PCBs and organochlorine pesticide residues in otter (Lutra lutra) spraints from Welsh catchments and their significance to otter conservation strategies

Abstract

1.A survey is presented of PCB and organochlorine pesticide concentrations in otter (Lutra lutra) spraints (faeces) from 18 catchments/sub-catchments in Wales and adjacent English counties.2. There were wide differences in concentrations of lindane, dieldrin, DDE and PCBs between catchments and at sites within catchments. Only PCBs were considered likely to be of significance in influencing otter populations. Mean PCB concentrations (but not those of dieldrin and DDE) were inversely related to otter population performance (as measured by both catchment distribution and sprinting intensity) between catchments.3. It is suggested that PCB contamination is exerting a negative impact on otter populations in four catchments, while there is concern over four others. A study of food chain contamination should be an essential compunent of otter conservation strategies at both the national and local level.

Otter distribution in Lithuania

“…Chapman and Chapman, 1982) that otters utilize waterways irrespective of apparent habitat quality. The mean level of marking (3.0 spraints per sprainting site) is almost identical to that ORYX VOL 28 NO 2 APRIL 1994 found on rivers in Wales, where otters are widely distributed (from data in Mason and Macdonald, 1993).…”

Characterizing habitat preference of Eurasian river otter (Lutra lutra) in streams using a self-organizing map

“…From a practical point of view, sprainting spots were generally easier to record than the number of spraints, as it was occasionally difficult to distinguish spraints when several were present at one site (Jenkins and Burrows 1980a). Although the validity of using spraints as indicators of otter distribution and habitat use has been debated on some occasions (Kruuk et al 1986;Conroy and French 1987;Manson and Macdonald 1993;Ottino and Giller 2004), the use of sprainting as a broad indicator of otter activity patterns and habitat preferences is probably valid (Manson and Macdonald 1987;Hutchings and White 2000). Moreover, low Vegetation coverage (%) Fig.…”

Highly contaminated river otters (Lontra canadensis) are effective biomonitors of environmental pollutant exposure

“…To assess toxicological significance of the concentrations of Σ 40 PCBs measured in river otter scat in our study, we compared our data to the following threshold values established in Mason et al ( 1992 ) and Mason and Macdonald ( 1993a ), and also referenced in numerous other river otter contaminant studies (e.g., Elliott et al, 2008 ; Guertin et al, 2010 ; Huang et al, 2018 ; Lemarchand et al, 2007 ; Mason & Macdonald, 1993b ; Ruiz-Olmo et al, 2000 ): a critical level of ΣPCBs > 16 mg/kg lw; a level of concern of ΣPCBs 9–16 mg/kg lw; maximum allowable level of 4–9 mg/kg lw; and no effect level of < 4 mg/kg lw. These thresholds were developed using a two-stage model that uses empirical data on the relationships between contaminant levels in otter feces and prey, then prey and otter liver tissue (Mason et al, 1992 ).…”

“…To assess toxicological significance of the concentrations of Σ 40 PCBs measured in river otter scat in our study, we compared our data to the following threshold values established in Mason et al (1992) and Mason and Macdonald (1993a), and also referenced in numerous other river otter contaminant studies (e.g., Elliott et al, 2008;Guertin et al, 2010;Huang et al, 2018;Lemarchand et al, 2007;Mason & Macdonald, 1993b;Ruiz-Olmo et al, 2000) For all four contaminant classes modeled (PCBs, PBDEs, DDTs, and PAHs), pollutant concentrations increased with increasing development along the rural-suburban-industrial gradient and with increasing lipid content, but the importance of these and other factors varied by contaminant class. Concentrations of Σ 40 PCBs in river otter scat were best predicted by the model that included development zone, lipid content, and δ 15 N (supplementary information, Table S4; adjusted r 2 = 0.852).…”