April 26, 2021 — The following was released by NOAA Fisheries:
A group of NOAA scientists has published a new paper in Marine Mammal Science that improves their estimations of reproductive rates in Hawaiian monk seals. Sighting patterns reveal unobserved pupping events, which revises reproductive rate estimates for Hawaiian monk seals in the main Hawaiian Islands. They couldn’t have done it without the help of citizen scientists reporting monk seal sightings. NOAA relies on public reports to collect data on seals in the main Hawaiian Islands. It would be impossible to consistently survey all of the beaches along 750 miles of inhabited shoreline.
Hawaiian monk seals are among the world’s most endangered marine mammals, with only around 1,400 remaining. Most of the population (about 1,100 seals) inhabit the remote Northwestern Hawaiian Islands. The remainder (about 300 seals) live in the heavily populated main Hawaiian Islands. The monk seal has recently shown positive population trends in these islands. At the core of these encouraging data is the number of pups born each year.
Counting Pups
Hawaiian monk seals have pups throughout the year. NOAA sends teams of biologists to the Papahānaumokuākeakea Marine National Monument every year to count the monk seal population. And while the main Hawaiian Islands are densely populated with humans, monk seals often select secluded beaches for pupping. This makes it hard to know when and where to look, so it’s easy to miss some. And since we don’t always witness their birth, we don’t see or identify many of those seals until they are adults. That makes it difficult to estimate their age when they have pups of their own.
If we can improve how we measure maternal age and pup production, we can improve our estimate of the population’s reproductive rates. That enhances our ability to track population trends.
Citizen Scientists Make it Possible
Unlike our work conducted from remote camps in the Northwestern Hawaiian Islands, it is not possible to routinely survey all beaches along more than 700 miles of coastline in the inhabited (main) Hawaiian Islands. NOAA relies on public reports and volunteer citizen scientists to collect data on seals in the main Hawaiian Islands. Public reports and the contribution of volunteer citizen scientists allow our researchers to record many more pupping events on the main Hawaiian Islands. Our researchers were able to use these data in their study.
Public participation in monk seal monitoring vastly extends the coverage that agency biologists can accomplish alone. It also engages the community in stewardship of natural resources in Hawaiʻi. For example, with so many things shut down in 2020, NOAA biologists weren’t able to survey monk seals in the Northwestern Hawaiian Islands. However, our information flow in the main Hawaiian Islands remained strong thanks to citizen scientists.
You can add to our data set by reporting your own monk seals sightings to the state-wide hotline at (888) 256-9840! Keep in mind, there is no need to approach a monk seal to make a report—always keep a safe distance from wildlife.
Thanks to these efforts, the newly published research describes the reproductive cycle and estimates reproductive rates of female Hawaiian monk seals in the main Hawaiian Islands.