Whale populations were drastically reduced in the 20th century from intensive whaling, which lead to a moratorium on hunting by the International Whaling Commission in 1982.[7] Smaller cetaceans are at risk of accidentally getting caught by fishing vessels using, namely, seine fishing, drift netting, or gill netting operations.[8]
^Agnarsson, I.; May-Collado, LJ. (2008). "The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide reliable species-level phylogenies". Mol Phylogenet Evol. 48 (3): 964–985. doi:10.1016/j.ympev.2008.05.046. PMID18590827.
^Price, SA.; Bininda-Emonds, OR.; Gittleman, JL. (2005). "A complete phylogeny of the whales, dolphins and even-toed hoofed mammals – Cetartiodactyla". Biol Rev Camb Philos Soc. 80 (3): 445–473. doi:10.1017/s1464793105006743. PMID16094808. S2CID45056197.