out of the main structure (Fig. 1a–e). There was no evidence of the presence within the cysts of microscopic organisms, comparable to the ciliates and nematodes observed by Linke and Lutze (1993) inside the cysts of Elphidium incertum.

Taxonomic composition and distribution of soft-walled monothalamid foraminifera in the area of Zernov’s Phyllophora Field (NW Black Sea)

Abstract: We studied assemblages of soft-walled, single-chambered foraminifera (monothalamids) at eight stations in the area of Zernov's Phyllophora Field (ZPF) on the NW continental shelf of the Black Sea. This work is based on samples collected during Cruise 70 of the RV Professor Vodyanitsky and provides the first analysis of the taxonomic composition of monothalamids from this region. These delicate, poorly known foraminifera were found at all stations in the studied area. They were represented by nine forms that are identified to species or genus level as well as 14 undescribed species, nine of which are found in the Black Sea for the first time. Four species, Psammophaga sp., Vellaria pellucida, Goodayia rostellata and Krymia fusiformis, were most abundant, with Psammophaga sp. being the dominant species overall. Previous studies have suggested a link between members of this genus and eutrophication. There are a number of taxonomic parallels between these ZPF assemblages and those from the Adriatic Sea, e.g. the occurrence of the genera Goodayia, Psammophaga and Vellaria, although it is possible that some other taxa are endemic to the Black Sea.

Memorial to Martin David Brasier (1947–2014)

Abstract: Martin Brasier, Professor of Palaeobiology at the University of Oxford and Adjunct Professor at Memorial University, Newfoundland until his retirement in 2013, died in a car accident on 16 December 2014. He is most famous for his outstanding studies of the early biosphere, from the first appearance of life on Earth to that of essentially ‘modern’ animals and protists in the Cambrian. The enormous influence he had in this field, and the respect that he inspired, are evident from the meeting held in his honour in Oxford on his retirement in 2013 (http://www.palaeocast.com/evolution-and-early-life/), and the award of the Lyell Medal by the Geological Society of London in 2014. However, his contributions to science extended in many directions, among them the emerging discipline of astrobiology where he applied his research in Precambrian palaeobiology to the search for life on Mars. His achievements in both these fields have been explored in other memorials (e.g. Wacey, 2015; McMahon & Cockell, 2015; McLoughlin et al., 2015). Here, we will emphasise his work on modern benthic ecosystems and particularly foraminifera. This has received less attention than other parts of his scientific output, although the study of microfossils, a topic on which he published a standard textbook (Brasier, 1980a; a second edition by Armstrong & Brasier, appeared in 2005), is a theme that underpinned his research. Incidentally, the book was written while Martin was in bed recovering from a slipped disc acquired while collecting large rock samples for microfossil papers on the Cambrian of …