Norwegian version of this page

Disputation: Anouk Tosca Klootwijk

Doctoral candidate Anouk Tosca Klootwijk at the Department of Geosciences, Faculty of Mathematics and Natural Sciences, is defending the thesis Benthic foraminiferal biomonitoring in northern Norway: Establishing reference conditions, Ecological Quality Statuses and responses to organic matter for the degree of Philosophiae Doctor.

Anouk Tosca Klootwijk. Photo: Private

Anouk Tosca Klootwijk. Photo: Private

The PhD defence and trial lecture are fully digital and streamed using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation. 

Trial lecture

As a recording:

Environmental DNA and paleogenetic approaches as a next-generation biomonitoring tool: potentials and pitfalls

Conferral summary

By using benthic foraminifera to reconstruct pre-human impact environmental conditions, the first study of this thesis found no clear impact of fish farming in an intensively fish farmed fjord at 2-3 km distance from the farms. The second study showed that the amount of microalgal-carbon (food) foraminifera can process may strongly vary within a fjord. Additionally, oxygen concentrations in the sediment may influence the ability of foraminifera to process microalgal-carbon. The third study suggests that analysing benthic foraminifera from the less labour intensive larger size fraction (> 125 µm) may be sufficient to assess human impact in relatively unpolluted fjords. This thesis, therefore, made important steps towards using foraminifera to study human impacts on the environment.

Main research findings

Popular scientific article about Klootwijk’s dissertation:

Benthic foraminiferal biomonitoring in northern Norway: Establishing reference conditions, Ecological Quality Statuses and responses to organic matter

Benthic foraminifera are microscopically small organisms that live in the sediment of marine environments where they live in little houses also referred to as tests. Foraminifera respond rapidly to environmental changes and as many of their tests preserve in the sediment their assemblages can provide estimates of previous environmental conditions. This makes them good candidates to study human impacts on the environment but for that, we also have to increase our understanding of their responses to environmental changes (e.g. changes in sediment oxygen concentrations).

By using benthic foraminifera to reconstruct pre-human impact environmental conditions, the first study of this thesis found no clear impact of fish farming in an intensively fish farmed fjord at 2-3 km distance from the farms. The second study showed that the amount of microalgal-carbon (food) foraminifera can process may strongly vary within a fjord. Additionally, oxygen concentrations in the sediment may influence the ability of foraminifera to process microalgal-carbon. The third study suggests that analysing benthic foraminifera from the less labour intensive larger size fraction (> 125 µm) may be sufficient to assess human impact in relatively unpolluted fjords. This thesis, therefore, made important steps towards using foraminifera to study human impacts on the environment.

Bildet kan inneholde: vann, grønn, himmel, vannskuter, flaske.
Pictures of the fieldwork and carbon processing experiment conducted for this doctoral thesis. A) shows one of the five fish farms in Øksfjorden and B) shows the twin-barrelled Gemini corer used for sampling in the Inner Øksfjorden, Finnmark. C) is a picture of sediment cores taken in Inner Øksfjorden, where the bottom part represents the oldest sediments and the upper part represents more recently deposited sediments. D) is a picture of the microalgae that were grown in a medium with an unnaturally high 13-Carbon content so the algae would have a distinct carbon signature that was used to investigate how much microalgal-carbon foraminifera could potentially process. E) shows a box-corer that is being sampled for experimental chambers used in the carbon processing experiment of this thesis. F) is an experimental chamber treated with both the algae and jellyfish detritus at the end of the 2-day experiment. Photo and figure credit: Anouk Tosca Klootwijk.

Photo and other information:

Press photo: Anouk Tosca Klootwijk, portrait; 500px. Photo: Private

Other photo material: Figure with description and credit as specified in the article above, size 1000px.

Published Nov. 25, 2021 11:38 AM - Last modified Dec. 3, 2021 11:25 AM