NOAA Fisheries observes, measures, and monitors the impacts of climate change on our marine life and ecosystems. The environmental changes occur both locally and globally, and include warming oceans, rising seas, ocean acidification, and an increase in the frequency and intensity of extreme weather events. These shifting oceanographic conditions, which will likely increase in the future, are already affecting the distribution and health of many marine species. Several seal and sea lions species are vulnerable given their dependence on specific environmental conditions during different times of the year.
Ice Seals
There are several species of ice-associated seals including bearded seals, ringed seals, spotted seals, ribbon seals, harp seals, and hooded seals. They are generally found in the Arctic, and depend on sea ice for at least part of the year to rest, breed, nurse and rear pups, molt, and avoid predators. However, the warming climate is changing the reliability, quality, and extent of sea ice and negatively impacting ice seal health and behavior. Warming spring temperatures and earlier ice breakup could force pups into the water before they are independent from their mothers and able to feed on their own. If the seal is not strong enough to survive in open water, it could be killed and eaten by a marine predator—such as a killer whale or shark—or drown.
From 2007 to 2018 in the Bering Sea, sea ice decreased by 47,000 square kilometers each year on average. The extent of the sea ice fluctuated from record highs to record lows. Scientists observed declines in the body condition of ribbon and spotted seal pups during this period. This may have been due to poor foraging conditions for their mothers during pregnancy and while nursing. In low ice years, the Marine Mammal Stranding Network responds to a greater number of ice seal strandings (mostly of immature animals) in areas further south than the typical range of ice seals. Ice seals are key ecological components of Arctic marine ecosystems and provide vital resources—such as food and handicrafts— that support a traditional way of life for Alaska Native communities.
Hawaiian Monk Seals
Hawaiian monk seals are one of the most endangered seal species in the world and one of NOAA Fisheries’ Species in the Spotlight. They are found almost exclusively in the Hawaiian Archipelago. Hawaiian monk seals spend time on small low-lying islands to give birth, nurse their pups, and escape predators such as sharks. Climate change impacts include terrestrial habitat loss from sea-level rise, erosion, and more frequent and stronger storms. Already important pupping beaches at the French Frigate Shoals (Lalo), part of the Papahānaumokuākea Marine National Monument, have been mostly or entirely lost. Many more atolls within the Monument are predicted to experience similar impacts within the next 30–50 years.
Guadalupe Fur Seals
Guadalupe fur seals live and breed on small rocky islands off southern California and the Pacific coast of Mexico. These areas are susceptible to warming waters, ocean acidification, and harmful algal blooms, all of which are increasing in frequency due to climate change. Guadalupe fur seals mostly eat squid and may be unable to adapt their diet to changes in prey availability. In recent years, marine heatwaves in the Pacific Ocean (e.g., “The Blob”) have negatively impacted prey distribution and abundance. Poor prey conditions have likely led to higher numbers of stranded animals, including a recent Unusual Mortality Event from 2015–2021. The UME included more than 700 seals, particularly younger animals, with signs of malnutrition and weakened immune systems.
Responding to Climate Change
The effects of climate change on marine species and habitats will continue and increase in the coming decades. NOAA Fisheries is committed to our mission to conserve protected species in the face of these threats. With our partners, we have taken a series of steps to advance climate-focused science and management including:
- Climate vulnerability assessments for marine mammals and sea turtles to understand which species are most vulnerable and why
- Scenario planning to address uncertainties, predict impacts, and prioritize mitigation and recovery actions
- Climate-smart conservation training to educate staff on how to implement climate adaptation tools in their work These activities strengthen our understanding of the impacts of climate change on protected species and their habitats so we can better plan, adapt, and mitigate impacts for the future.
