This week Peter and Marla returned for a brief visit to Kona. This afforded me a chance for some excellent snorkeling, if only Peter could fit me into his crowded dance card. Yesterday morning, the four of us, and even more as it turned out, met at Kawaihae.
| Note the gills on this Trembling Nudibranch |
It was a beautiful day, with just a bit of mist at the foot of Kohala mountain as we completed our drive to the harbor. Tuesday was one of those odd tropical days, when there was very little tidal exchange; as we arrived the tide was low, about plus half a foot and it would stay that way for roughly eight hours.
Soon, Peter and I were finishing our preparations, and he noted that I wasn't wearing much in the way of lead, only two pounds compared to the eight that he was wearing. This is the usual amount that I carry at Kahalu'u where the swimming is much different, with shallow rocks, currents and waves (so maybe I'm more concerned about drowning) than the situation at Kawaihae with still, deep water. He was polite enough not to criticize me, leaving it up to me to experience the error of my ways on my own.
As we entered beside the LST ramp, it was obvious that the water was not too cold and very cloudy. Visibility was less than five feet. We gave a gentleman who was fishing from the foot of the ramp a wide berth and we swam out to the first platform. This is the smallest of the three that the army uses to moor the LST which brings some amazingly large, wheeled vehicles from Oahu for maneuvers at the Pohakuloa training base up on the Saddle Road . A clump of branching coral that once housed a developing Klein's Butterflyfish was still there, with no baby butterflies, and little else.
| Painted Nudibranch Kawaihae 2026 |
We swam out to the second platform, bigger with many more pilings, but still with no significant finds. And so, empty handed, we went to the third platform. Halfway around the shady side I encountered a beautiful soft coral. When I showed it to Peter, he said that this was likely an octocoral and it may be an invasive species. Suffice it to say, I took plenty of pictures and we continued our perusals.
Simultaneously, we found nudibranchs on opposite ends of the platform. I found a pretty trembling about eight feet down on one of the inside pillars. I dove several times in this tight quarter to get a picture that while in focus, is still above the nudibranch.
| Radioles and pinnules, A closeup of a feather duster worm |
As an aside, I have been making a set of larger nudibranchs out of Anne Van Brunt's clay and while this picture is not perfect, it provides a really good look at the gills. I had not noted the white base in the past and I'm going to have to go back and make tiny alterations to my model.
Extricating myself, I swam around to where Peter was working with his nudibranch which was thankfully still visible. Peter had a Painted nudibranch which was now about four feet deep on the outer, sunny side of a corner pillar. His nudibranch was small and dark. Four feet is a difficult depth if you are not wearing enough weight. If you are trying to flip and free dive, your fins aren't able to get a purchase in the water, and you bob right back to the surface. If you are appropriately weighted, you can just sink down that short distance. So that's my excuse for this mediocre picture. On the bright side, it does illustrate how far forward the gills are on the slender body.
| Snowflake Octocoral. Kawaihae, March 2026 |
I'm going to bet that Peter has an excellent picture of this nudibranch, so watch his blog, onebreathkohala, for his excellent pictures and insights.
There were at least three feather duster worms on display on these pilings ranging from eight to ten feet deep. I commented that I could still remember how delighted I was to see my first feather duster and Peter noted that at the minimum they were very photogenic. With that in mind you are going to be treated to a duster photo or two.
The individual feathers are called radioles, The tiny side branches that hold the feather together are called pinnules. And these are covered with microscopic cilia that beat rhythmically, drawing food to the center of the crown. More than you wanted to know about feather duster worms?
The water near shore was impossibly cloudy and so we were soon showering off in what I maintain is the best shower, worldwide. A few feet from the glimmering Hawaiian ocean with a view of Mauna Kea not too far away, this is one spectacular location and the fresh water on a warm day is pretty delightful. And the perfect place to clean my bleeding leg wounds...swimming around encrusted pilings is bound to inflict some damage!
| The orange stalk is actually an encrusting sponge. |
Our friends, Hai and Lottie and their daughters had arrived, and we visited for a few minutes before Sandra and I needed to dash off for our appointment in Waimea.
So what about that octocoral. Back at the ranch, I reviewed the octocoral in Joh Hoover's critter book. This piece was written in 1999 and, what with the warming of the oceans, things have changed. Hoover lists a single species, Sarcothelia edmonsoni, and he notes, as we suspected, that octocoral derives its name from the eight tentacles that are borne by the polyps. Other corals in Hawaii have six tentacles.
At this point I repaired to Gemini AI. Say what you will about the people at Google, but between Google lens and Gemini, they have provided the amateur naturalist with a couple of powerful tools with which to explore, identify and explain our world.
So let's scoot ahead to 2026 and see what Gemini has to say about our octocoral situation.
The really big news is that there is now an exceedingly nefarious octocoral found mostly near Oahu. This is Unomia stolonifera. Gemini writes, "This is an aggressive, fast growing soft coral that smothers native reefs and has no natural predators in Hawaii. It has already devastated native reefs in Venezuela.
"It is pinkish white, and is known for its dancing, 'pulsing' motion of its polyps."
Snowflake Coral, Carijoa riisei, is our established invasive...it's been in Kona for decades. "It is particularly destructive below 75 meters, where it overgrows and kills Black Coral." FYI Black Coral is the stuff from which jewelers fashion Hawaii's state gem.
You will notice in my excellent pictures (you see, I do OK when I'm not bobbing up and down like a frickin cork) that the octocoral appears to have brownish orange stalks leading up to the tentacles. This is a symbiotic red encrusting sponge, Desmapsamma anchorata. The relationship makes both species more effective at taking over the reef. The sponge produces a cytotoxin which defends the octocoral against predators and it strengthens the runners (stolons), enabling the coral and the sponge to overwhelm the reef more effectively.
| And the world will never be the same. |
Snowflake coral grows in diving depths, but is also known from snorkeling depths, especially in harbors where the piers with their pilings provide high water flow and dense shade.
Voila. If you see an octocoral in Kona today, it is probably Snowflake Coral. Like real snowflakes the coral tentacles are bright white. Real snowflakes are reputed to be infinitely singular. These polyps, on the other hand, dependably bear eight tentacles.
The world is changing, so enjoy it while you can,
jeff




















