Long-term dataset for contaminants in fish, mussels, and bird eggs from the Baltic Sea

Abstract

Widespread persistent contaminants are a global environmental problem. In the Baltic Sea, wildlife contamination was first noticed in the 1960s, prompting the Swedish Environmental Protection Agency to establish a comprehensive Swedish National Monitoring Programme for Contaminants in Marine Biota (MCoM) in 1978 run by the Swedish Museum of Natural History. Eight species have been analysed, four fish species (Atlantic herring, Atlantic cod, European perch, viviparous eelpout), one bivalve species (blue mussel), and egg from three bird species (common guillemot, common tern, Eurasian oystercatcher). Here, we present a dataset containing MCoM data from its start until 2021. It includes 36 sets of time-series, each analysed for more than 100 contaminants. The longest time-series is for common guillemot and starts in 1968. We describe the structure of MCoM including historic changes to the number of stations, sample treatment, analytical methods, instruments, and laboratories. The MCoM data is available at the Bolin Centre repository and on GitHub through our R package mcomDb. The latter will be updated yearly with new MCoM records.

Fig. 1

Stations within the MCoM. The colours indicate the ICES basin to which the station belongs (for info on ICES basin divisions see https://www.ices.dk/). Station names, species collected and ICES basin numbers are presented in the table to the right. A map with HELCOM basins is shown in Supplementary Information 2 (Figure S1).

Fig. 2

Number of individual or homogenate observations of contaminant concentrations for the eight substance groups per year for each species (as determined by unique “specimen_ID”; see Table 2). Retrospective analyses done for some substance groups are included. Number of individuals or homogenates observations of contaminant concentrations in the eight substance groups per year by station are shown in Supplementary Information 2 (Figure S3).

Fig. 3

Time-series examples from the MCoM after technical validation for mercury (ng.g-1.ww-1) and PFOS (ng.g-1.ww-1) concentration in herring (Clupea harengus) from the autumn sampling at the stations: Ängskärsklubb and Utlängan and in the guillemot (Uria aalge) eggs from Stora Karlsö.