Environmental influences on recruitment of benthic invertebrates in the Arctic
Marine Group/CEES Extra seminar by Kirstin Meyer-Kaiser
Hard-bottom habitats are uniquely abundant in glacially-influenced polar regions because of the presence of dropstones, i.e. terrestrial stones that were deposited on the seafloor by melting icebergs. These hard substrata contribute to habitat heterogeneity, abundance, and diversity of organisms in the polar benthos. Recruitment is the process by which substrata are colonized by invertebrate larvae, and it is influenced by environmental factors such as temperature and current velocity. Working with German and Norwegian collaborators, I have studied environmental influences on recruitment in the eastern Svalbard waters at depths 7 – 2500 m. Fouling panels (15 x 15 cm plexiglass, roughened with sandpaper) were outplanted for one year on docks and moorings in Svalbard fjords. In addition, panels made from plastic and brick were outplanted on a long-term lander at 2500 m and recovered after 18 years. At shallow depths in fjords, barnacles, spirorbid polychaetes, and bryozoans dominated the recruit communities early on, while at greater depths, hydroids and foraminiferans were the first colonists. Recruitment was lower at greater depths and in colder fjords, indicating that communities in these environments may take longer periods of time to develop. After 18 years, the long-term deep-sea panels still did not resemble the background community, indicating that community assembly in the Arctic deep sea takes decades.
Dr. Kirstin Meyer-Kaiser
Woods Hole Oceanographic Institution