Gollner, S.; Zekely, J.; Govenar, B.; Le Bris, N.; Nemeschkal, H. L.; Fischer, C. R.; Bright, M. (2007). Tubeworm-assocated permanent meiobenthic communities from two chemically different hydrothermal vent sites on the East Pacific Rise. Marine Ecology Progress Series. 337: 39-49.
Gollner, S.; Zekely, J.; Govenar, B.; Le Bris, N.; Nemeschkal, H. L.; Fischer, C. R.; Bright, M.
Tubeworm-assocated permanent meiobenthic communities from two chemically different hydrothermal vent sites on the East Pacific Rise
The permanent meiobenthic community associated with aggregations of the tubeworm
Riftia pachyptila was characterized at 2 different hydrothermal vent sites, Tica and Riftia Field, on the
East Pacific Rise near 9° 50’ N. The maximum effluent temperatures were similar at both sites, but the
chemistry of the hydrothermal fluids differed between sites. The abundance of meiobenthos was very
low in 5 out of 6 samples (<61 ind. 10 cm–2) and was higher at Tica (20 to 976 ind. 10 cm–2) than at
Riftia Field (<1 to 12 ind. 10 cm–2). Meiobenthos abundance was positively correlated with the volume
of sediment within the tubeworm aggregations. Sediment consisted mainly of particulate organic
material and contained only a few mineral grains. A total of 33 meiobenthic species (15 of them new
to science) was identified, comprising nematodes, copepods, ostracods, tanaidaceans, and foraminiferans.
The meiobenthic fauna contributed a third to the total species richness in the benthic community
associated with these tubeworm aggregations. There were 19 meiobenthic species shared
between the 2 sites. The majority of meiobenthic species were first-order primary consumers. The
most abundant taxa were nematodes and copepods, and other taxa were rare at both sites. Nematodes
numerically dominated the community at Tica, while no clear dominance of a higher taxon
could be detected at Riftia Field. Species richness was similar at both sites, whereas Shannon-Wiener
diversity index and Pielou’s evenness index were higher at Riftia Field. Due to the differences in the
relative abundance of some species and unique occurrence of others at each site, the meiobenthic
communities from the 2 different sites had an average Bray-Curtis dissimilarity of almost 70%.