For its preparation, the authors obtained fish otoliths, which are small stones in the inner ear of bony fish used for sound and balance perception, from 800-700 thousand-year-old sedimentary developments on the island of Rhodes in the Aegean Sea. They then examined the otoliths to keep track of changes in fish body size throughout interglacial and glacial durations.
Mesopelagic fishes are an essential aspect of marine food webs, a substantial, still primarily untapped food resource, and fantastic factors to the biological carbon pump, whose future under climate change circumstances is unidentified.
According to a brand-new study carried out by the ICM-CSIC, ocean warming will likely cause smaller sized fish in the deep sea. This conclusion was reached through the analysis of fish otoliths discovered in geological formations going back 700-800 thousand years.
A research study led by the University of Vienna, with participation from the Institut de Ciències del Mar (ICM-CSIC), has actually found that fish living in the dark depths of the ocean (below 200 meters in the water column) will likely diminish in size due to climate warming, which might have significant ecological consequences.
The findings of this research study have been released in the journal Proceedings of the Royal Society B: Biological Sciences. For its preparation, the authors acquired fish otoliths, which are little stones in the inner ear of bony fish used for sound and balance understanding, from 800-700 thousand-year-old sedimentary developments on the island of Rhodes in the Aegean Sea. They then evaluated the otoliths to keep track of changes in fish body size throughout interglacial and glacial periods.
Every night, lanternfishes take a trip hundreds of meters upward to the surface of the oceans and return to the mesopelagic zone, therefore bringing big quantities of carbon from the surface area to the deep ocean.
The morphology of these structures is specific to each fish species and their size directly reflects the size of the fish person they originate from, which allows researchers to determine them in order to reconstruct previous fish animals.
” Thanks to the otolith analysis we have actually discovered that fishes during the interglacial duration were smaller in size by 35%, when the worldwide temperature level had increased by 4 ° C, which might occur once again nowadays due to the ocean warming”, describes the leading author of the research study, Konstantina Agiadi, from the University of Vienna.
Little fishes, huge effects
The research study, that is one of the couple of works that have up until now resolved the repercussions of climate warming on the much deeper part of the oceans, the mesopelagic zone (200– 1000 m depth), focused on the changes in “lanternfishes”, a group of little mesopelagic fishes that are called for their capability to produce their own light.
” Knowing the response of these organisms to ocean warming is key, because they add to ecosystem stability, decrease atmospheric co2, and are a substantial food resource for other organisms in the marine food web”, explains the ICM-CSIC researcher and co-author of the study Marta Coll, who adds that “these fish comprise over half the fish biomass in the deep sea, and about 100 times more than the overall international annual fishery catches”.
Lately, lanternfishes are essential factors to the biological carbon pump, a natural mechanism for reducing atmospheric carbon dioxide (CO2). Phytoplanktonic organisms absorb CO2 from the environment through photosynthesis. Then, every night, lanternfishes take a trip numerous meters up to the surface area of the oceans and return to the mesopelagic zone, thus bringing big amounts of carbon from the surface to the deep ocean.
Recommendation: “Palaeontological evidence for community-level decline in mesopelagic fish size during Pleistocene climate warming in the eastern Mediterranean” by Konstantina Agiadi, Frédéric Quillévéré, Rafał Nawrot, Theo Sommeville, Marta Coll, Efterpi Koskeridou, Jan Fietzke and Martin Zuschin, 11 January 2023, Proceedings of the Royal Society B: Biological Sciences.DOI: 10.1098/ rspb.2022.1994.
