1–2 master projects
- Main supervisor: Yngvild Vindenes
- Co-supervisors: Jan Heuschele, Ketil Hylland, Øystein Langangen
Background
Marine organisms have evolved in highly dynamic environments. Many habitats show strong diurnal and seasonal variation in temperature, oxygen, and other abiotic and biotic factors. Oxygen availability is a key determinant of how well organisms cope with thermal stress, because metabolic and respiratory demands increase at higher temperatures. To predict how organisms will respond to events such as marine heatwaves, we therefore need a good understanding of local variation in dissolved oxygen and its covariance with temperature.
While the solubility of oxygen in water decreases with increasing temperature, oxygen-producing organisms (e.g. algae) can create a positive relationship between temperature and oxygen through photosynthesis, leading to daytime supersaturation in parts of the year. This mechanism has been shown to enhance survival of marine organisms in warm tropical waters, allowing them to tolerate higher temperatures than they otherwise would in the absence of algae.
The Oslofjord is currently under pressure from human activities and environmental change. Reduced oxygen levels have been documented, especially at deep layers in the inner fjord, and more recently also in outer areas. [JH1.1]However, diurnal and seasonal patterns of oxygen, and how it covaries with temperature, are not well known especially in littoral surface waters. In a warming climate where marine heatwaves are expected to become more frequent, it is important to understand the thermal tolerance of key organisms in the Oslofjord, and how this tolerance depends on fluctuating oxygen conditions in different locations.
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(Photos (Jan Heuschele). Examples of focal habitats in the Oslofjord.)
Aims
The overall aims of this master project (or projects) are 1) to measure and analyze the daily variation and covariation in oxygen and temperature at different coastal locations in the Oslofjord (in macroalgae habitats), and 2) to test the thermal tolerance and other stress responses of marine invertebrates such as amphipods, isopods and copepods from these locations, by collecting field samples and performing experiments at the Drøbak field station. This project will provide new knowledge on important abiotic variation in key coastal habitats, as well as on the thermal tolerance of species living in these habitats.
Up to two master students can work in parallel on related but distinct projects, collaborating on field work and experimental work at the Drøbak field station. There is much flexibility in the project and room for developing the project to fit your own ideas and interests, for example if you are interested in particular organisms or groups of organisms.
Methods and tasks
With help from supervisors, the project(s) will involve the following tasks and methods:
• Field work
o Assist in deploying and maintaining loggers for oxygen, salinity and temperature at selected locations.
o Collecting marine invertebrates at the selected locations.
• Experimental work
o Classify sampled organisms to taxonomic group.
o Conduct thermal tolerance experiments on sampled organisms at the Drøbak field station (e.g. critical thermal limits, survival under short heatwaves), potentially also in Oslo(depending on specific needs).
• Data analysis
o Analyze logger data to characterize diurnal and seasonal patterns in temperature, oxygen, and their covariance at the different locations.
o Analyze experimental data from different locations, comparing results across taxa and locations.
• Thesis work / writing
o Develop detailed experimental protocols and specific research questions.
o Write the master thesis, with possibilities for scientific publication of the results.
Working environment
The experimental part of the project is based at the Drøbak field station[JH2.1] (some experiments may also be performed using temperature cabinets at the department locations in Oslo), with field sampling at coastal locations in the Oslofjord (to be determined with the student). The student(s) will be included in the working environment in the section, with regular group meetings and interaction with other students working with other questions in the same habitat. Get in touch (yngvild.vindenes@ibv.uio.no) if you want to know more or have any questions.