Feeds:
Posts
Comments

Posts Tagged ‘science’

(V93-BrendaBecker)P1020470

PC: B. Becker

In September, two Hawaiian monk seals were outfitted with dive recording tags that not only capture the seals’ location but time spent hauled out, time at the surface of the sea, and time spent (and depth of ) diving. Data from the tags is transmitted whenever the seals come within range of a cell phone tower. The instruments tags were affixed to the middle of the seals’ backs using an epoxy. When the seals next molt, the tags will fall off.

This first graphic shows the movement of the two tagged seals. The yellowish-green dots represent R1KT, a male. The red dots represent R7AA, a female. The graphs give us a look into three week’s worth of these two seals’ lives.Slide1In the graph on the right, we see the depths of R7AA’s dives. She records several dives in excess of 150 meters, but the vast majority of her dives log at under 100 meters of depth.Slide2

On the other hand, the majority of R1KT’s dives record upwards of 150 meters. There are numerous factors that could explain the differences. One, age. R7AA is a juvenile; whereas, R1KT is older. Too, underwater topography may affect their dive depths. Generally, according to science, monk seals like to forage on or near the ocean floor. They are generalist feeders and their diet includes a variety of fishes (eels, wrasses, squirrelfish, soldierfish, triggerfish, parrotfish), cephalopods (octopus and squid), and crustaceans (crab, shrimp, and lobster). Diet studies indicate they prefer prey that hides in the sand or under rocks, unlike most of the locally popular game fish (e.g. ulua, papio and ʻoʻio) and the proportion and type of prey consumed varies significantly by island, year, age and sex. Slide3

Advertisements

Read Full Post »

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

Read Full Post »

Happy Summer from the Kauai Hawaiian Monk Seal Conservation Hui!

Hawaiian monk seal and marine debris

Photo credit: Mary Werthwine

On June 13, juvenile male seal RA36 was reported with a decaying water bottle stuck to his face!  Luckily, the bottle was open at both ends, so RA36 could breathe, but he could not eat or use his whiskers.  Our team mobilized immediately to try to remove the bottle, and RA36 ended up dislodging it himself by knocking his head on our rescue equipment and causing the bottle to pop off!

June brought the PIFSC Monk Seal Research team to Kauai!  Their goals were to apply flipper tags to our newly weaned pups, to apply cell phone tags to more seals, and to conduct health assessments on a couple seals of concern.  They succeeded on all fronts!

Hawaiian monk seal on the beach

Photo credit: Lloyd Miyashiro

Our first 2011 Kauai pup’s new permanent ID number is RK54.  His brand-new tags read K54 and K55.  The second pup is female RK52, with tags reading K52 and K53.  RK52 is plumper than RK54, and is seen here exploring her own Seal Protection Zone!  When the weaned pups received their tags, they were also measured and given pit tags (like your pets’ microchips.)

Adult male RK36, with flipper tags 4DI/4DJ, was fitted with a cell phone tag.   We use the cell phone tags to monitor habitat use, dives and foraging behavior!

The PIFSC team got to take a good look at our aging male seal TT40.  While his advanced age seems to be causing his body’s normal processes (like molting) to slow down, our vets and scientists agree that he looks great for his age.

We also assessed the health of subadult female RB24, who has been observed to be losing body condition (i.e., getting thinner).  The cause of her weight loss has not yet been determined, but results of her blood samples, tissue samples and de-worming medication should help us learn more.

At the end of June, we rode out to Miloli’i to flipper-tag our third Kauai pup of the year.  This little male’s permanent number is RK56, and his tags say K56 and K57.  Special thanks to PIFSC and DLNR’s Department of Boating and Ocean Recreation for making this tagging trip possible!

Read Full Post »