PT  - JOURNAL ARTICLE
AU  - Konstantina Agiadi
AU  - Frédéric Quillévéré
AU  - Rafał Nawrot
AU  - Theo Sommeville
AU  - Marta Coll
AU  - Efterpi Koskeridou
AU  - Jan Fietzke
AU  - Martin Zuschin
TI  - Palaeontological evidence for community-level decrease in mesopelagic fish size during Pleistocene climate warming in the eastern Mediterranean
AID  - 10.1101/2022.10.04.510798
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.10.04.510798
4099  - http://biorxiv.org/content/early/2022/10/07/2022.10.04.510798.short
4100  - http://biorxiv.org/content/early/2022/10/07/2022.10.04.510798.full
AB  - Mesopelagic fishes are an important element of marine food webs, a huge, still mostly untapped food resource, and great contributors to the biological carbon pump, whose future under climate change scenarios are unknown. The shrinking of commercial fishes within decades has been an alarming observation, but its causes remain contended. Here, we investigate the effect of warming climate on mesopelagic fish size in the eastern Mediterranean Sea during a glacial–interglacial–glacial transition of the Middle Pleistocene (marine isotope stages 20–18; 814–712 Kyr B.P.), which included a 4 °C increase of global seawater temperature. Our results based on fossil otoliths show that the median size of lanternfishes, one of the most abundant groups of mesopelagic fishes in fossil and modern assemblages, declined by ~35% with climate warming at the community level. However, individual mesopelagic species showed different and often opposing trends in size across the studied time interval, suggesting that climate warming in the interglacial resulted in an ecological shift toward increased relative abundance of smaller-sized mesopelagic fishes due to geographic and/or bathymetric distribution range shifts, and the size-dependent effects of warming.Competing Interest StatementThe authors have declared no competing interest.