Seasonal variability in metal and metalloid burdens of mussels: using data from the German Environmental Specimen Bank to evaluate implications for long-term mussel monitoring programs

Abstract

Background: Metal and metalloid concentrations in mussels can vary between seasons. In biota monitoring, the sampling time is therefore an important issue. Within the German Environmental Specimen Bank (ESB) program blue mussels (Mytilus edulis Complex) are sampled regularly since the 1980s. The samples are collected in two-monthly intervals at two North Sea sites and in 6-month intervals at one Baltic Sea site. All samples from one site and year are combined to annual composite samples and archived as sub-samples under cryogenic conditions. In order to investigate a possible reduction of the number of annual sampling intervals while maintaining comparability with the long-term composite sample data, the seasonal variability of metals/metalloids was analyzed based on the half-yearly and bimonthly samples of 2013, 2015 and 2017.Results: In mussels from the North Sea site Eckwarderhoerne seasonality of metals/metalloids was comparable in all 3 years (arsenic being the only exception). At the North Sea site Koenigshafen seasonality of cobalt, nickel, cadmium, copper, lead, and arsenic was comparable in 2013 and 2015 but not in 2017, while selenium showed the same seasonality in all 3 years. Within 1 year, concentrations of metals and metalloids can vary by the same order of magnitude as observed between annual composite samples of different years making it impossible to select just one representative sampling time point per year that would provide the same information as the respective annual composite sample. Conclusions:The findings highlight the importance of carefully selecting the sampling time point when using mussels in biota monitoring. For the German ESB program it is recommended to continue with the current sampling strategy and analyze annual composite samples in order to maintain comparability with the long-term data series, which are a special feature of the ESB.

Trace Metal Residues in Marine Mussels: A Global Survey

“…show differences in chemical bioaccumulation, and it is important to identify the species for environmental monitoring studies (Brooks et al, 2015). In addition, metal burden in mussels is seasonally influenced (Knopf et al, 2020), and samples from the Northern and Southern hemispheres were simultaneously collected to achieve the snapshot, resulting in opposite seasons.…”

“…show differences in chemical bioaccumulation, and it is important to identify the species for environmental monitoring studies (Brooks et al, 2015). In addition, metal burden in mussels is seasonally influenced (Knopf et al, 2020), and…”

Experimental accumulation of microplastics in acorn barnacle Amphibalanus amphitrite and its use in estimating microplastic concentration in coastal waters

“…In the field environment, the accumulation of pollutants can be influenced by multiple uncontrollable factors, such as disease, weather, and other environmental stresses (Su et al, 2019). For example, the seasonal variability in metal and metalloid burdens was reported for mussels (Knopf et al, 2020). In the ocean quahog (Arctica islandica), copper, zinc, and cadmium concentrations were generally lower in winter when the lead concentration was the highest (Swaileh, 1996).…”

Organochlorine Compounds in Beached Plastics and Marine Organisms

“…Despite these uncertainties, they have been extensively used, for example, as the pioneers in NOAA's Mussel Watch Program launched in 1985-1986(Farrington et al, 2016. Other similar programs were later implemented throughout the world (Hamilton, 1989;Ramu and Kajiwara, 2007;Knopf et al, 2020). In more recent years, more emphasis is being put on assessing key biomarkers of biological responses to evaluate the health of organisms, linking observed responses to contaminant exposure, as in the European Marine Strategy Framework Directive (Directive 2008/ 56/EC, 17 June 2008).…”