Larval dispersal and recruitment of benthic invertebrates in the Arctic Ocean

• Published in: Progress in Oceanography
• Main Authors: Meyer-Kaiser, Kirstin, Schrage, Kharis R, von Appen, Wilken-Jon, Hoppmann, Mario, Lochthofen, Normen, Sundfjord, Arild, Soltwedel, Thomas
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: PERGAMON-ELSEVIER SCIENCE LTD 2022
• Subjects: Arctic; Arctic Ocean; Greenland; Svalbard; Climate change; East Greenland; east greenland current; Fram Strait; Spitsbergen
• Online Access: https://epic.awi.de/id/eprint/54664/; https://hdl.handle.net/10013/epic.39c59d10-9e0b-41b2-af26-ce4928eb5812

Larval dispersal is a fundamental process responsible for colonization and connectivity of benthic invertebrate populations. It is difficult to study larval dispersal in polar environments because weather and climate conditions restrict sample collection to certain seasons. In this study, we leveraged oceanographic moorings as long-term scientific platforms for collecting larvae and recruits of benthic invertebrate species in the Fram Strait and along the continental slope north of Svalbard in 2017–2021. Larval traps and fouling panels were deployed at various depths on 15 moorings at 8 locations, and additional specimens of biofouling were obtained opportunistically from moored instruments. Our results showed a significant difference in species composition between samples collected in Atlantic Water in the West Spitsbergen Current (WSC) and samples collected in Arctic Water near the seafloor and in the East Greenland Current (EGC) in the western part of the Fram Strait. There was also a stark difference between Atlantic Water species in the Fram Strait and on the north Svalbard slope. Most specimens collected in the WSC belonged to species with long-duration planktotrophic larvae, such as the ubiquitous bivalve Hiatella arctica, the bryozoan Alcyonidium mamillatum, and two nudibranchs. Samplers exposed primarily to Arctic water at their given depth and location were dominated by hydrozoans. We observed medusae budding off of the hydroids Stegopoma plicatile and Rhizoragium roseum. Our study demonstrates that the WSC is an important vector for larval dispersal into the central Arctic Ocean. Integration of biological samplers on oceanographic moorings holds great promise for monitoring efforts as climate change progresses, especially in environments where research is challenging and seasonally limited, such as the Arctic. 1. Introduction For benthic invertebrates, especially those with sessile adult stages (e.g., sponges, anemones), larval dispersal is the primary mechanism of dispersal to new habitats (Pechenik, ...