TY - JOUR
T1 - Testing the deep-sea glacial disturbance hypothesis as a cause of low, present-day Norwegian Sea diversity and resulting steep latitudinal diversity gradient, using fossil records
AU - Jöst, Anna B.
AU - Huang, Huai-Hsuan M.
AU - Hong, Yuanyuan
AU - Wei, Chih-Lin
AU - Bauch, Henning A.
AU - Thibodeau, Benoit
AU - Cronin, Thomas M.
AU - Okahashi, Hisayo
AU - Yasuhara, Moriaki
PY - 2024/7
Y1 - 2024/7
N2 - Aim: Within the intensively-studied, well-documented latitudinal diversity gradient, the deep-sea biodiversity of the present-day Norwegian Sea stands out with its notably low diversity, constituting a steep latitudinal diversity gradient in the North Atlantic. The reason behind this has long been a topic of debate and speculation. Most prominently, it is explained by the deep-sea glacial disturbance hypothesis, which states that harsh environmental glacial conditions negatively impacted Norwegian Sea diversities, which have not yet fully recovered. Our aim is to empirically test this hypothesis. Specific research questions are: (1) Has deep-sea biodiversity been lower during glacials than during interglacials? (2) Was there any faunal shift at the Mid-Brunhes Event (MBE) when the mode of glacial–interglacial climatic change was altered?. Location: Norwegian Sea, deep sea (1819–2800 m), coring sites MD992277, PS1243, and M23352. Time period: 620.7–1.4 ka (Middle Pleistocene–Late Holocene). Taxa studied: Ostracoda (Crustacea). Methods: We empirically test the deep-sea glacial disturbance hypothesis by investigating whether diversity in glacial periods is consistently lower than diversity in interglacial periods. Additionally, we apply comparative analyses to determine a potential faunal shift at the MBE, a Pleistocene event describing a fundamental shift in global climate. Results: The deep Norwegian Sea diversity was not lower during glacial periods compared to interglacial periods. Holocene diversity was exceedingly lower than that of the last glacial period. Faunal composition changed substantially between pre- and post-MBE. Main conclusions: These results reject the glacial disturbance hypothesis, since the low glacial diversity is the important precondition here. The present-day-style deep Norwegian Sea ecosystem was established by the MBE, more specifically by MBE-induced changes in global climate, which has led to more dynamic post-MBE conditions. In a broader context, this implies that the MBE has played an important role in the establishment of the modern polar deep-sea ecosystem and biodiversity in general. © 2024 The Authors. Global Ecology and Biogeography published by John Wiley & Sons Ltd.
AB - Aim: Within the intensively-studied, well-documented latitudinal diversity gradient, the deep-sea biodiversity of the present-day Norwegian Sea stands out with its notably low diversity, constituting a steep latitudinal diversity gradient in the North Atlantic. The reason behind this has long been a topic of debate and speculation. Most prominently, it is explained by the deep-sea glacial disturbance hypothesis, which states that harsh environmental glacial conditions negatively impacted Norwegian Sea diversities, which have not yet fully recovered. Our aim is to empirically test this hypothesis. Specific research questions are: (1) Has deep-sea biodiversity been lower during glacials than during interglacials? (2) Was there any faunal shift at the Mid-Brunhes Event (MBE) when the mode of glacial–interglacial climatic change was altered?. Location: Norwegian Sea, deep sea (1819–2800 m), coring sites MD992277, PS1243, and M23352. Time period: 620.7–1.4 ka (Middle Pleistocene–Late Holocene). Taxa studied: Ostracoda (Crustacea). Methods: We empirically test the deep-sea glacial disturbance hypothesis by investigating whether diversity in glacial periods is consistently lower than diversity in interglacial periods. Additionally, we apply comparative analyses to determine a potential faunal shift at the MBE, a Pleistocene event describing a fundamental shift in global climate. Results: The deep Norwegian Sea diversity was not lower during glacial periods compared to interglacial periods. Holocene diversity was exceedingly lower than that of the last glacial period. Faunal composition changed substantially between pre- and post-MBE. Main conclusions: These results reject the glacial disturbance hypothesis, since the low glacial diversity is the important precondition here. The present-day-style deep Norwegian Sea ecosystem was established by the MBE, more specifically by MBE-induced changes in global climate, which has led to more dynamic post-MBE conditions. In a broader context, this implies that the MBE has played an important role in the establishment of the modern polar deep-sea ecosystem and biodiversity in general. © 2024 The Authors. Global Ecology and Biogeography published by John Wiley & Sons Ltd.
KW - deep-sea diversity
KW - faunal turnover
KW - macroecological patterns
KW - Mid-Brunhes Event
KW - North Atlantic
KW - Ostracoda
UR - http://www.scopus.com/inward/record.url?scp=85191193288&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85191193288&origin=recordpage
U2 - 10.1111/geb.13844
DO - 10.1111/geb.13844
M3 - RGC 21 - Publication in refereed journal
SN - 1466-822X
VL - 33
JO - Global Ecology and Biogeography
JF - Global Ecology and Biogeography
IS - 7
M1 - e13844
ER -