Multi-scale spatio-temporal distribution of faunal assemblages on the Lucky Strike hydrothermal vent field (-1,700 m)
| Main Author: | Loïc Van Audenhaege |
|---|---|
| Format: | info Proceeding Journal |
| Terbitan: |
, 2021
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| Online Access: |
https://zenodo.org/record/5572318 |
Daftar Isi:
- My PhD thesis aims to investigate how environmental and biotic factors act on assemblage distribution and temporal dynamics at deep-sea hydrothermal vents. It is divided in three imagery surveys according to distinct scales of biological organisation. In fact, identifying relevant drivers depends on the study scale and therefore, requires a multi-scale approach. For the first chapter, we used the deep-sea EMSO-Azores observatory to assess the infra-daily dynamics and long-term evolution of an endemic hydrothermal mussel assemblage (Lucky Strike, -1,700 m). Spatio-temporal dynamics were investigated following three different analyses defined for imagery data. While local change in hydrothermal activity triggered decimetre-scale mussel migration over three years, we observed a 7-year stability with no major mortality event. Predation activities was not a source of individual mortality. Following a review of literature, the striking stability of the assemblage contrasted with the higher variability observed for the intertidal communities. Therefore, this study questions the postulate that hydrothermal vent assemblages are necessarily variable and ephemeral ecosystems. The second chapter uses a time series of 3D models of a hydrothermal edifice in order to put our results in perspective. Long-term stability of the fauna is expected while local variability will be influenced by small-scale repositioning of vent exits and the interaction with currents. With larger seabed mosaics acquired over the vent field, the last chapter aims to investigate the spatial sphere of hydrothermal influence also depending on the hydrothermal circulation.