Giant Aliens of Kona

Okay, so they aren’t aliens.  They are actually giant fish- Manta Rays to be exact-and when people visit us in Kona one of their top priorities is to see these rays.  It’s a breathtaking show of tumbling, spinning, and, well, eating really.  It has been described as an underwater Vegas show which is spot on.  However,  in this version the showgirls are trying to put on the pounds!  There are lights shining everywhere and constant action, there’s so much going on that you’re not even sure where to look.

Manta1

The show is really all about the manta rays, but just like Vegas, every once in a while we get a cameo so amazing it blows even the local divers minds.  No, I’m not referring to Celine Dion or Frank Sinatra, for us islanders we get giddy when a native Hawaiian Monk Seal appears on the show!

H01 Monachus schauinslandii watermarked

Don’t get me wrong, the manta rays are incredible, but I am more a mammal girl myself.  It’s what I focused on while obtaining my marine science degree right here on island and they have been the center of my careers since then.  Heck, they still occupy my life on my weekends when I volunteer.  But for those of you from New England and California I’m sure you are saying “seal, What’s exciting about that?”  Well, let me tell you.

Currently, there are only about 1,000 of these seals left in the world and they are only found in the Hawaiian archipelago.  Of those thousand animals only about 6 of them are residents to our Big Island.  And of those 6, one of them has found an affinity for our Manta Ray night dive.  This individual, one of a few very highly endangered seals, is named Waimanu.  Born in Waimanu valley (they got really creative with names, huh?)  she is a gorgeous, chubby 8 year-old pinniped.  Some may live to be between 25-30 years old, so Waimanu is a relatively young girl.

Monk seal yawn copy

That being said, she has already been a mom twice, that we know of… Unfortunately, even with all the watchful, helpful eyes of the locals, neither pup (baby) made it.  This is the reality with these animals. They are endangered by unrelenting pollution, trash, wayward and discarded fishing line, hooks, and even reduced prey source.

I am proud to say that our community is working to protect all our ocean wildlife.  In the past few years we have banned plastic shopping bags completely. There is currently a bill to ban one use plastics (Styrofoam, plastic utensils, etc.) so less of it ends up in our oceans. We are also constantly participating in beach clean-ups and ocean clean-ups.  We make sure the fish we chose to eat is locally and sustainably caught.  There is even a hospital in Kona specifically set-up to rehabilitate Hawaiian Monk Seals (Ke Kai Ola).  I’m more than proud to call this place home and even more proud to call Kona and Kona Honu Divers my community.

So why is it exciting to see Waimanu?  Maybe it’s partly because she’s a highly endangered species, maybe it’s because she’s an extremely graceful, big, beautiful animal, maybe it’s because she has an extremely cute face that melts your heart.  For me, it’s exciting to see her because she is a part of our community, a contributing member just like the rest of us and every time we see her it inspires us to be stewards to our ocean and share the love with our guests.  Plus, let’s face it, it is just cool!

-Tara Spiegel

 

 

Black Water: Squid

Most squid, Sthenoteuthis included, have less than a year to be born, grow, and reproduce before they expire.  This translates into an incredibly high metabolism. Young squid in captivity can eat nearly half their body weight five times per day 2.5 times their body weight per day! That would be like me eating 450lbs of food!  Adult Sthenoteuthis are easily the most common cephalopods we see on blackwater dives.  They can be seen as the large shoals the edges of our lights as we drift through the pelagios on our bi-weekly Black Water Dive.

Sthenoteuthis oualaniensis school small watermarked (1)

This week we get to meet the anomaly that is the purpleback flying squid (Sthenoteuthis oualaniensis).  They are called “flying squid” because, like Exocoetids (aka flying fish) they can leap and glide across the surface of the water to escape predators that skirt the edges of our lights as we drift through the pelagios.  They spend their days hiding in a region between 200-1000 meters deep in the midwater known as the oxygen minimum zone.  This is an area where animals with higher metabolic demands cannot sustain their bodily functions due to low levels of available oxygen.  So while the low oxygen levels keep the squid safe from their most fearsome predators like tuna, the squid itself requires large concentrations of oxygen as well, thus the conundrum.  It turns out that squid kept in tanks containing low-oxygen water can shut their metabolism down to a tenth of the normal rate of consumption.  This means that the squid may not only be hiding from predators in the oxygen minimum zone, but it may be using the cold, dark, low-oxygen environment of the OMZ to shut down its metabolism and wait out daily periods of low-foraging opportunity when the squid would otherwise just starve.

Sthenoteuthis ouahaniensis small watermarked (3)

Sthenoteuthis oualaniensis watermarked (1)

Pan-tropical spotted dolphins (Stenella attenuata) often come in to forage on the schools of Sthenoteuthis attracted to our lights.  One night, a dolphin pod came in to dine and hit the squid school just under the water’s surface.  I watched this shiny object drifting down under the scene and recognized it as a squid’s eyeball drifting into the blackness.

Squid Eyeball 2 watermarked (1)

-Jeff Milisen

MSc.

http://milisenphotography.yolasite.com/

Women in Diving

Written by: Cassandra Martin

In great celebration of International Women’s Day, a day dedicated to the great strides women

Naval Special Operations Officer Susan Trukken

Naval Special Operations Officer Susan Trukken wearing more than 200 pounds of diving equipment

have made through social, economic, and political movements I would like to pay tribute to all of the exceptional females who have and are continuing to make a greater contribution to the underwater community. The original members of the diving community bravely paved the way for the present female influence on global marine and underwater education. The Women Divers Hall of Fame celebrates the pioneers, leaders, innovators, and world record holders throughout the international diving community. Pioneer Susan Trukken set standards high for both women and men in 1980 when she graduated as the first female special operations officer at the Naval School of Diving and Salvage in Washington DC. When compiling research in the naval document “Equipment Development for the Fleet” Trukken began her research document regarding first-hand knowledge about the primitive diving technology used by saying “Experience is a great teacher…”

 

Thirty six years later women continue to master their skills using the same mantra. Pushing boundaries in competitive diving women are also making waves in freediving world records. Recently Mandy-Rae Cruickshank of Canada reached a depth of 289 feet in two minutes and 48 seconds off of the Cayman Islands using no weights and a single breath A technique freedivers categorize as “constant ballast.” Competitive freediving came out of the woodwork’s in the late 1940’s and while a fairly new sport its’ growth has thus far been exponential. The practice of diving on a single breath of air can be dated back thousands of years. Japanese women known as “Ama” meaning “sea woman” used this same practice to collect pearls over two thousand years ago.

Mandy rae freedive

Competitive Freediver Mandy-Rae Cruickshank

 

ama pearl diver

Ama pearl diver in Japan

 

 

 

 

 

 

Along with intensive competitive diving women are making major contributions to oceanic research. The Marine Megafauna Foundation was founded by Andrea Marshall in 2008 she was the first person worldwide to receive a PhD in Manta Ray studies. She is involved in innovative research, education, and legislation constantly striving to advocate for the protection of our oceans. At age 12 Andrea became a certified diver and was originally interested in being a shark conservationist however upon her first encounter with Manta Rays on a vacation to Mozambique she uncovered her true calling. She began conducting research which lead to the discovery that there are two different types of Manta Rays, Pelagic Birostris Manta Rays and Coastal Alfredi Manta Rays (the coastal species we encounter in Kona!) earning her the title “Queen of the Mantas.” In Andrea Marshall’s promotional video for the Marine Megafauna Foundation she passionately says “To know that our efforts are making a difference, to actually see that momentum is what keeps us going, is what keeps us fighting here.” This type of conviction appears again and again in the underwater world. To learn more about how to become involved with Andrea Marshall visit www.marinemegafauna.org. To all of you underwater women I would like to say Congratulations and thank you for taking upon our greatest challenges, here at Kona Honu Divers we celebrate and thank you!

andrea marshall # 1

Dr. Andrea Marshall founder of The Marine Megafauna Foundation

andrea marshall # 3

Dr. Andrea Marshall with a Manta Ray

andrea marshall #2

Dr. Andrea Marshall

Gold Lace Nudi

Nudibranchs

Nudibranch (pronounced noodabrank) means “naked gill”.  This refers to the gill-like appendages sticking out of the backs of most nudibranchs and is the organ that allows them to breath.  Most nudibranchs also have appendages called rhinophores, usually located at the head.  These have scent receptors and are used to taste, smell, and navigate.  Most nudibranchs can retract these tentacle-like organs into a pocket in their skin so they are protected from hungry predators.

Nudibranchs are Gastropods in the phylum Mollusca. They are related to snails, slugs, limpets, and sea hares.  Unlike other mollusks nudibranchs do not have shells as adults.  The shell is only found in the larvae stage and disappears when it becomes an adult.

There are over 3,000 species of nudibranchs and new species are being added to the list all the time.  Nudibranchs come in all sizes from just a few millimeters to over 12 inches and weighing up to 3 pounds like the beautiful Spanish dancer.   They can be a myriad of colors, spotted, striped or solid with trim. They are found in cold temperatures and warm temperatures.

There are two main types of nudibranchs dorids and eolids.  The dorids breathe through gills that are located on their backs in a cluster.  Eolids have appendages called cerata that can cover their entire backs and can be threadlike, club-like, branched or clustered in several groups.  The cerata have multiple functions including breathing, digestion, and defense.

Nudibranchs see only light and dark.  Information about their environment is gathered by the rhinophores or sense of smell and some by sense of taste through tentacles surrounding the mouth.  Nudibranchs and all other mollusks, have a radula, an organ with many tiny teeth, which they use to scrape up food.  All nudibranchs are carnivorous.  They feast on a variety of foods including sponges, hydroids, anemones, fish eggs, barnacles and even other nudibranchs.  Some species dine exclusively on one type of food and one species of that food.

The colors of nudibranchs come from the colors of the foods they ingest.  Color can camouflage them or, when bright and flamboyant, signal to predators that they are poisonous.  Some nudibranchs eat corals that contain algae. They absorb the algae’s chloroplasts and store them in their cerata where the chloroplasts will continue to photosynthesize and supply the nudibranch with nutrients.

What they eat can also supply a means of defense.  Eolid nudibranchs that eat organisms that have nematocysts, or stinging cells, can store them in their cerata and use them to sting predators if they are attacked.  Some dorid nudibranchs, like the fried egg nudibranch, have a unique defense system.  They secrete toxic slime that stinks and mucks up the water, warding off would-be predators.  True to their classification as slugs they do very little work to prepare these defenses. They simply absorb toxins manufactured by the foods they eat.  Not to stereotype the character of all nudibranchs, there are some industrious species of nudibranchs that manufacture their own toxins.

The majority of nudibranchs cannot harm humans.  Two exceptions are Glaucus atlanticus and a close relative Glaucus marginata.  They eat Portuguese man-o-war, absorb the nematocysts, and can use them to cause a pretty nasty sting even to humans.

All nudibranchs are hermaphrodites which means one individual is both male and female.  The lucky little guys can mate with any individual that happens by.  This is a plus because during the majority of a nudibranchs life they live alone and searching for a mate is inhibited by the fact that they never move very far and they can’t move very fast.  When two adults meet they each extend a tubular organ that they connect together and through this they fertilize each other’s eggs. The eggs are deposited in a spiral pattern, all rings evenly spaced from one another.  They are suspended in a gelatinous substance that holds them in place and gives the egg mass a ribbon-like appearance.  The larger “ribbons” of the Spanish dancer eggs can even look like an underwater rose.

Sadly nudibranchs don’t live very long.  Some live up to a year but most live only a matter of weeks.

Facts about some common Hawaiian nudibranchs:

Phyllidiidae varcosa, more commonly known as the Scrambled Egg Nudibranch or the Fried Egg Nudibranch.  The latter name seems more fitting to me because the white ridges on the body with the yellow spots resemble an egg white and yolk.  These are very commonly seen in the waters off Kona.  An individual can reach up to 3.5 inches (14cm) in length. They are common throughout the Philippines and the Indo-Pacific too.  The fried egg nudibranch, like all other Phyllidiidae species, will secrete a toxic mucous when disturbed.  This excretion is deadly to other marine animals.  The toxin comes from sponges they eat.  They eat the toxic sponges than store the toxin in their bodies to use as a defense mechanism.

Fried Egg Nudi (1)

Glossodoris rufomarginata also known as the White Margin Nudibranch is another species seen in Kona.  It is also found in other areas of the Indo-Pacific and the Red Sea. These are small nudibranchs ranging from 1-2 inches (2.5 to 5cm).  They will be found in depths of 15 to 100ft (5 to 30m) but I usually see them in the 25 to 35 foot (8-12m) range hanging on the ceilings of arch formations.

White Margin Nudi

Halgerda terramtuentis, the gold lace nudibranch, is endemic to Hawaii which means it is only found in Hawaiian waters.  They are abundant in Hawaii and can be found in shallow waters usually no deeper than 30ft (10m).  They grow to a maximum of about 2in (5cm).

Gold Lace Nudi

Pteraeolididae ianthina, or blue dragon nudibranch is an example of a nudibranch that gets its color from the food that it eats.  They eat hydroids that have zooxanthellae living in them.  The zooxanthellae photosynthesize to produce nutrients and this also produces the color that is transferred to the nudibranch when it eats the hydroid.  Curiously, just like plants, the zooxanthellae can produce different colors so the “blue” dragon nudibranch can be colors other than blue.  In Hawaii I have only seen blue colored blue dragon nudibranchs but they are found throughout the Indo-Pacific in various colors.  No matter the color of the body, they all have purple band markings on their oral tentacles. These nudibranchs also ingest the nematocysts of the hydroids, store them in their cerata and use them for self-defense.

Blue Dragon Nudi

Hiatodoris fellowsi is another endemic nudibranch.  Its common name, Fellow’s Nudibranch.  They are named after biologist David Fellows who was the first to collect a specimen.  These are strikingly beautiful nudibranchs with their snowy white bodies and contrasting jet black gills and rhinophores.

White Margin Nudi

~Stacey Herman

Black Water: Marlin

Anyone who has spent any time around Honokohau Harbor has seen a few of these strung up at the fuel pier. Marlin get huge, so it is excusable if you gawked in awe at the 400 pound dead sea monster on display, but the lifeless form is missing what makes them really special.  By nearly every measure, living marlin are probably the most impressive fish swimming in our oceans today.  For starters, they are world travelers.  One animal was tagged off the coast of Delaware and later recovered near Mauritius- a journey of over 9000 miles!  At 50 miles per hour, marlin are not only faster than anything most divers have seen underwater, they are faster than most speed boats.  And while that 400 pound animal may be more than twice your bodyweight, at 1400 pounds, the largest animal on record was more than 3 times a big as that.  Thus, I’d like to use this blackwater blog to celebrate the marlin for the oceanic apex predator that it is.  And I’d like to start with a little known species of odontocete called the dwarf sperm whale (Kogia sima).
Dwarf sperm whales have never been photographed underwater.  They are notoriously difficult to approach and are known for slipping under the water and descending just out of sight of humans.  So imagine my excitement as I found myself in the water with my camera as a pod slowly swam toward me!  The boat crew watched in near silence as their fins dipped below the surface, and the animals descended.  I may have seen a shadow in the distance, but that was probably my imagination.  I just floated hoping the animals would get curious and come back to play.  A minute or so later, the boat crew saw me nearly jump out of the water, muffling some sort of alarm through my snorkel.  Angry reef fish are quickly calmed by simply swimming away.  Even aggressive sharks can be stiff-armed.  But what can you do when a 12-foot long marlin charges you in blue water?
Marlin series (1)
Three photos taken in sequence during the encounter.
We have never seen an adult marlin on a blackwater dive, but we have seen quite a few of their young.  Marlin breed in the late summer and into the early fall and are capable of spawning as many as 7 million eggs at one go.  The resulting young (pictured below) will take 2 years to reach sexual maturity but grow at a rate of more than half an inch per day.  Out of that 7 million eggs, maybe one or two will reach sexual maturity and far fewer will reach the legendary benchmark of “grander” (over 1000 pounds).
Istiophoridae larva best 2 watermarked
Istiophoridae larva head on watermarked
Post flexion marlin photographed on a blackwater dive in May of this year (2015)
Fortunately for me, the apex predator granted me life as it decided to turn at the last minute (as seen in the sequence of photos above), but I’m afraid we have not been so sympathetic to the fish.  Blue marlin have declined by more than 30% of their population in just the last 14 years alone and fishing pressure for this species is increasing.  No blue marlin fisheries are considered to be sustainably managed. Thus, like other banner-species of ocean conservation such as oceanic sharks and even bluefin tuna, marlin are in a lot of trouble.  Sure, they provide a lot of meat, but because they are apex predators, pollutants such as mercury bioaccumulate in their tissues, so they have some of the highest levels of mercury (>.5 parts per trillion) of any marine fish!
-Jeffrey Milisen
MSc.

Black Water: Sea Moth

When we speak of Gasterosteiformes in Hawaii, we are generally referring to the order of pipefishes and seahorses.  Offshore, that usually refers solely to the pelagic seahorse, Hippocampus fisheri.  We see seahorses infrequently in the late summer and fall, usually at a rate of one seahorse for every ten dives or so.  Imagine Bryce and my surprise, one night, when we came across a member of this family that we didn’t even realize was possible in Hawaii.

Meet the Hawaiian seamoth (Eurypegasus papilio).  Sea moths are related to seahorses, pipefish, sea dragons, and sticklebacks in that they all possess bony external plates.  Seamoths shed their plates, and in some cases they will go through a set of plates every 5 days.  As an adult, this strange little fish will settle in water between 80 and 115 meters deep from the Big Island to Kure.  The underslung mouth implies that the Hawaiian sea moth feeds on benthic animals, and the snout is probably used to help extricate small crustaceans from their holes in the sea floor.  For now, the young is limited to the epipelagic zone, attracted to our lights just like, well, a moth.

-Jeffrey Milisen
MSc.

Black Water: Clown Squid

Young animals stay near the surface until maturity, but large ones like the squid pictured above, stay down deep and only come to the surface at night.  Adult animals are so rare, it is likely that none have been seen alive and only a few exist in museum collections.  A quiet hush fell over the blackwater divers when I picked up the large specimen for shipment to a cephalopod expert as we all realized that at our feet lay one of the rare night beasties that could show up on our favorite dive.  Once again, we are reminded of just how many animals we have yet to see down there.

-Jeffrey Milisen
MSc.