Predicting habitat use by the Argentine hake Merluccius hubbsi in a warmer world: inferences from the Middle Holocene

BAS, MARIA; SALEMME, MÓNICA; GREEN, ELEANOR JOAN; SANTIAGO, FERNANDO; SPELLER, CAMILLA; ÁLVAREZ, MYRIAN; BRIZ I GODINO, IVAN; CARDONA, LUIS

OECOLOGIA

SPRINGER

Año: 2020

0029-8549

Fish skeletal remains recovered from two archaeological sites dated in the Middle Holocene of Tierra del Fuego (Argentina)were analysed to describe habitat use patterns by hake in the past and predict changes in a warmer world. MitochondrialDNA was successfully extracted and amplified from 42 out of 45 first vertebra from ancient hake and phylogenetic analysisassigned all haplotypes to Argentine hake (Merluccius hubbsi). According to osteometry, the Argentine hake recovered fromthe archaeological site were likely adults ranging 37.2?58.1 cm in standard length. C and N stable isotope analysis showedthat currently Argentine hake use foraging grounds deeper than those of Patagonian blenny and pink cusk-eel. Argentinehake, however, had a much broader isotopic niche during the Middle Holocene, when a large part of the population foragedmuch shallower than contemporary pink cusk-eel. The overall evidence suggests the presence of large numbers of Argentinehake onshore Tierra del Fuego during the Middle Holocene, which allowed exploitation by hunter-gatherer-fisher groupsdevoid of fishing technology. Interestingly, average SST off Tierra del Fuego during the Middle Holocene was higher thancurrently (11 °C vs 7 °C) and matched SST in the current southernmost onshore spawning aggregations, at latitude 47 °S.This indicates that increasing SST resulting from global warming will likely result into an increased abundance of adultArgentine hake onshore Tierra del Fuego, as during the Middle Holocene. Furthermore, stable isotope ratios from molluscshells confirmed a much higher marine primary productivity during the Middle Holocene off Tierra del Fuego.