BENTHIC FORAMINIFERAL DISTRIBUTION AND ABUNDANCE CHANGES IN SKAGERRAKSURFACE SEDIMENTS - 1937 (HOGLUND) AND 1992 1993 DATA COMPARED/

Both living (stained) and dead (unstained) foraminiferal assemblages f rom surface sediments (0-2 cm) in the northwestern part of the Skagerr ak have been studied in order to (1) define and characterize the distr ibution of various modem benthic environments and (2) by comparing the se findings with surface samples collected 40-60 years ago, to documen t possible faunal changes that might have occurred. The investigated a rea is physiographically divided into the Norwegian slope, the Skagerr ak Basin, and the Danish slope. The latter is under the influence of t he Jutland Current, while the basin and the investigated parts of the Norwegian slope are bathed in Atlantic water. All areas have bottom wa ters with a high oxygen concentration. Three living (stained) and thre e dead (unstained) assemblages occupy the three physiographic areas. O nly one assemblage (on the Norwegian slope) is common to both the livi ng and dead assemblages but the boundaries between them lie at compara ble depths. The higher standing crops are found on the fertile Danish slope while the lower ones are in the deep basin where the diversity i s at a maximum. In the dead assemblages, the relative abundance of agg lutinated tests increases with depth. Comparison with data collected 4 0 to 60 years ago shows increases in absolute numbers of tests, especi ally in the deep basin. There are changes in assemblage compositions i n all areas. The dominant species found in 1937 are different from tho se of 1992/1993. There is a major change in the basin where one agglut inated species has changed its depth distribution downslope and two pr esent day abundant species are new arrivals. These faunal events are p robably linked to environmental changes.