Friday, 2 October 2009

Situation report from D.F. Nansen 12.08.2009

Dear all,

The R/V Dr.Fritjof Nansen is at 15 08S, 40 57E on station 5 on the second environmental line from the north (line 5 in the Cruise orders). We spent most the daylight hours of 11.08.2009 surveying Nacala bay. Today the wind has subsided and the sea is calmer even in deeper (>500m water).

Both Domingos and Sven have pointed out the utility of samples of the juvenile fish. We therefore did a "blind" haul in Nacala bay, with a small catch of juveniles.

In Nacala bay some few small schools at about 200m depth were observed during daylight hours. The ships crew considered them too small and far apart to have a chance of catching them using the trawl during daylight. Therefore we have no biological samples of the schooling fish, but we have allocated them to the PEL 2 group in the acoustic analysis.

It will be interesting to see if we continue to observed such schools close to shore further south. Hopefully the aggregations will increase so that trawl sampling can be carried out.

In Nacala bay we again observed seabirds (a species of tern), although in smaller numbers than in Bai de Memba. We observed some birds feeding at the surface, but no fast schools of fish at the surface. Humpback whales were also observed, but in smaller numbers than in Bai de Memba. These observations are very qualitative in nature as we have no dedicated observer effort for whale s or birds onboard. There are neither any protocols for conducting such investigations. Therefore it will be impossible to make any kind of quantitative assessment of their numbers. We're only able to detect major changes (ie. No birds or birds present), or new species of marine mammals. However, for future surveys including marine mammal and seabirds observers might considered.

Best Regards

Erik Olsen
Mozambican Scientists on the R/V Dr. Fridtjof Nansen. (L-R): Mauricio Lipassula, Pedro Pires, Isaias Tembe, Martinho Padera


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