Otters (Lutra lutra) used to be common in The Netherlands. In the last century the otter population disappeared, which has been related to contaminants (Leonards, 1995). Recently, the situation in parts of The Netherlands has improved, and PCB concentrations have declined as such, that a program was started to reintroduce the otter in The Netherlands. For this program, non-invasive methods need to be developed to monitor the ecotoxicological and reproductive status of the free ranging otters individually. In the current paper the experimental validation of the use of spraints (feces) of otters for monitoring PCBs will be presented. Based upon multivariate analyses it is possible to select spraints in which the PCB levels reflect the levels in the otters that produced them. This approach is based upon the fact that spraints that contain a PCB pattern similar to otters are considered to reflect PCB concentrations in otters, while the spraints reflecting patterns similar to prey items do not. When selecting only spraints with an ¿otter¿ PCB pattern, a linear relationship could be established between PCB concentrations in spraints and the producing otter. This indicates that, when selecting the appropriate spraints, monitoring of PCBs in otters is feasible using spraints. Furthermore, the paper will address the application of molecular DNA-techniques, based on micro-satellites, to identify the individual otter which produced the spraint. This allows the monitoring of PCB concentrations in time using spraints from individual free living otters. In addition to the above mentioned methods, the analysis of steroid hormones in spraints will be illustrated as a methodology to assess the reproductive status of the otters. It can be concluded that the set of methodologies, that is presented here, enables the monitoring of PCB concentrations and reproductive status of individual free ranging otters, without the need to even see them!
|Title of host publication||Understanding the complexity of enviromental issues; a way to sustainability; abstract book SETAC Europe 13th annual meeting, Hamburg, Germany, 27 April - 1 May 2003|
|Place of Publication||Brussels (Belgium)|
|Publication status||Published - 2003|
|Event||SETAC Europe 13th Annual Meeting - Hamburg, Germany|
Duration: 27 Apr 2003 → 1 May 2003
|Conference||SETAC Europe 13th Annual Meeting|
|Period||27/04/03 → 1/05/03|