A ROV study on the feeding and metabolism of Antarctic hexactinellid sponges


Contact
luisa.federwisch [ at ] awi.de

Abstract

On Antarctic shelves, glass sponges (Porifera, Hexactinellida) dominate the megabenthic epifauna. But in spite of intensive research on epifauna community structure, process studies on the ecophysiology of key species are so far lacking, due to the difficulty of accessing glass sponges in their habitat and keeping them alive for experimental work. Here, we present preliminary results of an in situ study carried out in the Weddell Sea using a remotely operated vehicle (ROV) to measure feeding, respiration, ammonium excretion and silicate uptake in the common glass sponges Rossella nuda / Anoxycalyx joubini, R. racovitzae and R. villosa. A custom-developed ROV-mounted water sampler was successfully deployed. A total of 22 samples from sponge oscula and 21 samples from ambient waters were analyzed for picoplankton, ammonium and dissolved silicate concentrations. Optode measurements in the ambient water and inside the sponge oscula revealed a measurable difference of ~0.5 µM oxygen between ambient and exhalant waters. Together with estimates of the exhalant volume flow from concomitant fluorescein dye experiments, the oxygen and silicon uptake as well as the ammonium excretion of individual sponges can be estimated. Our findings will help elucidate the role of hexactinellid sponges in carbon and silicon cycling and contribute to understanding future effects of sea-ice and productivity changes on Antarctic ecosystem structure, functioning and services.



Item Type
Conference (Talk)
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Primary Division
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Peer revision
Not peer-reviewed
Publication Status
Published
Event Details
XXXIV SCAR Biennial Meetings & Open Science Conference, 20 Aug 2016 - 30 Aug 2016, Kuala Lumpur, Malaysia.
Eprint ID
41828
Cite as
Federwisch, L. , Holtappels, M. , Cantzler, H. , Johansson, R. , Andersson, E. and Richter, C. (2016): A ROV study on the feeding and metabolism of Antarctic hexactinellid sponges , XXXIV SCAR Biennial Meetings & Open Science Conference, Kuala Lumpur, Malaysia, 20 August 2016 - 30 August 2016 .


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