Mary Anne Pella-Donnelly, September 19, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 19, 2008

Weather Data from the Bridge 
Latitude: 3624.8888 N Longitude: 12243.8013 W
Wind Direction: 261 (compass reading) SW
Wind Speed: 8.0 knots
Surface Temperature: 16.385

Figure indicating migration of different genetic stocks of Pacific leatherback turtles.

Figure indicating migration of different genetic stocks of Pacific leatherback turtles.

Science and Technology Log 

Turtle Genetics 
Peter Dutton is the turtle specialist on board, having studied sea turtles for 30 years.  His research has taken him all over the tropical Pacific to collect samples, study behaviors and learn more about Dermochelys coriacea, the leatherback turtle. Mitochondrial DNA (is clonal=only one copy) is only inherited maternally (from the mother), so represents mother’s genetic information (DNA), while nuclear DNA has two copies, one inherited from the mother and the other from the father .By looking at the genetic fingerprint encoded in nuclear DNA it is possible to compare hatchling “DNA fingerprints”, with their mother’s and figure out what the father’s genetic contribution was. This paternity (father’s identifying DNA) analysis has produced some intriguing results.

Peter Dutton looking for turtles with the ‘big eyes’.

Peter Dutton looking for turtles with the ‘big eyes’.

An analysis of chick embryos or hatchling DNA indicates all eggs were fertilized throughout the season from the same dad. It is thought that the female must store sperm in her reproductive system. Successively, throughout the nesting season, a female will lay several clutches, one clutch at a time.  Females come in to the beach for a brief period (leatherbacks – approx 1.5 hrs) every 9-10 days to lay eggs for the 3 or 4 month nesting season (they lay up to 12). Sometimes it is the same beach; sometimes it is a beach nearby. Research done on other sea turtles is showing some species have actually produced offspring with other species of sea turtle. One example is of a hawksbill turtle with a loggerhead turtle in Brazil. In this case, the phenotype appeared to indicate one species, while the DNA analysis indicates the animal was a hybrid, with a copy of DNA from each of the two different species. At some point geneticists may need to re-define what constitutes a “species”.

The last few eggs most of the leatherback turtles lay are infertile, yolkless eggs.  No one is certain about the function of these eggs, although several theories have been suggested. Many unknowns exist about these turtles. Scientists have not yet found a means to determine the age of individual sea turtles, so no one knows how long-lived they are. The early genetic research on leatherbacks showed some information that surprised the scientists.  It had been thought that all leatherbacks foraging off the northwestern coast of USA originated in the eastern tropical Pacific, from nesting beaches in Mexico.  Careful DNA analysis, however, found that animals at California foraging grounds are part of the western Pacific genetic stock recently identified by Dutton and colleagues. Both Peter and Scott have emphasized that there is still much to learn, and they have just begun, however, much has also been learned during the past six years, including the origin of leatherbacks that utilize California waters.

Personal Log 

Yesterday the sun came out and it was a glorious evening.  A group of us watched the sunset from the flying bridge, and then later watched the moon rise.  It was spectacular, and with the ‘big eyes’, it was possible to see many of the moon’s craters.  The stars were also magnificent!  Today has been cloudy with a layer of fog eventually drenching the boat.  This weather has made yesterdays blue skies all the sweeter.

Words of the Day 

Mitochondrial DNA: DNA found within the mitochondria – originates from the mother; Clonal: identical to the original; Clutch: a single batch of eggs, laid together; Hybrid: one gene from one species and the second gene from a second species; Species: an organism that can mate with another of its own kind and produce fertile offspring.

Animals Seen Today 

Common dolphin Delphinus delphis, Fin whale Balaenoptera physalus, Black-footed Albatross Phoebastria nigripes, Moon jellies Aurelia labiata, Sea nettle jellies Chrysaora fuscescens, and Common dolphins Delphinus delphis.

Questions of the Day 

  1. Geneticists are beginning to obtain new tools to figure out how similar animals are related to each other. What are some questions you have related to leatherback turtle genetics?
  2. Scott’s turtle map shows that leatherbacks nesting in the Western Pacific migrate across the Pacific to the coast of North America, while leatherbacks that nest in Costa Rica only migrate to waters off the South American coast.  Why might some populations stay in the same region, while others cross the Pacific Ocean?
Sunset over the port side

Sunset over the port side

Mary Anne Pella-Donnelly, September 18, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 18, 2008

Weather Data from the Bridge 
Latitude: 3543.3896 N Longitude: 12408.3432 W
Wind Direction: 129 (compass reading) SE
Wind Speed: 7.8 knots
Surface Temperature: 17.545

Blue shark seen on 9/18

Blue shark seen on 9/18

Science and Technology Log 

Today was an exciting one scientifically. The team has been examining all of the oceanographic data so far in order to pinpoint frontal edges for further data collection. They selected a point last night that might contain a biologically rich layer and hopefully, with jellies. After closely looking over every thing they have learned on this trip so far and plotting a destination to sample, we traveled to that station. We found an ocean water ‘river’ full of kelp, moon jellies, sea nettles and pelagic birds! It was exactly where the team predicted there might be a biotic stream!! This confirmed that offshore habitats can be found using oceanographic data and satellite imaging.  There certainly were offshore areas that would give leatherbacks a chance to eat their fill.  And through that period, the sun came up!  With only a slight breeze, the flying deck was warm and relaxing. It put us all into excellent spirits.

Personal Log 

Ray Capati shows off his Turtle Cake. (photo by Karin Forney)

Ray Capati shows off his Turtle Cake.

A few days ago, the chief steward made a cake- there are daily baked goods offered in the mess hall. This cake, however, was decorated for the LUTH Survey with turtles, kelp and jellyfish!  Today would have been another good day for that treat.  It is also time to get some pictures with C.J. our school mascot.  He was pretty happy to get out and see the ship.  He even tried to help up on the flying bridge, but without thumbs, it was hard for him to enter in observation comments.

Animals Seen Today 
Moon jellies Aurelia labiata, Sea nettle jellies Chrysaora fuscescens, Salps Salpida spp., Sea gooseberries Pleurobrachia bachei, Red phalaropes Phalaropus fulicaria, Cuvier’s beaked whales Ziphius cavirostris, Common dolphins Delphinus delphis, Blue sharks Prionace glauca, and Arctic terns Sterna paradisaea.

C.J. helps out on the flying bridge.

C.J. helps out on the flying bridge.

Questions of the Day 

  1. What might be some oceanographic conditions that would create a water mass filled with kelp and jellyfish?
  2. What other organisms (than we observed) might be attracted to such a water mass?

Mary Anne Pella-Donnelly, September 17, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 17, 2008

Weather Data from the Bridge 
Latitude: 3614.8661 W Longitude: 12402.7415 N
Wind Direction: 190 (compass reading) SW
Wind Speed: 2.1 knots
Surface Temperature: 15.230

Science and Technology Log 

Above is a spreadsheet of some of the Chrysaora fuscescens data that was collected on September 15.  The first trawl was at 4:48 pm, the second at 6:39 pm and the third at 8:20 pm.  A fourth trawl was deployed at 10:49 pm. A total of 204 jellies were sorted and measured.  Of these, the first 7jellies measured from trawl numbers’ 46, 47 and 48 are recorded above. All of the species in this data set are Chrysaora fuscescens. Using the spreadsheet, create a graph that compares mass to length for these 21 animals.  When you believe you have completed this, answer the questions listed below.

Screen shot 2013-04-20 at 1.48.14 AM

Questions:

  1. Is your graph complete?
  2. Check to see if you have included; all units-mass in kilograms, length in millimeters; a legend that includes the code of the points; title for each axis(length of jelly in millimeters, mass of jelly in kilograms); title for graph.
  3. Did you make a scatter plot, bar graph or line graph? The best choice would be a scatter plot, this may give an indication of patterns in the relationship between length and mass.
  4. Can you see any pattern?  Is there a relationship between mass and length? This would be indicated by a linear pattern in the points?
  5. Do there appear to be any points that do not fit a general pattern?  What might cause these points that do not fit the norm to exist?
  6. Compare your graph with the one shown below, generated by the computer.

Screen shot 2013-04-20 at 1.48.32 AM

These Chrysaora fuscescens were caught in “jelly lane”, in the waters near Pacifica, CA that are known to have large jelly populations.  It is also an area known for leatherback sightings because of this food source. A great deal of information is known about the oceanographic conditions in this near-shore habitat. The reason the LUTH survey is crisscrossing off the continental shelf, is that much less is known about deeper offshore waters as a potential food source for migrating leatherbacks.  The routes they travel on must have some food available, so we are working to find out where that is, and gain information about relationships to oceanographic variables so that researchers will be able to eventually estimate where that food is using satellite images that will be translated into jellyfish habitat.

Chico Gomez and Scott Benson sorting jellies.

Chico Gomez and Scott Benson sorting jellies.

Personal Log 

There was quite a bit of excitement today up on the flying bridge. Although we were traveling out beyond the continental shelf, we moved over a front of water that had an abundance of moon jellies.  It was unexpected and the scientific team became very excited. New plans were made based on this observation and a decision was made to cross back across the front and collect temperature data within the water column every 10 minutes.  Quantitative observations were made of all jellies seen port and starboard and a net trawl was deployed at one point along the zone of interest.  It was quite a day. We also spotted blue sharks, ocean sunfish, and a swordfish jumping.  It was a good day.

Animals Seen Today 

Extracting stomach contents from large C. fuscescens

Extracting stomach contents from large C. fuscescens

  • Sooty shearwater Puffinus griseus 
  • Sea nettle jellies Chrysaora fuscescens 
  • Moon jellies Aurelia aurita 
  • Northern Fur seal Callorhinus ursinus 
  • Elephant seal Mirounga angustirostris 
  • Swordfish Xiphias gladius 
  • Blue shark Prionace glauca 
  • Buller’s shearwater Puffinus bulleri 
  • Ocean sunfish Mola mola 
  • Rhinoceros auklet Cererhinca monocerata 
  • Black-footed Albatross
  • Phoebastria nigripes 

Questions of the Day 

  1. What might be possible reasons the scientific team was excited at finding jellyfish out beyond the continental shelf?
  2. The weather has been very calm and mostly overcast.  One of the officers told me he would much rather have those conditions, than windy and sunny.  What effect might wind have on a sturdy, ocean-going ship?
Ocean sunfish seen from flying bridge.

Ocean sunfish seen from flying bridge.

Sunset seen from flying bridge, the first sunset we’ve seen on this leg.

Sunset seen from flying bridge, the first sunset we’ve seen on this leg.

Mary Anne Pella-Donnelly, September 16, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 16, 2008

Weather Data from the Bridge 
Latitude: 3720.718 N Longitude: 12230.301
Wind Direction: 69 (compass reading) NW
Wind Speed: 12.0 knots
Surface Temperature: 15.056

Scott measures a moon jelly as Amy records data.

Scott measures a moon jelly as Amy records data.

Science and Technology Log 

The LUTH Survey is a collaborative effort to gather as much oceanographic data from this small part of the Pacific Ocean as possible.  Although the primary objective is to characterize this area for its potential as leatherback habitat, it is also an opportunity for other scientists to gather data that reinforces their studies. Everyone on this cruise, aside from myself, is employed by the National Oceanographic and Atmospheric Administration’s National Marine Fisheries Service.  The regional area that this group works in is the Southwest Fisheries Science Center.  There are nine scientists who have very different specializations.  The following flow chart outlines how each department is related to the others.

Crewmembers practice suction cup tagging of leatherbacks from a Rigid Hull Inflatable Boat (RHIB).

Crewmembers practice suction cup tagging of leatherbacks from a Rigid Hull Inflatable Boat (RHIB).

Every division is focused on different aspects of oceanography.  Scott Benson is our chief scientist and leatherback specialist.  Karin Forney is the research biologist on the team whose expertise is marine mammals and regulations out to the limit of United States waters.  This limit is the EEZ – Exclusive Economic Zone – and extends for 200 miles west of the coast. Peter Dutton is currently the leader of the Marine Turtle Genetics Program, here to gain additional insight into foraging habitats of the leatherback.  Liz Zele, oceanographer, and Justin Garver as oceanography intern, manage the collection and processing of oceanographic data from the CTDs and XBTs. Steven Bograd is supporting the data collection as a research oceanographer. Both George (Randy) Cutter and Juan Zwolinski collect and interpret the acoustic data.  Randy’s area of expertise is with fisheries acoustics, seafloor mapping and autonomous underwater vehicles.  Juan’s specialty is in acoustic estimation of small pelagic fish.  Amy Hapeman is aboard as a permit analyst to gain a better understanding of how the science data are collected.  Together, this dynamic group will work to put together a better picture of what habitat might be available to leatherback turtles here off the continental shelf of California. They are all excited to be here, greatly enjoy their professions, and hope to assist in leatherback turtle protection.

Justin prepares to collect head and organs for research.

Justin prepares to collect head and organs for research.

The night of September 13, a few members of the research team, with assistance from crewmembers, took advantage of the relatively warm water the Jordan was crossing and tried to fish for squid. Not really expecting much more than a short fight with a 12 inch mollusk, we were in for a surprise. Using a fluorescent lure, and a 50lb test, the line was dropped about 200m into the dark sea. Within 5 minutes, the line began to tug, and tug, AND TUG!!  The oceanographer/fisher used a tremendous amount of strength to reel in the organism on the other end of the line. Victor, crewmember and experienced squid fisher, gaffed the squid as soon as it surfaced in the water. Shock was on every face as we acknowledged we were not expecting a 65cm long, 30-40lb animal!  As soon as the tentacles that it grabbed the lure with were detached from the lure, Justin was ready to go again!  And within 5 minutes another squid was caught, easily the same size as the first.  This brought another three scientists and one crewmember out with additional reels. 

Two Humboldt squid fresh from the Pacific!

Two Humboldt squid fresh from the Pacific!

Within an hour, eight squid were aboard, plans were made for a calamari feast and measuring began. Karin Forney, after observing the commotion, quickly retrieved an email from a colleague who is conducting research on this species of squid, and who requested that we preserve the head and internal organs for later genetic analysis.  Several Ziplock bags were readied and the cleaning began. In the end there were calamari steaks for everyone and their 10 best friends, tentacles for several pots of soup and research samples collected for additional analysis. This species of squid is of concern since it had been uncommon off the central California coast until after the 1998 El Nino event, which brought warm waters up from the tropical Pacific side. Now it is much more abundant. The Humboldt squid is a voracious predator and there is great interest in understanding its potential impact on other species, especially those of commercial value.

Randy and Mary Anne cleaning Humboldt Squid.

Randy and Mary Anne cleaning Humboldt Squid.

Animals Seen Today 
Blue shark Prionace glauca, Humboldt squid Dosidicus gigas, Arctic tern Sterna paradisaea, and Common redpoll Carduelis flammea.

Words of the Day 
Gaff: hook attached to a long pole used to bring in a catch Characterize: to decide what the parts are that together create something Acoustic: sound wave information El Nino: a cyclic climate event originating in the tropical Pacific that is associated with unusually warm waters that impact the west coast of North and South America.

Joao preparing his secret calamari marinade.

Joao preparing his secret calamari marinade.

Questions of the Day 

  1. A squid is classified as a mollusk, which is a single shelled marine animal.  Where is the single shell on this animal?
  2. What are some of the reasons the study of leatherback turtles is so complex?

Screen shot 2013-04-20 at 1.46.35 AM

Mary Anne Pella-Donnelly, September 15, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 15, 2008

Weather Data from the Bridge 
Latitude: 3720.718 N Longitude: 12230.301
Wind Direction: 69 (compass reading) NW
Wind Speed: 12.0 knots
Surface Temperature: 15.056

Computer generated images showing acoustic scattering during the day

Computer generated images showing acoustic scattering during the day

Science and Technology Log 

A lot of physical science is involved in oceanographic research.  An understanding of wave mechanics is utilized to obtain sonar readings. This means that sound waves of certain frequencies are emitted from a source.  The concepts to understand in order to utilize acoustic readings are:

  1. Sound and electromagnetic waves travel in a straight line from their source and are reflected when they contact an object they cannot pass through.
  2. Frequency is defined as the number of waves that pass a given point per second (or another set period of time).  The faster the wave travels, the greater the number of waves that go past a point in that time. Waves with a high frequency are moving faster than those with a low frequency. Those waves travel out in a straight line until they contact an object of a density that causes them to reflect back.
  3. The speed with which the waves return, along with the wavelength they were sent at, gives a ‘shadow’ of how dense the object is that reflected the wave, and gives an indication of the distance that object is from the wave source (echo sounder). As jellyfish, zooplankton and other organisms are brought up either with the bongo net or the trawl net, examinations of the acoustic readings are done to begin to match the readings with organisms in the area at the time of the readings.  On the first leg of the survey, there were acoustic patterns that appeared to match conditions that are known to be favorable to jellyfish.  Turtle researchers have, for years, observed certain characteristics of stretches of ocean water that have been associated with sea nettle, ocean sunfish and leatherbacks. Now, by combining acoustic readings, salinity, temperature and chlorophyll measurements, scientists can determine what the exact oceanographic features are that make up ‘turtle water’.
Computer generated images showing acoustic scattering at night.

Computer images of acoustic scattering at night.

Acoustic data, consisting of the returns of pulses of sound from targets in the water column, is now used routinely to determine fish distribution and abundance, for commercial fishing and scientific research. This type of data has begun to be used to quantify the biomass and distribution of zooplankton and micronekton. Sound waves are continuously emitted from the ship down to the ocean floor. Four frequencies of waves are transmitted from the echo-sounder.  The data is retrieved and converted into computerized images. Both photo 1 and photo 2 give the acoustic readings. The “Y” axis is depth down to different depths, depending on the location.  The frequencies shown are as follows for the four charts on the computer screen; top left is 38kHz, bottom left is 70 kHz, top right is 120kHz and bottom right is 200 kHz.  In general the higher frequencies will pick up the smallest particles (organisms) while the lowest reflect off the largest objects. Photo 1 shows a deep-water set of images, with small organisms near the surface. This matches the fact that zooplankton rise close to the surface at night.  Photo 2 gives a daylight reading.

A Leach’s storm petrel rests on the trawl net container.

A Leach’s storm petrel rests on the trawl net container.

It is more difficult to interpret.  The upper one-fourth is the acoustic reading and the first distinct horizontal line from the top represents the ocean floor.  Images below that line are the result of the waves bouncing back and forth, giving a shadow reading.  But the team here was very excited: for this set of images shows an abundance of organisms very near the surface. And the trawl that was deployed at that time resulted in lots and lots of jellyfish.  They matched.  Periodically, as the acoustic data is collected, samples are also collected at various depths to ‘ground truth’ the readings.  This also allows the scientists to refine their interpretations of the measurements.  The technology now can give estimates of size, movement and acoustic properties of individual planktonic organisms, along with those of fish and marine mammals.  Acoustic data is used to map the distribution of jellyfish and estimate the abundance in this region. By examining many acoustic readings and jellyfish netted, the scientists will be able to identify the acoustic pattern from jellyfish.

Karin releases a petrel from nets he flew into.

Karin releases a petrel from nets he flew into.

The sensor for the acoustic equipment is mounted into the hull, with readings taken continually.  Background noise from the ship must be accounted for, along with other types of background noise. Some events observed on board, such as a school of dolphins being sighted, can be correlated (matched) to acoustic readings aboard the ship.  Since it is assumed that only a portion of the dolphins in a pod are actually sighted, with the remaining under the surface, the acoustic correlation gives an indication of population size in the pod.  The goal of continued acoustic analysis is to be able to monitor long term changes in zooplankton or micronekton biomass. This monitoring can then lead to understanding the migration, feeding strategies and monitor changes in populations of marine species.

A Wilson’s warbler rests on the flying deck.

A Wilson’s warbler rests on the flying deck.

Personal Log 

Several small birds have stopped in over the week, taking refuge on the Jordan. Many bird species make long migrations, often at high altitude, along the Pacific flyway.  Some will die of exhaustion along the way, or starvation, and some get blown off their original course.  Most ships out at sea appear to be an island, a refuge for tired birds to land on.  They may stay for a day, a week, or longer. Their preferred food source may not be available however, and some do not survive on board.  Some die because they are just too tired, or perhaps ill, or for unknown reasons. We have had a few birds, and some have disappeared after two days.  We hope they took off to finish their trip. Since we were in site of land all day today, it could be the dark junco headed to shore. ‘Our’ common redpoll did not survive, so he was ‘buried at sea’, with a little ceremony.  About half an hour ago, a stormy petrel came aboard.  He did not seem well, but after a bit of rest, we watched him take off.  We wish him well.

Words of the Day 

Acoustic data: sound waves (sonar) of certain frequencies that are sent out and bounce off objects, with the speed of return an indication of the objects distance from the origin; Echo sounder: device that emits sonar or acoustic waves Dense or density: how highly packed an object is  measured as mass/volume; Distribution: the number and kind of organisms in an area; Biomass:  the combined mass of a sample of living organisms; Micronekton: free swimming small organisms; Zooplankton: small organisms that move with the current; Pacific flyway: a general area over and next to the Pacific ocean that some species of birds migrate along.

Animals Seen Today 
Leach’s Storm-petrel Oceanodroma leucorhoa
Herring gull Larus argentatus
Heermann’s gull  Larus heermanni
Common murr  Uria aalge
Humpback whale  Megapterea novaeangliae
California sea lion Zalophus californianus
Sooty shearwater Puffinus griseus
Brown pelican Pelecanus occidentalis
Harbor seal Phoca vitulina
Sea nettle jellies Chrysaora fuscescens
Moon jellies Aurelia aurita
Egg yolk jellies Phacellophora camtschatica 

Questions of the Day 
Try this experiment to test sound waves.  Get two bricks or two, 4 inch pieces of 2 x 4 wood blocks. Stand 50 ft opposite a classroom wall, and clap the boards together. Have others stand at the wall so they can see when you clap. Listen for an echo.  Keep moving away and periodically clap again. At some distance, the sound of the clap will hit their ears after you actually finish clapping. With enough distance, the clap will actually be heard after your hands have been brought back out after coming together.

  1. Can you calculate the speed of the sound wave that you generated?
  2. Under what conditions might that speed be changed?
  3. Would weather conditions, which might change the amount of moisture in the air, change the speed? 

Mary Anne Pella-Donnelly, September 13, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 13, 2008

Weather Data from the Bridge 
Latitude: 3645.9407 N Longitude: 12501.4783 W
Wind Direction: 344(compass reading) NE
Wind Speed: 13.5 knots
Surface Temperature: 14.197

Computer generated map of sampling area using satellite and in situ data. The satellite image on the right includes land (white) on the right edge, of the area between San Francisco and San Luis Obispo.

Computer generated map of sampling area using satellite and in situ data. The satellite image on the right includes land (white) on the right edge, of the area between San Francisco and San Luis Obispo.

Science and Technology Log 

As the scientific team conducts its research locating areas where jellyfish congregate, they have determined that samples need to be taken along both sides of a warm water/cold water boundary.  The charts below comprise a computer-generated chart of water temperature in the area we are focusing on. The chart on the right was created from remotely sensed data obtained from a satellite, and a small square of that is enlarged on the left. The chart on the left is produced from a computer model that smoothes out the lines and includes data taken continuously from the ship and integrated into the chart. Although hard to read at this resolution, the legend shows where CTD’s have been deployed, along with XBT’s, which record temperature. It also marks where upcoming deployments will take place. Net trawls were also deployed to collect samples of jellyfish that might be in the region. The quest is on for good turtle habitat.

After examining these charts above, please answer the following questions:

  1. What can you tell about the temperature of the water just off the coastline for most of that area of California?
  2. What range temperature of water does it appear that the LUTH survey is currently sampling in?
  3. Would you expect to find the same organisms in each of the samples? Why or why not?
  4. What might cause temperatures to be different in some parts of the ocean?

The Expendable Bathy Thermograph (XBT), consists of a long copper wire shot into the water down to 760 m.  When kept in the water for 2 minutes, the cable registers a signal to a dedicated computer, giving temperature readings along the wire, which are immediately plotted onto a graph.

After looking at this graph, answer the following questions:

  1. What temperature is measured at the surface?
  2. At what depth below the surface does the temperature start to drop dramatically? How many degrees Celsius is the drop?
  3. How many more degrees does the temperature drop, after the initial quick decrease? In how many meters does this gradual drop occur?

The LUTH survey is very interested in finding out whether jellyfish are found in the colder water (yellow and green), and how the distribution changes through the changing temperature of the water. Their questions surround what conditions would allow leatherbacks to travel along certain routes to and from the California coast, and how to identify areas of productivity so that commercial fishing can occur without harming protected species. Every jellyfish caught, either by the net trawls or the bongo net, and oceanographic data collected at the same time, provides more insight into where favorable conditions might exist.

Personal Log 

Computer generated graph of XBT data from 8/28/08 at 18:15:30 (6:15 pm)

Computer generated graph of XBT data from 8/28/08 at 18:15:30 (6:15 pm)

It is a very different lifestyle to have a profession that involves living for periods of time aboard a ship. Most of us land-based folks get up, wander through the house, eventually rounding up food and heading off to school or work.  For me, after a day full of movement all over Chico Junior High’s large school grounds, I may go to the store, run errands and then return home to read the paper, clean house, and prepare dinner.  My family will eventually arrive home and we will go over the day’s events.  Here, the crew spends up to 23 days in this home, office and recreational area, away from their families.  Two cooks prepare, serve buffet-style and clean up after all meals; serving at 7am, 11am and 5pm.  During off hours, I have observed T.V. or movie watching, card games in action and some gym use.

Many people have iPods and in some areas music is broadcast. Personal computers with satellite internet capabilities are used, I assume, to communicate with friends and family on land.  It is interesting that the ‘living room’, which is also the mess hall, may have 10 colleagues in it sometimes watching a show. I am used to cooking when I choose, or just making cookies if I want or heading outside to jog with my dog after school. No such activities like that happen here.  Every one in the crew seems to get along, is extremely polite to each other, and is also very pleasant.  It takes a very flexible person to enjoy living on a ship and a certainly love for the ocean.  I am enjoying this very different way of living, and will also enjoy when I can run a few miles through the park again.

Animals Seen Today 
Sea nettle jellies Chrysaora fuscescens
Comb jellies Kiyohimea spp.
Sea gooseberry Pleurobrachia bachei
Common dolphins Delphinus delphis
Jack mackerel Trachurus symmetricus
Wilson’s warbler Wilsonia citrine
Yellow-rumped warbler Dendroica coronata 

Questions for the Day 
1. What part of your regular pattern would be easiest to give up, if you were to live aboard a ship?  Which parts would be hardest?

Mary Anne Pella-Donnelly, September 11, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 11, 2008

CTD deployment

CTD deployment

Weather Data from the Bridge 
Latitude: 3647.6130 W Longitude: 12353.1622 N
Wind Direction: 56 (compass reading) NE
Wind Speed: 25.7 knots
Surface Temperature: 15.295

Science and Technology Log 

One important piece of equipment on many NOAA research ships is the CTD (Conductivity and Temperature with Depth).  This eight chambered water collection device is attached to electronic sensors. When the CTD is deployed below the ocean’s surface, it is dropped carefully to a predetermined depth; today’s was 500 m. All water collection chambers are open for water to flow through. After the oceanographer in charge of deployment examines a computer readout of the CTD after it has been lowered to its’ maximum depth, it is decided at which depths water samples will be collected as the CTD is brought back up.At these intervals, water sample collectors (Niskin bottles) are closed and water collected.  Up to eight samples are collected as it rises to the surface.

CTD reading; salinity, oxygen, pressure, and fluorometer voltage

CTD reading: salinity, oxygen, pressure, and voltage

After the CTD has been secured on deck, each sample is carefully extracted into collection bottles. Each water sample is filtered through a vacuum system in order to extract chlorophyll from that water sample.  The extracted chlorophyll is later run through a fluorometer, which calculates the volume of chlorophyll a and chlorophyll b which indicates the intensity of photosynthetic microorganisms in that layer. Lots of chlorophyll indicates a rich biological region, which may support many types of marine life.  In addition, the CTD collects samples that will be analyzed for the amount of salts they contain in order to confirm the sensors values. Values that change to the left are decreasing. The reading on the top right shows how the temperature, in red, changes very quickly from the surface down to 500 m.  The green indicates some chlorophyll until it drops significantly below 100 m, where light no longer penetrates well. Oxygen levels are in blue, also decreasing with depth.

Questions of the Day 

  1. What is the importance of chlorophyll to marine mammals and amphibians?
  2. Why is an understanding of how pressure and depth below the ocean’s surface are related critical to marine sciences?
Water samples being filtered through a vacuum system to extract chlorophyll.

Water samples being filtered through a vacuum system to extract chlorophyll.