Angler am Fluss (Angler at a river) © Ruben van TreeckFischen im Morgennebel (Fishing at dawn) © A. Müller-BeleckeEin ruhiger Morgen auf dem Wasser (A calm morning on the water) © Sven MaternAuengewässer mit Schilfbewuchs (Backwater with reedbelt) © Sven MaternInstitut für Binnenfischerei e.V. - Jägerhof (Potsdam Institute of Inland Fisheries) © A. Müller-Belecke
 

Diary - Project KoMoDo

Welcome to the diary page for the project "Cormorant-induced mortality in Western Baltic Cod", or short: KoMoDo

There's information on the current development of the research to be found here, including images and insights into the daily work of the researchers as well as first results.

July 2025

a large number of petri dishes containing otoliths and other important structures extracted and cleaned from cormorant spit balls

Processing cormorant pellets in the lab – many samples mean lots of data (Photo: © K. Mehrwald, IfB).

a flounder otolith, observed tthrough the microscope lens

A look through the microscope – a flounder otolith extracted from a cormorant pellet (Photo: © K. Mehrwald, IfB).

latest delivery of a box of cormorant pellets to be stored in the freezer for later processing

Our latest sample delivery: two large styrofoam boxes filled with pellets for the freezer (Photo: © K. Mehrwald, IfB).

April 2025

the search for regurgitated pellets on Musholm Island, Denmark (photo K. Mehrwald, IfB)

Searching for the regugitated pellets at a cormorant-colony's resting place on a small secluded island of Denmar, Musholm (photo © K. Mehrwald, IfB)

the regurgitated pellets are blending into the pebbles and hard to find (photo K. Mehrwald, IfB)

The spitballs are difficult to find and discern amongst the large pebbels of the resting place (photo © K. Mehrwald, IfB)

cormorants settling for the night in Nysted, Denmark (photo K. Mehrwald, IfB)

Cormorants are starting to settle in the trees of their resting place in Nysted, Denmark (photo © K. Mehrwald, IfB)

August to October, 2024

Island of Fehmarn, cormorant resting place (photo © K. Mehrwald, IfB)

1. View of a cormorant resting place near the pier of the Island Fehmarn, through binoculars (photo © K. Mehrwald, IfB)

microscopic identification of otoliths (photo © K. Mehrwald, IfB)

2. Identification of otoliths under the microscope (photo © K. Mehrwald, IfB)

successful practicing of suturing "wounds" on banana peel and artificial pig skin (photo © K. Mehrwald, IfB)

3. We had to practice the suturing of wouds on banana peel and synthetic pig skin (photo © K. Mehrwald, IfB)

Neasuremtn of otoliths (photo © K. Mehrwald, IfB)

4. Measurement of cleaned and prepared otoliths (photo © K. Mehrwald, IfB)

Successful participants of class "Molecular Analysis of Environmental Samples" at University of Innsbruck in Austria (photo © B. Thalinger, with permission)

5. The successful participants of the course "Molecular Analysis of Environmental Samples" at the University of Innsbruck, Austria (photo © B. Thalinger, with permission)

May to July, 2024

cormorant breeding colony in Wallnau,  on the Island of Fehmarn, Denmark (photo © B. Koop, with permission)

A breeding colony on the Island of Fehmarn is entered once for attachment of identification rings to juvenile cormorants. Spitballs are collected at the same time (photo © B. Koop, with permission)

Spitballs (photo © U. Krumme, with permission)

A visual impression of a spitball when found hanging in branches (or lying on the ground); the ornithologists collect them and freeze them for transport to and analysis at the institute's lab facilities in Potsdam (photo © U. Krumme, with permission).

a lot of interest for the project by the attendants of the Science Day Potsdam 2024 (photo Valentin Paster/Event Photographer, with permission)

K. Mehrwald, IfB, explains the microscopic identification of otoliths (ear bones) to an interested audience at the 2024 Science Day in Potsdam (photo Valentin Paster/Event Photographer, with permission)

sorting of spitball contents for otoliths, bones and other hard structures (photo © K. Mehrwald, IfB)
complete cod scull found in a spitball (photo © M. Mehrwald, IfB)

April 2024

Cod otoliths (photo © K. Mehrwald, IfB)

Cod otoliths on a millimeter-grid (photo © K. Mehrwald, IfB)

semi-digested "Aalmutter") - a type of small fish (photo © K. Mehrwald, IfB)

A semi-digested eelpout, found in a spitball pellet (photo © K. Mehrwald, IfB)

semi-digested small fish-species (photo © K. Mehrwald, IfB)

Various semi-digested small fish-species found in spitball pellets (photo © K. Mehrwald, IfB)