Archive for November, 2021

Monk Seal Monday #149: Sense of Smell

Let’s talk smell.

Hawaiian monk seals have two vertical slits for nostrils that are adapted to close when they dive, begging the question how much do Hawaiian monk seals rely on a sense of smell when flipping over rocks on the ocean floor in search of, say, flat fish like flounder? Or when they stick their nose in a puka in rock, hopeful to snag a lobster or eel for a good meal? For that matter, what about when Hawaiian monk seals are hauled out on the beach, and their nostrils are open?

Turns out there are probably more questions at this point in time than there are published scientific papers on Hawaiian monk seals and their sniffing prowess.

Let’s tackle the use of smell on land (air) by taking a look at other seal species. 

Take Antarctic fur seals. According to The Wire, when this species gives birth, mothers nurse their young for some four months. During that time, mothers leave their pups on the beach and head to the sea to search for food. They may be gone for up to 10 days. When they return, researchers suggest mothers rely on smell to sniff out their own pup from the many others on the beach. 

Researchers believe the same is true of Harbor seals.

More closely related to Hawaiian monk seals, the Mediterranean monk seal is also thought to use smell in mother-pup bonding. According to the Eastern Adriatic Monk Seal Project, “…sense of smell plays an important role in the life of a Mediterranean monk seal as scent and sniffing is used intensively in the first weeks of a newborn pup’s life in order to communicate and find its mother in the dark caves where they live.”

Compared to Antarctic fur seals, Hawaiian monk seals nurse their young for a fraction of time—four to six weeks instead of four months. While nursing, Hawaiian monk seals don’t leave their pups alone on the beach to forage. And Hawaiian monk seals birth their pups on beaches, not in caves like Mediterranean monk seals. Interestingly, especially at islands and atolls in Papahānaumokuākea Marine National Monument, it’s not uncommon for pup-switches to occur among Hawaiian monk seals. That is, moms and pups get mixed up. It happened on Kauai in 2018 when there were three moms and pups on the same beach.

Researchers propose there are more uses of smell among Antarctic fur seals. They may rely on “signature scents” to mate with unrelated seals, according to the same article in The Wire. Because fur seals tend to colonize, they may use smell as a way to form stable social groups.

But what about when foraging? How might smell be involved? Steller sea lions possess a large number of olfactory receptor genes, possibly because they are more terrestrial, that might help them hunt for food. 

This unique research paper posits that “aquatic carnivores” forage “noseblind,” that is without airborne chemical cues and, thus, have reduced olfactory anatomy, especially among deep-divers, relative to closely related land-based carnivores. That is, if sense of smell isn’t a critical component to their way of life, the anatomy that supports it diminishes over time in an adaptive response. Why build it if it’s not needed?

Over millennia, Hawaiian monk seals have adapted to their tropical ecosystem in unique ways. They don’t “colonize” in the same ways as some seals. They don’t birth their pups in caves. They spend the vast majority of their lives at sea. They can dive as deep as 1,800 feet; however, average foraging dives of several hundred feet. So, just how great—or not—is Hawaiian monk seals’ sense of smell? Good question.

This will be updated as more information come to light.

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Field Report: October 2021

Monthly Totals: The Kauai team logged 229 seal sightings this month. This included 29 individually identified seals.

  • October: 229
  • September: 251
  • August: 213
  • July: 286
  • June: 218
  • May: 209
  • April: 155
  • March: 137
  • February: 119
  • January: 125
  • December: 119
  • November: 133
  • October: 152


·       Flipper-tagged KP3 (3rd pup of the year) as RP28 and vaccinated for morbillivirus.

·       Morbillivirus Vaccination: RP28 received her initial vaccine this month.

·       Molting: 4 seals molted this month

Research/Support of PIFSC:

·       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.

News from Ke Kai Ola:

Unfortunately, the adult male monk seal known as RW22 died after more than five weeks in care at the Monk Seal Hospital in Kona, Hawaii Island. RW22 was flown from Oahu to Hawaii Island for treatment of a parasitic disease known as toxoplasmosis. RW22 was also suffering from malnutrition, the effects of ingested fishing gear.

Toxoplasmosis is the number one disease threat to Hawaiian monk seals.

In a press release issued by The Marine Mammal Center, Angela Amlin, Hawaiian Monk Seal Recovery Coordinator at NOAA Fisheries, said. “With no vaccine available for toxoplasmosis, preventative measures must be taken by the general public. This disease is spread into the environment exclusively via cat feces. To help protect endangered Hawaiian monk seals like RW22 from toxoplasmosis, simply dispose of cat litter in the trash, keep your cats safe indoors and tell your community about how they too can prevent this disease from harming more marine mammals.”

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After canceling last summer’s field season in the Northwestern Hawaiian Islands of Papahānaumokuākea Marine National Monument, NOAA’s field crew returned this spring, staying through the summer, making every day and minute count.

They collected population data, identified individual seals, tagged weaners and yearlings, disentangled seals and turtles, surveyed basking and nesting turtles, surveyed Laysan ducks, staged marine debris for pickup, and assisted in numerous additional conservation and research activities on behalf of conservation partners.

The field crew left civilization behind for tents, canned food, and starry starry nights, and you can read about their efforts and their experiences here in a very thorough report of their tremendous effort. 


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Long-time volunteers with the Kauai Hawaiian Monk Seal Conservation Hui will remember working with David Schofield. David served as the point person with NOAA for marine mammal strandings. In his early days, he was also more heavily involved in monk seal response. Now, after 16 years, David has announced his retirement from NOAA, and he’s planning to move to the East Coast and start a Christian outrigger canoe ministry through New Hope Church.

Last week, Hawaii News Now interviewed David about his work at NOAA and his plans for the future. Click on this link to watch the video interview; it provides a good history of NOAA’s work in this field, as well as, a history of David’s hair styles!

David Schofield

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Turtle Tuesday #9: Questions

With the ongoing recovery of Green sea turtles in Hawaii, some common questions come up:

  1. Is it now legal to harvest turtles for human consumption; and
  2. Is it now legal to harvest turtle eggs?

The answer to both questions is: No. 

Hawaiian green sea turtles—honu—are still protected federally under the Endangered Species Act, and, as well, by state laws. 

Yes, their numbers have improved, but they still face threats, primary among them is sea level rise, due to climate change, and the subsequent loss of nesting habitat, especially on low-lying nesting beaches in the Northwestern Hawaiian Islands in Papahānaumokuākea Marine National Monument. 

What’s more there are dangers associated with the consumption and handling of honu. 

One concern is fibropapillomatosis. Or “FP,” a tumor-causing disease that affects some sea turtles, forming cauliflower-like tumors on the body, often around the eyes and mouth but also internally around organs. FP is closely associated with a herpesvirus. Some sea turtles develop non-threatening tumors; others develop tumors that interfere with vital functions. While some viruses can move from animals to humans and there are similar diseases in humans, there are currently no known cases of sea turtle FP transmitting to humans, according to NOAA.

But consumption of sea turtles—specifically meat, adipose tissue, organs, blood, eggs—can pose a health risk to humans.

According to a scientific study published in EcoHealth reports, “…there may be hazards associated with this consumption due to the presence of bacteria, parasites, biotoxins, and environmental contaminants. Reported health effects of consuming sea turtles infected with zoonotic pathogens include diarrhea, vomiting, and extreme dehydration, which occasionally have resulted in hospitalization and death.” (Update: This study has more to do with the consumption of Hawksbill turtles than Green sea turtles.)

Little can be done to treat Chelonitoxism, considered a type of food poisoning, with only supportive care offered. Symptoms can present within hours to a week following ingestion and recovery can take weeks. Children are particularly susceptible. 

In terms of the effect of turtle tumors on people who might eat them, there hasn’t been too much direct research on that since people haven’t been eating them. 

Remember the recommended viewing distance of sea turtles is a minimum of 10 feet—on land and in water. Because honu are still protected in Hawaii, it’s illegal to harm, harass, or even touch a sea turtle.

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