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During the week of May 14, 2018, three Hawaiian monk seals were found dead on O`ahu. One was RK60 (Nani) who was born on an islet off Oahu known as Rabbit Island in 2011. She’d given birth to one pup in May of 2017.

The second dead seal was RT10 (Ua Malie) who was born at Turtle Bay to R5AY (known as Honey Girl on Oahu and K01 on Kauai). She’d pupped three times before.

The third dead seal was a small but fully developed pup. NOAA officials feel this pup was born dead and, based on an examination, likely to RT10.

The Hawaiian Monk Seal Research Program responded by conducting necropsies on all three and today released the news that the cause of death for all three was toxoplasmosis.

In 2015, Kaua`i-born RB24 (Haupu) died of toxoplasmosis.

B24 scars L head

According to a joint statement from the Hawaii Department of Land and Natural Resources and Hawaii Department of Health, “The recent deaths of of three critically endangered Hawaiian monk seals on Oahu due to toxoplasmosis is very sad and could have been entirely preventable.”

The rest of the press release reads:

Cats are the only known reproductive host of the toxoplasmosis parasite. It reproduces in the feline digestive system. A single cat can excrete 145 billion eggs per year in its feces. Once released into the environment, these eggs can infect other animals, including humans, both on land and in the ocean. Toxoplasmosis parasites create cysts in muscle and organ tissues and can cause inflammation of the heart, liver, and brain.

Health Director Dr. Bruce Anderson explained that the parasite that NOAA veterinarians found caused the deaths of the seals is far more impactful than just killing seals.” In addition to impacting marine mammals and wildlife, toxoplasmosis is a risk to humans. It is known to cause serious problems for pregnant women and their unborn children,” Anderson said. “During pregnancy, infection by the toxoplasmosis parasite can damage the unborn child, causing miscarriages, stillbirth, or substantial birth defects including enlargement or smallness of the head.

For healthy individuals, symptoms and signs of toxoplasmosis infection are most often benign because a healthy person’s immune system usually keeps the parasite from causing illness. Very few people will have symptoms similar to the flu and most people probably do not know they have been infected. The Centers for Disease Control and Prevention estimates that approximately 10 percent of the population in the U.S. six years of age and older have developed antibodies to the parasite from a past infection. However, for those with compromised immune systems, those undergoing chemotherapy or with AIDS, and for pregnant women the disease can be very serious.

“The only thing certain about toxoplasmosis is that there are far more cases in humans and more deaths in seals, dolphins, native birds and other animals today than are recognized and reported,” said Anderson. “Since cats are the only animal that transmit the disease, it only makes sense that reducing the number of feral cats will reduce the risk of infection and serious illness or death,” Anderson added.

DLNR Chair Suzanne Case, is again encouraging people not to feed cats and other animals near water. “In addition to preying on native wildlife, cats pose a significant health risk to people, marine wildlife and birds,” Case explained. Toxoplasmosis can also infect Hawai‘i’s native birds, including the nēnē and the newly released Hawaiian crow, the ʻAlalā.

“Feeding cats near water obviously increases the risk of transmission but, given the nature of the watersheds in Hawai‘i, cats almost anywhere are probably contributing to the problem,” Case said. “The cysts can live for months in soil and can wash into streams and runoff and be carried into the ocean from almost anywhere. Feeding cats at state parks, boat harbors and other coastal areas increases the risk of transmission because the cysts don’t need to travel very far to get into the ocean.” Case added, “Frankly, feeding cats anywhere where their feces can ultimately wash into the ocean is a problem.”

One of the seals, RK60, killed by toxoplasmosis gave birth to a pup on Moku Iki off shore from Lanikai in the spring of 2017. This seal and her pup moved to Moku Nui and were featured in a safe wildlife viewing video produced by DLNR and shown over the past year to thousands of people who rent from Kailua kayak rental firms (see video link below).

In Hawai‘i, the National Oceanographic and Atmospheric Administration has recorded at least eleven Hawaiian monk seal deaths that are attributable to toxoplasmosis infection since the first confirmed deaths in 2001. Spinner dolphins are the only other marine species that have been documented as dying from toxoplasmosis in Hawai‘i, but there are many other marine mammal species around the world that have also been affected and infections have been linked to the marine food web. This, according to Case and Anderson, should be enough to prompt people to stop feeding feral cats near any bodies of water.

“With only an estimated 1,400 Hawaiian monk seals still in existence, we simply cannot afford to lose even one of these critically endangered mammals to a disease that is preventable. We hope people will provide as much love to our few very special seals as they do to the hundreds of thousands of feral cats around our islands,” Case said.

Multiple tests were conducted on each seal, all of which pointed to toxoplasmosis as cause of death in each case. Toxoplasmosis causes inflammation and disrupts organ function of the blubber, brain, heart, lung, uterus, and for the pup, placenta. Eventually, this led to multiple organ failure and death.

The total number of known monk seal mortalities due to toxoplasmosis is now 11. Toxoplasmosis is the leading cause of disease-related mortality in Hawaiian monk seals and a growing concern for the recovery of the species.

Alongside the growing threat of toxo is the emerging trend whereby more female seals are disproportionately affected–three males and eight females. This exacerbates the impact on the entire species, as each female lost means all her potential future offspring are lost as well.

Toxoplasmosis is caused by a microscopic protozoan parasite, Toxoplasma gondii. It enters the environment when its eggs are shed through the feces of cats. Billions of eggs can be dispersed into the environment from just one cat over a two week period of infection. The eggs remain alive and infectious for months to years after they leave the cat, where they can infect birds and mammals. The disease is responsible for killing native birds like the `alala and nēnē in the terrestrial environment. The organisms can also be washed downstream by rainfall and flow into the nearshore environment, where they infect monk seals as well as spinner dolphins. Because this is a mauka to makai problem, cats that roam and defecate outdoors in any part of the island ecosystem can become carriers and spreaders of toxoplasmosis and ultimately cause the death of native wildlife.

Seals that are sick from toxoplasmosis may not show obvious warning signs of illness, but some have shown subtle indications such as floating lethargically close to shore in areas with calm, protected waters in the past.

A more concerted effort to mitigate the risk of toxoplasmosis to endangered Hawaiian monk seals, as well as other wildlife species, is urgently needed. This primarily requires dealing with the source of environmental contamination: Hawaii has a large population of cats, including hundreds of thousands of feral cats,, that are allowed to freely roam and defecate outside. Infected cats typically do not show any signs of disease themselves. There is currently no vaccine against Toxoplasma gondii in cats. To diminish the threat of toxoplasmosis to seals, the input of organisms into the environment must be reduced, necessitating a significant reduction in the number of feral cats on the islands. Spaying and neutering cats does not change their capacity to perpetuate the parasite and spread it into the environment.

Cats that are kept exclusively indoors have a much lower chance of completing the T. gondii life cycle and are therefore highly unlikely to shed infective oocysts into the environment. Preventing abandonment and keepings cats indoors is best for the welfare of all animals – cats, native birds, monk seals and dolphins.

To learn more about toxoplasmosis, see our post from late March, entitled Toxo Talk.

Field Report: May 2018

Sightings:

The Kauai team logged 33 individually identified monk seals on Kauai in May, for a grand total of 332 sightings. This equates to more than 10 monk seals sighted and reported per day.

New:

  • Juvenile female R7AA hauled out onto roads or parking lots three times in the Poipu area this past month. In order to prevent injury from vehicle traffic she was quickly displaced back onto the beach and into the water.
  • We are currently tracking several pregnant females that we expect to pup any day now. That includes the well known RK30 and a more reclusive seal RK22. Two other females, RH58 and RO28, that are typically on Oahu but come back to their birth beaches on Kauai to pup, are both pregnant and approaching their due dates.

Updates:

  • RK13 gave birth to PK1 at Mahaulepu Beach on 4/20/2018. Extensive monitoring was immediately set-up and continues. Pup weaned after 37 days of nursing. Tagged as RK42. Mother, RK13, became unusually thin prior to weaning, but has been sighted several times since weaning. The pup has begun socializing with other seals, specifically with a 3-year old female bleach-marked V2.

Last week, PK1 became RK42. She now sports a set of red tags in her rear flippers. The left tag reads K42 and the right tag reads K43. At the same time she was flipper-tagged, morphometric measurements were taken. RK42’s axillary girth (circumference of body just below her fore flippers) came in at 100cm while her length from the tip of her nose to the tip of her tail was 126cm.

In other pup news, here is the final report of the necropsy (animal autopsy) of RK52’s pup that was found dead on a North Shore beach on April 24th:

  • The pup’s total length (104.5cm) indicated that it was a full-term pup, and was not premature.
  • Histopathology confirmed the pup as stillborn – in other words, there was no air inflating the lungs and this indicates that it never took a breath of air outside the mother’s uterus.
  • There was also evidence of mild fetal distress (cells and amniotic fluid that were aspirated into the lung tissue) leading to hypoxia (lack of oxygenation of vital tissues). While not severe, this does lead us to conclude that the pup died in utero and likely due to dystocia, or difficulty in the birthing process.
  • Histopathology did not identify any evidence of underlying disease.
Sadly, this is not an uncommon finding, especially for first-time moms like RK52. The hopeful news is that females who lose their first pup in this manner often go on to have healthy pups in subsequent years. The other thing this event reveals is that RK52 is fertile and able to carry a pup to full-term.

A few weeks ago, we reported the gender of PK1 as male. Well, she fooled both volunteers and veteran monk seal biologists, because more recent photographs reveal that PK is not male. She’s female. That’s good news. It takes more females (than males; sorry guys) to grow the Hawaiian monk seal population. Here’s the photographic evidence.

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See the five dots in the shape reminiscent of the number five on a pair of dice? That’s the tell-tale sign.

In other pup news, we now have a “weaner.” After 37* days of care for her newborn, this pup’s mom, RK13, weaned her not-so-little one. This is normal monk seal biology. During the time from birth to weaning, monk seal moms do not forage. They stick by their pup’s side, nursing them and taking near-shore swims with them. Moms eventually lose half their body weight or more, and hunger drives them back to the sea for nourishment. This is how weaning occurs. Kauai’s first weaner of 2018 will now spend the next few months figuring out what’s good to eat in the sea. Weaners tend to stick around their natal birth site while doing this. Now is also a vulnerable time for new weaners, as they explore their surroundings, both near-shore and on the beach, making it as important as ever to give them wide space to do so safely–away from interactions with humans and dogs.

In the next few weeks, PK will be outfitted with flipper tags. Stay tuned. We’ll announce pup’s official tag numbers once she’s tagged.

Here are a few more photos of PK1’s last days with RK13. (Photo credit J. Thomton.) Note the molting on a couple closeups of the muzzle and tail flippers. You can also see in a few of these the size differential between mom and pup, indicating how much weight mom has lost and how much pup has gained.

 

*UPDATE: The official number of nursing days was changed from 41 to 37. It seems RK13 gradually weaned her pup. She first left her pup for a few hours on Friday and, again, on Saturday and Sunday. As of Sunday evening at sunset, the two had hauled out on the beach about 40 yards from each other. By the next morning, Monday, RK13 was gone. PK1’s first entire day alone was Memorial Day, May 28, 2018.

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Field Report: April 2018

 

Sightings:

The Kauai team logged 303 seal sightings this month. This included 30 individually identified seals.

April: 303
March: 299
Feb: 259
Jan: 336

New:

  • RK13 gave birth to PK1 on 4/20/2018. Extensive monitoring was immediately set-up and continues. Unfortunately, the location is notorious for off-leash dogs and past conflict between beach users and the monk seal program. Thus far, only minor issues have risen. Pup continues to thrive.
  • RK52 gave birth to stillborn female pup. This was RK52’s first birth. Carcass was sent to Oahu for necropsy.

Updates:

  • NG00 was re-sighted once this month and is likely still hooked. (See previous monthly updates for background.)
  • Poipu Keiki Pool: 2 displacements took place this month.
  • Bleach markings: 2 seals bleach marked this month.
  • Molting activity: one seal continues to molt this month.

Research/Support of Pacific Islands Fisheries Science Center:

  • Sub-sampled scat, molt, and tissue plug samples.
  • Logged all seal sightings. Thomton organized photos and reported sightings, molt tallies, survival factors to send to PIFSC.

 

PK1 is 3.5 weeks old today, and he’s healthy-looking, active, and spending more and more time swimming. His routine of late finds him exploring the nearshore waters in the mornings and sleeping on the sand in the afternoons. Such is the life of a young Hawaiian monk seal pup.

Here’s a sweet sequence of images of PK1 and his mom RK13. You can also see how mom is losing weight, the natural course of a nursing monk seal mom’s biology. Her rib and shoulder bones are starting to become visible. She basically fasts the entire time she nurses her pup–all the while he packs on the pounds. Eventually, hunger will drive her to the sea to forage, at which point, he’ll be weaned.

Now, enjoy the slide show. (Photo credit goes to Jamie Thomton.)

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And now for the big gender reveal: The pup born on April 20th is a boy.

Mom (RK13) and pup (PK1) are doing great. Pup is growing stronger, and the two are swimming farther. They’ve even started to swim outside their large enclosure but for now continue to return to it to haul out, rest and nurse. But likely, not for long. As pup enters week three, he and mom will swim and explore more, notching total swim times of four to five hours a day. Soon, we’ll switch up their enclosure to a more portable one utilizing mesh fence panels. This can make for a busy time for our volunteers.

But there are interesting things to observe, as well, in pups of this age. Soon, he’ll start his first molt, losing his shiny black natal coat. Typically, it starts with the muzzle, face, chest, neck, and sides.

When pup wants to eat, he’ll vocalize and maybe even nip at mom to get her to roll over, so he can access her teats. Here’s an interesting factoid: The bearded seal (Erignathus barbatus) (Mohr, 1952) and the monk seal are apparently the only phocids having four functional teats. Those four are apparently getting good use with PK1. Let’s run some numbers: Say PK1 weighed 25 pounds at birth. And let’s say mom weans him at five weeks when pup weighs 150 pounds. That means pup is gaining 25 pounds per week. Or 3.5 pounds per day. Maybe more.

Little is known about Hawaiian monk seal milk. Much is inferred from other seal species. Like the fact that milk composition changes throughout the course of lactation. A newborn needs more water than fat. Whereas, an older pup can derive water metabolically from fat stores, a newborn can only obtain water by ingesting its mothers’ watery milk. As a pup ages, its mother’s milk fats increase while the water content decreases.

Screen Shot 2018-05-07 at 4.26.23 PM

As pup starts swimming more, he’s also started exploring his surroundings on land. Unfortunately, this can include rubbish and marine debris on the beach. Some time between weeks three and four, pup’s teeth will start to erupt through his gums.

Screen Shot 2018-05-07 at 4.26.35 PM

As is often the case whenever a pup is born, some males have been visiting the scene, as well. Here’s a video of RK13’s response to a curious male (R330). It’s fair to say that this is the same way she’d respond to a person or a loose dog who gets too close to her, as well–and in the water, she’s much more swift and agile. A mother’s tenancy is protect her pup is strong and why we encourage people and their pets to give monk seal mamas plenty of space.

Speaking of videos, here’s one taken of a Hawaiian monk seal weaner with a knife in his mouth. This was taken in April off Hawaii Island. While this pup was uninjured and the knife eventually retrieved by a DOCARE officer, it’s a good reminder to properly dispose of trash. However, there are other ways dangerous items may accidentally make their way to the shoreline, such as during the recent heavy rains and flooding on Kauai, making beach cleanups all the more important for humans and animals.

Monk Seal and Knife from Hawaii DLNR on Vimeo.