Short Cruise Report, RV ATAIR, Cruise 0671041-1, Bremerhaven - Thyboron - Aberdeen, 22 Jul — 14 Aug 2025 |
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1. Purpose of the Cruise & Research Objectives
Cruise 067/041-1 with RV ATAIR served to carry out the annual large-scale North Sea Summer
Survey (NSSS) on behalf of the Federal Maritime and Hydrographic Agency of Germany (BSH).
Surveys similar to cruise 067/04 1-1 have been conducted by the BSH every year since 1998.
These surveys generally follow a predefined net of standard stations forming zonal sections
across the North Sea at different latitudes between 54°N and 60°N. Additional stations located to
the south of 54°N form a loop-like station pattern extending to about 52°N near the southern
entrance to the North Sea. In addition, two survey lines located to the west and east of the Orkney
and Shetland Islands cover the inflow of Atlantic Water into the North Sea. The cruise is typically
interrupted at halftime in order to allow for a crew and team change. The North Sea Summer
Survey of 2025, cruise 067/04 1-1, started in Bremerhaven, Germany, on 22 July 2025, led to
Thyborgn, Denmark, with a port stay in the period 03 to 06 August, and ended in Aberdeen, UK,
on 14 August 2025 (see Fig. 1).
The annual North Sea Summer Survey is usually carried out at or near the time when maximum
stratification and phytoplankton productivity are expected to have passed their peak. The primary
objective of cruise 067/041-1 is to assess the physical and chemical state of the North Sea in the
summer of 2025, using data collected during the cruise. Large-scale data will be used to investi-
gate the hydrographic state of the water column in different regions of the North Sea. Furthermore,
temporal hydrographic changes will be addressed, which will become apparent when the data
are put into context with data from previous cruises. Sampling water for radionuclide analysis is
part of the BSH’s standard monitoring of radioactive contamination in the North Sea. This is based
on several legal and regulatory provisions, as well as the corresponding requirements for fulfilling
them. The sampling will assess spatial changes in the concentrations of these radionuclides, as
well as changes over time compared to previous cruises.
For the purpose of the cruise the BSH team has been joined by members from the Helmholtz
Centre Hereon in Geesthacht, Germany. The Hereon group addresses three topical foci during
cruise 067/04 1-1: carbonate system dynamics, trace metal dynamics and microplastic distribu-
tions in the North Sea basin.
Another cruise participant affiliated with both, the Max-Planck-Institute for Chemistry (MPIC),
Mainz, Germany, and the Research Centre for Toxic Compounds in the Environment (RECETOX),
3rno, Czech Republic, Joined the cruise after a crew change in Thyborgen in order to analyse
pesticides in air and water in the central to northern North Sea en route from Thyborgn/DK to
Aberdeen/UK.
Specific objectives related to cruise 067/04 1-1 addressing the state of the North Sea in the sum-
mer of 2025 are the following:
How far south does the Atlantic Water (AW) that enters the North Sea at its northern
DdounNdary spread in the summer of 2025?
ANhere is the main inflow of AW into the North Sea in summer 2025?
dow far north does the AW entering the southern North Sea via the English Channel
oenetrate northwards in summer 2025?
