Which dangers have contributed to the decline of some cetacean populations?

Several human-driven factors have contributed to the decline of various cetacean populations, often placing species at risk of extinction. These dangers include:12

• Commercial Whaling and Illegal Hunting: Historically, intensive whaling decimated populations of large whales, such as blue and fin whales. Despite the International Whaling Commission implementing a moratorium on commercial whaling, illegal hunting and limited whaling activities continue to impact certain stocks.13
• Bycatch: Cetaceans are frequently captured unintentionally in commercial fishing equipment, such as gill nets and longlines. This bycatch is a significant threat, as animals often suffer fatal trauma or drown before they can be released.12
• Noise Pollution: Marine environments are increasingly filled with chaotic sounds from shipping, seismic testing, oil drilling, and naval sonar. This noise interferes with the ability of whales and dolphins to communicate, navigate, and use echolocation, and has been linked to mass strandings.45
• Plastic and Water Pollution: Cetaceans ingest plastic debris, which can cause fatal intestinal blockages or introduce toxic chemicals into their systems. Additionally, water pollution from industrial and agricultural sources can degrade habitats and threaten the health of marine ecosystems.67
• Ship Collisions: Large cetaceans, such as the gray whale and northern right whale, remain vulnerable to being struck by vessels in busy shipping lanes.1