Recruitment and growth of Arctic deep-sea invertebrates in a long-term (18-year) colonization experiment at the HAUSGARTEN observatory (Fram Strait, Arctic Ocean)

• Main Authors: Meyer, Kirstin, Bergmann, Melanie, Soltwedel, Thomas
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Arctic; Arctic Ocean; Foraminifera*; Fram Strait; Svalbard
• Online Access: https://epic.awi.de/id/eprint/46845/; https://hdl.handle.net/10013/epic.9c9db251-5def-4e7e-a6b1-946e035d6330

The early life-history stages of deep-sea invertebrates are understudied, particularly in polar regions. It is especially difficult to estimate growth rates for species which may grow just millimeters per year and are, therefore, difficult to monitor in situ. A long-term (1999 – 2017) colonization experiment at the LTER (Long-Term Ecological Research) observatory HAUSGARTEN in the Fram Strait (Arctic Ocean) provides valuable insights into the recruitment and growth of polar deep-sea invertebrates, and how these processes are influenced by environmental factors. After 18 years on the Svalbard continental slope (79⁰ N, 04° E, 2500 m water depth), panels were colonized by 13 metazoan species as well as calcareous and agglutinating foraminiferans. Significant differences in the community composition and abundance of recruits on panels made from different materials (i.e. stone, plastic), at different altitudes off bottom, and at different angles to the predominant bottom current reveal species-specific microhabitat preferences of the recruits. We calculated maximum growth rates for two common species, the crinoid Bathycrinus carpenterii and the sponge Cladorhiza gelida, and used these rates to calculate the ages for most recruits. In years with higher estimated recruitment, there was a predominantly westerly bottom current (average bearing 270 – 280⁰), which might indicate that a densely-populated rocky reef located at similar water depths to the east of the experimental site may have served as a source population.