By Christie Wilson
he 2009 Hawaiian monk seal breeding season produced the fewest pups in at least 10 years as the highly endangered marine mammal species continued its slide toward possible extinction.
NOAA Fisheries biologists counted 119 seal pups born in the Northwestern Hawaiian Islands last year, compared with 138 in 2008.
Charles Littnan, lead scientist with the National Oceanic and Atmospheric Administration’s Fisheries Hawaiian Monk Seal Research Program, said the numbers are discouraging, even though monk seal sightings are becoming more frequent in the main Hawaiian Islands, where 15 births were recorded.
“We’re still seeing a pretty steady decline. Every location (in the Northwestern Hawaiian Islands) was down this year,” he said.
There are an estimated 1,100 monk seals in the Islands. With the population declining at a rate of 4 percent annually, biologists predict their numbers will dip below 1,000 in the next three to four years, making the Hawaiian monk seal one of the world’s rarest species.
“The biggest problem is poor juvenile survival. Less than 1 in 5 pups that are born live to adulthood,” Littnan said.
Although most of the monk seal population inhabits the protected waters of the Papahanaumokuakea Marine National Monument, large numbers of juveniles are starving to death, he said.
“The Northwestern Hawaiian Islands is not a pristine system. It’s experienced hundreds of years of disturbance,” Littnan said. “Now, with greater protections, it’s trying to find a new balance, and for whatever reason, these young animals aren’t getting enough food. Whether it’s competition with other apex predators such as ulua, sharks and other monk seals, these smaller animals are losing out.”
Other threats to the seal population are entanglement in marine debris, loss of haul-out and pupping beaches caused by erosion of the region’s small atolls and sandbars, disease outbreaks, low genetic diversity and male aggression toward potential mates that causes injury or death to females.
“The problem is that all of these affect all the age classes, but they seem to affect juveniles the most, and seal pup numbers keep going down,” Littnan said.
“Even if we fix the problems today, it will impact the breeding class for years to come.”
Monk seal pups, are about 3 feet long and weigh 35 pounds at birth, and have a 90 percent survival rate during their first six weeks. But once the pups are fattened up and weaned, their mothers abandon them and return to sea.
“Once they seem to make it past 4 or 5 years of age, they are pretty much in the clear. They’ve learned the tricks they need to survive,” Littnan said.
At French Frigate Shoals, young monk seals are being picked off by a small population of Galapagos sharks that has been observed attacking still-nursing pups in as little as 2 inches of water.
The sharks claim up to 35 percent of pups born at the shoals, Littnan said.
To reduce the carnage, scientists tested a variety of shark deterrence methods over the last two years, including amplified boat engine noise and electromagnetic arrays, but none worked, he said.
Biologists are now experimenting with two new strategies — relocation and deworming — to improve the survival odds for juvenile monk seals.
Six weaned seals were taken from French Frigate Shoals in August and released at Nihoa Island, where sharks are not as much of a threat. This is the second year of a pilot study to determine the feasibility of moving seals, Littnan said.
As part of a trial deworming program started last year, several juvenile seals at Laysan Island were given the first of several doses of medication to eliminate parasites to boost their health.
“Winter is a hard time for younger animals. It’s colder and it takes more energy,” Littnan said. “If the parasite burden is decreased, we might be able to make them a little more efficient when they do get to eat.”
Littnan said that if the monk seal population continues in “free fall,” tough decisions and “fairly bold action” will be needed to prevent extinction. Monument managers may need to consider expanding relocation programs, developing vaccines in anticipation of possible disease outbreaks, and even taking some pups into captivity, he said.
As it stands, monk seal numbers are so low that a single outbreak or mass toxic algae bloom could wipe out the population.
Littnan said “a little ray of hope” can be found in the growing monk seal population in the main Hawaiian Islands, which is estimated at 100-plus animals.
In 2009, six pup births were reported on Moloka’i, five on Kaua’i, and two each on O’ahu and Maui.
Seals in the main Islands face additional threats from human interaction, including getting caught in fishing gear, mother-pup pairs being disturbed on beaches and exposure to disease.
Recent seal shootings and encounters in which swimmers were injured by seals indicate conflicts with humans will increase with monk seal numbers.
“Even with people shooting them, they are still doing well (in the main islands), but that could change tomorrow,” Littnan said. “It’s important that people learn to accept them as part of the ecosystem and a native species that belongs here.”
Seal protection bills pending
In addition to low birth rates, intentional killings by humans — including three last year — have threatened the long-term survival of endangered Hawaiian monk seals.
In response, state legislators have introduced several initiatives to protect the seals and other endangered species in the Islands.
On Friday, state Sen. Gary Hooser introduced legislation (SB 2441) that would increase the penalty for harming or killing Hawaiian monk seals and other endangered species from a misdemeanor to a Class-C felony.
“Passing this legislation will send a message that the people of Hawai’i will not stand by and allow individuals to take their anger out on innocent animals,” Hooser said in a statement.
State Rep. Chris Lee’s HB 2767 was introduced as a companion to Hooser’s bill.
In addition, state Rep. Mina Morita has introduced a bill (HB 2235) that would also raise the penalty for harming or killing monk seals to a Class-C felony, as well as a companion bill that would introduce endangered species informational kiosks at airports.
State Sen. Mike Gabbard introduced a pair of conservation bills (SB 2362 and SB 2263) designed to educate tourists who visit Hawai’i beaches. Also, state Rep. Danny Coffman introduced a House version of Gabbard’s SB 2362 calling for a public-service announcement about endangered species to be played on all flights coming here.