Ecology

Diversity of deep-sea scale-worms (Annelida, Polynoidae) in the Clarion-Clipperton Fracture Zone

Our study is the first to describe the diversity patterns of polynoid assemblages along a 1400 km transect crossing a productivity gradient in the CCFZ with the aim to assess the factors possibly driving alpha and beta diversity. Polynoids are a very diverse group of scale worms living at water sediment interface that can only be accurately sampled in the abyss with an epibenthic sledge (EBS). Although the EBS may suffer from methodological biases, our findings are surprisingly contrasting with previous studies examining mostly sedentary polychaetes in that we found high abundance and species richness in the most oligotrophic site. We suggest that during their radiation in the deep sea, macellicephalins have adapted to the exploitation of meager resources at the benthic boundary layer. Our findings contribute to understanding of how food-limitation could drive diversification in the deep-sea by accessing the water column and thus exploiting new benthopelagic niches.

Toward a reliable assessment of potential ecological impacts of deep-sea polymetallic nodule mining on abyssal infauna

The increasing demand for metals is pushing forward the progress of deep-sea mining industry. The abyss between the Clarion and Clipperton Fracture Zones (CCFZ), a region holding a higher concentration of minerals than land deposits, is the most …

Patterns of Macrofaunal Biodiversity Across the Clarion-Clipperton Zone: An Area Targeted for Seabed Mining

Macrofauna are an abundant and diverse component of abyssal benthic communities and are likely to be heavily impacted by polymetallic nodule mining in the Clarion-Clipperton Zone (CCZ). In 2012, the International Seabed Authority (ISA) used available …

A local scale analysis of manganese nodules influence on the Clarion-Clipperton Fracture Zone macrobenthos

The present investigation focuses on the Global Sea Mineral Resources contract area B4S03 site in the Clarion-Clipperton Fracture Zone nodule fields. We investigated the sedimentary characteristics and the higher-taxon (order/class) and lower-taxon …

Alpha and beta diversity patterns of polychaete assemblages across the nodule province of the eastern Clarion-Clipperton Fracture Zone (equatorial Pacific)

The patterns observed in the composition of polychaete assemblages were attributed to variations in food supply at the regional scale and nodule density at the local scale. The high levels of species replacement were mainly driven by rare species, leading to regional species pool estimates between 498 and 240 000 species. The high proportion of singletons seems reflect an under-sampling bias that is currently preventing the assessment of potential biodiversity loss due to nodule mining.

High diversity and pan-oceanic distribution of deep-sea polychaetes: Prionospio and Aurospio (Annelida: Spionidae) in the Atlantic and Pacific Ocean

_Prionospio_ Malmgren 1867 and _Aurospio_ Maciolek 1981 (Annelida: Spionidae) are polychaete genera commonly found in the deep sea. Both genera belong to the Prionospio complex, whose members are known to have limited distinguishing characters. …

SEDIMENT MACROFAUNA – A synthesis of sediment macrofaunal biodiversity in the Clarion-Clipperton Zone

Climate-driven changes in macrobenthic communities in the Mediterranean Sea: A 10-year study in the Bay of Banyuls-sur-Mer

Marine ecosystems worldwide are affected by both natural variation and human activities; to disentangle and understand their individual role in influencing the macrobenthic community composition is challenging. The relationship between interannual …

Molecular analysis and new records of the invasive polychaete Boccardia proboscidea (Annelida: Spionidae)

The spionid polychaete _Boccardia proboscidea_ Hartman, 1940 is a tube-dweller and shell/stone-borer widely occurring in temperate waters across the world and considered invasive in many areas. It was originally described from California, USA, and …

Long-term (1998 vs. 2010) large-scale comparison of soft-bottom benthic macrofauna composition in the Gulf of Lions, NW Mediterranean Sea

We achieved a long term (i.e., 1998 vs. 2010) large scale (i.e., whole Gulf of Lions) study of benthic macrofauna composition in the Gulf of Lions based on the resampling of 91 stations located along 21 inshore-offshore transects. Results show that …