USF Marine Metal Isotope and Trace Element Laboratory

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New News (2024)

Congratulations to Claire Onak who successfully defended her excellent MS thesis on redox cycling of Fe and Fe isotopes in the Saanich Inlet (March 2024)!

Congratulations to Hung-an Tian who sucessfully defended his amazing PhD thesis on trace metal cycling in coastal Antarctica (March 2024)! Two chapters are already published and two are in prep.

New paper alert - Nicole Buckley led a paper that re-evaluates sulfide as a water column sink for trace metals in the ocean, addressing a hypothesis we first proposed back in 2014 (Mar 2024)!

Lab members Tim Conway, Claire Onak, Hannah Hunt, and Hung-an Tian all gave great posters at Ocean Sciences in New Orleans, with all lab members (+ Dylan Halbeisen and Zach Bunnell) also contributing to a range of great co-authored presentations on range of biogeochemical topics (February 2023).

New paper alert - Rene Boiteau led a paper that uses LC-UH-MS to look at the nature and persistence of organic matter in the ocean (February 2023). 

New paper alert - Yaqing Ruan led the first paper to look simultaneously at the behavior and fractionation of four trace metal isotope systems (Fe, Ni, Cu, Zn) across an estuarine gradient in the Pearl River Estuary, China (February 2023).

Old News (Pre-2024)

Hannah Hunt's trip to the Amundsen Sea as part of GEOTRACES GP17-ANT (Nov-Feb) was the feature of a nice USF news story on the USF Homepage (December 2023).

New paper alert - Hung-an Tian led an exciting paper on Fe isotope cycling in the Amundsen (December 2023).

Our recent paper in Science Advances was the focus of a GEOTRACES Science Highlight on Fe bioavailability (November 2023).

The Goldschmidt Conference in Lyon featured presentations by some of our awesome collaborators (August 2023).

Lab members Zach Bunnell, Hannah Hunt, Dylan Halbeisen, and Claire Onak presented posters (and Hannah an invited talk) at the Gordon Research Seminar and Conference in Chemical Oceanography in New Hampshire (July 2023).

New paper alert - led by collaborator Marion Fourquez, our new paper out in Science Advances looks at Fe speciation and bioavailability across the Southern Ocean (July 2023).

Lab members Hannah Hunt and Emma Chestang set sail on the second of the two STING cruises aboard the R/V Endeavor on the West Florida Shelf. Emma's work was featured in a University of Tampa story (June 2023).

Congratulations to Hannah Hunt who was awarded the USF CMS Renate E. Bernstein Outstanding Authorship Award for her recent paper on Fe isotope cycling in the South Atlantic, and who gave a great talk on Fe in Florida rivers at the Aquatic Sciences Conference in Mallorca (June 2023).

We welcome Emma Chestang from the University of Tampa who will be an undergrad technician over the summer. Welcome Emma! (May 2023).

Our Southern Ocean science was featured in a USF CMS news article on ongoing Southern Ocean Research at the College (May 2023).

New paper alert - led by Matthias Sieber, our new paper out in JGR Oceans presents a story of Zn cycling in the North Pacific from GP15. GEOTRACES highlight (April 2023).

The MarMITE lab had a great time at the St Petersburg Science Festival, talking to the general public about GEOTRACES and rivers. USF News Story (February 2023).

Lab members Hannah Hunt and Claire Onak set sail on the first of two STING cruises aboard the R/V Atlantic Explorer on the West Florida Shelf (February 2023).

Congrats to lab member Hannah Hunt who was awarded a SeaGrant Fellowship (February 2023).

Dylan Halbeisen returned from being a super tech on the successful GP17-OCE cruise from Tahiti to Chile (February 2023).

New paper alert - led by Hung an Tian, our new paper out in Marine Chemistry takes a deep dive into Zn and Cd cycling in the Amundsen Sea (February 2023).

New paper alert - collaborator Jessica Fitzsimmons and Tim Conway co-authored a new comprehensive review of marine Fe isotopes in Annual Reviews of Marine Science. GEOTRACES highlight and CMS News Story (February 2023)

New paper alert - led by Matthias Sieber, our new paper out in Global Biogeochemical Cycles presents a synthesis of Cd cycling in the North Pacific. GEOTRACES highlight (January 2023).

We wish lab member Dylan Halbeisen and all the members of the GP17-OCE expedition the best of luck with completing their section from Tahiti to Chile (December 2022).

New paper alert - led by Hong Chin Ng, our new paper in Global Biogeochemical Cycles investigates Fe and Si cycling in Fjord Sediments  (December 2022).

Congrats to lab member Hannah Hunt, who had her first first author paper on Fe in the South Atlantic published! (December 2022).

Our new paper in Nature Geoscience on global Nickel cycling was the focus of a USF CMS news story and a GEOTRACES highlight (October-November 2022).

New paper alert - led by Mathijs von Manen, our new paper out in Marine Chemistry takes a close look at Fe and Mn near the Dotson Ice Shelf and in the Amundsen Sea Polynya (October 2022).

Our new NSF-funded project on the WFS was the feature of a USF CMS news story, coincedent with the launch of the river and submarine groundwater sampling part of the project (August 2022).

A flurry of recent news! Congratulations to Zach Bunnell who passed his MS defense with flying colors and graduated. Zach will stay in and do a PhD in the lab! Also congrats to Claire Onak who successfully defended her MS proposal. Lab Members Dr. Eniko Toth and Dr. Matthias Sieber gave great talks at the recent Goldschmidt Conference in Hawai'i, and Dylan Halbeisen attended the International GEOTRACES Summer School in Germany. (July 2022).

New paper alert - led by Daniela König, our new paper in Geophysical Research Letters investigates the role of aerosols in setting oceanic surface iron isotope signatures (June 2022).

Lab member Dylan Halbeisen was awarded a NSF Graduate Research Fellowship. Congrats, Dylan! (April 2022).

New lab paper alert - led by Gregory de Souza, our new paper in Geochimica et Cosmochimica Acta re-evaluates the role CdS plays in the marine Cd cycle (Feb 2022).

Lab members Zach Bunnell, Dylan Halbeisen, Hannah Hunt, and Claire Onak all gave great presentations at this year's USF CMS Graduate Student Symposium, and Hannah won 1st Prize for her Poster! Congrats, Hannah! (Feb 2022).

Our recent NSF grants on GEOTRACES GP17 were a feature of a USF CMS news story (September 2021).

We welcome Dylan Halbeisen who joins us in the lab as a new graduate student. Welcome! (August 2021).

Our collaborators Janelle Steffen, Dr. Gregory de Souza and Dr. Jon Hawkings gave great presentations at the virtual Goldschmidt 2021, featuring work MarMITE lab members have been involved in! (July 2021).

Tim Conway was lead guest editor on a recently completed Virtual Special Issue in Chemical Geology. Check out the exciting contents here, and the editorial review here! This special issue was dedicated to Prof. Thomas Church who was pioneering in the field and sadly passed away in 2021. As featured by NSFUSF CMS and GEOTRACES (June 2021).

Our new assessment in GBC on trace-metal isotopes as paleoproductivity proxies, led by Dr. Tristan Horner at WHOI (and featuring a heroic team of authors) was the subject of a GEOTRACES Science Highlight.

Our recent work on iron cycling in the Southern Ocean (Sieber et al., 2021) and in the Arctic Ocean (Krisch et al., 2021) were the feature of a GEOMAR story, a USF CMS story, and a GEOTRACES Science Highlight (May 2021).

Congratulations to lab members Zach Bunnell who was awarded the Kent Fanning USF CMS Endowed Fellowship for 2021-22, and to Claire Onak who was awarded the Southern Kingfish Association's USF CMS Endowed Fellowship for 2021-2022! (March 2021).

Our new paper on the importance of colloidal sedimentary iron to the ocean led by Dr. Will Homoky at the University of Leeds is the feature of an USF CMS news story, a University of Leeds news story, a Yorkshire Post story, and a GEOTRACES Highlight. It was also featured by UPI Science News, Flipboard News, NewsbreakGephardt News, Spot on Floridathe Deep Sea Stewardship Initiative Weekly Roundup, AZO Cleantech news, Ecomagazine,, todayUKnews,  Samacharcentral, Science Daily, notimerica, and many tweets! (March 2021).

Tim Conway gave an invited OCB webinar. Check it out here (March 2021).

We say goodbye to Brent Summers, who was the first student in the lab. We wish him all the best for the future! (December 2020).

We welcome Dr. Eniko Toth who begins as a postdoc with us, working on dust dissolution (November 2020).

Congratulations to Brent Summers for graduating with his MS degree from USF. We are all very proud of you! Brent now stays with us as a lab tech, working on seawater samples. (August 2020).

Welcome to new lab members, Claire Onak and Hannah Hunt who join us as new graduate students in the group! (August 2020).

Lab members Tim Conway and Matthias Sieber gave successful talks at the Virtual Goldschmidt, and Tim chaired a session (June 2020).

Congratulations to Brent Summers who successfully defended his MS Thesis! (May 2020).

We welcome Claire Onak and Hannah Hunt who have accepted offers to join the lab in Fall as new graduate students. Welcome! (April 2020).

Lab member Zach Bunnell was awarded the USF CMS Paul Getting Endowed Memorial Fellowship for 2020-21! Congrats, Zach! (April 2020).

Our lab was involved in sixteen presentations at OSM in San Diego, with many great presentations by students and postdocs (February 2020).

Tione Grant did a fantastic job presenting his REU research at the ERN STEM conference in Washington DC, where he won first prize for his poster! Congratulations, Tione! (February 2020).

We carried out a successful test cruise for USF's new trace metal CTD rosette, led by chief scientists Matthias Sieber and Salvo Caprara. Thanks to FIO for the free ship days! (February 2020).

Our new paper investigating Fe cycling under the Larsen Ice Shelf, with collaborators from the Rosenheim Lab and from Korea, was the subject of a CMS news story (December 2019).

We say goodbye to Ryan Schlaiss who is leaving the lab, and wish him the best in his future career (December 2019).

The CMS-taught (Conway, Hu, Luther, Naar and Peebles) Honors Course on Estuaries at USF Tampa was the subject of a CMS news story (October 2019).

Tim Conway and Matthias Sieber gave successful talks and Brent Summers presented a great poster at Goldschmidt in Barcelona (August 2019).

Zachary Bunnell joins the lab. Welcome! (August 2019).

Tim Conway gave an invited talk at the IUGG Conference in Montreal, Canada (July 2019).

Dr Matthias Sieber rejoins the lab as a USF Postdoctoral Research Fellow. He will be working on metal isotope cycling on the US GEOTRACES GP15 section. Welcome back! (July 2019).

Our new paper using iron isotopes to trace and constrain natural and human-derived aerosol iron to the oceans was the focus of a CMS news story, a GEOTRACES Science Highlight and a Scientific American story! (June-July 2019).

Ryan Schlaiss participated on a successful cruise at Bermuda, collecting low-metal seawater and organic molecules for our NSF-funded collaboration with Rene Boiteau at OSU (June 2019).

Tione Grant joins us as an NSF-funded REU student for the Summer to work on Ni isotope methods. Welcome! (May 2019).

Matthias Sieber successfully defended his PhD Thesis. Congratulations Dr Sieber! (March 2019).

Ryan Schlaiss rejoins us as in the lab. Welcome back Ryan! (March 2019).

MarMITE scientists Tim Conway, Brent Summers and Ryan Schlaiss, completed a successful transit of the Gulf Stream from West Palm on board the R/V Angari. This cruise, funded by USF Research, collected surface water for analysis of trace metals, trace metal isotopes, nutrients, chlorophyll, nitrogen isotopes and Fe binding ligands. Also on board were scientists from FSU (Peter Morton) and the Buck Lab (Travis Mellett) at USF. This cruise is the focus of ANGARI Expedition 23 report and several CMS blog stories by CMS media Sean Beckwith, who was also on board - Part 1 - Part 2 (March 2019).

Some of our recently-published collaborative GEOTRACES synthesis work focusing on elemental cycling and residence times of elements in the North Atlantic, led by Chris Hayes, was featured in the latest issue of EOS, and in a CMS news story (Jan 2019).

Brent Summers and the successfully-completed GP15 section are featured in a series of US GEOTRACES blog posts (part 1 and part 2) and are the focus of a CMS news story (November 2018).

Brent Summers set sail on the R/V Revelle from Seattle as a 'supertech' as part of the US GEOTRACES GP15 section. The cruise will go to Alaska, Hawaii and Tahiti, collecting water, aerosols and particles (September 2018).

Tim Conway, Brent Summers and Matthias Sieber gave successful presentations at Goldschmidt Conference in Boston, and Tim co-chaired Session 07i (August 2018).

NSF awarded us a grant to study the isotopic fractionation of Fe from atmospheric dust in concert with different natural and model organic ligands and phytoplankton communities, in collaboration with Rene Boiteau at Oregon State (July 2018).

Matthias Sieber joins us for a visit from ETH Zürich, measuring some Antarctic Fe isotope samples (July 2018).

Our new paper on iron cycling across the Gulf Stream, out in Nature Geoscience, was featured as a news item on the CMS website. Other news coverage - USF Research - GEOTRACES Science Highlight - ETH Zürich (July 2018).

Minako Kurisu visited us again from Tokyo to measure some surface Pacific Ocean samples (July 2018).

Hung-An Tian joins us for a visit from NIOZ in the Netherlands, working on some isotope samples (July 2018).

Ryan Schlaiss rejoins us a Summer Undergraduate Intern working in the lab. Welcome back, Ryan (June 2018).

Brent Summers received an honorable mention for his NSF GRFP application. Congrats Brent (April 2018)!

Prof Takahashi and Minako Kurisu visited us from Tokyo to measure some surface Pacific Ocean samples (March 2018).

Tim Conway chaired a session and presented a talk at Ocean Sciences Meeting in Portland (Feb 2018).

Brent Summers gave a talk at CMS' 35th Annual Graduate Student Symposium (Jan 2018).

Tim Conway completed a successful visit and guest seminar at NIOZ in the Netherlands (Oct 2017).

Brent Summers joins the group as a new graduate student. Welcome, Brent! He goes straight off on a Line P sampling cruise in British Columbia (Aug 2017).

NSF awarded us a grant to take part on US GEOTRACES GP15 section in the North Pacific. In collaboration with USC and a number of other groups, we will collect particles, aerosols and water samples from Alaska to Tahiti in order to better understand the cycling of Fe, Zn, Cd, Cu and Ni and their isotopes in this understudied region. MarMITE graduate student Brent summers will sail as a super tech on the cruise in Sept 2018 (June 2017).

Trace Metal Chemistry - less is more! CMS news story and video interview with Tim Conway talking about trace metals, GEOTRACES and our work (May 2017).

Ryan Schlaiss joins us in the lab for the Summer as an Undergraduate Intern from Ekhardt College to help out with lab setup and getting our seafast going. Welcome, Ryan (May 2017).

Tim Conway and Rob Middag awarded NWO Travel and Subsistence Grant for Tim Conway to visit Royal Netherlands Institute for Sea Research (Sept-Oct 2017).

Our collaborative Antarctic Netherlands Organisation Research Proposal ‘Iron limitation and viral lysis, phytoplankton caught between a rock and a hard place’ with PI Rob Middag was funded (May 2017).

Tim Conway awarded USF New Researcher Grant from USF Office of Research and Innovation, entitled "Investigating the influence of the Gulf Stream System on micronutrient cycling in the North Atlantic Ocean (April 2017).

MarMITE took part in a successful collaborative sampling of the Saanich Inlet, British Columbia, Canada, and Tim Conway gave a seminar at University of Victoria, BC (March 2017).

Tim Conway and collaborator Will Homoky presented talks at the ASLO Meeting 'Mountains to the Sea' in Honolulu, Hawaii (Feb 2017).

Tim Conway hired as a new Assistant Professor at the College of Marine Sciences and School of Geosciences at the University of South Florida (Summer 2016).

Tim Conway awarded Editor's citation for reviewing by AGU (May 2016).

GEOTRACES Science Highlight: Temporal and Inter-lab comparison of iron isotope profiles - features an article in Marine Chemistry by Conway et al. (May 2016).

GEOTRACES Science Highlight: GEOTRACES Intermediate Data Product Motivation and Details - features an article in Marine Chemistry publishing the motivation and methodology for the IDP 2014 (November 2015).

GEOTRACES Science Highlight: Why is the deep ocean zinc isotopic signature so heavy? - features our article in GBC with the first high-resolution seawater-dissolved Zn isotope ratio section (November 2014).

News Coverage on our Letter to Nature - USC - Earth Sky - Daily Climate - Climatewire - - Science Daily - Science World Report - Nature World News - eScience News - Science 2.0 (July 2014).

Iron Fingerprints - State of the Planet - awesome Geo-poetry about Fe in the Atlantic by Dr Kat Allen (July 2014).

Ocean Chemistry: Fingerprints of a trace nutrient - Resing et al., Nature News and Views article featuring the content of our Letter to Nature (July 2014).

GEOTRACES Science Highlight on quantifying Fe sources to the North Atlantic - features our Letter to Nature on dissolved Fe isotope data from the GA03 North Atlantic Section (July 2014).

GEOTRACES Science Highlight on evidence for undocumented Cd, Zn and Cu sinks in the ocean (from Pacific and Atlantic ODZ samples) - features our PNAS paper with co-authors in the Cullen Lab from the University of Victoria (2014).

GEOTRACES Science Highlight on new evidence that scavenging is important in the biogeochemical cycling of Zn - features our EPSL paper on North Atlantic dissolved Zn isotopes (2014).

Nature News feature on 3D section of dissolved Fe concentrations in the Atlantic Ocean from the GEOTRACES Intermediate Data Product - including some of our dissolved Fe data (2014).

GEOTRACES Science Highlight on our new method for determination of Fe, Zn and Cd isotope ratios in a single litre of seawater - detailing our ACA methods paper (2013).

BBC News feature on Fe release from oceanic sedimentary margins - focuses on our Nature Communications paper with co-authors from the University of Southampton (2013).

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