Editing Whale (section)

===Other threats===
{{further|Cetacean bycatch|Cetacean stranding|Marine mammals and sonar}}

Whales can also be threatened by humans more indirectly. They are unintentionally caught in fishing nets by commercial fisheries as [[bycatch]] and accidentally swallow fishing hooks. [[Gillnetting]] and [[Seine fishing|Seine netting]] is a significant cause of mortality in whales and other marine mammals.{{sfn|NOAA Fisheries|2014}} Species commonly entangled include beaked whales. Whales are also affected by [[marine pollution]]. High levels of [[Persistent organic pollutant|organic chemical]]s accumulate in these animals since they are high in the food chain. They have large reserves of blubber, more so for toothed whales as they are higher up the food chain than baleen whales. Lactating mothers can pass the toxins on to their young. These pollutants can cause [[gastrointestinal cancer]]s and greater vulnerability to infectious diseases.{{sfn|Metcalfe|2012}} They can also be poisoned by swallowing litter, such as plastic bags.{{sfn|Tsai|2015}} Advanced [[Marine mammals and sonar|military sonar harms whales]]. Sonar interferes with the basic biological functions of whales—such as feeding and mating—by impacting their ability to [[Animal echolocation|echolocate]]. Whales swim in response to sonar and sometimes experience [[decompression sickness]] due to rapid changes in depth. Mass [[Cetacean stranding|strandings]] have been triggered by sonar activity, resulting in injury or death.{{sfn|Stockton|2016}}{{sfn|Carrington|2013}}{{sfn|Scientific American|2009}}<ref>References prior to 2010, before a more definitive conclusion:
* {{harvnb|Rommel et al.|2006}}
* {{harvnb|Schrope|2003|p=106}}
* {{harvnb|Kirby|2003}}
* {{harvnb|Piantadosi et al.|2004}}
</ref> Whales are sometimes killed or injured during collisions with ships or boats. This is considered to be a significant threat to vulnerable whale populations such as the [[North Atlantic right whale]], whose total population numbers less than 500.{{sfn|WWF}} It is believed that up to two thirds of whale-ship collisions are not reported; either because they are not noticed in large ships, they occur at night or during conditions of adverse weather or some other reasons.<ref name=shipstrike/> From 2013 up to at least 2023 [[Chile]] has been the country in the world with most registered fatal whale-ship collisions.<ref name=shipstrike>{{Cite journal |title=High rate of ship strike to large whales off Chile: Historical data and proposed actions to reduce risk |journal=[[Marine Policy]] |year=2025|author=Toro, Frederick; Buchan Susannah J.; Alvarado-Rybak, Mario; Bedriñana-Romano, Luis; Garcia-Cegarra, Ana M., Hucke-Gaete, Rodrigo; Olavarria, Carlos; Sepúlveda, Maritza; Galletti-Vernazzani, Barbara; Sielfeld, Walter; Aguayo, Anelio; Capella, Juan; Perez-Alvarez, Maria José; Viddi, Francisco; Caceres, Benjamin; Gibbons, Jorge; Acevedo, Jorge; Guzman, Hector; Guerra, Jorge; Saez, Ricardo; Seguel, Mauricio; Fishbach, M. Michael|page=106577}}</ref>