Prevalent fingerprint of marine macroalgae in arctic surface sediments

TY - JOUR

T1 - Prevalent fingerprint of marine macroalgae in arctic surface sediments

AU - Ørberg, Sarah Bachmann

AU - Quesada, Carlos M Duarte

AU - Geraldi, Nathan

AU - Sejr, Mikael Kristian

AU - Wegeberg, Susse

AU - Hansen, Jørgen L. S.

AU - Krause-Jensen, Dorte

PY - 2023/11

Y1 - 2023/11

N2 - Macroalgal forests export much of their production, partly supporting food webs and carbon stocks beyond their habitat, but evidence of their contribution in sediment carbon stocks is poor. We test the hypothesis that macroalgae contribute to carbon stocks in arctic marine sediments. We used environmental DNA (eDNA) fingerprinting on a large-scale set of surface sediment samples from Greenland and Svalbard. We evaluated eDNA results by comparing with traditional survey and tracer methods. The eDNA-based survey identified macroalgae in 94 % of the sediment samples covering shallow nearshore areas to 1460 m depth and 350 km offshore, with highest sequence abundance nearshore and with dominance of brown macroalgae. Overall, the eDNA results reflected the potential source communities of macroalgae and eelgrass assessed by traditional surveys, with the most abundant orders being common among different methods. A stable isotope analysis showed a considerable contribution from macroalgae in sediments although with high uncertainty, highlighting eDNA as a great improvement and supplement for documenting macroalgae as a contributor to sediment carbon stocks. Conclusively, we provide evidence for a prevalent contribution of macroalgal forests in arctic surface sediments, nearshore as well as offshore, identifying brown algae as main contributors.

AB - Macroalgal forests export much of their production, partly supporting food webs and carbon stocks beyond their habitat, but evidence of their contribution in sediment carbon stocks is poor. We test the hypothesis that macroalgae contribute to carbon stocks in arctic marine sediments. We used environmental DNA (eDNA) fingerprinting on a large-scale set of surface sediment samples from Greenland and Svalbard. We evaluated eDNA results by comparing with traditional survey and tracer methods. The eDNA-based survey identified macroalgae in 94 % of the sediment samples covering shallow nearshore areas to 1460 m depth and 350 km offshore, with highest sequence abundance nearshore and with dominance of brown macroalgae. Overall, the eDNA results reflected the potential source communities of macroalgae and eelgrass assessed by traditional surveys, with the most abundant orders being common among different methods. A stable isotope analysis showed a considerable contribution from macroalgae in sediments although with high uncertainty, highlighting eDNA as a great improvement and supplement for documenting macroalgae as a contributor to sediment carbon stocks. Conclusively, we provide evidence for a prevalent contribution of macroalgal forests in arctic surface sediments, nearshore as well as offshore, identifying brown algae as main contributors.

KW - Blue carbon

KW - Carbon stocks

KW - Eelgrass

KW - Environmental DNA

KW - Kelp

KW - Stable isotopes

UR - http://www.scopus.com/inward/record.url?scp=85165963674&partnerID=8YFLogxK

U2 - 10.1016/j.scitotenv.2023.165507

DO - 10.1016/j.scitotenv.2023.165507

M3 - Journal article

C2 - 37442464

SN - 0048-9697

VL - 898

JO - Science of the Total Environment

JF - Science of the Total Environment

M1 - 165507

ER -