Thursday, July 17, 2014

Coral Breakage, teaching and a summer internship

CEP interns (from right to left) Sarah Rappaport, Zachary Boone, Dana Gazerwitz, Raven Cammenga, and Jason Dulin

Every time I tell someone that I am an intern at Coconut Island the first response I get is, “what do you do as an intern there?” The main goal during my internship has been to learn as much as I can in the short 8 week time span. As an intern with the community education program (CEP) I not only have gotten to learn but also to educate others on the importance of marine life. I have gotten to lead many tours as well as help with an invasive algae lab for young children. During the invasive algae lab we have the young students pick through a clump of invasive algae, separate out all the organisms by phyla, then do counts of each group to learn how to numerically characterize a habitat. It is amazing all that turns up. I had been looking for a sea slug the whole time I have been here and this week I finally found one in the samples, the painted nudibranch. 
One of the main side projects I have gotten to take part in was a coral breakage project. The target of the project is to monitor human impacts in the coral reef research reserve. We set up a new set of surveys for three different areas around the island. The sites we chose were the ones with the highest use by outside groups. These included the Mangrove channel, Sandy beach, and Maile Point.  

We set out transect lines and then did a belt transect method, counting all the coral breaks two meters to each side of the line. Since the reef drops steeply, one side was very shallow and one slightly deeper (about as deep as a fin kick might hit). We counted the breaks on the two main corals of Moku o Lo’e, Montipora capitata (rice coral), and Porites compressa (finger coral). To ensure that we were not counting the same breaks every day we photographed the breaks and only counted the most recent breaks. The most recent breaks are very white, while a break that’s a few days old will have green or brown algae growth. It is good to know that a study I helped start will potentially continue now for at least a year or more to come.

This picture is a good example of a fresh coral breakage spot
During my 8 weeks here I have also gotten a chance to become very familiar with the many different marine species of Hawaii. It’s been a very educational experience getting to see all of the endemic  and native species here in Hawaii. Some of my favorite species sightings have been the green sea turtle, Moorish idol, oval butterflyfish, and the scrawled filefish.

My time here has flown by and I have gotten to learn so much as well as had the opportunity to teach others. I can’t wait to be able to come back to Coconut Island one day. 

Oval butterflyfish found on reef by sandy beach at Coconut Island (photo credit: Dana Gazerwitz)

Green sea turtle found by the Mangrove channel at Coconut Island (photo credit: Zachary Boone)
Scrawled filefish found by Opakapaka pens at Coconut Island (photo credit: Zachary Boone)
Moorish Idol found on reef by sandy beach at Coconut Island (photo credit: Dana Gazerwitz)


Dana Gazerwitz

Thursday, July 3, 2014

UV Spot Treatment for Reduction of Coral Bacteria

Since coming to HIMB, I have seen both healthy and diseased corals. I discussed my interest in cellular biology and the issues with corals and coral diseases with my sponsor, Mark Heckman, who brought up the subject of UV radiation and coral bacteria.  I decided to specifically look at coral disease and see what effects spot treatment with UV radiation might have on a coral’s bacterial growth. Corals are constantly producing fluid-like mucus, which would make it easy to obtain a specimen to test. 

Mark introduced me to Dr. Amanda Shore of the Callahan and Aeby labs at UH-Manoa and HIMB, who had some bacteria streak plates and other gear I could use and loaned me a Steripen© that hikers use to sterilize water to drink in the back country.
Pre treatment in containers
I gathered three small Montipora capitata (rice corals) pieces, about 5 cm across, from our touch table and placed them each in a beaker containing one liter of salt water.  Prior to UV exposure, I gathered mucus from each coral (about 150 microliters worth of mucus) and placed each sample in an Eppendorf tube.  Three samples were taken from each coral.  Next, I exposed each coral to UV radiation.  the UV radiation source came from the SteriPen.  These pens are used to sterilize fresh water in order to make it safe for consumption.  It works by emitting an ultraviolet wavelength in the 250 nm range.  At this wavelength, the UV light breaks down the bacteria’s DNA to keep it from replicating.  The SteriPen shows best results in either one liter to two liters of water.  The pen was placed in each beaker containing the coral and was used to agitate the water for a minute while the UV light was on.  This was done to the two remaining beakers. 

Once the corals were exposed to the UV light, another sample of mucus was taken—the same quantity as the first trial.  There was  a total of 9 pre-exposure specimens (three from each coral) and 9 post-exposure specimens (three from each coral).  After gathering the pre- and post-UV radiation specimens, 50 microliters of each specimen was smeared onto an agar plate and left to incubate overnight. 

Coral 2 - no treatment
I expected less bacterial growth to form in all the post-exposure plates when compared to the pre-exposure plates due to the nature of the SteriPen.  It is designed to slow, or, in some cases, even stop bacterial growth.  However, I didn’t expect there to be such a wide variety of results as what I got.
Coral 2 - treated (ignore two large bubbles in the agar)
Although the majority of the post-exposure plates contained less bacteria than the pre-exposure plates and the ones that did form were more intermittent and isolated from other colonies than on the pre-exposure plates, in some plates, there was more growth in bacteria after UV exposure.

These varied results could be due to a variety of errors in the experiment.  Some of the specimens in the beakers may not have received the same amount of exposure as other corals, not all the beakers were uniform (two were transparent glass beakers and one was an opaque plastic beaker), the bacteria types on the corals may have had differences, some of the corals may have had thicker or more mucous to start with and they did not all come from the same colony.

To remedy these errors for the next experiment, all the corals would need to be in the same type of beaker.  I would prefer all of them to be opaque.  This will allow for maximum UV exposure within the beaker and less UV light escaping through the transparent beakers.  To ensure the corals are the same, the corals will be taken from the same colony to ensure similar DNA is being tested, and it would be good to do many more samples and then specifically look at possible effects on diseased corals rather than healthy ones. 
Overall it was an interesting first try to see if there was a potential for UV treatment of bacterial diseases. The coral fragments themselves showed no adverse effects of the treatment immediately after and as well as after several days. Perhaps there will be a follow up on this experiment in the future.


Kenzie Gauck/ HIMB Education Intern

Thursday, June 19, 2014

40 million dollar grant to University of Hawaii-SOEST

As of Monday (June 16), the University of Hawaii's School of Ocean and Earth Science Technology (SOEST) program was awarded $40 million to study microscopic organisms and their natural processes.

"The Simons Foundation has awarded Edward DeLong and David Karl $40 million to lead the Simons Collaboration on Ocean Processes and Ecology (SCOPE), making it the largest private foundation gift UH has ever received. SCOPE aims to further our understanding of the microscopic organisms that inhabit every drop of seawater and how those creatures control the movement and exchange of energy and nutrients, from the surface waters to the deep sea. UH is leading the project, with partners joining from the Massachusetts Institute of Technology (MIT), Woods Hole Oceanographic Institution (WHOI), University of California-Santa Cruz (UCSC) and University of Washington (UW)".

Click here to watch this great short video!
Kenzie G, and Dana G./ CEP Interns

Friday, June 13, 2014

Tracking the life of a seahorse

Some may think that a seahorse would be in the species of a horse, but it really is a fish! They are related to pipefish and belong to the family of Syngnathidae. They have an elongated body with enclosed bony rings. To sum up the physical features of a seahorse, they have a horse-like head, monkey-like tail, and kangaroo-like pouch. Along with this, they are great at camouflaging and blending in with their surrounding environment.

 Photo by Mark Rosenstein / Active Window Productions, Inc.

Seahorses in Hawaii have been scarce until about 10 years ago (M. Heckman pers. comm.). It is not clear why there has been a rise in their population the last several years.

There has been a threat to seahorses for a few different reasons. There has been direct exploitation (using something in a cruel manner) of seahorses, capturing of seahorses in accidental ways, and the destruction and degradation of their habitats. These seahorses are being exploited by being sold primarily for use in Chinese medicine and the aquarium trade. According to Traditional Medicine Trade, it is believed that seahorses can cure ailments that range from asthma to arteriosclerosis, but there is no statistical data to prove this yet. The research and use of seahorses for medicine is causing a reduction of the number of seahorses in the ocean. 

Seahorses are predators of zooplankton. They have to eat constantly because they lack teeth and a stomach, so their digestive process is extremely quick. Another interesting fact about seahorses is that the males are actually the ones to give birth. The male seahorse has a pouch on its stomach in order to carry the eggs. The female will deposit the eggs onto the male and he will carry through the process of pregnancy. 
                                                                                              Photo by HIMB CEP

Photo by HIMB CEP
There has been a lot of current research about tagging seahorses and tracking them within the ocean. One experiment was conducted in the Ria Formosa lagoon in southern Portugal. In a paper by Iain Robertson Caldwell, he completed tagging and tracking seahorses with the use of external transmitters that were tied with cotton thread around their necks. He used a VEMCO directional hydrophone and receiver in order to locate each tagged seahorse. Iain would tag the seahorses by placing them in a seawater filled container on a boat during the process. This would take no longer than a minute. Once the tags were secure, he would monitor the seahorses to make sure they did not show any distress before releasing back into the ocean. 

After tracking the movement of Hippocampus guttalatus for 150 minutes using GPS, he found that these seahorses moved from between 0 and 238 cm (about 7 feet), on average. The GPS allowed Iain to find the measurement of the straight line distance between each sighting location and release location, between sighting locations and the total distance traveled. The total distance moved did not differ a significant amount between tagged and untagged seahorses. It was also found that the behavioral status of the tagged seahorses did not change very much on a daily basis. It was also discovered that the male seahorses moved a significantly greater distance than the female seahorses. This experiment can be very useful in determining the movements of seahorses throughout the ocean. To learn more about his experiment, you can view his paper Habitat, Movement, and Vulnerability of Sedentary Fishes in a Dynamic World.

If you would like to learn about other research experiments involving seahorses, then visit these websites:








Jason Dulin

Friday, June 6, 2014

Why do science? Excerpts from student Thank You's to HIMB

Dear Hawaii Institute of Marine Biology,

"...Some of the animals we learned about, such as the sailor's eyeball and the conspicuous sea cucumber, I had never heard of or seen before. It was funny, because when I was pulling out a big clump of seaweed from the bucket to look through for sea creatures, a tiny white crab went scuttling up my arm. I almost shrieked, but it was fun. It was so funny afterwards that we were all laughing really hard." (4th grade student)

And a few other quotes:

"... I had a very fun time doing all the activities, but if I  had to pick a favorite then it would be surveying the reef. I love the ocean and one day I hope to be a marine biologist and this trip really inspired me to follow my dream."

 "I really thought it was going to be boring, but it was so fun, there are many plankton such as zooplankton, phytoplankon ...."

"... Thanks again for giving me an unforgettable experience and lots of knowledge that will last me a life time!"

"It was really cool doing the night plankton lab....Your Lanai Suites are very nice and your sink water tastes like Dasani. Very delicious."

"Please thank the volunteers for all their help and for making our trip as wonderful as possible."

"It was so fun when we did science."

"Thank you for letting us stay at coconut island... I miss you guys and the view of the island."

When groups come to the island, they encounter our wonderful volunteers, grad students, researchers and HIMB staff. All of us help make these positive impressions for the kids, but - they also remind us of why we are here - because of the quest for knowledge, to make our world a better place, to be in a place with good people, to make a difference and once in a while, to laugh and have fun.



File shell  from the invasive seaweed lab. Image HIMB

Friday, May 30, 2014

Chaetognaths- The truth about Arrow Worms

During our first plankton lab, we noticed some interesting worm-like creatures with vicious looking teeth. Under the microscope, we were able to observe some features that helped distinguish this creature as an arrow worm, also known as a Chaetognath (keet oh nath). They are not really worms in the traditional sense, in that they do not have segmented bodies. They are actually unlike any other set of marine animals, so they are their own phylum (group). There are about 150 species of chaetognaths known, all of them are marine and can be found in oceans worldwide.

Chaetonagth head.  Image Image M Onuma, HIMB

Arrow worms are zooplankton, small animal plankton (drifters of the sea). Unlike many zooplankton, which may be the young stage of familiar reef animals such as fish, seastars or even corals, arrow worms are holoplankton, they stay the same and remain plankton for their entire life.

One interesting fact about arrow worms is that they swallow their prey whole. Since they are clear, you can often see what they ate in their gut when looking at them under a microscope. Their main source of food is copepods and they find their prey in quite an amazing way. According to an article by Hiroaki Saito and Thomas Kierboe, Feeding rates in the chaetognath Sagitta elegans: effects of prey size, prey swimming behaviour and small-scale turbulence , chaeotognaths sense the vibrations from their moving prey and then attack them.

Arrow worm head.  Image M Onuma, HIMB

Group of arrow worms.   Image D Gazerwitz and J Dulin, HIMB

Arrow worms play an important role in the food web.  They are zooplankton predators that eat other zooplankton, which is an important initial step in the ocean food chain. The arrow worm in turn becomes food for fish larvae, which either grow up or are then eaten by larger marine animals.

Image from Climate Kids at

These very cool, clear worms are not well studied. If you would like to know more details about arrow worms, you can visit our sources:


Dana Gazerwitz and Jason Dulin 

Friday, May 23, 2014

What can you learn from a dead turtle?


Turtle carcass--M Heckman image

Over the last weekend, we noticed a bit of a smell along the shore by the Corrosion Lab site. A dead turtle carcass had washed up, so like any good biologists, we went to look. It was upside down, without a head or flippers and with what appeared to be parts of the shell missing.

The obvious conclusion would be that a tiger shark had been feeding on it and when we sent in the pictures that Larry had taken, Devon Franke from NOAA concurred that some of the scrape marks looked to be tooth marks.

Under side of turtle--Larry Stamey photo

So, did this animal get killed and eaten by a tiger shark? After all, tiger sharks eat turtles, but what if the turtle died from some other cause and then was just a convenient floating meal? I know that I prefer my food to be dead before I eat it. It is so much easier when it is not still trying to run away.

I think people have the impression that tiger sharks kill and eat more sea turtles than they probably do. Our new intern Kenzie Gauck went looking for information on this issue. She found a paper by W.N. Witzell in which an examination of 201 mid-Pacific tiger sharks revealed only 31 with turtle remnants in their stomachs.  So 15% of the sharks had recently eaten turtle - a reasonable amount, but not a huge number. They did not measure how much of the turtle was in the stomach, how digested it was, or so on, just whether it was present or not. A study done on dietary habits of tiger sharks here in Hawaii, by Lowe, et. al. showed that of 281 tiger sharks examined, only sharks over 7.5 feet in length had any turtle in their stomachs and that the proportion rose to 15% when they examined sharks over 9.8 feet in length. Turtle shell and parts might stay in the stomach longer than other food types, leading to an over reporting of  turtle compared to other items that might move through the system faster and be eaten more often, but I am just speculating here. Someone can set me straight if they know more.

We know that once turtles were protected by Federal legislation back in 1978, it took decades for their numbers to grow to the point that we actually commonly see them now - and they were never protected from sharks eating them during this time, only people. I suspect that the real issue for turtles is us.

We decided to flip the turtle over and look for any additional damage on the top of the shell before bagging it up for NOAA. By this time the decomposition had really set in. The nice shiny scutes had all fallen off. The main parts of the shell were starting to come apart, and the smell was actually not so bad. Leon picked up a bit of scute with some barnacles on it.

Below is an image of the top of the animal when we finally flipped it over. The shiny scutes are gone, only the bony plates below remain. You can see some additional breakage up near the center of the shell.

Green sea turtle carcass with possible boat strike injury, washed up at Moku o Lo'e.  M Heckman/HIMB photo
There is the possibility that the break is the result of a boat strike, but the shell is so decomposed that we will never know. I would think that with all of the power boats speeding around the bay, boat strikes must happen fairly often. In fact, the 1998 Green Turtle Recovery Plan lists boat collisions in Hawaii as a "primary threat" to green turtles. 16 years later with more turtles and certainly no less boats, it is hard to imagine that this is still not an issue.

We will never really know what came first, but I put my money on a boat strike, followed by a nice meal for a local shark, then the finishing smorgasbord for a whole host of very well fed crabs.

Sad for the turtle, it looked to be a good size. This reminds us to go slow and watch for turtles in the Bay.



Thanks to Intern Kenzie Gauck for the following links.

Selective Predation on Large Cheloniid Sea Turtles by Tiger Sharks (Galeocerdo cuvier):

Recovery Plan for U.S. Pacific Populations of the Green Turtle (Chelonia mydas):

Ontogenetic dietary shifts and feeding behavior of the tiger shark, Galeocerdo cuvier, in Hawaiian waters
University of Hawaii at Manoa. 
Christopher G. LoweBradley M. WetherbeeGerald L. CrowAlbert L. Tester Environmental Biology of Fishes (Impact Factor: 1.31). 09/1996; 47(2):203-211. DOI:10.1007/BF00005044