Community dynamics over 14 years at the Eiffel Tower hydrothermal edifice on the Mid‐Atlantic Ridge

Abstract

The Lucky Strike hydrothermal vent field, situated on the Mid-Atlantic Ridge (MAR), has been visited on a regular basis since 1992. The video imagery analyzed in this study originated from 10 cruises and was acquired either with the Nautile submersible or with the Remotely Operated Vehicle Victor 6000 between 1994 and 2008. Four faunal assemblages and two substratum types were identified on a large mussel-dominated sulfide edifice named ''Eiffel Tower.'' Their dynamics over 14 yr were investigated both at the scale of the entire edifice, between the edifice sides, and at small patch scales, making this the first high-time-resolution long-term variations study on the MAR. Overall percentage of biological colonization and overall mussel coverage were stable on a decadal scale. However, on shorter time scales as well as on smaller spatial scales, significant differences in microbial cover and in individual assemblage coverage and distribution were observed. The small fluctuations in the rather constant overall percentage of colonization (, 50%) were explained by subtle changes in hydrothermal activity, which showed a significant negative correlation. However, not all variations occurring in the community structure could be explained by the hydrothermal activity, whereas the orientation of the edifice appeared to play an important role. We proposed a succession model for the shallower MAR fields, in addition to the first quantification of the rate of change in community dynamics at this slow-spreading ridge. This rate of change appeared to be about 15% slower than that observed on sulfide edifices from faster-spreading ridges in the Northeast Pacific.

Biological and environmental rhythms in (dark) deep-sea hydrothermal ecosystems

“…While relative stability in faunal composition has been observed on a number of edifices, even reaching decadal-scale stability at some (e.g. Eiffel Tower), smaller-scale variations, both in space and time, do occur (Cuvelier et al, 2011b). Hence, the variations in faunal densities observed during this study may not apply to the hydrothermal edifice as a whole; the presence of rhythms in the organisms and in temperature, although observed on a smaller surface, is likely to apply for the entire hydrothermal structure.…”

“…Bathymodiolus azoricus mussels visually dominate the shallow water (< 2300 m) vents along the MAR and appear to be a climax community, being present for a few decades on the same edifices within the Lucky Strike vent field (Cuvelier et al, 2011b). They form dense faunal assemblages in relatively low-temperature microhabitats (De Busserolles et al, 2009;Cuvelier et al, 2011a).…”

Exploring the Ecology of Deep-Sea Hydrothermal Vents in a Metacommunity Framework

“…However, vent habitats are not equally represented along a tectonic feature. Low temperature venting does not include the complex communities of black smoker chimneys Cuvelier et al, 2011). Thus, habitat suitability and stability will regulate recruitment and, ultimately, connectivity.…”

“…Long-term studies at the Logatchev and Lucky Strike sites on the Mid Atlantic Ridge that experience volcanic eruptions on millennia time scale (Perfit and Chadwick, 1998) revealed rather stable mussel assemblages over 10-14 years of observations with small-scale variations in community composition related to changes in fluid flow (Gebruk et al, 2010;Cuvelier et al, 2011;Sarrazin et al, 2015). At Juan de Fuca Ridge, directed changes in community composition from polychaetes (Paralvinella sulfincola and P. palmiformis) to limpets (Lepetodrilus fucensis) to tubeworms (Ridgeia piscesae) over 4 years were related to both changes in fluid flow and associated interactions, appearing to follow a dynamic succession model that allows reversal with changes in fluid flow (Sarrazin et al, 1997).…”

Rapid colonisation by nematodes on organic and inorganic substrata deployed at the deep-sea Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge)

“…The Eiffel Tower edifice is a well-defined active edifice 11 m high and one of the mostvisited sites within the Lucky Strike vent field. It has been the focus of ecological research over the last ten years (e.g., Van Dover et al 1996;Comtet and Desbruyeres 1998;Desbruyères et al 2001;Cuvelier et al 2009;Cuvelier et al 2011a;Cuvelier et al 2012;Sarrazin et al in press;Matabos et al in press), and also recently in regards to short-term ) and long-term (Cuvelier et al 2011b) temporal variation studies.…”