May 12, 2016

Wednesday 11 May 2016, London

Patterns of biodiversity in the deep ocean are fundamentally different from those that govern species richness in shallower waters or on land, according to a paper published by Marine Biodiversity Hub researchers in the journal NatureThe study analyses the global distribution of thousands of species of brittle and basket stars — close relatives of the starfish — and provides a baseline for conservation efforts across the global sea floor, which faces increasing pressures from deep-sea fishing, pollution and mining.

The authors found that deep-sea (below 2000 metres) species richness peaks at higher latitudes than on the continental shelf and upper continental slope (0-2000 m). Although diversity at shallower depths is explained by water temperature and light availability, deep-sea diversity is not correlated with temperature, but instead with high levels of chemical energy export (which reflects food availability). They also found that proximity to the continental margin, where a continent meets the ocean floor, is a significant predictor of diversity in the deep sea.



Global abyssal diversity: Red and orange areas represent the highest level of species diversity. Museum Victoria
Brittlestar (M
acrophiothrix spongicola) from southern Australia Image:  Julian Finn, Museum Victoria