SEASONAL PHENOLOGY OF APPENDICULARIAN TUNICATE POPULATIONS IN THE NORTHWATER POLYNYA
The Northwater Polynya (NOW) is among the most productive Arctic polynyas. An extended diatom bloom supports a long food web which includes humans. Polynyas may be ecological harbingers of an ice-free Arctic Ocean. Thus, it is important to understand how their food webs work. Appendicularian tunicates are important members of polynya food webs. We used multivariate techniques to test explicit hypotheses regarding the seasonal phenology of appendicularian populations in relation to the evolving physical, chemical, and biological environment. Cluster analysis of 21 environmental variables separated stations into pre-bloom (April-May), bloom (May-June), and post-bloom (July & September) stations. Appendicularians reproduced in response to the diatom bloom, which began first along the Greenland coast in Baffin Bay water. However, abundance of Oikopleura vanhoeffeni and Fritillaria borealis did not peak until late summer and fall, over a large area in the central NOW, where Baffin Bay and Polar waters mixed. Best environmental predictors of appendicularian abundance were silicate concentration (-), salinity (-), and temperature (+). Thus, the strongest predictors of appendicularian abundance were seasonal rather than spatial.
Deibel, D., Memorial University, Canada, firstname.lastname@example.org
Saunders, P., Ashland University, USA, email@example.com
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: No