Project ILES

The project "Illuminating lake ecosystems — ILES" aims at elucidating the ecological consequences of light pollution and the underlying mechanisms. The experiments are performed in the LakeLab, where skyglow is simulated in 10 enclosures using a specially developed light system.


ILES start page

Public relations contact

Dr. Martina Bauchrowitz
(Public relations LakeLab)

Phone: +49 (0)151 40 38 09 62

Home > Research > Projects > Project ILES - Detail view newsentry english

ILES – Illuminating Lake Ecosystems

Monday, 12.09.2016

Who invented it?

The Swiss!

With chocolate, Lucerne Birewegge* and a self-developed respiration system in his luggage, Dany Steiner, technician at the Swiss Federal Institute of Aquatic Science and Technology – Eawag, arrived at Lake Stechlin. His main objectives: To break out from the usual work routine and get insights into the operation of another research institute and at the same time to implement his technique of respiration measurements at IGB Stechlin. By the end of August, he was successfully involved for three weeks with the LakeLab experiment on light pollution before he returned with many new impressions to Lake Lucerne.

A privilege that otherwise only scientists have, namely to leave for a sabbatical, is offered by the Swiss Federal Institute of Aquatic Science and Technology – Eawag also to its technicians. This does not mean to go on holidays, but to become acquainted with a different research institution and the local working practices and to establish new contacts. Thus, Eawag technician Dany Steiner visited IGB Stechlin for three weeks and participated at the LakeLab experiment dealing with the effects of light pollution by using his self-developed respiration system.


During the LakeLab samplings, Dany Steiner was part of the filling team.


The system allows measuring the respiration of plankton and answering the question of whether carbon turnover in lakes is changed by light pollution. The reasoning behind this: The more organisms are present and active in the water samples, the more oxygen is consumed and carbon dioxide released. Respiration is therefore a measure of carbon turnover.



Dany Steiner had put many months of development work into the construction of the respiration system. It contains so-called optodes as optical sensors which react in the presence of oxygen with light. Because the temperature during the measurement must be very stable, Dany Steiner designed a special cooling block to hold the vessels. Built-in agitators ensure a homogeneous distribution of oxygen in the water samples during the measurements. The result is a well-thought-out system which provides robust data even at very low respiration activity. During his sabbatical, Dany Steiner was able to implement the respiration measurement at IGB Stechlin and to instruct the IGB technicians who now will build their own system.


In return, the IGB colleagues could also persuade Dany Steiner of their methods: Not only of the meticulous organization of a large outdoor experiment and of specific techniques such as the integrated water sampling using 20 meters long tubes, but also of the East German method to prepare the coffee as mocha… And by the way, Dany Steiner easily talked the IGB team into sweetening the bitter mocha with delicious Swiss chocolate and Birewegge*.


* Lucerne cake specialty with dried pears


Text and photographs: Martina Bauchrowitz, IGB

Go back