Could Norwegian fjords serve as an analogue for the future of the Svalbard fjords? State and fate of high latitude fjords in the face of progressive “atlantification”

Abstract

Benthic foraminifera are one of the most widely and abundantly distributed organisms in the fjords of Svalbard and Norway. Due to their short life span and quick reactivity to environmental changes they can be used as indicators of the “atlantification” process. Here, we compare the benthic foraminifera assemblages along the latitudinal gradient, from the fjords of northern Svalbard to southern Norway to assess whether the “atlantification” process may homogenise the foraminiferal assemblages in terms of their abundance and species composition. Furthermore, the previously published data on benthic foraminiferal faunas was updated to identify changes in distribution that have occurred over the last few decades. For this purpose, fjord mouths in western and northern Svalbard (Isfjorden, Wijdefjorden and Rijpfjorden) and northern and southern Norway (Balsfjorden, Raunefjorden and Hjeltefjorden) were resampled. The analysis revealed similarities between the Svalbard and Norwegian foraminiferal assemblages of up to 30%; however, there were essential differences in terms of abundance and biodiversity. These results suggest that Svalbard fjords will remain distinct in the future, even under conditions of further warming or “atlantification”. Svalbard fjords may be dominated by Atlantic Water- preferring species, whereas, in Norwegian fjords, pressure from human activity will probably be the main driver of environmental changes, leading to changes in the foraminiferal assemblages with the increasing dominance of opportunistic, hypoxia-tolerant species.

Metabarcoding Reveals High Diversity of Benthic Foraminifera Driven by Atlantification of Coastal Svalbard

“…On the other hand, recent model projections indicated low mean habitat loss of benthic macrofauna under recent climate changes, which questions the vulnerability of Arctic benthos to atlantification 98 . This stands in clear opposition to the morphological observations that testate foraminifera communities from Svalbard fjords revealed significant changes, both in terms of abundance and species composition, related to atlantification 99 . Our study confirms the impact of AW on foraminiferal communities, suggesting that AW is one of the primary factors shaping the benthic foraminifera assemblages and thus foraminifera may be potential indicators of atlantification.…”

“…One of the major signs of atlantification is the northward shift of boreal species, the trend observed in the case of zooplankton, fish, and benthic organisms 97 . A recent morphological study of Svalbard foraminifera revealed the presence of boreal species Melonis affinis in the northern part of the archipelago 99 . Reophax sp.…”

Metabarcoding reveals high diversity of benthic foraminifera linked to water masses circulation at coastal Svalbard

“…On the other hand, recent model projections indicated low mean habitat loss of benthic macrofauna under recent climate changes, which questions the vulnerability of Arctic benthos to atlantification (Renaud et al, 2019). This stands in clear opposition to the morphological observations that testate foraminifera communities from Svalbard fjords revealed significant changes, both in terms of abundance and species composition, related to the influence of AW (Kujawa et al, 2021). Our study confirms the impact of AW on foraminiferal communities, suggesting that AW is one of the primary factors shaping the benthic foraminifera assemblages and thus foraminifera may be potential indicators of atlantification.…”

“…A recent morphological study of Svalbard foraminifera revealed the presence of boreal species Melonis affinis in the northern part of the archipelago (Kujawa et al, 2021). Reophax sp.…”

Drivers of change in Arctic fjord socio-ecological systems: Examples from the European Arctic

“…https://doi.org/10.1017/cft.2023.1 Published online by Cambridge University PressAccepted ManuscriptNorway due to the greater direct human influence on the continent(Kujawa et al, 2021).…”