**Acknowledgements**

We would like to thank Stranding Network Hokkaido (SNH) for providing the cetacean samples and stranding information used in this study. We would like to thank to Inter-Research Science Publisher for permission of reproduce use of Table 5 from Lee et al. (2005) published in Marine Ecology Progress Series. We would like to thank to Aquatic Mammals for granting permission to use Figure 2 from Endo et al. (2021).

*Typical Changes in Carbon and Nitrogen Stable Isotope Ratios and Mercury Concentration… DOI: http://dx.doi.org/10.5772/intechopen.103067*
