2023-2024 / OCEA0027-1

Applications of stable isotopes in marine sciences

Duration

15h Th, 15h Pr

Number of credits

 Master in biology of organisms and ecology (120 ECTS)3 crédits 
 Master in oceanography (120 ECTS)4 crédits 

Lecturer

Gilles Lepoint, Loïc Michel

Coordinator

Gilles Lepoint

Language(s) of instruction

French language

Organisation and examination

Teaching in the first semester, review in January

Schedule

Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

Natural distributions of stable (= non-radioactive) isotope ratios of light biogenic elements (C, H, N, O, S) in numerous ecosystem compartments are commonly used as tracers of processes in multiple disciplines ranging from hydrography to physiology. This course's objective is to present and exemplify how they can be useful to diverse research problematics in marine ecology and biogeochemistry.

By combining ex cathedra classes, practical work and tutored sessions, this course aims to teach theoretical notions necessary to understand stable isotope-based methods (e.g. isotopic effects and fractionations), to present examples and case studies using isotopic tracers to describe marine ecosystem structure and function, but also to prepare students to use those methods. Using a scientific question chosen together, students will have the occasion to set up a sampling protocol, to get familiar with sample preparation and analysis of stable isotope ratios of biological matrices, and, using the obtained results, to use widely applicable data analysis methods (mixing models, isotopic niche models, trophic position models).

Learning outcomes of the learning unit

  • Understand drivers of stable isotopes' natural distribution in the environment
  • Understand general principles underlying the functioning of analytical devices
  • Understand how stable isotope ratios can be used as ecological and biogeochemical tracers trough selected case studies (food webs, carbon and nitrogen cycle, water cycle)
  • Understand concepts underlying the main data analysis methods associated to stable isotopes, as well as their application conditions, strengths, weaknesses and limitations.

Prerequisite knowledge and skills

Elementary knowledge of chemistry and ecology.
The course is mostly aimed at students using stable isotopes for their research (master, PhD), but students willing to inform themselves about theses tracers' uses are welcome as well.

Planned learning activities and teaching methods

  • Theoretical classes : ex cathedra PowerPoint presentations
  • Practical work : isotopic ratios measurements (carbon, nitrogen, sulphur) on samples collected by students, to illustrate how isotopic tracers can be used in trophic ecology
  • Tutored sessions : analysis of data collected during practical work to answer one or several scientific questions

Mode of delivery (face to face, distance learning, hybrid learning)

Face-to-face course


Additional information:

In order to maximize and facilitate interactions between students and teachers, all sections of the course will be organized in person as long as it remains possible. If required by the circumstances (e.g. sanitary situation), some parts will be taught remotely. In this case, recordings will be shared with the students, and specific time slots will be dedicated to discussion.

 

Theoretical part: 6 sessions

Practical work (TP): 1 day of sampling + 1 day of sample preparation and isotopic analyses.

Tutored sessions (TD): 3 sessions of data analysis + setup of the personal research work based on an exchange between students and teachers.

Recommended or required readings

Documents presented during the classes as well as R scripts used during the tutored sessions will be given to students.

Although it is by no means necessary, students willing to complement information presented during the course or to begin their learning on their own can refer to Brian Fry's « Stable Isotope Ecology » book (Springer-Verlag NY, 2006, https://doi.org/10.1007/0-387-33745-8).

Tutored sessions will be using the R statistical computing environment. It is not necessary to master the R programming language to participate, as the bases will be learned during the session. However, students willing to get familiar with R can do so using those video tutorials: https://www.youtube.com/playlist?list=PLXXzyqr0tEhPRNDuEQ6wcvMcpAkGRjVqs

Other : Oral presentation


Additional information:

Evaluation will be based on a personal research talk, presneted to both teachers and fellow students. Each student will have the choice to present this talk in French or English. This work should by no means merely be a factual report on practical work, but instead an original research work based on data generated during this practical work and aiming to answer a precise research question chosen with the teachers beforehand. The duration of this talk will not exceed 10 minutes.

During the last tutored session, students will discuss with teachers about a scientific question they would like to tackle based on this data. For the talk, they will have to summarize the theoretical context underlying the chosen question, explain their reasoning regarding the method(s) chosen to answer it, apply this (those) method(s) to acquired data, present the obtained results in a correct way, and analyse them critically.

The quality of this work will be assessed through an evaluation grid which will, for transparency's sake, be communicated to students during the last tutored session. This grid will include criteria about the content (well defined theoretical context, mastering of used concepts, presence of a clear scientific question, choice of appropriate tools to answer it, correct application of these tools) as well as the form (terminology used, language and presentation clarity, respect of length instructions, adequate presentation support) of the work.

Work placement(s)

None.

Organisational remarks and main changes to the course

Attendance to all course's parts mandatory.

Improvements to the course are made yearly according to new developments on relevant topics and to formal and informal feedback from the students.

Contacts

  • Gilles Lepoint, Laboratory of Trophic and Isotope Ecology, 04/366.33.27, g.lepoint@uliege.be
  • Loïc Michel, Animal Systematics & Diversity, loic.michel@uliege.be

Association of one or more MOOCs