Surge nymphs

The bouldery surge zone north of the Mahukona dock is kind of a no-man’s zone, and pretty much a no-fish’s zone as well.  Few people snorkel there because the water tends to be murky under all but the calmest conditions, it’s easy to get raked across the rocks, and fish diversity is low.  It’s a good place to find subadult blackspot sergeants though.  These petite, pretty damselfish sway in and out between the boulders with the surge, often enveloped  in curtains of turbulence-produced bubbles.  The effect can be quite nice.

Water here was less than two feet deep and swell about one foot. I had to steady myself with one hand on a boulder to keep from getting scraped up.

This bold little fellow is a bit older than the fish in the top photo. Lots or particulates in the water.

Adult blackspot sergeants are—as with many fish species—drabber than juveniles and subadults..

Queen chub

Chubs (or nenue in Hawaiian) are a group of plain looking fish abundant on shallow reefs, especially in the surge zone, throughout Hawaii.  While most chubs are a uniform gray color, rare individuals are bright yellow.   Hoover* tells us that “in old Hawaii a yellow nenue was regarded as ‘queen’ of the school, but these color variations are not known to have any social significance.”  I’ve seen yellow chubs only three times—once at Keokea Beach Park, and twice at Mahukona.  Here’s a photo from last Saturday at Mahu:

There are four common species of chub in Hawaii. Two—the gray (or Paciific) chub and the brassy chub—are rather hard to tell apart, at least for me. I’m pretty sure this is a gray chub. In case it’s not apparent, the mottling on the fish’s back is due to sunlight refracting through the rather disturbed water surface on this day.—the fish is actually uniform yellow.

 

Normal chub coloration. The fish in the foreground looks to me like a gray chub, while I’m fairly sure the others are brassy chubs.

Sometimes agitated chubs, possibly dominant males, will take on this vivid spotted coloration. This gray chub was at Mahukona last month.

*Check out Hoover’s (as well as Randall’s and Stender’s) work, referenced on the “About” page of this blog.

Back from Samoa

We’ve returned and recovered from almost three weeks in Samoa.  The first week involved, as usual, oceanographic water sampling in American Samoa.  The next two weeks were playtime, mostly in independent Samoa.  We stayed a few days on the north coast of the beautiful, rural island of Savai’i, getting in four scuba dives with our friends Olov and TIna who run the Dive Savai’i* shop in Manase.  We also snorkeled extensively both in Savai’i and near Apia, Samoa’s capitol and main city, on the island of Upolu.  Photos of “clownfish” are pretty much de rigueur for diving/snorkeling trips to the South Pacific.  Here are some of mine (all from Savai’i):

This is an orangefin anemonefish in the standard pose, peeking out from an anemone. Anemonefish, a group of colorful damselfish that live mutualistically with various sea anemones, are also called clownfish. (The former term seems to be preferred by ichthyologists. Some reserve the term clownfish for a couple of particularly clownish-looking species found in the Australia-Indonesia-New Guinea region.)

These are also orangefin anemonefish, this time associated with a different, huge anemone. They are somewhat yellower than the individual in the above photograph. Apparently the color of these fish depends to a considerable degree on what type of anemone they’re living with.

A different species, either red-and-black anemonefish or a Fiji anemonefish.

* Dive Savaii is the only dive shop on Savaii and one of only three or so in Samoa.  Proprietors Olov and Tina are professional, affable, and eager to accommodate the underwater wishes of visiting divers and snorkelers.  Highly recommended!

One man’s woo-hoo is another’s ho-hum

A few days ago we joined our friends Jeff and Sandra Hill to snorkel at a spot Jeff refers to as Paul Allen Reef.  The name alludes to the Microsoft co-founder’s estate that dominates the shoreline at the north end of Kailua Bay, just north of the Kailua-Kona pier.  It’s a nice reef that Jeff and Sandra know very well.  Jeff showed us a couple of rather uncommon fish species—Potter’s angelfish and yellowtail filefish.  I wandered away from the group and ran into a school of Thompson’s butterflyfish, an uncommon species for me, but apparently not for Sandra and Jeff.

After around forty minutes of snorkeling in the rather cool water we decided to head back to shore and lunch.  As usual, I lingered behind the others on the way back, stopping to investigate—and hopefully photograph—anything interesting that I came across.  Almost back at shore, in just a few feet of water, I spotted a fish that really got me excited.  I vaguely recognized it as a Whitley’s boxfish, but I was not sure whether or not I’d ever seen one of these fish before.  I recalled a scuba dive off Kohala a few years ago in which the divemaster brought us down to a depth of one hundred feet to view what I thought he called a Whitley’s boxfish, and which he asserted was a rather special fish.  (My recollection was a little foggy, partly because this was a training dive, and we were rather preoccupied with the training aspects.  At this depth, a little nitrogen narcosis may have been involved as well.)  However, the fish I was looking at did not look like my memory of the Whitley’s I’d seen in the earlier dive.

So after taking some photos I finally got out of the water and rather excitedly told Jeff that I thought I’d seen a Whitley’s boxfish.  His response was “oh yeah, we see them here regularly.”  This left me a bit deflated and a bit confused.  Was this the same so-called rare fish I’d seen on the earlier dive, or was it just a common everyday species?  Back at home, a consultation with John Hoover’s Ultimate Guide to Hawaiian Reef Fish, as usual, resolved my confusion.  It turns out that the female Whitley’s boxfish is not rare, but only “uncommon.”  Hoover describes the male, however, as “rare” and usually found at depths greater that 70 feet.  Further, the male and female are quite different in appearance.  The one I’d seen on the dive was a male and the one on this day was a female.  So now I’ve seen both sexes of Whitley’s boxfish.  Woo-hoo!

The female Whitley’s boxfish I saw on the way in from “Paul Allen Reef.” She was quite tame.

A female pearl wrasse from the same outing. I see these active, somewhat wary fish quite often at Mahukona, but haven’t managed to get a decent photo of one there. This one was much easier to approach than those at Mahukona. Fish in general seem to be less approachable at Mahukona than at many other sites, likely due to the constant spearfishing activity there.  There’s a photo of a male pearl wrasse a few posts back.

Lizardfish are a family of cryptically colored bottom-dwelling ambush predators common in Hawaii and throughout the tropical Pacific.  The different species—Hawaii has about ten—can be hard to tell apart.  I think this one that I ran into at about fifteen feet at Paul Allen is a reef (also called variegated) lizardfish.

 

 

A world famous dive—and deservedly so

Numerous dive magazines and web sites describe the Kona manta dive/snorkel as one of the best in the world.  About a dozen outfits in Kona offer this boat dive, and all seem pretty similar.  Last week Marla and I joined our friends Peter and Edna, along with their mainland relatives, for the version of the dive offered by Jack’s Diving Locker*.  We left Kona’s Honokohau Harbor on their 46-ft boat, carrying about fifteen divers and snorkelers, at around 4:00 PM and motored eight miles north to a spot called Garden Eel Cove (also called Manta Heaven), just off the Kona airport.  There were already a couple of other boats there when we tied up to one of a handful of moorings in about 35 feet of water.  We suited up for an afternoon dive prior to the arrival of nightfall and the mantas.  (Most boats arrive somewhat later, skipping the pre-manta dive.)  The afternoon dive was quite nice, the highlight being a close approach to a large group of garden eels at about seventy foot depth.  These small eels stay partially buried in the sandy bottom, their heads and upper bodies protruding upward, swaying in the water column like grass in the wind.  If you approach too close they quickly disappear into the sand.  On this particular dive we were able to get quite close—maybe six feet or so.  Unfortunately, my little Olympus underwater camera is only rated for forty feet, and it wouldn’t take photos at seventy feet.  To its credit, it didn’t flood, and it resumed functioning when I got back up to 35 feet.

After the first dive we spent about 45 minutes on the boat, having the not-bad sandwiches, snacks, and drinks provided by Jack’s and watching darkness approach.  Back in the water, we descended to the bottom where a battery of lights, kind of like car headlights, were permanently installed pointing upward into the water column.  The idea is that lights attract the zooplankton (or for you New Yorker readers, zoöplankton) that the mantas like to eat.  This has been going on at this site for a couple of decades now, and the mantas have learned that this is a good spot for dining.  Since they are wild animals, the mantas’ presence is voluntary, and they don’t show up every night.  But on most nights there are at least a handful of these monsters—ranging from 8 to 14 feet across**—at the site.  Sometimes more than two dozen show up.  By identifying individuals based on their markings and other distinguishing features, researchers and dive operators have established that many of the mantas are regular visitors.

Anyway, divers from the numerous boats either sit, kneel, or lie on the bottom holding dive lights pointed upward.  Snorkelers stay on the surface, holding onto group floatation devices, shining their lights downward.  This leaves the entire water column open for the mantas.  Two mantas showed up almost before we reached the bottom.  Four more soon followed.  We spent the next forty minutes watching the six mantas scoop up the plankton in their cavernous mouths.  Slowly, calmly, and surprisingly gracefully, they swooped, somersaulted,  and pirouetted through the light beams full of plankton.  Over and over, the mantas glided within inches of us, sometimes even brushing up against us, drawn by the dense plankton concentrations in the beams of our dive lights.  This allowed great views of their placid-looking cow-like eyes, as well as their awesome maws and gill openings.  One of the smaller mantas—only about eight feet across—repeatedly brushed, and on one occasion bumped Marla.  We decided it must have, like me, found her very attractive.

This was not the first time we’ve been on one of these magical trips, and it won’t be the last.  It’s about as close as you’re going to get to a 500-pound (my conservative estimate) wild animal on the animal’s own terms.  You should try it.

One of the big fellows passing close to Marla. The pattern of dark spots on the belly allows fairly easy identification of individuals.

All the bright lights give the experience a surreal look. There are a lot of other interesting fish besides the mantas. Those are flagtails in the background at the top of the photo; at lower right is a bluestripe snapper.

*The people at Jack’s provided great service, and are highly recommended.  I’ve also done this with Big Island Divers, also recommended.

**There are two species of manta ray.  These are the smaller coastal manta species.  The other species, pelagic mantas, are even larger—up to 23 feet.

Forty angry tons

The whale season has been disappointingly slow this year.  Until a couple of weeks ago Marla and I had been completely skunked in our attempts to get close to humpbacks on our kayaks.  Last week was our first good encounter of the season.  We saw a mother-calf pair making its way north past Mahukona.  The calf breached dozens of times, and the pair passed quite close to our boats—maybe one hundred yards*.  I didn’t manage to get any photos though.

This Monday morning we had an even better encounter.  We were about a third of a mile off Mahukona when we saw some surface activity a few hundred yards to our north.  Paddling (technically peddling, since we were in our Hobies) in the direction of the activity, we saw a couple of breaches and a couple of dives, then nothing.  We stopped at a spot we estimated to be close to where the whales had disappeared and suddenly an adult humpback breached around a hundred feet from us.  This was as close as I ever want to be to a breaching whale—the last thing you want is for one of these guys to land on you.

So we moved off a bit and watched.  Since most of the activity was underwater, it was difficult to know exactly what was going on.  We surmised from the number and timing of blows that there were at least three individuals—one female and two males was our guess.  The presumed males were clearly involved in a dispute, probably over the female.  There were repeated breaches; flukes were raised above the water and brought down hard, apparent attempts to render blows; and we saw the two whales together on the surface, apparently engaged in a shoving match.  There were also auditory cues—the most amazing vocalizations, shrill roars reminiscent of the trumpeting of elephants.  All this went on for several minutes.  We’re not sure, but it seemed to us that the female had in the meantime departed for someplace quieter.

We don’t know whether or not we’ll have more whale encounters before the season ends next month, but either way it’s been a good year.

This close breach was exciting, but a little too close for comfort. Unfortunately, my camera lens had fogged, so these are the best photos I could get.

Landing hard a fraction of a second later.

A fraction of a second later.  While we didn’t get splashed, we almost did.

*Approaching closer than one hundred yards is illegal, although some of the tour boats seem to ignore this law.  We don’t do it (okay, maybe a little closer than 100 yards) but sometimes the whales approach us much closer than this.  Earlier on the morning described above a humpback surfaced out of nowhere just a few yards from us.  It was headed straight at us and swam right under our boats about ten feet below the surface.  This happens fairly often.  So often—much more than the density of whales in the big ocean would suggest—that we’re convinced that this is not random, but that the whales are deliberately coming to check us out.

Some recent Mahukona oddities

Conditions have remained quite good at Mahukona through last week.  Here are a few of the more unusual—and rather weird-looking—fish we’ve seen lately.

One of a pair of scrawled filefish that had been around for several days. These fish are usually absent at Mahukona, but when they show up they often stay for weeks before moving on. These wanderers are extremely adaptable, occurring in most of the world’s tropical and subtropical oceans.

Yellowtail filefish are apparently fairly common, but are very difficult to approach, and therefore not often seen. I catch a glimpse of one now and then in the shallows at Mahukona, but they usually don’t stick around long enough to allow a photograph.

This is a juvenile barred filefish. The adults, which lack the white spots, are very common throughout Hawaii, but juveniles are, according to Hoover, “almost never seen,” so I was pleased to get a photo of this one. It was just a few feet from Mahukona’s swim ladder.  It’s the second juvenile barred filefish I’ve seen at Mahukona.

Finescale triggerfish seem to be present at Mahukona most of the time, but they’re widely dispersed in rather deep water, so we don’t see them that often. This one was in about twenty feet of water just north of the “first point.” It’s smaller than most I’ve seen—maybe 14 inches long—and it was somewhat more approachable than most. Hoover and Randall (see “About” section of this blog) explain that the finescale filefish was not known to breed in Hawaii until the 1990s. It’s still considered rare in the state except along the west coast of the Big Island.