Similar outcomes were found for the single grab sampling
strategy (Fig. 3), the 24-h sampling strategy (Fig. 4), the 48-h
sampling strategy (Fig. 5) and the 7-d sampling strategy
(Fig. 6). Except for the single grab sampling strategy in dataset
1, the chance of obtaining an estimated EF that is within 15%
of the true EF was higher than the chance of obtaining an
estimated EF that is more than 15% higher than the true EF
(Table 1). Except for the single grab sampling strategy in
dataset 2, these sampling strategies had a higher chance of
estimating an EF that is more than 15% higher than the true
EF, than estimating an EF that is more than 15% lower than the
true EF. For the long-term weekly grab sampling strategy, the
chance of obtaining an estimated EF that is within 15% of the
true EF was 100% for both datasets and for all days (data not
shown).
For the single grab, the 24-h, the 48-h and the 7-d sampling
strategy, the precision (defined as the dispersion of the his-
tograms) for the results from dataset 2 was higher than for the
results from dataset 1. For the long-term weekly grab sam-
pling strategy, no apparent difference in precision could be
found between both datasets.