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Faroe Islands Associated Investigators: Related Time Series: The Faroese Fisheries Laboratory operates four standard transects radiating north, west, east, and south from the Faroe Islands. This report summarizes results from the northern transect (North Faeroe Islands), which runs northwards into the southern Norwegian Sea, and the southern transect (Faeroe Shelf/South Faeroe Islands, which covers the southern waters of the Faroe Shelf). Along each transect, zooplankton were collected once a year in May, with vertical hauls from 50 m depth to the surface using a WP2-net (200 mm mesh). The northern transect is dominated by cold East Icelandic water (EIW) flowing from the northwest, with an average May water temperature of 4.4 C (Standard Co-sampled Variables Plot). The southern transect is dominated by warmer Atlantic water (AW) in the Faroe Current, which flows from the southwest and has an average May water temperature of 7.8 C (Standard Co-sampled Variables Plot). The May sampling period corresponds to the spring phytoplankton bloom in both areas. In general, Chlorophyll a concentrations are slightly higher in the northern transect (Standard Co-sampled Variables Plot), but are generally more variable from year to year along the southern transect. The northern transect also has a higher zooplankton biomass, caused by higher abundance of overwintered Calanus finmarchicus (CV and adults) and Calanus hyperboreus in the northern transect waters. In contrast, the southern transect has a high abundance of smaller life stages, but fewer large individuals, creating a higher copepod abundance, but a lower total biomass than in the northern transect Since 2003, the May abundance of young C. finmarchicus copepodite stages in the northern transect has increased significantly, whereas C. hyperboreus has not been seen in northern transect samples since 2003. As C. hyperboreus was a significant proportion of the biomass, the differences between the northern and southern transect biomass values have decreased significantly since 2003. Changes in the timing of C. finmarchicus development and the distribution of C. hyperboreus in the northern transect may be due, in part, to water temperature changes and/or weakening of the East Icelandic Current. Long-term SST values in both the northern and southern transect areas are currently above a 100-year average for each region (Standard Long-term Comparison Plot). Water temperatures since 2002 have also been near or above the previous 100-year maximum temperatures seen in each region. Sixty years of CPR data are available for the region surrounding the Faroe Islands (CPR standard area B4 , Standard Long-term Comparison Plot). Copepod abundance data from CPR and the Faroe Island transects do not demonstrate much synchrony where the sampling years overlap. This is most probably caused by the large differences in the spatial sampling areas of the two programmes. The CPR data suggest that the larger area around the Faroe Islands may be in a recovery period (an upward trend in copepod abundance) after a 40-year period (1950-1990) of steady decrease. A comparison of the CPR data with the SST record also suggests that there is a positive relationship between copepod abundance and SST at the interdecadal scale. |