Dating 40 Mariagerfjord
It is known that blooms of Pseudo-nitzschia species, like many other harmful phytoplankton species, are especially common in nutrient rich waters such as areas of up-welling (Trainer et al., 2008) and in locations with a high run-off from land (Smith et al., 1990).
Samples from the core were analysed for 210 Pb, 226 Ra and 137 Cs by direct gamma assay using Ortec HPGe GWL Series well-type coaxial low background intrinsic germanium detectors (Appleby et al., 1986).
Radiometric dates were calculated using the CRS dating model (Appleby and Oldfield, 1978) and the depth of 19 were independently determined from the 137 Cs stratigraphic record (Appleby, 2001).
The core was correlated with MF8 and another core from the same location and day using diatom stratigraphy as easily discernable changes occurred in the diatom assemblages (Ellegaard et al., 2006).
A supplementary sample from another core was included in the study. delicatissima appeared in smaller percentages ( ABSTRACT: Seasonal variation of DA in bivalves was monitored from August 2008 to March 2009 at a shellfish station in Bizerte Lagoon, one of the most important shellfish areas in Tunisia.
A previous multi-proxy survey on the sediment cores from Mariager Fjord, Denmark found increasing primary production and nutrient loading during the past 100 years (Ellegaard et al., 2006).