Use constraints: Data can be used freely given that the source is cited (following creative commons license CC-BY). The source should be cited as: “HELCOM HOLAS 3 Dataset (2023)"

Data host for Swedish amphipod data is IVL but from 2018 SGU (Geological Survey of Sweden) is data host. Project data from BONUS project BEAST are stored in the BONUS haz database hosted by Aarhus University in Denmark. Data are under development to be delivered to ICES. Project data from BONUS project BEAST is also stored in the BONUShaz database hosted by Aarhus University in Denmark ( http://gis.au.dk/BALCOFISH/default.aspx).

To decrease statistical uncertainty of the analysis, a high number of sampling stations per assessment unit is recommended. Since sample size (i.e., number of gravid females available for the analysis) may have high temporal (year-to-year) and spatial (stations within assessment unit) variability, bootstrapping can be applied to control for the sample size. For each station, a sample size of 50 gravid females and about 1,500 embryos is the recommended sample size within the Swedish National Marine Monitoring Program for evaluating the proportion of malformed embryos in the population. Depending on the area of the assessment unit, distribution of sustained populations of the species in question, and heterogeneity of hydrography, several survey regions should be included, with several stations per region (Assessment Protocol figure 1).

The confidence of the indicator in the assessed areas is moderate to high since more than 20 years data for setting the threshold values has been used and the assessment data are collected from multiple stations surveyed on annual basis within each assessment unit.

Additional information:

http://www.helcom.fi/baltic-sea-trends/indicators/reproductive-disorders-malformed-embryos-of-amphipods