Tag: Kona

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Suzanne Acord: Cetaceans Are Among Us! March 26, 2014

NOAA Teacher at Sea
Suzanne Acord
Aboard NOAA Ship Oscar Elton Sette
March 17 – 28, 2014

Mission: Kona Area Integrated Ecosystems Assessment Project
Geographical area of cruise: Hawaiian Islands
Date: March 26, 2014

Weather Data from the Bridge at 13:00
Wind: 6 knots
Visibility: 10+ nautical miles
Weather: Hazy
Depth in fathoms: 2,473
Depth in feet: 14,838
Temperature: 26.0˚ Celsius

Science and Technology Log

Cetaceans Are Among Us!

We use these cameras to take close up shots of the marine mammals.
Commanding Officer, Koes (right), and scientist, Gadea, during MMO on the flying bridge.

Our Marine Mammal Observation (MMO) crew was in for a treat today. Just after lunch, we spot a pod of sperm whales. We spotted them off the port side, off the starboard side, and eventually off the bow of the Sette. We frequently see Humpback whales in Hawaii, but sperm whales often evade us. Sperm whales can dive down to extreme depths and they feed on squid. These same squid feed on the micronekton that we are observing during the cruise. Sperm whales are the largest of the toothed whales. Their enormous size is obvious when they slap the ocean with their giant tails. Another unique characteristic of the sperm whale is their blow hole, which sits to the left rather than on top of the head. This feature allows our MMO team to easily identify them.

Our MMO lead, Ali Bayless, determines that we should take the small boat out for a closer examination of the pod. Within minutes, the small boat and three scientists are in the water following the pod. We think that a calf (baby) is accompanying two of the adult whales. Throughout the next few hours, our small boat is in constant contact with our flying bridge, bridge, and acoustics team to determine the location of the whales. We keep a safe distance from all of the whales, but especially the calf. While on the small boat, MMO scientists also identify spotted and spinner dolphins. We are essentially surrounded by cetaceans. The small boat is just one of the many tools we use to determine what inhabits the ocean. We also use an EK60 sonar, our Remotely Operated Vehicle, our hydrophone, and sonar buoys.

Notice the location of the blow hole on the sperm whale. Photo credit: Ali Bayless
Sperm whale sighting during MMO operations. Photo credit: Eric Mooney
Two adult sperm whales and a calf. Photo credit: Erin Mooney
This sperm whale is about to dive deep to feed. Photo credit: Gadea Perez-Andujar

Our acoustics lead, Adrienne Copeland, is especially excited about our sperm whale sightings. Adrienne is a graduate student in zoology at the University of Hawaii. She earned her Bachelor’s of Science in biology with a minor in math and a certificate in mathematical biology from Washington State University. She has served on the Sette four times and is currently serving her third stint as acoustics lead. This is a testament to her expertise and the respect she has earned within the field.

Adrienne Copeland monitors our acoustics station during our 2014 IEA cruise.
Adrienne Copeland monitors our acoustics station during our 2014 IEA cruise.

Adrienne Copeland studies the foraging behavior of deep diving odontocetes (toothed whales). She shares that some deep diving odontocetes have been known to dive more than 1000 meters. Short finned pilot whales have been observed diving 600-800 meters during the day. During night dives we know they forage at shallower depths on squid and fish. How do we know how deep these mammals dive? Tags placed on these mammals send depth data to scientists. How do we know what marine mammals eat? Scientists are able to examine the stomach contents of mammals who are stranded. Interestingly, scientists know that sperm whales feed on histioteuthis (a type of squid) in the Gulf of Mexico. A 2014 IEA trawl operation brought in one of these squid, which the sperm whales may be targeting for food.

Notice the distinct blue and gray lines toward the top of the screen. These are the think layers of micronekton that migrated up at sunset. The number at the top of the screen expresses the depth to the sea floor.
Notice the distinct blue and gray lines toward the top of the screen. These are the thick layers of micronekton that migrated up at sunset. The number at the top of the screen expresses the depth to the sea floor.

Examine the acoustics screen to the left. Can you identify the gray and blue lines toward the top of the screen? These scattering layers of micronekton ascend and descend depending on the sun. Adrienne is interested in learning how these scattering layers change during whale foraging. Our EK60, Remotely Operated Vehicle, and highly prescribed trawling all allow us to gain a better understanding of the contents of the scattering layers. A greater understanding of whale and micronekton behavior has the potential to lead to more effective conservation practices. All marine mammals are currently protected under the Marine Mammal Protection Act. Sperm Whales are protected under the Endangered Species Act.

Interesting fact from Adrienne: Historical scientists could indeed see the scattering layers on their sonar, but they thought the layers were the ocean floor. Now we know they represent the layers of micronekton, but old habits die hard, so the science community sometimes refers to them as false bottoms.

Live Feed at 543 Meters! 

The ROV prior to deployment.
The ROV prior to deployment.

Our Remotely Operated Vehicle (ROV) deployment is a success! We deploy the ROV thanks to an effective team of crew members, scientists, and NOAA Corps officers working together. ROV deployment takes place on the port side of the ship. We take our ROV down to approximately 543 meters. We are able to survey with the ROV for a solid five hours. A plethora of team members stop by the eLab to “ooh” and “ahh” over the live feed from the ROV. Excitingly, the ROV is deployed prior to the vertical migration of the micronekton and during the early stages of the ascent. The timing is impeccable because our acoustics team is very curious to know which animals contribute to the thick blue and gray lines on our acoustics screens during the migration. In the ROV live feed, the micronekton are certainly visible. However, because the animals are so small, they almost look like snow falling in front of the ROV camera. Periodically, we can identify squid, larger fish, and jellies.

ROV deployment requires teamwork. These are our winch operators.
Two scientists connect the umbilical and the winch line to ensure our ROV is stable.
Scientist, Eric Mooney, operates our ROV during its deployment using the live feed and the joy stick.

Did you Know? 

Kevin Lewand of the Monterey Bay Aquarium constructs a hyperbaric chamber for marine life on board the Sette.
Kevin Lewand of the Monterey Bay Aquarium constructs a hyperbaric chamber for marine life.

Mini hyperbaric chambers can be used to save fish who are brought to the surface from deep depths. These chambers are often used to assist humans who scuba dive at depths too deep for humans or who do not effectively depressurize when returning to the surface after SCUBA diving. The pressure of the deep water can be life threatening for humans. Too much pressure or too little pressure in the water can be life threatening for marine life, too. Marine life collector, Kevin Lewand, constructed a marine life hyperbaric chamber aboard the Sette. He learned this skill from his mentor. Be sure to say Aloha to him when you visit the Monterey Bay Aquarium in Monterey, California.

 

 

 

 

Personal Log

Daily Life Aboard the Sette

Our chief scientist, Dr. Don Kobayashi, examines a specimen after a trawl.
Examining a cookie cutter shark in the wet lab.
Night watch on the Sette.

There is never a dull moment on the ship. Tonight we have ROV operations, squid jigging, acoustics monitoring, and a CTD deployment. We of course can’t forget the fact that our bridge officers are constantly ensuring we are en route to our next location. Tonight’s science operations will most likely end around 05:00 (tomorrow). Crew members work 24/7 and are usually willing to share their expertise or a good story. If they are busy completing a task, they always offer to chat at another time. I find that the more I learn about the Sette, the more I yearn to know. The end of the cruise is just two days away. I am surprised by how quickly my time aboard the ship has passed. I look forward to sharing my new knowledge and amazing experiences with my students and colleagues. I have a strong feeling that my students will want to ask as many questions as I have asked the Sette crew. Aloha and mahalo to the Sette.

 

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Suzanne Acord: Preparing to Embark! March 12, 2014

NOAA Teacher at Sea
Suzanne Acord
(Almost) On board NOAA Ship Oscar Elton Sette
March 17 – 28, 2014

Mission: Kona Area Integrated Ecosystems Assessment Project
Geographical area of cruise: Hawaiian Islands
Date: March 12, 2014

Personal Log

Aloha, from Honolulu, Hawaii! My name is Suzanne Acord. I teach high school social studies with Mid-Pacific Institute in Honolulu, Hawaii. More specifically, I teach Asian Studies, World History, and IB History. I also teach one Pacific Island History course with Chaminade University. In addition to teaching, I advise our Model United Nations delegation and coordinate our school’s History Day efforts.

Prior to teaching in Hawaii, I served as a Peace Corps volunteer in Yap, Micronesia. Two years of living a subsistence lifestyle in Yap helped me to understand our intimate and reciprocal relationship with our earth. Yap State Legislator, Henry Falan, sums up this relationship by stating, “In Micronesia, land is life.” Both man-made and naturally occurring disasters can be felt throughout the Pacific. World War II, El Nino, tsunamis, and nuclear testing are just a few world events that have left their mark on the Pacific Ocean. Their impacts on the reefs, the fish supplies, and the water quality are apparent daily.

Peace Corps hut
My first hut in Yap, Micronesia. I lived here while serving in the Peace Corps.

I applied for the NOAA Teacher at Sea program to gain a better understanding of the human relationship with our oceans. My history students frequently determine how our relationship with the ocean changes as a result of environmental change, political change, economic change, and cultural change. My experiences during this cruise will allow my educational community to consider real world solutions for the environmental challenges we face and will face in the future.

I couldn’t be happier to set sail on NOAA Ship Oscar Elton Sette on March 17, 2014. We will travel from Ford Island (a WWII place of interest) to the Big Island of Hawaii, which is also known as Hawaii Island. The Big Island is the largest of the Hawaiian Islands and is the home of Volcanoes National Park. Most of our time will be spent on the Kona coast of the island.  One of the many goals of the Kona Area Integrated Ecosystems Assessment Project is to gain “a complete understanding of the Kona ecosystem, from the land to the ocean…to provide scientific advice used in making informed decisions in the Kona area.”

Suzanne at desk
Anticipating the adventure in my classroom.
Photo credit: Scot Allen

The thorough NOAA Teacher at Sea training has given me peace of mind. I feel much better prepared for the TAS journey now that I have read the official requirements and the tips from past Teachers at Sea. The videos helped me to visualize the experience. Don Kobayashi, our Chief Scientist, has kept all members of the scientific expedition in the loop throughout the planning process. I was excited to see my name listed on the “science party” document and amused when I learned that my daily shift would span from 3 am to noon daily. I will surely experience amazing sunrises over the Pacific. This will definitely be an intellectually stimulating adventure!

My next blog will be written aboard the Sette. Aloha for now.

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Becky Moylan: Preliminary Results, July 13, 2011

NOAA Teacher at Sea
Becky Moylan
Onboard NOAA Ship Oscar Elton Sette
July 1 — 14, 2011


Mission: IEA (Integrated Ecosystem Assessment)
Geographical Area: Kona Region of Hawaii
Captain: Kurt Dreflak
Science Director: Samuel G. Pooley, Ph.D.
Chief Scientist: Evan A. Howell
Date: July 13, 2011

Ship Data

Latitude 1940.29N
Longitude 15602.84W
Speed 5 knots
Course 228.2
Wind Speed 9.5 knots
Wind Dir. 180.30
Surf. Water Temp. 25.5C
Surf. Water Sal. 34.85
Air Temperature 24.8 C
Relative Humidity 76.00 %
Barometric Pres. 1013.73 mb
Water Depth 791.50 Meters

Science and Technology Log

Results of Research

Myctophid fish and non-Myctophid fish, Crustaceans, and gelatinous (jelly-like) zooplankton
Crustaceans
Chief Scientist guiding the CTD into the ocean
Chief Scientist guiding the CTD into the ocean

Beginning on July 1st, the NOAA Integrated Ecosystem Assessment project (IEA) in the Kona region has performed scientific Oceanography operations at eight stations.  These stations form two transects (areas) with one being offshore and one being close to shore. As of July 5th, there have been 9 CTD (temperature, depth and salinity) readings, 7 mid-water trawls (fish catches), over 15 acoustics (sound waves) recordings, and 30 hours of marine mammal (dolphins and whales) observations.

The University of Hawaii Ocean Sea Glider has been recording its data also.The acoustics data matches the trawl data to tell us there was more mass (fish) in the close to shore area than the offshore area. And more mass in the northern area than the south. This is evidence that the acoustics system is accurate because what it showed on the computer matched what was actually caught in the net. The fish were separated by hand into categories: Myctophid fish and non-Myctophid fish, Crustaceans, and gelatinous (jelly-like) zooplankton.

Variety of Non-Myctophid Fish caught in the trawl
Variety of Non-Myctophid Fish caught in the trawl

The CTD data also shows that there are changes as you go north and closer to shore. One of the CTD water sample tests being done tells us the amount of phytoplankton (plant) in different areas. Phytoplankton creates energy by making chlorophyll and this chlorophyll is the base of the food chain. It is measured by looking at its fluorescence level. Myctophids eat phytoplankton, therefore, counting the amount of myctophids helps create a picture of how the ecosystem is working.

The data showed us more Chlorophyll levels in the closer to shore northern areas . Phytoplankton creates energy using photosynthesis (Photo = light, synthesis  = put together) and is the base of the food chain. Chlorophyll-a is an important pigment in photosynthesis and is common to all phytoplankton. If we can measure the amount of chlorophyll-a in the water we can understand how much phytoplankton is there. We measure chlorophyll-a by using fluorescence, which sends out light of one “color” to phytoplankton, which then send back light of a different color to our fluorometer (sensor used to measure fluorescence). Myctophids eat zooplankton, which in turn eat phytoplankton. Therefore, counting the amount of myctophids helps create a picture of how the ecosystem is working.   The data showed us more chlorophyll-a levels in the closer to shore northern areas.

Bringing in the catch

The Sea Glider SG513 has transmitted data for 27 dives so far, and will continue to take samples until October when it will be picked up and returned to UH.

Overall the mammal observations spotted 3 Striped dolphins, 1 Bottlenose dolphin, and 3 Pigmy killer whales.  Two biopsy “skin” samples were collected from the Bottlenose dolphins. A main part of their research, however, is done with photos. They have so far collected over 900 pictures.

Looking at all the results so far, we see that there is an area close to shore in the northern region of Kona that has a higher concentration of marine life.  The question now is why?

We are now heading south to evaluate another region so that we can get a picture of the whole Eastern coastline.

Personal Log

In the driver's seat
In the driver's seat
Krill
Krill

And on deck the next morning we found all kinds of krill, a type of crustacean. Krill are an important part of the food chain that feed directly on phytoplankton. Larger marine animals feed on krill including whales. It was a fun process finding new types of fish and trying to identify them.Last night I found a beautiful orange and white trumpet fish. We also saw many transparent (see-through) fish with some having bright silver and gold sections. There were transparent crabs, all sizes of squid, and small clear eels. One fish I saw looked like it had a zipper along the bottom of it, so I called it a “zipperfish”. A live Pigmy shark was in the net, so they put it in a bucket of water for everyone to see. These types don’t ever get very big, less than a foot long.

I have really enjoyed living on this ship, and it will be sad to leave. Everyone treated me like I was part of the group. I have learned so much about NOAA and the ecosystem of the Kona coastline which will make my lessons more interesting this year. Maybe the students won’t be bored!

Sunrise over Kona Region

Sunrise
Sunrise
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Geoff Goodenow, May 21, 2004

NOAA Teacher at Sea
Geoff Goodenow
Onboard NOAA Ship Oscar Elton Sette
May 2 – 25, 2004

Mission: Swordfish Assessment Survey
Geographical Area: Hawaiian Islands
Date: May 21, 2004

Time: 1600

Lat: 19 25 N
Long: 156 54 W
Sky: Overcast today. A bright unthreatening sky but clouds thick enough to prevent casting of shadows.
Air temp: 26.3 C
Relative humidity: 70%
Barometer: 1015.7
Wind: 146 degrees at 14 knots
Sea temp: 26.5 C
Depth: 4738 m (at 1645 hrs)
Sea: Rolling today with 3-5 foot swells but not uncomfortable. Much calmer this evening now that we are nearer the Kona coast.

Science and Technology Log

We began our retrieval of the longline at 0600 today; usually we begin at 0800. This change was made in light of the fact that we have been catching swordfish in this area and that they are dead when we get to them. These are animals (when alive) that we would like to tag. The thought is that if we get to them sooner we will have live animals to work with. I hate to see any of them dead, but it was especially hard to accept the loss of that big guy yesterday.

Did it work? Well, we didn’t lose any swordfish today, but then we didn’t catch any either. It was a very poor catch — several escolar (apparently the most abundant fish in the sea), one snakemackeral, and, the only thing worth getting up for (personal commentary), a bigeye thresher shark. This one was tagged by Rich who harpooned the pop up into its back with one swift and well aimed lunge. He was then cut free of the line — another mobile laboratory.

Tonight we are again off the Kona coast for the line set. I don’t know why the decision was made to come here as opposed to staying over one of the seamounts.

Yesterday I had a tour of the engine room. I thought I’d mention a couple things going on below deck and perhaps a few other tidbits about our floating city of 30-40 people. In an earlier log, I think I mentioned that we make our own fresh water. Waste heat from the engine cooling water heats sea water held in a partial vacuum where it can boil at less than 100 degrees C. then be recondensed to yield our water supply.

Our waste water treatment system is a Class 2 type according to chief engineer, Frank. All human waste and gray water goes to a holding tank. From there it is pumped through a unit to macerated solids. The slurry then passes through an electrical cell that completes the purification process before discharge to the sea.

Our little city generates its share of trash as well. Bins around the ship are marked as to the specific kinds of refuse we may put into each. Here’s is what I understand concerning disposal of sewage and trash. Within 3 miles of shore everything must be held although I think if sewage is treated, as ours is, it is OK to let it go even there. Plastics are never to be dumped. From 3-12 miles out, we can dump trash and food waste ground to less than an inch, but no packaging and such that floats. At 12-25 miles, food wastes can go but again the floating debris is prohibited. Beyond 25 miles, I think all can go but the plastics. Cardboard boxes and paper trash go over the side out here and untreated sewage can be flushed.

And, of course, we have to eat. Todd and Susan are our stewards. Todd insisted that I write that “the second cook (in this case Susan) has the hardest job on the ship.” Susan agrees. For a typical 24 day cruise, Todd (chief steward) spends $5000-$6000. To mention just a few of his purchases for this trip he packed on 48 gallons of milk, six cases of juices, a case being containing 4 three-liter bottles of 4-1 concentrate, and over 80 loaves of bread. Whatever he buys is supplemented by our catch. He noted too that in different areas, crews have different likes. For example, in Hawaii he packs on lots of fruits. In cold Alaska, crews like to have soup everyday whereas here it’s not as welcome because of the heat.

Well, that diversion got me (and you) away from fish science for today. Sorry if anyone is disappointed.

Personal Log

I think the early start jolted everyone’s biorhythms or perhaps just mine. I liked being done with the line by 0830, but I did feel kind of lazy all day afterwards. Perhaps that along with the humid, overcast sky and an antibiotic the doc gave me for an infected finger combined to make napping the desired task of the day for me. So aside doing this log, soaking my finger and a bit of reading that’s about all that happened for me today.

Questions:

Perhaps this should have preceded yesterday’s questions. The Hawaiian Islands are some of the most remote island in the world. How did they originally (before the hands of humans) become inhabited by plants, animals, fungi? What are some of the mechanisms that permit dispersal of life to such isolated places as these?

Geoff

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Geoff Goodenow, May 15, 2004

NOAA Teacher at Sea
Geoff Goodenow
Onboard NOAA Ship Oscar Elton Sette
May 2 – 25, 2004

Mission: Swordfish Assessment Survey
Geographical Area: Hawaiian Islands
Date: May 15, 2004

Time: 1550

Lat: 18 52 N
Long: 155 47 W
Sky: Bright and sunny over us but the island has a layer of stratus obscuring views to top
Air temp: 26.3 C
Barometer: 1012.72
Wind: 202 degrees at 12 knots
Relative humidity: 62.4
Sea temp: 26.2 C
Depth: 2015.4 m

Sea: Rolling along with 2-3 foot swells; no big deal.

Scientific and Technical Log

Scientific name for the pomfret we caught yesterday is Brama brama and for the silky shark (caught a week or so ago) it is Carcharhinus falciformis.

Today as we trolled just off the Hawaii shoreline as we steamed south to our longline set position. Mike and Chris teamed up again to land a shortbilled spearfish (Tetraturus angustirostris) 161 cm and 17 kg, silvery body with a deep blue dorsal fin — beautiful fish. This one was kept for eye studies and other tissue samples. We pulled a nearly intact fish about 20 cm long from its stomach. The 2 man team of Chris and Mike is working smoothly and efficiently; no fish has a chance against them now.

We will set the longline tonight southeast of the southern tip of Hawaii at Apuupuu Seamount, 929 m below. (18 31N, 155.24 W). Following the set we will be doing a plankton tow.

Vision (one more time):

Another aspect of the vision studies is trying to assess the animal’s speed of vision. Electroretinography measures the response of an eye to light pulses from a flickering source. So called flicker fusion (FF) is reached when the eye loses its ability to perceive individual pulses of light. A relatively high FF value is characteristic of shallow living species compared to deeper dwellers. In the dim light the speed of light gathering is slowed similar to the need to slow a camera’s shutter speed to gather sufficient light.

In concluding this abbreviated look at the vision studies, I’ll try to draw some of the pieces together. Pop up tags show where these animals spend their time in terms of depth, light and temperature realms. We can tell how sensitive an eye is to light and how fast it works. As you will recall, some of these fishes deep dwelling fishes have heat a exchange system located in the eye which keep it warm. It has been shown that speed of vision is affected by temperature change — a warm (above ambient) eye functions more effectively. Much more goes on, but perhaps you get a sense of how different areas of study contribute to a better picture of this function in these pelagic fishes.

To other (non-vision) studies tomorrow.

Personal Log

We steamed toward Kona through the night so that we could ferry Steven to shore and flights to other places. It was great to have met him; I’m sorry he had to jump ship. I got up at 5:30 to experience sunrise (around 6 o’clock). I thought it would be nice to see it rise over the island, but didn’t count on the clouds hanging over the mountains to obscure anything that might have been spectacular; it wasn’t even good from our perspective. But it was nice to see a color that I haven’t seen (except as a flash) in over a week — green. We have been wrapped in a beautiful blue and white world (which I am sure would excite fans of the Penn State Nittany Lions and the Mifflinburg HS Wildcats), but I tend to favor green fields and forests in the mix.

Unfortunately, we didn’t get to touch the green or for that matter the briny deep as snorkeling was denied us. So it was a day of leisure on board. I spent time reading (Diversity of Life), making some journal entries and enjoying the sight of land — perhaps the last for another 9 days (not complaining). I tried to ignore the typical signatures of human presence at Kona: autos, the Big K-Mart and Lowes perched to give exiting customers a grand view across the sea, a cruise ship at anchor, shore front hotels and homes dotting the mountainside. I directed my focus on the crashing surf, blankets of exposed black lava rock interrupting the predominant green, and shear black cliffs dropping to the sea — the natural stuff. It got better the further south we moved along the coast.

Dan guided Kylie and me through filleting of the spearfish this afternoon. Between the three of us (and the catch team, of course) we secured a good bit of food for the crew. This evening I split spool duty with Kerstin then took a chair from which to watch the rest of the set, read and talk with super fisherman Chris.

It’s a great night back in the world of blue and white.

Question:

Can you find the point on the sea where you would be most distant in any direction from land?

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Geoff Goodenow, May 14, 2004

NOAA Teacher at Sea
Geoff Goodenow
Onboard NOAA Ship Oscar Elton Sette
May 2 – 25, 2004

Mission: Swordfish Assessment Survey
Geographical Area: Hawaiian Islands
Date: May 14, 2004

Time: 1600

Lat: 18 40 N
Long: 158 14 W
Sky: Sunnny with widely scattered cumulus
Air temp: 26.4 C
Barometer: 1011.26
Wind: 172 degrees at 12 knots
Relative humidity: 61.4%
Sea temp: 26.4 C
Depth: 888.5 m

Sea: A few white caps out there; swells in 1-3 foot range — easy going today.

Science and Technology Log

A fairly exciting morning on the longline. Several escolar, a barracuda, and a pomfret (a laterally flattened fish about 30cm long but only 2-3 cm in width with a fine set of sharp teeth). Samples taken from all. We also had a blue shark from which samples were taken and an oceanic white tip shark which was tagged and released. I got to wrestle both. Picked up a few remoras from the sharks. We think we have at least two species of remoras.

This afternoon we passed over Cross Seamount and traversed it several times as we trolled but to no avail. There will be no longline set tonight since we have a date in Kona to drop off one of the current scientific party.

I want to fill in with more of the vision story this evening if I can stay coherent long enough to convey it sensibly. I will touch on the work of Steven, Kerstin, and Rickard.

I have been collecting samples of fish lenses. They vary in size, as you would expect, among different sized fishes. What makes the lenses different from those of most vertebrates is that they are spherical rather than oval in cross section. The cornea of fish is also optically non-functional. Since it has the same refractive index as water, focusing is done by moving the lens back and forth in the eye rather than by changing the shape of the lens as our eye muscles do.

Steven uses laser light to determine the focal point for different colors of light. He suspends lenses in a fluid medium then turns on a laser beam that makes two vertical passes through the diameter of the lens. You can watch light’s path change as the beam migrates. Computer analysis then determines focal point.

Kerstin and Rickard must have live cells from the retina for their studies. Among other things, they are looking at the sensitivity of these cells to different light intensities. Live retina cells convert light to electrical signals which travel via the optical nerve to the brain to produce an image. By attaching electrodes to tissue samples about 1 cm square in size and subjecting the cells to different intensities of light electrical responses of different strengths can be detected and measured. They appear as a wave pattern on a screen. As light intensity is increased, the amplitude of the wave pattern increases. So a flat line (no response) becomes one with small amplitude waves which grow as light intensity increases to a point where more light produces no greater effect.

Lets compare two species, mahi mahi, which stay nearer well lit surface and bigeye tuna which like deeper environs. Which eye would you expect to be more light sensitive? The bigeye. Their cells are stimulated by much lower intensities of light than the mahi’s. They (bigeye) have to be able to detect their prey under minimal light conditions and need the more sensitive eye to do that. Big eyes, big pupils (fish pupil size is fixed) and a “super” sensitive set of retinal cells are adaptations of these fish to their deep environment.

I’ve had enough (as I suppose you have too). I will wrap up the vision story tomorrow or Sunday.

Personal Log

We are headed for Kona. Although we probably will not get any shore time, it has been suggested that there might be an excursion to a place where we can swim/snorkel for awhile. I am hoping very much this it true as are others. A plunge into this element (I guess I should say compound) that we have bobbed around on top of for the past 13 days would be a pleasant change in the routine and scenery.

Reading E.O. Wilson’s The Diversity of Life.

I would like to thank, Ron, a fellow teacher from Michigan who I have never met, for writing a note to tell me that he has been enjoying the logs and also to pose a question. Much appreciated!

Questions:

Sunrise here today is at 6AM and the great yellow ball sets here at 7PM. What time is it rising and setting in your area at this time of year? Find out sunrise and sunset times for the solstices for Honolulu and your area. From that determine A) how much longer the sun is above the horizon for each place in summer vs winter B) which place, Honolulu or your home has more sun time at each solstice? If you find that there are differences explain why they exist.

Geoff