December 26th, 2006 08:45 EST
Rare Monk Seal Twins are Cared for by NOAA
In May 2006, a rare pair of critically endangered Hawaiian monk seal twins—only the fourth set of twins ever documented and the first pair to survive past weaning—was brought to Honolulu from the Midway Atoll National Wildlife Refuge aboard a U.S. Coast Guard C-130 Hercules aircraft. Past observations indicated that twins have a high probability of mortality, and it will be a first if these twins survive and are successfully reintroduced back into the wild.
Tagged PO22 and PO26, the young seals, both females, appeared healthy but were undersized at weaning with only about half the blubber reserves needed to sustain them through the several months required to learn self-sustaining foraging behavior. Hence the decision to provide additional food in a captive care situation to increase their chances of survival was made.
The twins were first observed on April 4 and appeared to be only a day or two old. The mother of the twins was identified as a 19-year-old from Kure Atoll and a beneficiary of a 1987 captive care program. Monk seal mothers stay with their pups for about six weeks, never leaving them to feed. During that period, mothers may lose as much as 300 pounds, while the pups may triple their birth weight. After the mother leaves, the pups are left to fend for themselves.
Once back in Honolulu at the NOAA Pacific Islands Fisheries Science Center Kewalo Research Facility, the pups were introduced to their quarantine facility—a large seawater holding pool with ample deck space to bask in the sun. After their health was evaluated, they were slowly given increasing amounts of human quality herring to match their growth. Over the next five months at Kewalo their progress was carefully monitored by a team of monk seal experts on a daily basis.
In October 2006, the twins were transported back to Midway Atoll National Wildlife Refuge as the NOAA Pacific Islands Fisheries Science Center reinstated a Hawaiian monk seal captive care program after an eight year hiatus. Upon arriving at Midway, the twins were placed in a shore pen—a large area enclosed by fencing that includes beach area for basking and ocean area for swimming. They appeared to quickly acclimate to their new surroundings and resumed typical monk seal behavior of "body surfing" on the waves traversing the pen.
PO22 and PO26 have nearly doubled their weight since weaning, gaining 60 pounds and 73 pounds respectively. Researchers are hopeful that the pair can be released back into the wild toward the end of March or early April 2007, near their first birthday. Upon release, the twins will be instrumented with satellite linked telemetry to allow researchers to follow and monitor their foraging activities.
Presently, the endangered Hawaiian monk seal is in a crisis situation and its population is at its lowest level in recorded history. Now numbering only about 1,200 individuals, their numbers are expected to fall below 1,000 within the next 5 years.
In 2007 NOAA, an agency of the U.S. Commerce Department, celebrates 200 years of science and service to the nation. Starting with the establishment of the U.S. Coast and Geodetic Survey in 1807 by Thomas Jefferson much of America's scientific heritage is rooted in NOAA. The agency is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of the nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 60 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.