The oceanographic work of the Institute of Sea Fisheries in Greenland Waters, 1952-2008

Abstract

Summary In 1952 marked the onset of the Institute of Sea Fisheries’ Greenland research when fishery scientists of the Institute joined German trawlers fishing for cod in West Greenland waters. Later on research was done from chartered trawlers; so-called ‘scouting trawler’ cruises. Starting in 1955, the Institute of Sea Fisheries also used research vessels to obtain information on demersal fish stocks and environmental parameters off Greenland. The months September to November were chosen for this survey, since at this time of the year the waters off Greenland, especially off East Greenland are least frozen. The most common oceanographic instruments during the 1950s, 1960s and the first half of the 1970s were Nansen Bottles and Mechanical Bathythermograph. A CTD system was used from 1978 onwards, and then changing to the Seabird 911+ system from the end-1990s. Oceanographic measurements were obtained at a set of international oceanographic standard stations initiated by the International Commission for the Northwest Atlantic Fisheries (ICNAF), and of national standard stations off East Greenland. Long-term climatic information on water column temperature and salinity from Fyllas Bank autumn data, and on deep water profiles in the eastern Labrador Sea, is available from measurements made by the Institute of Sea Fisheries. Recently, an oceanographic section across the Davis Strait Sill was installed which reveals information on the flux of water masses between Greenland and Canada during early-November. The complete set of ICNAF/NAFO oceanographic sections off West Greenland, and of national sections off East Greenland, obtained during October and November 1984, is available through the internet http://www.klima-bml.de/wh067/. The sections show the distribution of major water masses of the North Atlantic from surface layer to the deep water layers of the Labrador Sea including the Denmark Strait Overflow Water. It was found that Overflow Water entering the Labrador Sea at its eastern slope had higher oxygen values than the Overflow Water leaving the Labrador Sea after completing its cyclonic path along the Labrador basin. The long-term time series from NAFO Standard Stations off West Greenland, and the series from the new hydrographic section across Davis Strait passage, show that the observed warming of the North Atlantic Subpolar Gyre has had a tremendous impact on West Greenland Shelf and off-slope waters. While sea-surface temperature warming and sub-surface ocean temperature warming seem to have peaked during 2003 (the year with warmest mean annual air temperatures at Nuuk since 1950), the long-term trend observed in the temperature time series of the upper 300 m of the ocean off southwest Greenland suggests further warming may be in store. As part of international co-operation of the Institute, a Russian-German oceanographic project resulted in a primary literature publication on ‘Greenland cod (Gadus morhua): modeling recruitment variation during the second half of the 20th century’. At the end of this paper, a table of research cruises of the Institute of Sea Fisheries to Greenland waters (1955–2008) is given. The basic idea of the present paper is to document the historical development of the oceanographic work of the Institute of Sea Fisheries in Greenland Waters. In this sense, the paper is not a research document which presents recent oceanographic research results.