Jennifer Fry: March 24, 2012, Oscar Elton Sette

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship, Oscar Elton Sette
March 12 – March 26, 2012

 

Mission: Fisheries Study
Geographical area of cruise: American Samoa
Date: March 19, 2012

CTD data collection graphs

These charts show levels of salinity, temperature, density of the waters of American Samoa.

Teacher at Sea, Jennifer Fry, Survey tech, Scott Allen, NOAA scientists, Evan Howell, Megan Duncan, Aimee Hoover work on the CTD operations performing 8 casts in the day.

5.Once the crane operator lifts the unit out of the water, scientists guide the C.T.D. onto the deck.

6. The C.T.D. unit is safely back on the deck. Scientists collect an array of data including density, temperature, and conductivity using the C.D.T. unit.

4. Using a crane to lift and a hook to grab, the C.T.D. unit is guided onto the deck.

2. The C.T.D. is ready to be deployed into the ocean. Using a team of scientists, a crane, and crane operator the heavy unit is carefully guided into the water.

3. Once is determined safe, the doors on the side of the ship are opened to deploy the C.T.D. unit into the water.

1. The ocean’s depth is always checked prior to a C.T.D. operation to know how deep the unit can be deployed.

CTD Operations: Conductivity, Temperature, and Depth

The CTD Operations onboard the Sette are conducted by Evan Howell, Pacific Islands Fisheries Science Center, Megan Duncan, Joint Institute for Marine and Atmospheric Research at the University of Hawaii, and Scott Allen, NOAA survey tech. The CTD platform, which resembles a giant wedding cake constructed of painted steel, contains multiple instruments that can measure water characteristics including pressure, temperature, salinity, oxygen levels, and chlorophyll concentration.

Jennifer Fry, Scott Allen, Evan Howell, Megan Duncan, and Aimee Hoover stand behind the CTD.

It takes 30 readings per second as it sinks towards the seafloor.

The CTD records data as it sinks and ascends, but only data from the downcast is used, insuring the instruments are recording data in an  uninterrupted “profile” of the water column.  All data collected helps capture ocean characteristics. The acquired data will be shared with the American Samoa Department of Marine and Wildlife Resources scientists and compared with the data they have collected previously.

Using prior data, current CTD data, and acoustic Doppler current profiler, a  type of sonar detecting water currents, scientists can determine patterns in the oceans of American Samoa and compare them.

Animals Seen:

Short-finned Pilot Whales

Dolphins, possibly Pacific Spinner

Jennifer Fry: March 9, 2012, Oscar Elton Sette

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship, Oscar Elton Sette
March 12 – March 26, 2012

Mission: Fisheries Study
Geographical area of cruise: American Samoa
Date: March 9, 2012

Personal Log

Pago Pago

With the morning light, the island’s landscape came into view.  Looking back toward land was the single road, a variety of buildings, consisting of numerous churches, restaurants, schools, and hotels.  I have come to learn that each small village has its own church and outdoor meeting hall.  Behind the buildings the topography extended upward forming a steep hillside covered with green, lush tropical plants, including a variety of palms and fruit trees laden with mangoes and papayas.

After a hearty Samoan breakfast with ten of the scientists that will be on the research vessel, we met with representatives from the local marine sciences community at the American Samoan government building.  Chickens, chickens, and a small clutch of baby chickens happily pecked on the lawn in front of the building which put a smile on my face.

These chickens found their home in front of the Government Building of Pago Pago, American Samoa.

Scientific Log

The chief scientist, Dr. Donald Kobayashi, began by introducing the team of scientists and gave a brief overview of the upcoming mission aboard NOAA Ship Oscar Elton Sette.

The variety of investigations that will be conducted during these next 2 weeks which include:.

  1. Midwater Cobb trawls:  Scientists, John  Denton, American Museum of Natural History, and Aimiee Hoover, acoustics technician , Joint Institute for Marine and Atmospheric Research of the University of Hawaii, will conduct nighttime tows that will focus on epipelagic and pelagic juvenile reef fish and bottomfish species.
  1. Bot Cam: Using a tethered camera that is later released to float to the surface, and using acoustics–a.k.a. sonar readings–scientists Ryan Nichols, Pacific Islands Fisheries Science Center , Meagan Sundberg, Joint Institute for Marine and Atmospheric Research of the University of Hawaii, and Jamie Barlow , Pacific Islands Fisheries Science Center, will collect samples of fish at selected sites during the cruise.
  1. CTD experiments: “Conductivity, Temperature, and Depth.”   At predetermined locations scientists Evan Howell, Pacific Islands Fisheries Science Center, and Megan Duncan, Joint Institute for Marine and Atmospheric Research at the University of Hawaii, will collect water samples called “profiles” taken of the water column at different depths.  This data is very important in determining the nutrients, chlorophyll levels, and other chemical make-up of the ocean water.
  1. Plankton tows:  Using plankton and Neuston nets, scientists Louise Giuseffi, Pacific Islands Fisheries Science Center, and Emily Norton,University of Hawaii, Manoa, Biological Oceanography department, will conduct day and nighttime plankton tows focusing on plankton and microplastic marine debris.  Scientists will be  looking at a specific species of plankton called the copepod.  This study will also be collecting microplastic pieces, some of which are called “nurdles” which are small plastic pellets used in the manufacturing process. Unfortunately most plastic debris will never degrade and just break into smaller and smaller pieces potentially working their way into the food web, making this research and its findings very important to environmental studies.
  1. Handline fishing using a small boat, the Steel Toe: Scientists Ryan Nichols, Pacific Islands Fisheries Science Center, Meagan Sundberg, Joint Institute for Marine and Atmospheric Research at the University of Hawaii, and Jamie Barlow, Pacific Islands Fisheries Science Center, will conduct daily fishing expeditions obtaining scientific data on bottomfish, grouper and snapper species.   They will be focusing on life history factors including age, growth, male/female ratios, length and weight.  This is very exciting research since the last data collected from this region was from the 1970s and 80s.

I am very excited and fortunate to be part of this important scientific research project, and the significant data collected by the scientists.

Did You Know?
American Samoa pronunciation: The first syllable of “Samoa” is accented.
Pago Pago (capital of American Samoa): The “a”  pronunciation uses a soft “an” sound as in “pong.”

Animals Seen Today
Frigate birds
Common Myna
“Flying Foxes” Fruit bats
Kingfisher
Brown tree frog
Dogs, various
Chickens, various

Steven Wilkie: June 26, 2011

NOAA TEACHER AT SEA
STEVEN WILKIE
ONBOARD NOAA SHIP OREGON II
JUNE 23 — JULY 4, 2011

Mission: Summer Groundfish Survey
Geographic Location: Northern Gulf of Mexico
Date: June 26, 2011

Ship Data:

Latitude 26.56
Longitude -96.41
Speed 10.00 kts
Course 6.00
Wind Speed 4.55 kts
Wind Dir. 150.72 º
Surf. Water Temp. 28.30 ºC
Surf. Water Sal. 24.88 PSU
Air Temperature 29.20 ºC
Relative Humidity 78.00 %
Barometric Pres. 1012.27 mb
Water Depth 115.20 m

Before getting down to work, it is important to learn all precautionary measures. Here I am suited up in a survival suit during an abandon ship drill.

Science and Technology Log

After two days of travel we are on site and beginning to work and I believe the entire crew is eager to get their hands busy, myself included.   As I mentioned in my previous post, it is difficult if not impossible to separate the abiotic factors from the biotic factors, and as a result it is important to monitor the abiotic factors prior to every trawl event.  The main piece of equipment involved in monitoring the water quality (an abiotic factor) is the C-T-D (Conductivity, Temperature and Depth) device.  This device uses sophisticated sensors to determine the conductivity of the water, which in turn, can be used to measure salinity (differing salinities will conduct electricity at different rates).   Salinity influences the density of the water: the saltier the water the more dense the water is.  Density measures the amount of mass in a specific volume, so if you dissolve salt in a glass of water you are adding more mass without much volume.  And since Density=Mass/Volume, the more salt you add, the denser the water will get.   Less dense objects tend to float higher in the water column than more dense objects, so as a result the ocean often has layers of differing salinities (less salty water on top of more salty water).  Often you encounter a boundary between the two layers known as a halocline (see the graph below for evidence of a halocline).

Temperature varies with depth in the ocean, however, because warm water is less dense than cold water. When liquids are cold, more molecules can fit into a space than when they are war; therefore there is more mass in that volume.   The warm water tends to remain towards the surface, while the cooler water remains at depth.  You may have experienced this if you swim in a local lake or river.  You dive down and all of a sudden the water goes from nice and warm to cool. This is known as a thermocline and is the result of the warm, less dense water sitting on top of the cool more dense water.

Here is the fancy piece of technology that makes measuring water quality so easy: the CTD.

Temperature also influences the amount of oxygen that water can hold. The cooler the temperature of the water the more oxygen can dissolve in it.  This is yet another reason why the hypoxic zones discussed in my last blog are more common in summer months than winter months: the warm water simply does not hold as much oxygen as it does in the winter.

The CTD is also capable of measuring chlorophyll.  Chlorophyll is a molecule that photosynthetic organisms use to capture light energy and then use to build complex organic molecules that they can in turn be used as energy to grow, reproduce etc.  The more chlorophyll in the water, the more photosynthetic phytoplankton there is in the water column.  This can be a good thing, since photosynthetic organisms are the foundation of the food chain, but as I mentioned in my earlier blog, too much phytoplankton can also lead to hypoxic zones.

Finally the CTD sensor is capable of measuring the water’s turbidity.  This measures how clear the water is.  Think of water around a coral reef — that water has a very low turbidity, so you can see quite a ways into the water (which is good for coral since they need access to sunlight to survive).  Water in estuaries or near shore is often quite turbid because of all of the run off coming from land.

This is a CTD data sample taken on June 26th at a depth of 94 meters. The pink line represents chlorophyll concentration, the green represents oxygen concentration, the blue is temperature and the red is salinity.

So, that is how we measure the abiotic factors, now let’s concentrate on how we measure the biotic!  After using the CTD (and it takes less time to use it than it does to describe it here) we are ready to pull our trawls.  There are three different trawls that the scientists rely on and they each focus on different “groups” of organisms.

The neuston net captures organisms living just at the water's surface.

The neuston net (named for the neuston zone, which is where the surface of the water interacts with the atmosphere) is pulled along the side of the ship and skims the surface of the water.  At the end of the net is a small “catch bottle” that will capture anything bigger than .947 microns.  The bongo nets are nets that are targeting organisms of a similar size, but instead of remaining at the surface these nets are lowered from the surface to the seafloor and back again, capturing a representative sample of organisms throughout the water column.   The neuston net is towed for approximately ten minutes, while the bongo nets tow times are dependent on depth.   Once the nets are brought in, the scientists, myself included, take the catch and preserve it for the scientists back in the lab to study.

The bongo nets will capture organisms from the surface all the way down to bottom.

The biggest and baddest nets on the boat are the actual trawl nets launched from the stern (back) of the boat.  These are the nets the scientists are relying on to target the bottom fish.  This trawl net is often referred to as an otter trawl because of the giant heavy doors used to pull the mouth of the net open once it reaches the bottom.  As the boat moves forward, a “tickler” chain spooks any of the organisms that might be lounging around on the bottom and the net follows behind to scoop them up.  This net is towed for thirty minutes, and then retrieved and we spend the next hour or so sorting, counting and measuring the catch.

Here you can see the otter trawl net extending off the starboard side of the Oregon II. When lowered into the water the doors will spread the mouth of the net.

Personal Log
I thought that adjusting to a 12 hour work schedule would be tough, but with a 5-month old son at home I feel I am more prepared than most might be for an extended day.  I might go as far as to say that I have more down time now than I did at home!  Although the ship’s crew actually manages the deployment of the majority of the nets and C-T-D, the science team is always involved and keeping busy allows the hours to tick away without much thought.  Before you know it you are on the stern deck of the ship staring at a gorgeous Gulf of Mexico sunset.

As we steam back East, the sun sets in our stern every day, and we have been treated to peaceful ones thus far on this trip.

The sun has long since set.  As I write this it is well after midnight and my bunk is calling.