The population of endangered Hawaiian monk seals has surpassed a level not seen in more than two decades, according to federal officials.
National Oceanic and Atmospheric Administration officials said this week that the seal population has grown steadily over the past two years.
Officials estimated that the population increased by more than 100 between 2019 and 2021, bringing the total from 1,435 to 1,570 seals. Monk seals live only in Hawaii, including the uninhabited northwestern Hawaiian Islands where most of the animals are found.
The Northwestern Hawaiian Islands are all within the Papahanaumokuakea Marine National Monument, the largest marine protected area in the United States and a UNESCO World Heritage Site.
Michelle Barbieri, senior scientist with NOAA’s Hawaiian Monk Seal Research Program, said the tally shows conservation efforts have helped. The group travels the archipelago to care for and rescue animals in difficulty.
“We are there ourselves and working with partners to deliver life-saving interventions for seals, prioritizing females, who will continue to create the future generation of seals,” Barbieri said. “We’re starting to really see this continued gain in intervening to save animal lives.”
NOAA has been monitoring the seal population for almost 40 years. The agency said it was the first time the population exceeded 1,500 in more than 20 years.
The animals are listed as endangered under the Endangered Species Act and depleted under the Marine Mammal Protection Act.
Officials said while the trend is promising, concerns remain about survivability as the low-lying islands and atolls the seals live on are threatened by rising sea levels associated with climate change.
Some islands in the region are only a few feet above sea level.
“Climate change is definitely something that really worries us,” Barbieri said. “We really see these impacts, we are experiencing them now. And that has real ramifications for seal survival.
The islets of French Frigate Shoals are home to approximately 20% of the monk seals of the Northwest Hawaiian Islands and have long supported the largest subpopulation of the species.
The land mass there shrank for decades, with some of the islands disappearing altogether.
Whaleskate Island, Trig and East Island were all washed away. Whaleskate and Trig were destroyed by erosion, and East Island was wiped out by Hurricane Walaka in 2018.
The loss of terrestrial habitat is just one of the problems facing the population. Seals often become entangled in fishing nets and other marine debris, ingest hooks, and some are targeted and killed by humans.
Monk seal populations declined for decades before the population began to recover in 2013.
Barbieri said animals not only play a vital role in the food chain, but are also an indicator of the overall health of the ocean.
“If we have healthy monk seals,” Barbieri said, “we know the ecosystem that supports these animals is healthy and thriving.”