Bundesforschungsanstalt für Fischerei
Institut für Seefischerei
Palmaille 9, 22767 Hamburg, Tel. 38905 177 Fax 38905 263 11.11.2002 Az.: Dr.Ehr./1826 WH241bre.doc
„WALTHER HERWIG III"
Cruise 241
REPORT 19.7. – 16.8.2002
Personnel
Name Institution Part
1. Dr. Siegfried Ehrich ISH-BFA I
2. Herr Dipl. Oz. Peter Cornus ISH-BFA II
3. Frau Svenja Cummerow ISH-BFA I + II
4. Frau Anna Schuhbauer ISH-BFA I + II
5. Herr Sascha Bednarz ISH-BFA I + II
6. Herr Ingo Wilhelms ISH-BFA I + II
7. Frau Sonja Walter ISH-BFA I + II
8. Herr Andreas Lemke ISH-BFA I + II
9. Herr Jens Ulleweit ISH-BFA I + II
10. Dr. Ingrid Kröncke Forsch. Senckenberg I 11. Herr Hermann Neumann Forsch. Senckenberg I + II
12. Frau Saskia Otto. FU-Berlin I + II
13. Herr Philipp Schwemmer FTZ-Büsum II
14. Herr Moritz Mercker FTZ-Büsum II
15. Frau Henrike Semmler FU-Berlin I + II
Objectives
1. To participate in the ICES co-ordinated 'International Bottom Trawl Survey' in the North Sea, 3. quarter 2. Biological monitoring of the fish fauna in 6 small areas (boxes)
3. Distribution of temperature, salinity and nutrients in the area of investigation 4. Monitoring of the benthic epi- and infauna in the boxes and in the German Bight
Narrative
The scientific programme started in the morning of 20th of July at ICES-rectangle 38F7. The vessel then sailed northwards to Boxes C, L, M and D and worked there for 3 days each. After finishing the program the 2nd of August in box D the Walther Herwig III stayed for the next 2 days in Aberdeen/Scotland. After having partly changed the scientific crew and having left Aberdeen we stayed for another 3 days in Box B (5.–7. of August). Then the vessel sailed into the German Bight fishing in 13 ICES-rectangles within the next 3 days.
The programme then was continued in Box A (3 days) and another 2 days for 6 ICES-rectangle in the inner part of the German Bight. The scientific program ended on the 15h of August. The 'W. Herwig III' docked at Bremerhaven on Friday, the 16th of August 2002.
Results
A total of 152 half an hour and valid hauls were made using the GOV trawl equipped with the standard ground gear, of which 22 hauls were carried out in BOX C, 21 hauls in BOX L, 21 hauls in BOX M, 21 hauls in BOX D, 21 hauls in BOX B, 20 hauls in BOX A and 26 hauls in different ICES-rectangles, mainly within the German Bight (IBTS-3. Quarter). At 99 stations salinity, temperature and at 62 stations nutrients were measured. Epibenthos was sampled by a 2m beam trawl at 54 stations and additionally 54 grab samples were taken.
The preliminary number at age data for the recruiting year-classes of the commercial important species and the catch data were submitted to ICES to make these data available within due time.
Fig. 1 shows the area of investigation. The mean species composition in the 6 boxes and the variability within the time periods are shown in Figs.2 to 7.
Dr. S. Ehrich Dipl.-Oz. P. Cornus
a re a s :
5 2E 5E 6E 7E 8E 9F 0F 1 F 2F 3 F 4F 5 F 6F 7 F 8F 9 G 06 2 °
4 4
5 9
3 6 4 8
4 0
3 2 5 0
4 2 5 7
3 4 5 3
4 6
3 8 5 5
3 0 2 9
5 1
5 0 ° 5 1
4 3
5 8
3 5 4 7
3 9
3 1 4 9
6 1
4 1 5 6
3 3
5 2 4 5
6 0
3 7
5 4
5 ° W4 3 2 1 0 1 2 3 4 5 6 7 8 9 1 0 1 1 ° E
D
L M
B
C
A
Fig. 1: „Walther Herwig III“. Cruise no. 241. Area of investigation and Boxes
Fig. 2: Box A: German Bight: Main species composition (kg/30min) from 1987 to 2002 (summer). Others in 2002 are mainly sprat.
Fig. 3: Box B. English coast. Main species composition (kg/30min) from 1987 to 2002 (summer)
0 500 1000 1500 2000
mean catch (kg/30min)
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
year
dab plaice cod whiting
herring mackerel scad others
Box A
0 500 1000 1500 2000
mean catch (kg/30min)
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 year
dab cod haddock whiting
herring mackerel sprat others
Box B
Fig. 4: Box C. Danish coast. Main species composition (kg/30min) from 1986 to 2002 (summer)
Fig. 5: Box D. Scottish coast. Main species composition (kg/30min) from 1986 to 2002 (summer)
0 100 200 300 400
mean catch (kg/30min)
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
year
dab cod haddock whiting herring others
Box C
0 500 1000 1500 2000 2500 3000
mean catch (kg/30min)
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2001 2002 year
cod haddock whiting Norway pout
herring mackerel others
Box D
Fig. 6: Box L. Norwegian coast. Main species composition (kg/30min) in 1999, 2001 and 2002 (summer)
Fig. 7: Box M. Norwegian coast. Main species composition (kg/30min) in 1999, 2001 and 2002 (summer)
0 200 400 600 800 1000 1200
mean catch rate (kg/30min)
herring cod
l. r. dab dab
haddock whiting
saithe
mackerel starry ray
Norway pout others
species
1999 2001 2002
Box M 0
200 400 600 800 1000 1200
mean catch rate (kg/30min)
herring cod
l. r. dab
haddock whiting
saithe
mackerel
starry ray
Norway pout others species
1999 2001 2002
Box L
