Climate change affects prey abundance, distribution and type. Ocean warming changes the timing of important life events including migration. Ice melt causes decline in critical habitat and provides less protection from predators.

Source: GISTEMP Team, 2025: GISS Surface Temperature Analysis (GISTEMP), version 4. NASA Goddard Institute for Space Studies. Dataset accessed 2025-05-01 at https://data.giss.nasa.gov/gistemp/.

Entanglement in fishing gear is the most significant threat to the survival of whale and dolphin populations globally.

Source: Avila IC, Kaschner K, Dormann CF (2018). Current global risks to marine mammals: Taking stock of the threats. Biological Conservation 221:44–58. https://doi.org/10.1016/j.biocon.2018.02.021

Reduction of prey availability due to overfishing threatens all cetaceans.

Source: Global Fishing Watch. 2025. Global Apparent Fishing Effort Dataset, Version 3.0. doi:10.5281/zenodo.14982712

Shipping poses multiple threats, including deaths caused by vessel strikes in areas where there is high vessel traffic in important ocean habitats.

The introduction of noise into the ocean from shipping, seismic survey, industrial operation, construction and military sonar interferes with the ability of whales and other noise-sensitive species to carry out many life functions. Underwater noise can result in disturbance, displacement, temporary hearing loss, permanent hearing damage and direct mortality.

Source: Jalkanen J-P, Johansson L, Andersson MH, Majamäki E, Sigray P (2022) Underwater noise emissions from ships during 2014–2020. Environmental Pollution 311:119766.

Introduced synthetic chemicals in the sea bioaccumulate in the marine food chain leading to toxic levels in top predators like whales.

Source: Frazier M (2019). Recent pace of change in human impact on the world's ocean: Organic chemical pollution. Knowledge Network for Biocomplexity. doi:10.5063/F12805ZF.

Toothed whales such as sperm whales ingest plastics, confusing them with prey. Baleen whales ingest plastic indirectly where their prey contains microplastics.

Source: Clark, B.L., Carneiro, A.P.B., Pearmain, E.J. et al. Global assessment of marine plastic exposure risk for oceanic birds. Nat Commun 14, 3665 (2023). https://doi.org/10.1038/s41467-023-38900-z

Oil and gas exploration and extraction disturbs whales and their prey through underwater noise pollution, construction of supporting infrastructure, oil leaks, associated shipping and the potential for large, catastrophic oil spills.

Source: Omara M, Gautam R, O'Brien M, Himmelberger A, Franco A, Meisenhelder K, Hauser G et al. (2023) Developing a spatially explicit global oil and gas infrastructure database for characterizing methane emission sources at high resolution. Earth System Science Data Discussions 2023 : 1-35.

Nations including Japan and Norway continue to kill whales for commercial purposes.

Proportion of marine mammal species affected by any threat in a given 0.5 degree x 0.5 degree cell.

Source: Avila IC, Kaschner K, Dormann CF (2018). Current global risks to marine mammals: Taking stock of the threats. Biological Conservation 221:44–58. https://doi.org/10.1016/j.biocon.2018.02.021