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Archive for the ‘RJ36’ Category

face_seal_J36_male_12DEC17_DLOn July 19, 2017, our second pup of the year was tagged RJ36 (born to RK30) at his natal birth site along a stretch of Napali Coast. But he wasn’t officially re-sighted again until late in the afternoon last week Tuesday when a field biologist at Pacific Missile Range Facility reported two seals had hauled out along Kauai’s southwestern shore. One was R8HY and the other turned out to be RJ36. The field biologist observed some unusual scars just forward of the weaner’s left fore flipper and across his dorsal above his rear flippers.

tail_seal_J36_male_12DEC17_DLAfter reviewing photos of RJ36 with the Hawaiian Monk Seal Research Program (HMSRP), the consensus is RJ36 had an encounter with a shark. The good news is RJ36 appears to be in good health. His wounds have healed, and he’s looking nice and plump.

left_seal_J36_male_12DEC17_DL

In the Main Hawaiian Islands, HMSRP does not rank sharks as a major threat to monk seal survival. According to HMSRP, there have been no documented cases of mortality from sharks in the Main Hawaiian Islands. However, that doesn’t mean they haven’t happened, as those events probably go completely undetected.

RJ36 isn’t Kauai’s only known seal with suspected shark encounters.

There’s also RJ36’s mom, RK30, who was first sighted as an adult by the HMSRP in 2005, already with what’s possibly a scar from a shark bite. She also has a dozen or more cookie cutter shark scars dotting her body.

More recently, another mature female RK13 was sighted in 2011 with two apparent shark wounds–one above her left fore flipper and the other on her right ventral side. We reported on it here. She was regularly sighted along Kapaa’s canals as she recovered from her injuries. She was also pregnant at the time but eventually gave birth to a healthy pup, RL10. Then, in May of this year, we reported here that RK13 was sighted with an unsightly wound to her nares (nostrils), possibly due to a shark bite. Monk seals have an amazing ability to heal themselves through a process called “tissue granulation,” and RK13’s wound healed nicely.

20170426,Fuji,RK13(Miyashiro)

There are two other known seals with shark wounds. RH92 was a newly weaned pup in 2016 when she turned up with a fresh and deep cookie cutter shark wound on her head.

RICOH IMAGING

R1KY has a large shark bite scar below her right fore flipper, most visible on her dorsal side. R1KY

It’s impossible to know for sure that all these scars are due to sharks and specifically what kind of shark; however, three shark species are common suspects:

  1. Tiger: Considered an apex predator, Tiger sharks grow to lengths of 18 feet and longer, wearing up to 2,000 pounds. This shark inhabits coastal and pelagic waters. Tiger sharks mature slowly and pup in litters of 35 to 55 individuals. Their name comes from the dark, vertical stripes that, interestingly, lighten in color as they age. They can live 30 to 40 years. They eat a wide variety of marine animals and carrion and have been called, “the garbage can of the sea.”
  2. Cookiecutter: The cookiecutter shark, also called the cigar shark, lives in warm, oceanic waters worldwide and particularly near islands. Its common name comes from the cookie cutter-like wounds it leaves in its prey. It lives at depths of 3,200 feet during the day but migrates up the water column at night to feed. To feed, the fish uses its suction cup-like lips to attach itself onto prey. Then, it spins its body, using the row of serrated teeth on its lower jaw to remove a plug of flesh, leaving behind crater-like wounds that are two inches across and approximately two-and-a-half inches deep.
  3. Galapagos: This shark grows to 10 feet in length and generally eats bottom fishes and cephalopods. In the Northwestern Hawaiian Islands, where approximately 85 percent of the Hawaiian monk seal species lives, Galapagos sharks have been recorded predating on monk seal pups in nearshore waters around French Frigate Shoals. It’s hypothesized that a small group of sharks are involved in this behavior. You can read more about this unusual mortality event and mitigation efforts here.

Not all appearances of sharks spell trouble for monk seals, as this video from National Geographic’s CritterCam shows. At 1:50, you’ll see sharks in the foreground but no interaction between the species. And at 4:42, you’ll see the Crittercam-toting monk seal chase off a couple reef sharks.

 

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Field Report: Summer

2017 pups are all weaned and tagged!

Monk Seal Pup RJ22-2All weaned pups this year are males (all three last year were females, born to the same moms at same locations!). RK30’s pup born along the Na Pali coast, is a nice big healthy weaner, now known as RJ36 (tagged J36/J37). We are grateful to Captain Tara Leota and Kauai Sea Riders for assistance to monitor and deliver the Kauai team to tag this pup.

RK22 weaned her pup RJ22 (tagged J22/J23) on the northeast coast and was found one morning entangled in in monofilament fishing line. Fortunately, while we were monitoring,  he was able to free himself from the fishing line. This demonstrates why it is so important to check the seals regularly–and to pick up marine debris whenever possible.

The last pup to wean, was RO28’s pup now known as RJ28 (tagged J28/J29). This pup remains on his natal beach while RJ22 has already started exploring more of the coast, moving south.

Seals of Concern Updates

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Photo credit: Miyashiro.

RH92, juvenile female was translocated from Kapaa to PMRF in March. We are pleased to report that even though she returned to the Fuji Beach area she is no longer logging nor feeding on fish scraps in the canal. She continues to forage normally along the east coast and just finished her first molt.

Another yearling female, RH38, is getting ready to molt along the north shore, and we are monitoring her closely as her weight is low.

Unusual hook discovery

20170704,Poipu,UAM(JDT)

Photo credit: Thomton 

An unknown, untagged, clean adult male seal showed up on the south shore with a large J-hook stuck in his back. A second J-hook was attached with a metal leader and there was 17 feet of very heavy (400 lb) monofilament trailing. Coordinators were able to cut away all of monofilament and the dangling second hook.

20170704,Poipu,UAM(JDT)a

Photo credit: Thomton

The remaining hook embedded in the skin is non-life threatening and will eventually come out on its own, however we will closely monitor this seal and intervene if necessary. Fishermen have informed us that the gear that hooked the seal is used to catch marlin by trolling behind a fast moving boat.

Meanwhile, in Waikiki

One of Kauai’s longtime breeding females, RH58 or “Rocky,” pupped on at Kaimana Beach in Waikiki on Oahu–and instantly became the darling of beachgoers. The mom and pup, a female, provided NOAA staff and volunteers with additional concern when they swam inside the Natatorium by way of an opening in its crumbling seawall. Eventually, once RH58 weaned her fat and healthy pup, the pup was relocated to a more remote location for her safety. As we’ve discussed here many times, young seals are most vulnerable right after weaning. This is a time they spend exploring their natal beach, learning what’s edible and what isn’t. At this age, they are quite curious and social, approaching other seals and, even, people on the beach and in the water as they go about figuring out how to survive as a seal on their own. For her safety, scientists decided to move RH58’s pup to a more remote location.

And at Midway Atoll

A mother monk seal bit a woman–an employee with U.S. Fish and Wildlife Service–several times while the woman was swimming in the only section of water open for recreational use. The monk seal approached the woman from an adjacent beach where she had pupped. The woman remained on Midway to recover from her injuries. While this incident is extremely unfortunate, it is a good reminder that monk seals are wild animals and that each seal is an individual, each reacting differently to what might seem to be similar situations.

 

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Last week, on a sunny day, our second pup of the year graduated to “weaner” status and was tagged RJ36. After about six weeks of dedicated nursing, RJ36’s mother, RK30, weaned him and headed back to the nourishing depths of the ocean to replenish the approximate one-third body weight she lost during the nearly six weeks she nursed RJ36 to a healthy weaner weight in the neighborhood of 175 pounds.

While the procedure to tag monk seal weaners only takes about five minutes, the effort to tag this pup took much longer–all due to the remote location of where RK30 chose to birth.

For years now, the Kauai Hawaiian Monk Seal Hui has been aided when accessing remote beaches by marine biologist Captain Tara Leota, sole owner-operator of Kauai Sea Rider Adventures. Captain Tara leads small groups of ecologically-minded guests on snorkeling adventures around Kauai. Captain Tara, her crew, and her guests welcomed our tagging team aboard her 25-foot rigid inflatable boat for the adventurous journey to find RJ36.

Currently, the way we track matriarchal lineage of monk seals is by visual observations of mothers and pups. As such, our goal is always to tag pups within days of their weaning. Once weaners start exploring other parts of the island and mixing with other monk seals, we cannot be sure of their lineage. Thus, Captain Tara has likely helped us know with surety the matriarchal lines of six or eight monk seals over the years. That’s a great effort.

Mahalo Kauai Sea Rider Adventures!

RJ36 (5) 7.19.17-2

Photo credit: V. Bloy

RJ36 (3) 7.9.17-2

Photo credit: V. Bloy

RJ36 tags 7.19.17-2

Photo credit: V. Bloy

Kauai Sea Riders Crew-2

Photo credit: V. Bloy

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