Report

Federal Research Institute for Rural Areas,
Forestry and Fisheries
Thünen-Institute of Sea Fisheries
Palmaille 9, 22767 Hamburg
Telephone +4940 38905-169
Telefax +4940 38905-263
16.01.2015
Az.: Dr.Fo./vS/3865
Report of the cruise
375 of the FRV Walther Herwig III
PREFACE – AWA cruise I
Jun 12 – July 19, 2014
Scientist in charge: Dr. Heino O. Fock
Summary
60 Stations were sampled during WH375. 55 stations were sampled in the MoroccanMauritanian upwelling system comprising 45 plankton and 10 fisheries stations. 5
stations were sampled for deep-sea ichthyofauna. First results are shown.
Résumé
60 stations ont été échantillonnées au cours WH375. 55 stations ont été
échantillonnées dans le système d'upwelling marocain mauritanienne comprenant 45
plancton et 10 stations de pêche. 5 stations ont été échantillonnées pour haute mer
ichthyofaune. Les premiers résultats sont affichés.
Verteiler:
TI - Seefischerei
Saßnitzer Seefischerei e. G.
DFFU
per E-Mail:
BMEL, Ref. 614
BMEL, Ref. 613
Bundesanstalt für Landwirtschaft und Ernährung, Hamburg
Schiffsführung FFS “
Präsidialbüro (Michael Welling)
Verwaltung Hamburg
TI - Fischereiökologie
TI - Ostseefischerei Rostock
Institutsleiter:
Dr. Gerd Kraus
Thünen-Institut
für Seefischerei
Palmaille 9
22767 Hamburg
FIZ-Fischerei
TI - PR
MRI - BFEL HH, FB Fischqualität
Dr. Rohlf/SF - Reiseplanung Forschungsschiffe
Fahrtteilnehmer
Bundesamt für Seeschifffahrt und Hydrographie, Hamburg
Mecklenburger Hochseefischerei GmbH, Rostock
Doggerbank Seefischerei GmbH, Bremerhaven
Deutscher Fischerei - Verband e. V., Hamburg
Leibniz-Institut für Meereswissenschaften IFM-GEOMAR
H. Cammann-Oehne, BSH
Deutscher Hochseefischerei-Verband e.V.
Fon 040 38905 177
Fax 040 38905 263
www.ti.bund.de
[email protected]
Aim
Cruise WH375 pursued two objectives:
(1) the first leg of the cruise addressed ichthyoplankton assemblages in the coastal
upwelling in the Canary Current Large Marine Ecosystem (CCLME) from Morocco to
Senegal. Pelagic catches are undertaken to analyse reproductive capacity of
Sardinella aurita in the area.
(2) the second leg of the cruise aimed at deep-sea pelagic ichthyofauna investigations
in oceanic waters from about 10°N to 22°N
Except for phyto-, pico- and nanoplankton samples (Univ. Las Palmas) and parasitological
samples (BiK-F, see list of acronyms at the end of the report), all samples are analysed at
the Thünen Institute of Sea Fisheries.
Cruise narrative
Port of embarkation and disembarkation was Las Palmas, Spain. After leaving Las Palmas,
coastal ichthyoplankton sampling started off the coast of Morocco at 22.5 °N. Six coastal
transects were sampled, plus two 24 h-stations sampled at 3-h intervals (Fig. 1).
Senegalese EEZ was not sampled due to lacking clarifications in the notification.
The second leg comprised 5 stations, of which 3 stations (558, 559, 562) were fully
sampled with regards to ichthyofauna while stations 556 and 557 had only incomplete
coverage due to handling problems.
Sampling
CTD casts
60 stations with CTD casts were sampled, accompanied by bottle samples. 6 stations were
arranged as transect (Fig. 3) to analyse the interactions between coastal upwelling and the
defelcting Canary Current system.
Ichthyoplankton, micro- and mesoplankton
Sampling at 45 stations in the upwelling area (see Fig. 1) was carried in round the clockoperations to a depth of 5 m below thermocline. Maximum operation depth was ca. 200 m.
Ichthyoplankton sampling was carried out with a modified GULF sampler (‘Nackthai’, 300
µm). Phyto, pico- and nanoplankton samples were taken from bottle probes, micro
zooplankton was additionally sampled with vertically towed Bongo nets.
24-h station
The GULF sampler was replaced by a vertically towed Multinet, mesh size 300 µm.
Samples were taken every 3-hours and accompanied by a CTD cast.
Coastal pelagic trawling
10 pelagic hauls were carried out based on records from the echo-sounder. Net deployed
was 205 ft pelagic trawl with 20 mm cod-end (Fig. 5). Parasitological samples were taken
from abundant species.
Deep-sea trawling
Deep-sea trawling was carried out during night time in the mesopelagic zone between 700
and 50 m water depth (Fig. 5).
First results
Intensive upwelling was present in ther northern part of the coastal sections, where it was
weakened south of Cap Blanc. Partly, cold water was entraining the Banc d’Arguin area
(Fig. 2). The upwelling was evident in the transect off Cap Blanc (Fig 3), reaching 16 °C at
3
sea surface. Intensive mixing between several water bodies is taking place in this area
(Fig.4), indicated by three groups of data points in the ST plot.
Ichthyoplankton results are not yet available. Fisheries data reveal very variable catches,
dominated by sardines in the north and anchovies in the south. Sardinella were caught in
only small quantities (Fig. 6).
Data availability
CTD, hydro-acoustic data and coastal fisheries data are available to all cruise participants
by Feb. 2015, ichthyoplankton data from the AWA project will be made available after
analysis has been accomplished. Plankton data from Univ. Las Palmas are subject to
Spanish data policy.
Acknowledgements
The Thünen Institute is deeply grateful to all who have contributed to this successful
cruise: fisheries departments and authorities in Morocco, Mauritania, Senegal and Cabo
Verde, and port authorities in Las Palmas, crew and management of the FRV Walther
Herwig III and last but not least a fantastic scientific staff with members from 5 countries.
Cruise participants
Name and affiliation
1 Heino Fock
2 Waly Ndiaye
3 Ahmed Taled
4 Tarik Baibai
5 Maik Tiedemann
6 Jose Maria Landeira
7 Stephanie Czudaj
8 Thomas Kuhn
9 Luc Badji
10 Cheikh Mbaye
11 Julian Döring
TI_SF, D
IFAN, SEN
IMROP, MAU
INHR, MAR
TI_SF, D
Univ. Las Palmas, ESP
TI_SF, D
BiK-F, D
IFAN, SEN
CRODT, SEN
ZMT Bremen, D
TI_SF
BiK-F
IFAN SEN
CRODT SEN
INHR MAR
IMROP MAU
Thünen-Institut für Seefischerei
Biodiversität und Klima Forschungszentrum
l‘Institut fondamental d'Afrique noire, Senegal
Centre de Recherches Océanographiques de Dakar-Thiaroye
l‘Institut national de recherche halieutique , Morocco
l'Institut Mauritanien de Recherches Océanographiques et des
Pêches, Mauritania
Zentrum für Marine Tropenökologie
Spain
Germany
ZMT
ESP
D
Dr. Heino O. Fock
4
Figures
Fig. 1: WH375 station plot
5
Fig. 2: WH375 SST plot
Source: CCAR Global MODIS SST Viewer
6
Figure 3: Cross section off Cap Blanc, station 508 indicated by box.
7
Figure 4: Hydrography at station 508 off Cap Blanc.
8
Figure 5: Hydrography at station 508 off Cap Blanc.
9
Figure 6: Results coastal pelagic fisheries