Winter Distribution of Brown Shrimp in the German Bight
The purpose of both research trips of RV Solea in January 2012 (650 and 651) was surveying the area of the German Bight and adjacent waters for distribution and abundance of brown shrimp (Crangon crangon).
74 fishing stations were achieved this year from Jutland, DK, to the Dutch border. Furthermore, some plankton hauls were done beside some comparative hauls with wider cod end mesh sizes (24 mm against 20 mm nominal mesh sizes) and a smaller 2-m-beam trawl with tickler chains.
The intended series of stations further west into British waters could not bee fished due to the loss of several fishing days because of stormy weather. The German-Danish cooperation - started in 2005 - could be continued. The depth range of hauls was between 10 and 43 metres and thereby well within the distributional area for brown shrimp in the southern North Sea. This year the mean catch of brown shrimp per half hour tow reached 6.7 kg, which was one of the highest rates compared to the years before. Higher concentrations were found west of Schleswig-Holstein and shrimp seemed to be at higher abundances everywhere. Some specimens were larger than 90 mm in total length indicating good stocks as well.
Water temperatures were high this winter ranging between 4.1 and 6.9 C and numerous shrimpers were seen especially on AMRUM BANK and north of Helgoland in the Schleswig-Holstein part.
Concerning the by-catch, 34 invertebrate and 37 fish species were recorded. The high rate of gobiid species was an especially unusual observation besides the increase of Alosa fallax.
Thomas Neudecker (Thünen Institute of Sea Fisheries, Hamburg)