Benthic ecosystem functioning of the western Clarion-Clipperton Zone, Pacific Ocean, and the West Antarctic Peninsula : a study to assess the effectiveness of Areas of Particular Environmental Interest (APEIs) in the context of deep-sea mining and the effects of climate change
Cecchetto, Marta M.
MetadataShow full item record
The deep sea encompasses the largest ecosystem on Earth and remains largely unexplored. With plans for deep-sea mining and the increasing impacts of climate change on our oceans, there is a growing necessity to understand and safeguard deep-sea biodiversity and ecosystem functioning. The cycling of carbon (C) by deep-sea benthic communities is a key ecosystem function and pulse-chase experiments are aimed to measure this process I conducted pulse-chase experiments in situ at abyssal depths (4800-5300 m) in three no-mining areas, called Areas of Particular Environmental Interest (APEIs), in the Clarion-Clipperton Zone (CCZ) and in ex situ experiments using sediments collected from a bathyal (500-600 m) fjord, Andvord Bay, and the continental shelf of the West Antarctic Peninsula (WAP). My results underline the importance of organic C in driving ecosystem dynamics at the abyssal seafloor and support the notion that Antarctic fjords are hotspots of benthic biomass and ecosystem functions. The microbial community was shown to be a key player in the short term (1.5 d) cycling of C on the abyssal plain of the western equatorial Pacific Ocean, which is consistent with other published studies, while the macrofaunal community (>300 µm) dominated the initial (~1 d) degradation of phytodetritus in Andvord Bay. My study provides important information on benthic ecosystem functioning in the western CCZ, an area targeted for commercial-scale deep-sea mining, and the WAP, a region that is becoming increasingly impacted by climate change.