Saturday, November 28, 2009

Commerson's Frogfish

Photo Copyright 2009 by Barry Fackler

This fantastic fish fits into the "common, but seldom seen" category of marine life. They can be found on any reef in Hawai'i if you are lucky enough to be looking in the right spot at the right time. This one happened to be standing out against the blue waterscape behind it. Usually, they are nestled into the reef where their camouflage renders them almost invisible.

Frogfish are sedentary ambush predators that lie in wait on the reef. A specially modified spine dangles a small "lure" directly in front of the cavernous mouth. When a small fish comes to investigate, it is sucked in by a sudden opening and closing of the jaws which takes only 6 milliseconds to complete. The lure is visible in the photo below.

Photo Copyright 2009 by Barry Fackler

Frogfish are very poor swimmers but get a little assist from a jet propulsion system that nature has provided them with. Again, they can suck in a large volume of water through the mouth, then expel it through small gill openings set about midway along the body.

Frogfish blend in well with their surroundings and, as such, can be found in a variety of colors. This particular specimen adapted to the purple-grey hue of the Leptolyngbya algae that has become very common in Honaunau over the last couple of years. In the first photo, a blob of this algae is visible on the left side of the photo between the coral and the body of the fish. We have seen red, yellow, tan, and brown frogfish at Honaunau. Juveniles are usually bright yellow and mimic a common variety of sponge.

Photo Copyright 2009 by Barry Fackler

The pectoral fins of frogfish are uniquely adapted to serve the roles of hands and feet, allowing the fish to stand upon the reef and even to grasp on to the coral. In the photo directly above you can see that these fins terminate into what appear to be stubby fingers.

Finding one of these is doubly gratifying. First, there is the satisfaction of finding the critter despite its extensive camouflage. Second is being able to appreciate the incredible adaptations that allow it to survive.

Monday, November 23, 2009

Big Longnose Butterflyfish

Photos Copyright 2009 by Barry Fackler

This bright little fish is known as lauwiliwili nukunuku 'oi'oi which is the longest of all the Hawaiian fish names. The name translates roughly to "leaf of the wiliwili tree". I never really thought it looked much like a leaf until one day when I saw a yellow leaf rolling in the surge looking just like the fish with the stem resembling the titular long snout.

On the Kona coast, some of these fish undergo an interesting transformation, turning a uniform brown-black shade. Scientists don't think it's related to sex or reproduction. Specimens captured and put in a tank revert to the normal yellow color scheme in a few days.

This color variation is common on the Kona coast but rare in the rest of the Hawaiian Islands as well as throughout the Indo-Pacific. These photos were taken earlier this year in Honaunau Bay.

Monday, November 16, 2009

Regarding Sharks

All photos Copyright 2009 by Barry Fackler

When someone learns you are a SCUBA diver, the conversation inevitably leads to the topic of sharks. Even people who have never been near the ocean feel dread and loathing regarding sharks as well as a certain fascination. Here in Hawai'i, sharks are fairly abundant but seldom seen. Every year there are, indeed, a handful of attacks in Hawai'i. Most are non-fatal and some "attacks" are little more than a nip. Even so, swimming in the presence of something significantly bigger than you that is equipped with nearly innumerable teeth is disquieting at best.

I took these photos in July of this year at Honaunau.  Betty and I have seen Scalloped Hammerheads like this probably more than a half-dozen times at Honaunau. Usually we see them far from the Two Step out near the southern lip of the bay. This big girl was in pretty close. When I took these photos the shark was cruising right by the drop off just several yards seaward of the "ALOHA" sand patch. This is an area of significant human traffic with a near constant presence of swimmers and divers during the daylight hours.

As impressive as this hammerhead was, it didn't display any behavior that could be interpreted as threatening. As I approached it in an attempt to get better photos, it casually turned and swam slowly away fading from view within moments.

With experience and knowledge, encounters like this are exhilarating as opposed to frightening. Hammerheads like this have a pretty low incidence of attacks on humans and an almost non-existent record of attacks on SCUBA divers. They usually feed on sea floor creatures like rays, crustaceans and octopi. This is not said to minimize the shark's capacity for injury. Like a dog, any shark can bite under certain circumstances. The circumstances on this day were in my favor:

1. Excellent visibility...the shark could not mistake me for typical aquatic prey.

2. A historically non-lethal species.

3. I'm on SCUBA...hammerheads generally don't like bubbles. The photos & videos of        
schooling hammerheads usually have to be taken by freedivers.

4. The presence of many splashing snorkelers presenting much more attractive targets.

Seeing an apex predator like this in the wild is a thrill you don't forget. No other fish swims like a big shark. The movement is like a muscular and endless sine wave. The creature seems to exude confidence and self-assurance. Aside from the head, the most striking feature of this shark is it's almost absurdly tall, straight dorsal fin. At first you think your looking at an Orca!

Having said all this, I'm not always at ease with sharks. One morning I was diving Honaunau alone in low light and poor visibility when I came upon my first Tiger Shark. It was in shallow water and the shark seemed huge. I felt pretty intimidated but not panicked. I let all the air out of my BCD and settled on the bottom to see what developed. The shark gave me no notice at all and swam away in less than a minute. The whole time the shark was present, my thoughts were "go away, go away". However, once it swam off I couldn't help thinking "where are you?" Just because you can't sense the shark, doesn't mean the shark doesn't sense you.

And, therein, lies the "take home message". Probably anytime you go swimming in the ocean there is something big and well-toothed out there that is aware of your presence. Sharks have tremendous senses of smell as well as acute perception of vibration and the electrical fields that all living things produce. When you're in their realm, they have all the advantages. As such, you can choose to stay on the beach or accept the statistical evidence that the sharks prefer to ignore the hundreds of thousands of swimmers that enter the water everyday. I'm going to go diving!

Monday, November 9, 2009

Good Friends, Good Times

Aloha, everyone. Sorry to have been missing for so long, but we had company last week and we were busy enjoying our time with them.

This is Rick, Kari and their son, Jack on the sunny shores of Honaunau. Rick & Kari are both certified divers and enjoy coming over to get a little bottom time and hanging out with us. I had a bit of a cold going on so I didn't dive with them nearly as much as I wanted to. I did take them on a couple of dives at Keauhou and saw a manta on each dive. We also saw the huge school of akule that lives in the bay. I didn't take my camera that day so I have no underwater pics to share.

Later in the week, Rick and I did get in another dive at Honaunau. We had a nice dive and Rick saw a lionfish.

Besides the pleasure of their company, visitors always bring an opportunity to participate in activities you don't usually do and, sometimes, wouldn't even think about!  Rick and Kari wanted to try zip-lining in North Kohala with an outfit that recently set up shop there. Zip-lining is an activity in which a cable is suspended over a crevasse, gorge or canyon and one zips across the gap on a pulley system attached to a harness. Sounds like fun! Here's some photos of the adventure.
This is us after getting geared up at the "base camp". Our helmets all have funny little nicknames on them. Mine was Romeo (how appropriate), Kari's was Hairball and Rick's was Cornbread.

This is a six wheel drive Swiss army vehicle that took us off-road to the high forest where we would be doing our zip lining. It was a bumpy ride but the scenery was great.

Here's Rick ready to try out a zip line. His harness certainly looks snug! I don't have many photos of him on this outing as he was taking most of the pictures.

This is your intrepid blogger making a zip line run early in the day. This is a short, low run. The course consists of 8 zip lines which get progressively longer and higher. There is a short hike between zip-lines.

Here I am making perhaps my only forward-facing landing of the day. Usually, by the time I reached the other side I was traveling very fast and backwards!

Besides the zip-lines themselves, altitude-phobes will get a real charge out of the very narrow suspension bridge swinging over a deep, dark valley.

A more agreeable surprise is this lovely waterfall. This is quite remote and most visitors would never see it without taking the zip-line tour.

This is me, again, enjoying the view over a deeper canyon.

Tres Amigos

The final zip-line crosses a 300' deep canyon and requires a running start before leaping into the abyss. Here, Kari displays her grace and derring-do on takeoff. I, however, jumped a little too soon, bouncing twice on my butt before soaring over the gulch. It was fun, but I got no style points!

That's me out there. Even after the inglorious takeoff, I had a great sail over the last canyon.

I highly recommend this activity to anyone who is truly interested in doing it. The operation is quite professional and the guides are fun but thorough and put safety first. However, much like SCUBA diving, people who sincerely don't want to do this shouldn't be forced or cajoled into participating. Fear of heights, like fear of water is a powerful and (pretty reasonable) phobia. But, if you feel the need for speed and delight in flight, this is a wonderful experience.

After a late lunch, we made it up Mauna Kea just in time to catch the sunset. Mauna Kea rises 13,796 feet above sea level and is home to many observatories. The landscape is almost alien in appearance and except for the wind, it is very quiet. In the winter time it's top is blanketed in snow. The name Mauna Kea literally translates to "white mountain".

And, with that, our day of adventure drew to an end. Good times with good friends!