UK long-term monitoring dataset: assessing factors affecting biomarkers commonly used in environmental programmes

Long-term programmes like the UK Clean Seas Environmental Monitoring Programme (CSEMP) rely on biological effects techniques, including biomarkers, to assess if chemical pollutants are affecting sentinel species in aquatic environment. In this study, we have applied mixed and fixed effect linear models long-term CSEMP dataset (2005-2018) evaluate factors such as region (location), sex, age, gonadosomatic index (GSI) condition factor (CF), contribute variability observed levels of 3 well established biomarkers (inhibition acetylcholinesterase muscle-AChE, induction hepatic 7-ethoxyresorufin- O -deethylase-EROD presence biliary 1-hydroxypyrene-1-OH pyrene) used monitor contaminants dab ( Limanda limanda ) around waters. Regional differences (location) were a significant explanatory variable for biomarkers. Substantial found regional average muscle AChE activity, overall indicating East Coast regions likely more impacted by inhibitors e.g . organophosphates carbamates). We report first time that, while accounting region, sex predictors isoform (R 2 = 0.13-0.15), therefore advise future analysis marker should be done when reporting marine environmental purposes. Dab is also predictor both enzymatic markers (AChE EROD) but not 1-OH pyrene. Sex their interaction, strongest variables 0.46) influencing EROD, showing that although females had higher male EROD increased with age. Correlations between three might assist discerning types prevalent contamination over studied period. Our results highlight account assessing contributing responses these dab, other flatfish species, monitoring programmes.