, 2007). At present, bridging the organism-population gap seems only feasible through use of population models as demonstrated for Arctic cod, capelin (Mallotus villosus), and herring (Clupea harengus) by Hjermann et al. (2007) and for northern shrimp (Pandalus borealis) by Ravagnan et al. (2010), or by employing a risk assessment approach. Beyer et al. (2012) performed a risk assessment for effects of C4–C7 APs in PW on three economically important fish populations on the NCS: Atlantic cod, haddock,

and saithe (Pollacius virens), based on fish distribution data, hazard information of APs in PW, data on PW discharges, and plume dispersion described by the exposure and risk model DREAM ( Reed and Hetland, 2002 and Reed et al., 2001). Their conclusion was that the environmental exposure to C4–C7 APs from Cyclopamine mw PW is too low to have any significant effect on the reproduction of fish stocks. Neff et al. (2006) and Durell et al. (2006) came to the same conclusion regarding the risk from PAHs in PW to the wider pelagic ecosystem in the NS when combining dispersion modeling by DREAM and PAH

measurements in passive samplers (SPMDs) and caged mussels. Smit et al. (2009) described a systematic relationship between sub-individual and individual sensitivity to oil from SSDs for DNA damage and oxidative stress biomarkers in 6 marine species and similar SSDs for whole-organism chronic fitness in 26 marine species. On average the selected biomarkers were a factor 35–50 more sensitive than the whole-organism response. The results implied that the 95% safety level (the lower 5 Alectinib concentration percentile or HC5, commonly used as PNEC in risk assessments), for whole-organism exposure to total hydrocarbons would safeguarded only 86% of the species from genotoxic damage and Protein kinase N1 79% from oxidative stress. The authors stress that their data were insufficient to support this as a general

relationship, but data from Bechmann and Taban, 2004, Bechmann et al., 2004, Buffagni et al., 2010 and Carls et al., 1999, (Hansen et al., 2011), Heintz et al., 2000, Jonsson and Björkblom, 2011, Pinturier et al., 2008 and Sanni et al., 2005, and Stien et al. (1998) provide supporting evidence from a wider range of sub-tropical to high-arctic species of fish and invertebrates that the whole organism responses are less sensitive to oil than biomarker responses. Smit et al. (2009) present a conceptual model suggesting further reduction in sensitivity as one moves up to the population level. This would concur with the idea that environmental factors governing the health and performance of a population, may override toxic effects on parts of the population. The studies above cover sensitivity to oil, but the authors suggest that the relationship may be valid for PW as well. If that is the case, it is even more unlikely that wide scale population effects should occur when individual effects are only seen locally.