The EcoQO on mercury and organohalogens in coastal bird eggs: report on the pilot study 2008–2010

To categorize the current environmental health status of the Northeast Atlantic and the North Sea, ecological quality objectives (EcoQOs) have been formulated by OSPAR in recent years for different ecological quality elements such as the contamination of the marine environment with anthropogenic heavy metals and organochlorines. To measure it, coastal bird eggs have proven to provide a favorable matrix. In 2005, following advice from ICES, OSPAR agreed on the threshold concentrations proposed as EcoQOs for these two major substance groups in bird eggs. In a pilot study, residues of the heavy metal mercury (Hg) and the organochlorines PCBs (62 congeners summarized = ΣPCB), DDT and metabolites (ΣDDT), HCB and the different HCH isomers (ΣHCH) were analyzed in Common Tern Sterna hirundo or Arctic Tern Sterna paradisaea and Oystercatcher Haematopus ostralegus eggs collected at in total 21 sites in seven nations surrounding the North Sea. For the majority of sites, sampling took place in 2008, 2009 and 2010. The methods of sampling and analyzing were performed according to internationally recognized standards (JAMP, OSPAR). The major aims of this report are: - to suggest an actualized threshold concentration for Hg for which only preliminary target values had been proposed - to test the suitability of the Arctic Tern as a potential alternative species to replace the Common Tern at sites where the latter does not occur in sufficient numbers - to present spatial contamination patterns and temporal developments - to address whether the hitherto existing EcoQO objectives are fulfilled - to give recommendations for monitoring, assessment and management of this EcoQO in the future - to mention the advantages of species and matrix as well as the limitations of the application of this EcoQO - to discuss how the preconditions for a potential inclusion of the chemical monitoring with seabird eggs into a coordinated environmental monitoring program (CEMP) can be fulfilled (see above) - to give suggestions for combining the EcoQO program with other existing or planned monitoring programs for the marine environment.