1 Department of Biological Sciences, Marine Ecology, Faculty of Science, Aarhus University, Aarhus University2 Faroe Marine Research Institute3 Department of Bioscience - Aquatic Biology, Department of Bioscience, Science and Technology, Aarhus University4 Department of Bioscience - Aquatic Biology, Department of Bioscience, Science and Technology, Aarhus University
The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter-annual variations in the onset of the spring bloom and its intensity have been observed. Since 1974 juvenile sandeels have been sampled annually on the Faroe shelf. These results also show large variations – both in number and in average length. Here, we investigate the variations in recruitment in relation to food availability. We compare the time series from the sandeel 0-group surveys with data on phytoplankton production and biomass. The results confirm that survival and condition of the early-life stages of sandeel on the Faroe Shelf is dependent on the magnitude of the primary production. Although the sandeel spawns several months before the spring bloom, the onset of the spring bloom does not seem to have a significant influence on the number nor the length of juvenile sandeel. Number and length seems to be mainly determined by the phytoplankton concentration just before the survey. The established link between primary production and juvenile sandeels may be helpful in explaining previously found links between primary production and commercially important fish stocks, as well as seabirds, on the Faroe Shelf.