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Sadly, on April 1, 2020, after a 10-week-long battle with toxoplasmosis, a deadly parasitic disease, the adult female seal RO28 passed away.

Also known as “Pōhaku,” RO28 was 14 years old, in the midst of her prime reproductive years, when she died. She was born on Kauai’s north shore in 2006 to RK06. (RK06 was tragically shot to death while she was carrying a full-term pup. The pup did not survive the shooting.)

Over the years, RO28 has made her fair share of appearances on these virtual pages. Throughout her life, she gave birth to seven pups, the first six of which she pupped and raised until weaning along the same stretch of coastline on Kauai’s north shore where she was born. (It’s not uncommon for females to pup near their own birth site.) However, RO28 spent her recent years on the island of Oahu, only returning to Kauai to give birth.

Here’s a recap of what we know about RO28’s life:

  • In her early adolescent years, RO28 spent much of her time hauling out on rocks along the Poipu coastline.
  • On Good Friday in 2010, she was successfully de-hooked.
  • She was first sighted on Oahu at Kaena Point during the 2010 Semi-Annual Hawaiian Monk Seal Count. She was re-sighted twice shortly thereafter, once with a fresh cookie cutter shark bite on her back.
  • In 2013, RO28 gave birth to RN30 who has traveled to Oahu and has been regularly sighted on Kauai’s north shore.
  • In 2014, RO28 gave birth to RF28 who has ventured to Niihau and is also commonly reported along the Poipu coastline.
  • In 2015, RO28 gave birth to RG28 who often hauls out on Kauai’s South Shore. This birth was miraculously captured on video by one of our volunteers.
  • In 2016, RO28 gave birth to RH80 who regularly circumnavigates Kauai.
  • In 2017, RO28 gave birth to RJ28 who can be found on beaches on Kauai’s north shore and east side.
  • In 2018, RO28 gave birth to RKA4 who was last sighted at Kipu Kai.

In 2018, RO28 and two other mothers pupped near each other, resulting in multiple pup-switching incidents. This occurs in the Northwestern Hawaiian Islands where more females are pupping on fewer suitable habitat. RO28 was successfully reunited with RKA4; however, one of the other moms, RH58, also known as “Rocky” eventually showed aggressive behavior toward her pup, and he was rescued by NOAA and successfully raised and eventually released back to the wild.

RO28 pupped on Oahu last year and weaned her pup. Unfortunately, the pup tragically died some time thereafter. NOAA reported, “The circumstances surrounding her death indicate that she did not die of natural causes.”

The loss of RO28 makes thirteen known deaths due to toxoplasmosis.

The first documented monk seal death due to toxoplasmosis occurred in 2001. That number has now risen to at least 13 monk seals, making it a leading threat to the main Hawaiian Islands population. Because seals disappear and die without being discovered, the actual number of deaths caused by toxoplasmosis is likely much higher. Unfortunately, the data indicates more females die than males, presenting another challenge to recovery of the species. According to NOAA Fisheres, “Every lost female means that her future pups, and their future pups, are lost to the world.”

What’s unique about RO28’s case is she was only the third monk seal with toxoplasmosis to be rescued alive. While the other two passed away within 48 hours, veterinarians and care-givers were able to work with RO28 for 10 weeks. During that time, she showed improvement at times, providing science with invaluable information that will, hopefully, one day allow for successful medical care for toxo-infected monk seals.

The parasite Toxoplasma gondii is a microscopic, single-cell organism. Just one of their eggs—known as oocysts— is enough to kill a monk seal. A single cat can excrete 145 billion eggs per year in its feces, according to DLNR. It’s a staggering number.

According to this NOAA report, “The parasite that causes ‘toxo’ sexually reproduces in cats, which shed T. gondii eggs into the environment via their feces. The feces of just one cat contains millions of T. gondii eggs that survive in the environment for many months.

“Any warm-blooded animal, including humans, can contract toxoplasmosis by ingesting a single T. gondii egg — and cats are essential for the reproduction and spread of the parasite.”

The loss of RO28 is yet another reason to keep cats indoors to protect cats and Hawaii’s native wildlife. Please.

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Today’s topic: vibrissae. More commonly known as whiskers.

You may have noticed Hawaiian monk seals have prominent vibrissae.

If this were a nursery rhyme, the little girl might say, “My what big whiskers you have.” And the monk seal would respond, “All the better to find food to eat, my dear.”


Basically, a monk seals’ whiskers help it to detect and analyze objects in the water. But they can also help monk seals maneuver through the water.

Hawaiian monk seals belong to the order of carnivorous aquatic mammals known as Pinnipedia or “pinnipeds,” which means flipper-footed. Basically, marine mammals that are characterized by front and rear flippers. There are 33 extant species of pinnipeds, of which Hawaiian monk seals are one.

IMG_4801According to Scholarpedia, “All pinnipeds possess prominent vibrissae (whiskers) in the facial region. Pinnipeds use their whiskers for orientation by directly touching objects and by perceiving and analyzing water movements.”

But not all whiskers are alike. In most true seals, the vibrissae is “waved” or “beaded,” often compared to the outline of a pearl necklace. Basically, the diameter changes throughout the length of the whisker. However, monk seals and bearded seals sport smooth whiskers as do eared seals and the walrus.

Each vibrissae emerges from a relatively large blood-filled follicle chock full of receptor cells and nerve endings. Some pinnipeds possess about ten times as many nerve endings at the base of their vibrissae than terrestrial mammals.

IMG_4756Another thing about monk seal whiskers: Mostly, they’re straight. Sometimes, however, they curl.

There’s some thought that curled whiskers might be an indication of seal health, in particular, dehydration. However, that’s not a hard and fast rule. Some very healthy seals have curled whiskers. Some really long whiskers curl at the end. Some curl the longer the monk seal spends out of the water.

Think of vibrissae this way: They’re another critical sensory modality to help monk seals navigate the sometimes murky waters of deep sea life and survive. Those whiskers? They’re not just about a cute face.

Due to the evolving COVID-19 situation, NOAA and DLNR has announced today that they will not be sending volunteers into the field to survey, monitor, ID, take photos, or pup watch. This means all volunteer activities will temporarily cease. Volunteers are asked to heed the advice of federal, state, and local leaders and stay-at-home as much as possible.

For the time-being, volunteers are asked to NOT set-up seal signs on beaches, do not email photos to the Kauai Hawaiian Monk Seal Conservation Hui, and do not call or text with seal haul-out reports.

NOAA and DLNR will respond to strandings (illness, injury, hookings, out-of-habitat, etc) ONLY, but only on a limited basis and only after careful evaluation and approval from leadership on Oahu.

Once this situation changes, volunteers will be alerted.

Be well.

Yesterday afternoon, before a massive storm rolled over the island and during the midst of the craziness that is our world right, a rather large Hawaiian monk seal galumphed up a Kauai beach and provided some hope and joy.

RB00 was born on Kauai in 2007 and has been sighted on every main Hawaiian Island since weaning. In 2016. RB00 gave birth to a stillborn pup. In 2018, she gave birth to a healthy–and large–pup on Lanai. Last year, on February 2019, she returned to her natal beach to give birth. Now, several weeks after her expected delivery date, she returned once again to her natal beach and gave birth to Kauai’s first Hawaiian monk seal pup of the year on March 15, 2020.

Here’s a photo of RB00 looking rather large in the hours before she pupped.

20200315 RB00

The gestation period for Hawaiian monk seals is 10 to 11 months. At birth, pups weight anywhere from 30 to 35 pounds and measure approximately three feet in length. Their lanugo coat is jet black. RB00’s large size should ensure her pup will be well-nourished in the weeks to come. Typical Hawaiian monk seal mothers nurse their pups for anywhere from four to six weeks. Last year, RB00 nursed her pup for nearly eight weeks–a whopping 54 days–and her pup turned out to be a whopper, too.

For more information about RB00, read this report.

Lucky for us, some stalwart Hawaiian monk seal volunteers witnessed the birth and provided some video footage post-birth, showing an active pup and an attentive mother.

Update: The Kauai team logged 264 seal sightings this month. This included 39 individually identified seals.

February: 264
January: 319
December: 180
November: 223
October: 258
September: 203
August: 324
July: 239
June: 179
May: 262
April: 348
March: 350


  • Adult female RK13 hauled out on the road shoulder at Fuji Beach, Kapaa, requiring one lane to be closed. She was displaced back into water by NOAA and DLNR staff, and the lane was re-opened.
  • Adult female RK13 hauled out with a small amount of gillnet wrapped around her muzzle and top teeth. A blunt hook attached to a pole was used to pull most of the net off. A small amount remained attached to the top left canine but did not pose a hazard and was gone by the next day.
  • Juvenile male R1NI was displaced from under a hazardous undercut bank at Kiahuna Beach, Poipu. The overhanging bank collapsed two days later.
  • Juvenile female NL04 sighted on Kauai. This seal was born on Niihau and flipper tagged during a Niihau survey. She hauled out on the north shore and was the first sighting her on Kauai. 

Updates on previously reported issues:

  • Five of the six pups born in 2019 have been sighted recently and continue to thrive, the sixth is likely on the remote Na Pali Coast.
  • Displacements: Adult male R4DW was displaced from Glass Beach at sunset due to the unsafe night time haul-out location.
  • Molting: 
    • RN44 completed his molt on the north shore.
    • RJ36 molted on the south shore.
    • RK58 molted on the south shore.
  • Bleach marking: 1 applied this month.

Research/Support of Pacific Islands Fisheries Science Center

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

Hawaiian monk seals are curious creatures, sticking their noses in places to find food. Unfortunately, some of those places can be dangerous for them. It seems those causing the most harm are a result of humans. Over the years, the Kauai Hawaiian Monk Seal Conservation Hui has removed all kinds of things from the muzzles of monk seals, including plastic rings and, even, a plastic water bottle. Thankfully, our team has gotten pretty creative at responding to these situations.

At 3:30 on the afternoon of February 10, a volunteer called the hotline to report that adult female RK13 was entangled with a small amount of lay gillnet (fishing net) around her mouth. Importantly, she was able to open her mouth and did not appear in distress.  

When NOAA officials arrived at 4:15, RK13 was resting comfortably. A small amount of light-weight gillnet was wrapped around her muzzle, nose, and upper teeth. What was unclear, however, was how much gillnet was in her mouth.  Or, even, if she’d ingested any of it.

After receiving authorization, the team approached the sleeping seal with a blunt hook attached to a pole. The object was to snag the gillnet in order to pull it off. When the hook made contact with her face, RK13 flinched and made an open mouth threat which revealed a small amount of net attached to her top left canine. Another small piece of similar size was removed with the pole hook. No further net was observed inside the seal’s mouth. The small piece remained attached to the top left canine but did not pose a hazard to the seal. The seal entered the water and swam away.

RK13 was sighted the next day free of the final small piece of the gillnet. 

(FYI: The gillnet size was 3 inches (8 cm) stretched mesh size, which is legal in Hawaii. Legal stretched mesh size is 2 inches or larger.)

As these photos illustrate, this gillnet could have easily gone unnoticed. (This is why a good pair of binoculars come in super handy.) Thankfully, a very alert volunteer didn’t miss it.

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Have you ever wondered how Hawaiian monk seals stay hydrated? Because unlike fish, they don’t purposefully drink salty seawater, right? Nor can they absorb water through their skin and gills, known as osmosis. But what about seawater? How do monk seals cope with all that salt?

Turns out, over millennia, Hawaiian monk seals, like other marine mammals, have adapted some unique metabolic systems that allow them to live in the ocean.

To start, monk seals “drink” whenever they eat in two ways. First, their favorite foods, fish and invertebrates, consist of 60 to 80 percent water. Monk seals also produce water as a byproduct when they metabolize carbohydrate and fat. But not all food sources are equal in their hydration benefits. Interestingly, the fattier the fish, the more water and energy available to seals.

While fish possess a similar salt content to that found in the blood of marine mammals, another food source of monk seals—invertebrates—possess a much higher salt content. Too, seals may ingest seawater as they feed. This presents a challenge: what to do about the excess salt? Turns out, the kidneys of marine mammals are uniquely adapted to handle saltwater that’s upwards of two-thirds saltier than their own blood. Their kidneys are multi-lobed like cows, in which each lobe has all the components of a metanephric (single) kidney the likes of humans. This multi-lobed kidney employs a two-step filtering process that allows seals to maximize water retention while excreting salt-rich urine that’s seven or eight times saltier than their blood.

Another metabolic process that monk seals employ is something called catabolism. This is when large molecules are broken own into smaller ones, as in when fat and protein reserves are broken down to provide energy and water. This comes in handy when monk seals fast. Fasting is a normal part of the lifecycle of Hawaiian monk seals. Healthy seals fast annually when they molt; females fast for five or six weeks while they nurse young, and pups, after weaning, generally fast, too, while they figure out where to find nourishment. Amazingly, monk seals are able to fast for extended periods without critical organ failure.

Hawaiian monk seals have been called “living fossils,” likely because they figured out long ago how to survive at sea and haven’t needed to make many adaptations since then.