FK UTHÖRN  

Dr. Alshuth performed ichthyoplankton research onboard the research vessels FS FRIEDRICH HEINCKE, FK UTHORN and FS VICTOR HENSEN in the North Sea. To study the fish reproduction and recruitment ecology of the North Sea sprat, part of a long-term fisheries research project of the Reproduction Biology of the sprat, Sprattus sprattus, in the North Sea - funded by the DFG (Deutsche Forschungs Gemeinschaft) - she participated year-round in oceanic research expeditions. Dr. Alshuth used a variety of specialized plankton nets for ichthyoplankton collections: Bongo nets, ring plankton nets, and the Multiple Plankton Sampler MPS were deployed on these research vessels to collect fertilized sprat eggs and larvae from the pelagic environment. Plankton samples were preserved for further sprat egg and larval density analysis in the institute’s laboratory while other plankton samples were kept alive and studied immediately upon return at the Helgoland Institute of Marine Sciences. At the institutes's laboratory, live sprat eggs were sorted for rearing sprat larvae under different environmental conditions to study larval growth and the onset of otolith increment production during the larval fish stage.



Click on any picture below to start slide show.

(placeholder)
(placeholder)
Research vessels FS HEINCKE and FK UTHORN in at the Helgoland Institute of Marine Research in Helgoland Island, Germany

Research vessels FS HEINCKE and FK UTHORN in at the Helgoland Institute of Marine Research in Helgoland Island, Germany

BONGO plankton net station grid for ichthyoplankton. collection.
BONGO plankton net station grid for ichthyoplankton. collection.
Helgoland Island Harbor - home of the research vessels FS HEINCKE and FK UTHORN.
Helgoland Island Harbor - home of the research vessels FS HEINCKE and FK UTHORN.
FS UTHÖRN on ichthyoplankton expedition.
FS UTHÖRN on
ichthyoplankton expedition.
Ring plankton net used for ichthyoplankton research: collection of pelagic fish eggs and fish larvae
Ring plankton net used for ichthyoplankton research: collection of pelagic fish eggs and fish larvae
Inclinometer use for collecting ichthyoplankton from surface waters
Inclinometer use for collecting ichthyoplankton from surface waters
Dr. Alshuth recording physical oceanographic data associated with the distribution and abundance of ichthyoplankton.
Dr. Alshuth recording physical oceanographic data associated with the distribution and abundance of ichthyoplankton.
BONGO plankton net equipped with flowmeter for quantitative ichthyoplankton sampling.
BONGO plankton net equipped with flowmeter for quantitative ichthyoplankton sampling.
Retrieving BONGO plankton net used for ichthyoplankton collection
Retrieving BONGO plankton net used for ichthyoplankton collection
Ichthyoplankton survey chart of the North Sea. Drawing by S. Alshuth

Ichthyoplankton survey chart of the North Sea. Drawing by S. Alshuth

The MPS is used to study the vertical distribution of ichthyoplankton
The MPS is used to study the vertical distribution of ichthyoplankton
Deck crew of FS UTHORN retrieving pelagic MPS.
Deck crew of FS UTHORN retrieving pelagic MPS.
Dr. Alshuth unscrews the five cod end collecting devices accumulating plankton from different water depths.
Dr. Alshuth unscrews the five cod end collecting devices accumulating plankton from different water depths.
Dr. Alshuth retrieving the fresh plankton samples for transfer to the research vessel’s wet laboratory
Dr. Alshuth retrieving the fresh plankton samples for transfer to the research vessel’s wet laboratory
Dr. Alshuth recording the flowmeter data - used for quantitative sampling and analyzing plankton densities
Dr. Alshuth recording the flowmeter data - used for quantitative sampling and analyzing plankton densities
Ichthyoplankton samples transferred to the wet lab area onboard the research vessel for preservation
Ichthyoplankton samples transferred to the wet lab area onboard the research vessel for preservation
FK UTHORN at Helgoland Island Harbor
FK UTHORN at Helgoland Island Harbor
Dr. Alshuth examining ichthyoplankton collections and sorting sprat eggs for transfer to the laboratory.
Dr. Alshuth examining ichthyoplankton collections and sorting sprat eggs for transfer to the laboratory.
Wild collected sprat eggs used for larval growth studies
Wild collected sprat eggs used for larval growth studies
Dr. Alshuth transferred artificial fertilized sprat eggs in temperature control research lab to rear sprat larvae for otolith increment studies.
Dr. Alshuth transferred artificial fertilized sprat eggs in temperature control research lab to rear sprat larvae for otolith increment studies.
Sagitta otolith of a 18-day old laboratory-reared sprat larva. 12 increments are visible (1,000x magnification w/phase contrast)
Sagitta otolith of a 18-day old laboratory-reared sprat larva. 12 increments are visible (1,000x magnification w/phase contrast)

EASTERN NORTH SEA EXPEDITIONS