COBALT-RICH FERROMANGANESE CRUSTS
16
Habitats and biodiversity
associated with cobalt-rich
ferromanganese crusts
2.1
Cobalt-rich ferromanganese crusts (Fe-Mn crusts) are found
throughout the global oceans on the summits and flanks of
seamounts, ridges, and plateaux. They form only on bare rock
surfaces, and are therefore distributed where oceanic currents
keep the seamounts free of sediment. The process is very slow,
taking millions of years for development of thick crusts.
3.1.1 Geographic context
In the Southwest Pacific region, crusts form on the summits and
flanks of seamounts, especially large flat-topped guyot features
(isolated volcanic mountains), at depths of about 400 metres
down to 4 000 metres. There are several thousand seamounts
Figure 6 Lower bathyal provinces.
Depth range 800 to 3000 metres (UNESCO, 2009).
Much of the open ocean has never been sampled, especially the
deep sea. Even in the case of seamounts, which have been the
focus of international efforts, only a few hundred have been stud-
ied, out of hundreds of thousands worldwide. However, we know
that the distribution of animals varies considerably between areas.
Biogeography: mapping the distribution of species
Biogeography examines the geographic distribution of fauna and
flora, generally at the larger scale of similar faunal communities.
A biogeographic classification puts together information on
biological composition, species distributions, and physical
1. Arctic
2. Northern North Atlantic
3. Northern North Pacific
4. North Atlantic
5. SE Pacific Ridges
6. New Zealand Kermandec
7. Cocos Plate
8. Nazca Plate
9. Antarctic
10. Subantarctic
11. Indian
12. West Pacific
13. South Atlantic
14. North Pacific
1
2
3
4
5
6
7
8
9
10
11
12
13
14
GOODS Bioregions bathyal
