Maggie Flanagan, June 30, 2007

Posted on June 30, 2007 by Teacher at Sea

NOAA Teacher at Sea
Maggie Flanagan
Onboard NOAA Ship Oscar Elton Sette
June 12 – July 12, 2007

Mission: Lobster Survey
Geographical Area: Pacific Ocean; Northwest Hawaiian Islands
Date: June 30, 2007

Science and Technology Log – Setting and Hauling Traps

Maggie Flanagan, scientists, and ship’s crew work together to set lobster traps

We’ve worked a lot with lobster traps by now, and I’ve had the chance to try every part of the job. The science crew works closely with the experienced fisherman of the ship’s crew – it takes teamwork! We take turns preparing bait in the early morning. Thawed mackerel are sliced twice through the middle – be sure to expose the guts which release fluids and oils that are especially attractive to our targets. Later, the traps are set in strings of 8 or 20. Historic data is based on strings of 8, which is why they’re still used even though experience has shown labor is more effective with strings of 20. The traps are all clipped to a gangion, a short line that is spliced (woven) into the length of the ground line (main line of the string) at 20 fathoms (120 feet) apart. Buoys are clipped in at one end for strings of 8 and at both ends for strings of 20. A little entertainment comes from the fun names on our buoys which are called out over the radio – Big Momma, 8-ball, Spifferino, Easy Target. Sadly, we lost the 8-ball float, which is the only gear we’ve lost so far. Setting baited traps happens from the fantail, or aft working deck, of the ship. The stackers (scientists on trap duty) lift and shuffle the traps up to the diamond plate (steel non-slip) at the very stern of the ship. A large pallet tub of our line waits there, with eye splices (loops) for attaching gear carefully stacked on a small pipe, keeping the loops ready, in order, and clear from the many coils of line in the tub. The crew clips a buoy or a trap to a gangion and carefully sends it off the stern. After beginning the string, the traps slide off on their own with the momentum of the line paying out.

Hauling back lobster traps in the pit aboard OSCAR ELTON SETTE

Everyone has to be careful to not accidentally step in a loop of line and get dragged off too. While the traps are going over another crew member, the heaver, manages the tension on the line by guiding it off the stern with a stick in great sweeping arcs. All the while the Chief Bosun, or supervisor, is in radio communication with the bridge to ensure strings are set at the prescribed depth and location. For our data standards, the traps soak overnight. Hauling back the traps happens in the pit, the low open area along the port side of the ship. The officer at the sticks (steering) operates from a side wing of the bridge, and the Chief Bosun operates the pot hauler, a wheel at the top of a tall J frame that helps pull in the line. As the bridge maneuvers close up to the buoy, a crew member throws the messenger (a 4 pronged type hook) to catch the buoy warp (rope). Once the crew pulls in and unclips the buoy, the ground line is led through the pot hauler, and with a steady hiss the traps are brought up. The pot hauler pauses briefly for each trap to be unclipped, and they’re slid down a table to the crackers (members of the science party) to open. Pretty quickly you open, remove creatures to a bucket, remove old bait, fill new bait, and close the trap. Everything and everyone in the pit gets wet and splashed with mackerel juice. A bucketeer keeps order of the specimens collected and helps with sharks and eels. A runner brings the specimens and trap out of the pit. Traps are re-stacked on the fantail and specimens go to the Wet Lab, where the intermediary, assistant, and measurer (more members of the science party) work to catalog them. Overhead, the ground line runs through fair leads (hanging metal circles) back to the pallet tubs on the fantail, where another crew member coils the line back in and stacks the gangion eyes in order.

The lobsters can surprise you with powerful snaps of their tails. The assistant has to hold them firmly while the measurer uses a digital caliper to find the length of the carapace (back of the shell) in millimeters. On certain females, we also measure the exopod part of the first left pleopod (appendages under the tail), which can indicate level of maturity. Females with eggs, spongy masses of tiny round orange or brown specks under the tail, are said to be berried. We also check the lobsters for PIT tags by waving them in front of a scanner – like electronic checkout at the supermarket. These tags are the same type implanted in pets and if sensed, the scanner shows that lobster’s unique number. After all the specimens have been recorded, or when a tagged lobster needs to go back in the same quadrant, the intermediary does a dump, releasing them. Lobsters are dumped through a special cage lowered on the pot hauler, which is designed to deliver them back to the bottom without exposing them to sharks.

Personal Log

It’s hard to say which job in the lobster survey is my favorite. Cracking open the traps is certainly the center of the action, but quite a wet, messy job. Being the measurer makes you feel closely involved with the scientific process, but keeps you working inside. Stacking empty traps is not as interesting, but happens out in the sun while talking and listening to music. I guess I’m enjoying all the jobs, and certainly learning a lot. Since I began writing, we had to stop our lobster survey for a few days to offer medical assistance to another scientist camping on one of the islands. It wasn’t life threatening, thank goodness, and we’re back to work soon.

Rebecca Himschoot, June 29, 2007

Posted on June 29, 2007 by Teacher at Sea

NOAA Teacher at Sea
Rebecca Himschoot
Onboard NOAA Ship Oscar Dyson
June 21 – July 10, 2007

Mission: Summer Pollock Survey
Geographical Area: North Pacific Ocean, Unalaska
Date: June 29, 2007

Pollock from a trawl sample

Weather Data from Bridge
Visibility: 10 nm (nautical miles)
Wind direction: 307° (NW)
Wind speed: 23 knots
Sea wave height: 5 foot
Swell wave height: 1 feet
Seawater temperature: 5.6°C
Sea level pressure: 1014.7 mb (millibars)
Cloud cover: stratus

Science and Technology Log: Survey Techniques and Data

When the science team on the summer pollock survey “see” enough fish to warrant trawling, a net is cast and a sample is collected. The deck crew on the OSCAR DYSON fish the same way commercial fishermen do, just in smaller quantities. The net is placed in the water, and the front end is attached to a “door” on the port and starboard sides. These doors are released into the water and help to open the net. The net is lowered to the depth where the scientists are “seeing” the most fish. After the net has been dragged long enough it is brought back on board and the sample is processed. Once the net is on board, the fish are placed in a bin.

The fishing and deck crew of the OSCAR DYSON release the net for a trawl sample.

The bin can be slowly emptied onto a conveyor belt, where the science team culls out the bycatch and sorts it by species. Each species is documented and weighed, then returned to the sea. Some of these bycatch fish will survive, most will not due to the trauma of the net and being moved so quickly from depth to the surface. Some common bycatch in the summer pollock survey are various flatfish, starfish, come cod and some crabs. The pollock are then also weighed and sorted by gender. Data are collected on gender and length for a large sample, and on a smaller sample more detailed information is collected, such as age. To weigh the fish, a large scale is used for the tubs of pollock, and a net weight can be obtained from the fishing crew. Individual fish are weighed on smaller scales. To know the gender of the fish, a slit is cut in the gut in order to see the gonads. For scientists to know the age of the fish, otolith, or ear bone, samples are taken for later analysis. Each bit of data is collected in the processing area using watertight touch screen computer equipment and scales. Rather than hand writing each fish weight, length and gender, the scientists use a barcode scanner to read each of these data points.

Scientist Sarah Stienessen weighs a sample.

Personal Log

We have settled into a routine, and the night shift is getting easier. The trawl samples are still unpredictable, but we’re doing more of them. Yesterday was a long shift in the lab, but it’s more interesting to see what we catch than to sit around waiting to fish. There were some storm petrels today, as well, to add to my Bering Sea bird list. The seas are getting calmer again, and I’m hoping for a good night’s sleep tonight!

Question of the Day

Answer to the last question: (Scientists use Latin names for each animal or plant they find even though Latin is no longer a living language. How do scientific (Latin) names get selected and why are they important?)

The scientific name for each organism is derived from two Latin names. The first name is the genus the organism belongs to, and the second is its species; these are the narrowest branches of scientific classification (kingdom, phylum, class, order, family, genus, species). In the case of the walleye pollock, it belongs to the genus Theragra, and within that genus it is the chalcogramma species. There could be many other fishes in the Theragra genus, but only one is the species chalcogramma.

Senior Survey Technician Colleen Peters measures a sample.

A scientific name can be descriptive, or it may indicate a geographical location, or it may even be named for the individual who discovered the species. In the case of the walleye pollock, Theragra is from the Greek roots ther (beast) and agra (food – of fur seals) and chalcos (brass) and gramma (mark). The first word in the Latin name is capitalized, the second begins with lower case, and the whole thing is always written in italics.

The scientific name of an organism is important because it is distinctive, so that each organism has only one name (usually). This way a scientist from Russia can communicate clearly with a scientist from Alaska and know that they are speaking about the same organism. Common names can be confusing, and there can be many different names for the same organism (for example, there are many kinds of “salmon,” but only the Oncorhynchus tshawytscha is the king, or chinook salmon). It is important to be aware that scientific names undergo changes as discoveries are made and classifications are refined.

Today’s question: What is an “otolith” and why is it important?

Beth Carter, June 29, 2007

Posted on June 29, 2007 by Teacher at Sea

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: June 29, 2007

Weather Data from the Bridge
Visibility: 8 miles
Wind Direction: Light
Wind Speed: Aires
Sea Wave Height: None
Swell Wave Height: None
Seawater Temperature: 12.8 C
Dry bulb Temperature: 13.3 C, Wet Bulb Temperature: 12.2 C
Sea level Pressure: 1009.4 mb
Cloud Cover: Cloudy, light rain, 8/8
Depth: 31 fathoms

ENS Meghan McGovern and Elishau Dotson are recovering the CTD. After recovery, Elishau connects the CTD to her computer and downloads the readings on temperature, conductivity (a function of salinity), and depth. NOAA uses Wilson’s Equation of Sound Velocity to convert the CTD information to something usable in the software

ENS Meghan McGovern and Elishau Dotson are recovering the CTD. After recovery, Elishau downloads the readings on temperature, conductivity (a function of salinity), and depth. NOAA uses Wilson’s Equation of Sound Velocity to convert the CTD information to something usable in the software

Personal Log (Just have to tell you about the whale first!)

On Thursday, Aug. 28, I went out on the #4 launch from the RAINIER. When the hydrographic team goes out, they go out for the whole day…8:15 until 4:30 p.m. It was sunny and clear, our first sunny day! I went out with ENS Meghan McGovern, Elishau Dotson, Assistant Survey Tech, and our pilot, Jodie Edmond, Able Bodied Seaman – an all female boat crew! First, I have to focus on the wildlife that we saw – it was totally incredible! We saw several sea otters floating on their backs, whiskery and cute! We saw a doe leading her two fawns on the shore of an island. Eagles soared overhead all throughout the day, and one dove to catch a fish (missed), but later, he grabbed one in his talons. We got a quick glimpse of a mother harbor porpoise and her calf feeding near the shore.

The highlight of the day, though, was seeing a humpback whale breaching near the boat – to say that I was totally enthralled is not adequate. I don’t think the dictionary has any words that truly fit! First, I saw a silver/gray shape under the water near the stern, and thought it was a stingray, a common sight on the East Coast. Then, I heard a gasp/blow as the whale surfaced to breathe. The sound was like the “grunt” that Monica Seles makes as she serves up a tennis ball, only lower and longer. We saw the whale surface a few more times, and then his great leap. I was trying to videotape, and of course, I missed it. But it will stay in my memory forever, if not on a memory card.

Science and Technology Log

This is the multi-beam transducer mounted on the hull of the #4 launch of the RAINIER. It can produce a broad band of sounds to “ping” off the bottom of the sea, and provide the data to create a 3-D picture of the ocean floor under and near the boat.

This is the multi-beam transducer on the hull of the #4 launch. It can produce a broad band of sounds to “ping” off the seafloor and provide the data to create a 3-D picture.

Now, to focus upon the hydrographic mission! Before beginning the surveying, the crew lowers a CTD to the sea floor to collect a reading on the Conductivity, Temperature, and Depth of the water. The way that the sonar “pings” travel through water is affected by all three factors. The higher the percentage of salinity, the greater is the ability of the water to conduct sound waves. Higher temperatures also increase sound conductivity in water, and deeper water also conducts sound waves better than shallow water. For example, if the launch is surveying the sea floor in an area near where a freshwater creek is flowing in, the conductivity of the water would decrease; therefore, the survey tech crew that does the night processing of the data would be able to correct the resulting data taking into account the lower conductivity. Number 4 launch has a multibeam sonar transducer mounted on the hull. The transducer produces a broad band of sound “pings” that bounce off the sea floor and return to the launch to be recorded by a sophisticated computer with four screens. The operator of the sonar equipment can see a digital display of the depth, and a real-time three-dimensional picture of the sea floor beneath and around the launch. The boat driver is constantly aware of the depth, so as not to run the launch aground on rock formations.

Elishau is monitoring the real-time data streaming in from the transducer as Jodie drives the “lines” to create pictures of the ocean floor.

The driver steers the boat along a pre-set grid of lines that are programmed into the ship’s computer the night before. Jodie said it is rather like “mowing the grass,” on the surface of the water. You “mow” the water in neat rows until you’ve mowed over every line on the chart established by the hydrographers. After all the lines were run, we returned to the ship, and then, other hydrographic scientists began to run a correction program on the data we gathered. In this way, they clean out errors that are caused by extraneous noises, kelp, echoes, and other obstacles. In the afternoon, we were “snagged” by a gigantic clump of kelp that got wrapped around the transducer. There was so much kelp, the launch could not maneuver effectively. ENS McGovern stabbed the kelp with a boat hook, and Jodie reversed the engines until we shook the kelp loose. Learn more about seafloor mapping here.

Questions of the Day

Later that night, Martha Hertzog, Physical Scientist, looks at the data from the #4 launch, and applies a correction program to the data to eliminate errors. The night processors often work until 11:00 p.m. in order to process the day’s data collections from the 3-4 launches that were out that day.

Later that night, Martha Hertzog, Physical Scientist, looks at the data and applies a correction to eliminate errors. The night processors often work until 11:00 p.m. in order to process the day’s data collections.

These questions are particularly for Ms. Southgate’s oceanography students at Hoggard High School in Wilmington, N.C. (and any other curious people!)

I’m learning that salinity affects conductivity of sound waves. Why does a high concentration of salt in water make sound travel faster? Does electricity travel faster or slower through fresh and salt water? Why?
As we drove different lines yesterday, we took three different CTD readings? Why do you think the hydrographers felt we should collect data three times?
The islands here are very craggy and steep, and made up largely of granite and limestone rock. Much of the sea floor is also rock. Why is the coast of Alaska so vastly different to America’s Eastern coast?
The islands here drop very sharply off into deep water. For example, just 3-4 meters from shore, the depth can drop to 20 meters. Why is this common here? How much is 20 meters measured in feet? In fathoms?

Chris Monsour, June 28, 2007

Posted on June 28, 2007 by Teacher at Sea

NOAA Teacher at Sea
Chris Monsour
Onboard NOAA Ship Oscar Elton Sette
June 12 – July 12, 2007

Mission: Lobster Survey
Geographical Area: Northwestern Hawaiian Islands
Date: June 26, 2007

An eel that was captured during lobster trapping on board OSCAR ELTON SETTE is held in a can until it can be released.

An eel that was captured during lobster trapping is held in a can until it can be released.

Science and Technology Log

My science logs will not have as much science for the next few days as there has been a change in plans. NOAA Ship OSCAR ELTON SETTE is currently responding to a medical emergency within the Monument, which may delay operations for six days. I am not sure what our course of action will be, but the circumstance has shown me just how vast these islands are and how I am essentially in a liquid desert. When I look at a map of all the Hawaiian Islands, it does not seem that big, but if placed over a map of the U.S. mainland, the island of Hawai’i would be in Georgia, along the coast, and Kure Atoll would be in the northeast corner of Utah.

I did some research and found that during the winter storms, which bring about quick currents and dangerous waves in shallow waters, juvenile spiny lobsters leave their shallow reef habitat and travel over 30 miles (19 km) to a deep reef habitat where they will live for their adult life. Spiny lobsters line up in single file when they migrate or move to another area, touching their antennae to the tail of the lobster in front of them. As many as 100,000 lobsters will get in this line, which is thought to look like one long eel or snake. If the lobsters are attacked, they gather in a circle with their tails pointing inward, displaying all of their spines outward. For the science part of this log I will highlight two of the juvenile spiny lobster predators. Essentially, everything is connected out here, and what happens to one eventually will happen to the other.

Hapu’u, a predator of the spiny lobster, caught during bottom fishing

One predator of juvenile spiny lobsters is the eel. The three species of eels that I have seen are the conger eel, lemonhead eel, and the steiny eel. Most often these eels have been in the traps and are regarded with much disdain when the traps are opened. The lemonhead and the steiny are moray eels while the conger is in its own group. Moray eels are numerous in Hawaii, found in holes and under large rocks during the day. They usually hunt in the open under cover of night but will during the day if the opportunity arises. Morays have thick leathery skin that envelops the continuous marginal fin and lack pectoral fins. Morays are rarely consumed by humans since they are likely to cause ciguatera poisoning, a serious neurological condition that can be contracted by eating certain kinds of reef fish.

The two Morays, the lemonhead and steiny attain about 3 feet. I have seen both species at varying lengths and they have an aggressive demeanor. Today one fell on deck as we were removing it from a trap and we were all glad to see it go over board on its own. The conger eels have smooth scaleless skin, large pectoral fins, and the continuous marginal fin rays are easily visible. They are much less common than moray eels in Hawaii. The generic Hawaiian name for eels is Puhi. Another predator of juvenile spiny lobster is the hapu’u, also called the Hawaiian grouper. Groupers are bottom fish, lying in wait near the ocean floor to ambush passing fish or invertebrates. When a likely meal gets close, the grouper opens its expandable mouth and inhales, sucking in both water and prey. As you might suspect, this action takes place with lightning-strike efficiency.

NOAA Teacher at Sea Chris Monsour captured this image of a Galapagos shark during a feeding frenzy. These followers of the ship are one of the reasons that swimming is not permitted.

Chris Monsour captured this image: Galapagos shark during a feeding frenzy. These followers of the ship are one of the reasons that swimming is not permitted.

Personal Log

As mentioned earlier with the change in plans, I will have a lot more time on my hands and will have to find other activities on the ship until we resume operations. We’ll return to Necker Island as soon as we can and begin setting traps. We did not put fresh bait in the traps and we secured all of our equipment on deck. For the next few days I will have time to review some of the data with the scientists, research the other animals we’ve collected, read more books and watch some movies. I have read five books so far and in reality, what else would I be doing? I just wish we could get in the water, but there is this little problem, sharks. The sharks follow the ship at times and I am sure they would love to snack on human if given the chance.

Did You Know?

1. Lobsters can cast off a leg if a predator bites it. This strategy helps to prevent the lobster from getting an infection in a bite wound and it is better to lose a leg than a life.

2. Spiny lobsters produce noises to warn other lobsters to stay out of their territory. They rub the hard area at the bottom of their antennae against ridges on their head. It makes a grating noise that warns others to stay away.

Malama pono….

Chris

Beth Carter, June 27, 2007

Posted on June 27, 2007 by Teacher at Sea

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: June 27, 2007

Weather Data from Bridge
Visibility: 6 miles
Wind direction: 034 degrees
Wind speed: 5 mph
Sea Wave Height: none
Swell Wave Height: none
Seawater temperature: 12.2 degrees C
Sea level pressure: 1017.2 mb
Dry Bulb Temperature: 12.2
Wet Bulb Temp: 11.7
Cloud cover, type: 8/8, stratus and cumulus
Depths: 31 fathoms

Researchers are kneeling in a Sitka spruce forest as they check the computer that is collects and records tidal data on a small island in Nossuk Bay, Alaska.

Science and Technology Log

On Tuesday afternoon, June 26, I went out with a crew of researchers to check the equipment that collects tidal data for Esquibel Bay. There are six main pieces of equipment used to collect this data: 1) a cylinder of nitrogen, 2) a hose attached to the nitrogen cylinder that emits small bubbles of nitrogen into the water, 3) a computer that collects and records data, 4) a solar collector to power the computer’s battery, 5) a transmitter that sends the data to a satellite, and 6) the tide staff (an actual wooden staff in the water), and GPS benchmarks. The staff is set and readings taken so that the vertical measurements of the staff are linked to the benchmarks. The gage, which is officially a “tertiary” gage, is set up concurrent with a “primary” gage that has been acquiring data for over one epoch (19 years or more). Sitka, Alaska, is the site of NOAA’s primary gage, which has similar tidal characteristics to the area that we are working now. Thus, only an amplitude and phase differential must be applied to the Sitka gage to get a water level for this area. Without the staff readings, there would be no way to tie the “bubbler” level to the ground surrounding the gage site, and thus no way to recover the actual local vertical datum (water level) relative to the gage in Sitka.

The nitrogen cylinder slowly leaks bubbles through the hose, which are released into the water. When the tide is high, there is more water and pressure above the hose which makes it more difficult for the bubbles to escape the hose. When the tide is low, there is less water above the hose, and therefore less pressure, which makes it easier for the bubbles to escape. Readings are recorded digitally every six minutes, averaged every six seconds. Staff-to-gage measurements are also recorded every six minutes whenever the site is visited, and 3 hours’ worth are recorded at installation and removal, so that the vertical measurements of the station are effectively “tied” to the measurements at the primary water level station at Sitka. (Good Working Question: Download data from both stations and compare the two – are there differences? Next, compare Sitka and Ketchikan and Kodiak – are there bigger differences?).

ENS Meghan McGovern, Junior Officer of RAINIER, and Shawn Gendron, survey technician, position the tripod which will hold the transmitter to collect the GPS information needed by the RAINIER.

For some reason, the transmitter is not emitting signals that can be read by the satellite, and therefore by the scientists at NOAA headquarters. This is why the skiff took several technicians over to check the equipment to see if it is still functioning and recording properly. They downloaded the water level data to send to headquarters via email while also setting up GPS equipment so that an ellipsoidal (GPSrelative) height can also be linked to the orthometric (gravitational) elevation determined through water level measurement, and will return to the ship and process the GPS data. The tides are important to hydrographic surveying, because obviously, the water is deeper at high tide than at low tide. The goal is to collect accurate information on tides, and then combine that with the data collected by the launches, in order to get accurate depth information. The tide-corrected depths on the chart they want to show are relative to the mean low low water, which is the average of the lowest of daily tides taken over the last 19 years. On the Atlantic Ocean, tides are semi-diurnal. This means that there are two high tides and two low tides per 24 hours. But, on the Northeastern Pacific, tides are mixed. See here for more details.

Today, (Wed. June 27), the crew returned to the small island to check on the HorCon station, which stands for Horizontal Controls. The RAINIER established this water level station in April of 2007, and set into place 5 benchmarks which are tied into the international framework of benchmarks that make it possible to utilize GPS, or Global Positioning Satellites to determine one’s exact location. RAINIER’s researchers placed a receiver antenna on top of a tripod, which was positioned exactly above the center of the metal disc benchmark cemented into a rock. The antenna receives from some of the 11 Global Positioning System satellites that orbit the earth and constantly change their relative positions. For a final position to be accurate, at least four satellites must be recorded in two different sessions of more than six hours duration separated by at least one day. They connected the cables, turned on the GPS receiver and then waited for the satellite constellation (also known as the ephemeris) to be downloaded so that all available satellites could be tracked. The first satellite was tracked around 1 hour later, and then we left the island, as the equipment was to be left in place for at least 6 hours. When we returned 6 hours later, 8 satellites had made contact, and the recordings were noted and will be taken for evaluation onboard the ship.

Anna-Liza Villard-Howe, the Navigation Officer of the RAINIER, explained to me that the GPS measurements of benchmarks are being conducted in order to get as precise a determination of sea level as is possible, so that all the hydrographic information collected by the RAINIER can be referenced to the ellipsoid. Sea level has changed in Alaska in the recent past due to glacial rebound, which means that as the glaciers recede, the land is actually rising. Also, many large earthquakes have occurred in Alaska in the last century, which also changed the shape of some landforms and affected sea level readings. Online Sea Floor Mapping Activity Targets Kids (CED, OCS). In celebration of World Hydrography Day, NOAA’s Ocean Service Communications and Education Division, in cooperation with NOAA’s Office of Coast Survey, launched a new educational offering — Sea Floor Mapping — on the National Ocean Service Education Web site. It is designed for students at the 3^rd – 5th grade level, and the media-rich activity teaches young people about mapping the seafloor and why it is important. This activity also conveys information about NOAA’s missions of discovery and service. The Sea Floor Mapping Activity is available online here.

Questions of the Day

Why are tides in the Pacific and Atlantic different? What are the factors that affect tidal changes?
Look up a tidal chart for the inlet or beach nearest to your home. How far apart are the high and low tides?
Who (which country or countries/which agencies) is responsible for the maintenance of the 11 Global Positioning Satellites that are now orbiting the earth? If a satellite fails, would it be replaced? By what agency?

Personal Log

While on the tiny island, one of the officers carried a shotgun…in case we met a bear! I’m pleased to say we didn’t encounter a bear, but did discover animal scat, and two eagle feathers. One was a tail feather – beautifully white – and we didn’t collect the feathers because it is illegal to collect eagle feathers. We also saw 7-8 harbor seals on a rock outcropping. We tried to sneak up on them to get good photographs, but they bobbed and rocked and slipped into the water before we got very close. Also, on the island I was surprised to find many clumps of saltwort, which Eastern coast students (and my first grade class!) should recognize from the mud flat near the salt marsh. It tastes….salty! No surprise there.

On Wednesday, there were so many white gnats that we sent the skiff back to the ship for bug repellant. They were like No-See-Ems, only we could See Em and Feel Em! We built a small, smoky fire, which made things somewhat better. The highlight of the day for me was kayaking after dinner with the XO (Executive Officer) of the ship, and Ian Colvert, an assistant survey technician. We saw a rainbow and paddled through a misty rain, then sunshine…a beautiful evening.

Rebecca Himschoot, June 26, 2007

Posted on June 26, 2007 by Teacher at Sea

NOAA Teacher at Sea
Rebecca Himschoot
Onboard NOAA Ship Oscar Dyson
June 21 – July 10, 2007

Mission: Summer Pollock Survey
Geographical Area: North Pacific Ocean, Unalaska
Date: June 26, 2007

Weather Data from Bridge
Visibility: .5 nm (nautical miles)
Wind direction: 80° (ENE)
Wind speed: 10 knots
Sea wave height: 1 foot
Swell wave height: 1 feet
Seawater temperature: 4.4°C
Sea level pressure: 1018.8 mb (millibars)
Cloud cover: stratus

Deck crew of the OSCAR DYSON retrieving sensors from a buoy.

Science and Technology Log: Data buoy retrieval and replacement

Luckily we had calm weather today to retrieve two data buoys that were deployed in 2006, and replace them. These buoys contained an Acoustic Doppler Current Profiler, a marine mammal voice recorder, and sensors for other data such as water temperature, nitrates, and salinity. Because the sensors are on a stationary buoy, the information is collected at depth (much of this same information is collected on board the OSCAR DYSON continuously, but at the surface), and over a long period of time.

Life Cycle of the Walleye Pollock
(Interview with Dr. Mikhail Stepanenko, scientist from TINRO)

Dr. Mikhail Stepanenko is assisting in the summer pollock survey from his home institution, the Pacific Research Fisheries Center (TINRO), which is located in Vladivostok, Russia. Dr. Stepanenko graduated with a degree in fish biology in 1968, the year before an agreement was signed for scientists in the Soviet Union and the United States to cooperate to help manage international fisheries. Dr. Stepanenko took some time to share what he knows about the life history of the walleye pollock. According to Dr. Stepanenko, walleye pollock are found throughout the Bering Sea, and south into the Gulf of Alaska. Their range extends as far west as Russian and Japanese waters, and east to the Eastern Aleutians. These fish can live up to 25 years, however the average age of a walleye pollock is 10-12 years. Pollock are related to the cod family.

Scientist Bill Floering with some of the new sensors deployed today

Pollock begin spawning around age 4, although the most productive spawning years for both males and females is between 5-8 years of age. Dr. Stepanenko has observed pollock spawning in an aquarium setting. The male will swim next to a female to show his interest. If she is also interested in that male, the female will swim next to him with sudden, short bursts of speed for several hours before they spawn. If she is not interested, she will continue to swim normally until the male gets the message.

Mature pollock spawn annually in nearshore areas, mostly in the Bering Sea and Gulf of Alaska (98% of pollock spawn in US coastal waters). Although the females will spawn only once annually and then move to the edge of the spawning area to feed, the males will spawn 4-5 times during the annual spawning season.

The eggs will hatch about 25 days later, or longer if the water temperatures are colder. The annual survival rate of the eggs and larvae is highly dependent on the sea conditions and salinity. At the correct salinity, the eggs sink and then are suspended at a certain depth due to a thermocline at that depth. Poor sea conditions or a dramatic shift in salinity can result in higher mortality for the eggs or the larvae. They must also survive predators such as jellyfish and other small fish.

Dr. Mikhail Stepanenko processes walleyed Pollock

Dr. Mikhail Stepanenko processes walleye Pollock

Directly after hatching the pollock larvae have enough yolk reserve to survive a few days, but they must find food within the first three days of hatching if they are to survive. The larvae are approximately 3.5 mm long when they hatch, and with enough food will grow several centimeters in the first year of life. Only two of the 30-40 types of plankton in the Bering Sea are small enough to serve as prey for these tiny fish. Harsh sea conditions, salinity changes, and scarce food resources in the first year contribute to a survival rate of only about .1% of pollock eggs. Adult pollock eat euphausids, as well as smaller fish such as capelin or smelt. In times of scarcity, pollock are given to cannibalism.

The international pollock fishery targets four-year-old fish, and the total Bering Sea harvest of pollock is around two million metric tons annually. Pollock is used in frozen seafood products, such as fish sticks, and as a central ingredient in surimi.

Personal Log

We have been in an area where there are very few fish, so much of my time has been spent learning about pollock and the work that is done here on board. The sea has been pretty rough at times, and I have continued to take some seasickness medication. We’re getting back into places with fish, so soon we’ll be collecting more data.

Question of the Day

Answer to the last question about the controlled variables in the summer pollock survey: (The scientific method includes controlling the variables in an experiment. What are some examples of variables the science team from the AFSC is controlling in the summer pollock survey?)

One example is the calibration of the acoustic equipment at the beginning of each leg of the survey. Another example is that the OSCAR DYSON cruises the same area of the Bering Sea during each summer pollock survey on transects of the same basic lengths and directions. The survey is conducted at the same time every year, as well.

Today’s question: Scientists use Latin names for each animal or plant they find, even though Latin is no longer a living language. How do scientific (Latin) names get selected and why are they important?

Walleye pollock

Beth Carter, June 26, 2007

Posted on June 26, 2007 by Teacher at Sea

NOAA Teacher at Sea
Beth Carter
Onboard NOAA Ship Rainier
June 25 – July 7, 2007

Mission: Hydrographic Survey
Geographical Area: Gulf of Esquibel, Alaska
Date: June 26, 2007

Weather Data from the Bridge
Visibility: 10 nautical miles
Wind Direction: 132 degrees, from the Southeast
Wind Speed: 6 knots
Sea Wave Height: 0-1 feet
Swell Wave Height – no swell
Seawater Temperature: 11.7 degrees Celsius
Sea Level Pressure: 1018.8 millibars
Cloud Cover & Type: 7/8 coverage, mixed cumulus and stratus
Air temperature: Dry Bulb: 15 degrees C, Wet Bulb: 10 degrees C
At anchor, water depth: 32 fathoms

NOAA Teacher at Sea, Beth Carter, prepares to set sail on NOAA Ship RIANIER.

NOAA Teacher at Sea, Beth Carter, prepares to set sail on NOAA Ship RAINIER.

Science and Technology Log

At 8:00 this morning, our CO (Commanding Officer) held a safety and mission briefing on the fantail of the ship. The fantail is the back open area of the ship. The RAINIER’s main mission is to conduct hydrographic mapping surveys from its six small launches that are carried aboard the RAINIER. Each launch has equipment that transmits sound waves that are directed toward the floor of the bay, or area to be mapped. The sound waves bounce back to a special receiver on the launch, and the depth data is recorded on the launch. These depths are plotted as dots, and so later in the evening, the technicians basically “connect the dots” to form a picture of the ocean floor in the area that was surveyed that day. When the RAINIER finishes this 3-week leg of its mission, all of this data will be given to the NOAA Office of Coast Survey, Pacific Hydrographic Branch, in Seattle, WA. They take the data and create digital terrain models, or DTM’s, which are color-coded maps of the sea floor. The maps look very cool…the deepest waters are shown to be dark blue, lighter blues show shallower water, and hazards and rocks and sand bars are shown in various shades of green, yellow, red and orange. The resulting DTM’s represent the most probable bathymetry of the area. The maps are so detailed you can see the outlines of sunken ships and large rocks on the bottoms of the bays. The information from our leg will be compiled for chart 17404, and for smaller scale charts. If you are interested in seeing maps that show the areas we are charting, try this website.

Crew of the NOAA Ship RAINIER prepare to deploy a launch.

Creating these maps is important because current maps of the waterways in Alaska are outdated – some of them very outdated. Yesterday, the CO showed me some sections of map that were created as long ago as 1834-1899, with more of the maps being created between 1900-1939, or 1940-1969. It is interesting that NOAA (National Oceanic and Atmospheric Agency) is using sonar in much the same way that whales and dolphins and bats use sound waves for echolocation so that they can determine locations of the sea floor, obstacles, or other animals.

I asked about the current debate over the Navy’s use of sonar, and the belief that its sonar is interfering with the whales/dolphins’ abilities to use their sonar. Vincent Welton, our Electronics Technician, explained to me that NOAA uses a higher frequency, less amplified type of sound waves that will not confuse the marine mammals. The Navy sometimes uses a very low frequency sonar to detect submarines. Today, two of the launches are out doing the hydrographic mapping. Later in the day, two divers will go out to check the bottom of the hull, and I will go out on a small skiff to watch some of the technicians gather some data on tides. It appears that some of the equipment to measure tides is working erratically, so we will go check that out.

Personal Log

I enjoyed watching the crew deploying the four skiffs and launches that are going out for today’s work. Everyone has to wear hard hats and float coats to stay safe when out on the fantail. The best part of the morning was when Steve Foye, the Boatswain Group Leader, pointed out to me that a humpback whale was swimming near the ship. I saw the whale spout several times, and twice, he seemed he rolled on his side, as I saw a fin pop up. Then, his fluke appeared above the water, and he slapped the water and disappeared. Steve told me he was “diving down to check out the groceries…he knows which aisle to shop on.” He also said he’d be down a long time, as he’d taken a big breath and was going to going to be eating until he needs to come back up to breathe. If you are a CFCI student (or any student!) and have a question for me, please E-mail this address: teacheratsea.rainier@noaa.gov. I’d love to hear from you, and promise to try to respond in my logs.

Terms Used Today

Fathom: 1 fathom equals 6 feet
Sea level pressure: Barometric, or air pressure. When air pressure is high as it is today (over 1000 millibars or mb) it indicates that the weather is sunny or overcast, with little threat of rain. When the pressure drops, it often means a storm or rain is on the way. The eye of a hurricane can have a barometric pressure reading as low as 875 mb.
Cloud cover: expressed in terms of portions of the sky covered out of 8 parts (whole coverage)
Wind direction: indicates which direction the wind is blowing FROM. 0 degrees is North, 90 degrees is East, 180 degrees is South, and 270 degrees is West.

Questions of the Day

Why is it important to have updated maps of waterways in Alaska, or anywhere? Who needs to use these maps? Why?
Before this sonar technology was developed, how were depth maps created?
We are anchored today. How deep is the water under the ship? (1 fathom equals 6 feet, and the water is 32 fathoms deep now)

NOAA Teacher at Sea Blog

Monthly Archives: June 2007

Maggie Flanagan, June 30, 2007

Rebecca Himschoot, June 29, 2007

Beth Carter, June 29, 2007

Chris Monsour, June 28, 2007

Beth Carter, June 27, 2007

Rebecca Himschoot, June 26, 2007

Beth Carter, June 26, 2007