Ecological and evolutionary consequences of benthic community stasis in the very deep sea (>1500 m)

• Published in: Paleobiology
• Main Authors: Buzas, Martin A., Hayek, Lee-Ann C., Culver, Stephen J., Hayward, Bruce W., Osterman, Lisa E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2014
• Subjects: Arctic; New Zealand; Norwegian Sea; Foraminifera*
• Online Access: http://dx.doi.org/10.1666/13010; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0094837300001615

An enigma of deep-sea biodiversity research is that the abyss with its low productivity and densities appears to have a biodiversity similar to that of shallower depths. This conceptualization of similarity is based mainly on per-sample estimates (point diversity, within-habitat, or α-diversity). Here, we use a measure of between-sample within-community diversity (β 1 H ) to examine benthic foraminiferal diversity between 333 stations within 49 communties from New Zealand, the South Atlantic, the Gulf of Mexico, the Norwegian Sea, and the Arctic. The communities are grouped into two depth categories: 200–1500 m and >1500 m. β 1 H diversity exhibits no evidence of regional differences. Instead, higher values at shallower depths are observed worldwide. At depths of >1500 m the average β 1 H is zero, indicating stasis or no biodiversity gradient. The difference in β 1 H -diversity explains why, despite species richness often being greater per sample at deeper depths, the total number of species is greater at shallower depths. The greater number of communities and higher rate of evolution resulting in shorter species durations at shallower depths is also consistent with higher β 1 H values.