Jekyll2026-03-08T21:25:19+00:00https://svenjahalfter.github.io/feed.xmlSvenja HalfterResearch website for Svenja Halfter, zooplankton ecologist and biogeochemist.Svenja Halfter, Ph.D.Invasive species in the Southern Ocean2024-12-26T00:00:00+00:002024-12-26T00:00:00+00:00https://svenjahalfter.github.io/blog/AEP-summaryEver wondered on if there are any invasive species in the Southern Ocean? Me and my amazing co-author team wrote a short summary upon request of the editor of the Antarctic Environments Portal. The aim of the portal is to link Antarctic science with policy, i.e., make science accessible for policymakers and managers in the Southern Ocean.

Check out the whole summary here.

]]>Svenja Halfter, Ph.D.Taking the precautionary approach to deep-sea exploitation2023-05-10T00:00:00+00:002023-05-10T00:00:00+00:00https://svenjahalfter.github.io/blog/JETZON-publicationTogether with a team of early-career exports from the JETZON ECR group, I recently published a comment in Communications Earth and Environment! We argue that before we exploit the deep sea and especially the ocean twilight zone (i.e. mesopelagic zone), we need to learn more about the ecosystem and the services it provides. Thanks to my amazing co-authors to make this possible and especially Kelsey Bisson in leading this effort. I’m looking forward to work with you in future!

Read the paper here or check out my summary on Twitter.

]]>Svenja Halfter, Ph.D.Back from the field2023-03-10T10:34:30+00:002023-03-10T10:34:30+00:00https://svenjahalfter.github.io/blog/Fieldwork2023I just returned from an interesting field season. I was lucky enough to go twice down south to the Ross Sea!

First, I spent 5 weeks south in October - November 2022. Together with a team of amazing colleagues from NIWA, Cawthron, and Otago Uni, I flew to Scott Base as one of the first teams in the season. After the first few days of field training, we went out and camped on the ice for 4 weeks. We used new gear to sample the platelet ice layer underneath the sea ice, and not even cancelled flights and delayed cargo could stop us! We even met the NZ Prime Minister Jacinda Ardern. I sampled the ice for metazoan and filtered thawed ice cores for chlorophyll and DNA, and drilled more ice holes than I can count. What an adventure!

Then, in January 2023, I went on the Tangaroa voyage to the Ross Sea. I was responsible for deploying the Continuous Plankton Recorder, towed the Bongo net and sampled the underway system for zooplankton. We were at sea for 5.5 weeks and explored the northern coastal Ross Sea around Cape Adare, Cape Hallett, Cape Wheatstone and Coulman Island. Because of too much ice, we could not go further south into Terra Nova Bay, but I collected enough samples to keep me busy for the next year. We even saw some whales and heaps of penguins. I feel very privileged to work with so many inspiring scientists!

If you are interested in more field experiences, I’ll give a talk on March, 16th for the NZ Antarctic Society:

Edit: If you missed the talk, you can watch it on YouTube.

]]>Svenja Halfter, Ph.D.New job with NIWA in New Zealand2022-04-17T17:34:30+00:002022-04-17T17:34:30+00:00https://svenjahalfter.github.io/blog/new-jobAfter finishing my PhD at IMAS (without corrections!!!) early this year, I found a job faster than expected! In July, I’ll move to Wellington in New Zealand to start a new position as plankton ecologist.

I’ll be involved in several projects, for example working with local Continuous Plankton Recorder data to understand the impact of climate change and marine heatwave on local plankton communities.

I’ll also study plankton in and under the sea ice of the Ross Sea in the Southern Ocean. The Ross Sea was declared a Marine Protected Area by CCAMLR in 2016/2017. My job will be to sample platelet ice, sea ice that is formed due to supercooling of water masses and leads to ice growth from the basis of the sea ice, with the aim to understand how sea ice and pelagic ecosytems are connected. I hope to be on the next trip down to Antarctica in early 2023 on the ice breaker RV Tangaroa. Exciting times ahead!

The Ross Sea Marine Protected Area. Figure by WWF.
]]>Svenja Halfter, Ph.D.New publication alert!2020-10-08T19:34:30+00:002020-10-08T19:34:30+00:00https://svenjahalfter.github.io/blog/new-publicationMy new publication on how zooplankton help establishing carbon export regimes in the Southern Ocean is finally out! Together with my amazing co-authors and mentors Emma Cavan, Ruth Eriksen, Kerrie Swadling and Philip Boyd, I wrote a mini-review as part of the IMBeR Special Issue.

We compared two sites: the northern Kerguelen Plateau, which is a naturally iron-fertilised region and characterised by high surface productivity but low carbon export, and the HNLC waters south of Australia, which are less productive and iron-limited but exhibit high carbon export. Zooplankton grazing plays an important role in establishing these contrasting export regimes. Check out the infographic below!

The role of zooplankton in establishing characteristic carbon export regimes in the subantarctic Southern Ocean. Published in Halfter et al. 2020, open access.
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