Nordic Master S Programme in Marine Ecosystems and Climate

Tags Physics

GEOF 230 / NMP- I

Physical – biological couplings (10 ECTS)

AUTUMN 2010

Institution responsible:

Geophysical Institute, University of Bergen

Number of ECTS:

Semester:

Autumn

Purpose and contents:

To give the student an introduction to how the ocean physics and ocean chemistry influence production and distribution of organisms at trophic levels of marine ecosystems from phytoplankton to fish, and how the physics and chemistry influence the flow of energy through the food web.

It will be emphasized that biology, physics and chemistry are integral components in the functioning of marine ecosystems and that the issue of spatial and temporal scales must be included to understand how climate fluctuations influence marine ecosystems. The understanding of the dynamics of the marine ecosystems will be based on first principles which imply that a certain mathematical basic skill is needed for the student. Particularly, the issues of diffusion and turbulence are important for describing distribution and trophic transfer at the levels of plankton.

Intended learning outcomes:

Upon completion of the course, the students will be expected to have an understanding of how the marine ecosystem dynamics is influenced by the interaction between physics, chemistry and biological processes.

At the end of the course the student should be able to:

1) Describe how the physics of the ocean interact with biological and chemical processes to influence plankton productivity and fish recruitment.

2) Describe how plankton can feed back to the ocean physics.

3) Argue that the various marine ecosystems function in different ways and that the organisms in the ecosystems develop a multitude of adaptive responses depending on the physical and biological setting.

4) Explain the general principles on trophic transfer and how ocean climate interacts.

5) Be able to apply simple models on turbulence to calculate the influence of small-scale turbulence on plankton contact rates.

6) Be able to apply simple models on buoyancy and mixing to calculate vertical distribution of fish eggs.

7) Be able to make a laboratory setup on salinity gradient columns to measure the buoyancy in live plankton.

Evaluation:

Written exam and approved report from the laboratory course.

Language:

English

Teachers:

Svein Sundby, Nils Gunnar Kvamstø, Corinna Schrum.

Lecture contents:

Total 46 hours

Climate variables and marine ecosystems I (2hours)

Introduce the concept of integration of physics, chemistry and biology in marine ecosystems. Describes how temperature, light and turbulence influence growth, reproduction and mortality of individual plankton.

Climate variables and marine ecosystems II (2 hours)

Describes how advection and diffusion influence distribution of plankton, and the interaction between physical variables in influencing plankton dynamics.

Phytoplankton dynamics and physics. (2 hours)

Dynamics of the microbial loop. Temperature-dependent growth. Stochiometry of nutrients and carbon. Sverdrup theory. Succession of phytoplankton species (diatoms, flagellates and coccolithophorids).

Zooplankton dynamics and physics (2 hours)

Describes the influence on current variability on the distribution, growth and hibernation of copepods. Describes the characteristic distributions the various species

Fish eggs and physics - vertical distribution of fish eggs I (2 hours)

Describes buoyancy, ascending speeds, turbulent mixing and the vertical distribution of pelagic fish eggs.

Fish eggs and physics - vertical distribution of fish eggs II (2 hours)

Describes the vertical distribution of mesopelagic eggs. Non steady-state distributions of fish eggs,

Workshop on calculation of vertical distributions of fish eggs (4 hours)

Calculations based on what is learned in the lectures “Mechanisms of fish eggs and physics I”, “Mechanisms of fish eggs and physics II”.

Atmospheric forcing of importance to pelagic communities I (2 hours Lectured by Nils Gunnar Kvamstø)

Gives an introduction to the dynamics of the atmosphere, particularly on the dynamics of weather pattern influencing marine ecosystem like the North Atlantic Oscillation, Arctic Oscillation, El Niño-Southern Oscillation and Pacific Decadal Oscillation.

Atmospheric forcing of importance to pelagic communities II (2 hours Lectured by Nils Gunnar Kvamstø)

Comparing the functioning of 4 major marine ecosystems: upwelling, spring-bloom, Southern Ocean, mid ocean gyres. (2 hours)

Described plankton productivity in four marine ecosystems. How the physical settings with respect to light cycles, wind forcing, mixing, stratification, temperature and nutrients in the various ecosystems determine plankton production, seasonal cycles and the transfer of energy to higher trophic levels.

Turbulence and plankton contact rates I (2 hours)

Describes the theories of plankton contact rates based on relative motion between predator and prey. Describes particularly the Rothschild and Osborn (1988) theory

Turbulence and plankton contact rates II (2 hours)

Application of the Rothschild and Osborn (1988) theory to feeding of cod larvae in the field. Influence of wind-induced turbulence on the feeding rate.

Feedbacks from plankton to the ocean physics (2 hours)

Describes how phytoplankton blooms traps the heat from solar insolation. Describes how diel vertical migration of krill can generate vertical mixing of the water column.

Fish recruitment mechanisms (2 hours)

Describes the various recruitment hypotheses and gives examples. Match-mismatch. Retention. Bigger-is-better. Stable ocean. Starvation vs. predation.

Workshop on calculation of turbulence and plankton contact rates (4 hours)

Calculations based on what is learned in the lectures “Turbulence and plankton contact rates I” and “Turbulence and plankton contact rates II”.

Measurement, analysis, and generation of turbulence (2 hours)

Describes the spectrum of turbulence energy, the energy dissipation rate. Ways of generating turbulence for plankton experiments in laboratory and mesocosms. Ways of measuring and estimating small-scale turbulence.

Climate variations, climate change and changes in habitats including fish stocks (2 hours)

Describes the responses of marine species, particularly zooplankton and fish species, to climate variability at various climate periodicity (e.g. decadal-scale and multidecadal-scale) and potential effects of climate change. Linear and reversible changes. Non-linear and irreversible changes.

Biophysical modelling (2 hours Lectured by Ute Daewel)

Gives an introduction the functioning of phytoplankton-zooplankton models coupled to circulation.

Lab course on measurement of buoyancy in fish eggs (4 hours)

Learn how to measure the buoyancy of fish eggs by setting up temperature-controlled salinity gradient columns with calibration floats. Writing of a laboratory report.

Summary of the course - discussion seminar (2 hours)

Discussion and summary on physical forcing and climate impacts on marine ecosystems.