DJ Kast, NOAA Ship Henry B. Bigelow, May 31, 2015

Posted on May 31, 2015 by dkast2015

NOAA Teacher at Sea
Dieuwertje “DJ” Kast
Aboard NOAA Ship Henry B. Bigelow
May 19 – June 3, 2015

Mission: Ecosystem Monitoring Survey
Geographical area of cruise: East Coast
Date: May 31, 2015

NOAA Ship Henry B. Bigelow

“National Oceanic and Atmospheric Administration (NOAA) Ship Henry B. Bigelow is the second of five new fisheries survey ships to be built by NOAA. The ship is named after Henry Bryant Bigelow (1879-1967), a Harvard-educated zoologist whose work helped lay the scholarly foundation for oceanography as a scientific discipline. He was an internationally known expert on the Gulf of Maine and its sea life, and on the world’s jellyfish, corals, and fishes” (NOAA NEFSC).

http://www.nefsc.noaa.gov/Bigelow/pdfs/bigelow_scientist_poster.pdf

Henry B. Bigelow and his goat Buck. PHOTO BY:

Henry B. Bigelow and the WHOI Mascot goat Buck. Photo by: NEFSC NOAA

Legacy of the name:

Henry B. Bigelow (1879–1967) was an American oceanographer and marine biologist. Bigelow described numerous new species to science, 110 of which are recognized today according to the World Register of Marine Species. In addition, some 26 species and two genera (Bigelowina, stomatopods in family Nannosquillidae, and Bigelowiella, protists in family Chlorarachniophyte) are named after him. The Henry Bryant Bigelow Medal in Oceanography is awarded by the Woods Hole Oceanographic Research Institute to honor “those who make significant inquiries into the phenomena of the sea”. Bigelow was the first recipient of the medal in 1960. He was honored by the naming of NOAA Ship Henry B. Bigelow.

Mission of the ship:

“NOAA ship Henry B. Bigelow will support NOAA’s mission to protect, restore, and manage the use of living marine, coastal, and ocean resources through ecosystem-based management. Its primary objective will be to study, monitor, and collect data on a wide range of sea life and ocean conditions, primarily in U.S. waters from Maine to North Carolina. The region includes Georges Bank, one of the world’s best known and most productive marine areas. The region is also home to the nation’s top-valued port, oldest commercial fisheries, and rare large whales and sea turtles. Data are used by a range of scientists who study variation in ocean conditions and sea life in order to better inform the nation’s decisions about both using and sustaining the ocean’s bounty.

“Henry B. Bigelow will also observe weather, sea state, and other environmental conditions, conduct habitat assessments, and survey marine mammal and marine bird populations. Henry B. Bigelow is a state-of-the-art research ship with multiple science mission capabilities. Foremost among these capabilities is the ship’s “quiet” hull, a design feature that minimizes sound made by the ship underwater. This allows scientists to use hydroacoustic methods for surveying marine life, and significantly reduces changes in the natural behavior of animals owing to the ship noise. In addition, the vessel can collect a variety of oceanographic data while marine life surveys are underway, resulting in both richer and more efficiently collected data.” (NOAA NEFSC)

Ship Details:

The ship! Photo from: http://www.nefsc.noaa.gov/Bigelow/pdfs/bigelow_sci_systems.pdf

Take a virtual Ship Tour here! : http://www.nefsc.noaa.gov/Bigelow/shiptour.html

Levels: 2 (staterooms, gym, laundry), 1 (Mess Hall), 01 (Lounge), 02, Bridge, Flying Bridge

Side view of the NOAA Henry B. Bigelow. Photo by: http://upload.wikimedia.org/wikipedia/commons/e/e7/NOAA_RV_Henry_B._Bigelow_–_side_plan.gif

Most of the main deck is reserved for mission functions. The aft working deck provides 145 sq m of open space for fishing and other over-the-side operations, with an additional 33 sq m of deck space at the Side Sampling Station. Space and support connections are provided for a laboratory van on the aft working deck.

Large, easily reconfigurable laboratories are designed to accommodate the varied needs of individual scientific cruises:

Fish/Wet Laboratory 56 sq m (602 sq ft)
Chemistry Laboratory 27 sq m (290 sq ft)
Dry Laboratory 14 sq m (150 sq ft)
Hydrographic Laboratory 9 sq m (96 sq ft)
Scientific Freezer 19 sq m (204 sq ft)
Preservation Alcove 5 sq m (54 sq ft)
Acoustic/Computer Laboratory 46 sq m (495 sq ft)

“Underwater radiated noise has been shown to influence fish behavior, and sonar self-noise can limit the effectiveness of hydroacoustic surveys and other functions. The International Council for Exploration of the Seas (ICES) has established a standard for ships’ underwater radiated noise in order to effectively employ hydroacoustic stock assessment techniques. Henry B. Bigelow has been designed and constructed to meet this ICES noise standard. This reduced noise signature will improve NOAA’s ability to accurately assess fish stocks and to compare standardized data with the international fisheries scientific community. Examples are the propulsion motors, which are specially constructed and balanced to reduce noise and vibration, and the diesel generators, which are mounted on double isolated raft systems. The hull form and highly skewed, five-bladed propeller were carefully designed and tested using U.S. Navy quieting techniques. Pumps, motors, ventilation and piping systems are all designed for low noise, with some critical systems resiliently mounted in the ship. Hull structure is treated in critical areas with special acoustic damping tiles. Airborne noise has been reduced throughout the ship for personnel safety and comfort.” http://www.omao.noaa.gov/publications/bigelow_final.pdf

To summarize that, this ship is so quiet I cannot tell when we are slowing down to 2 knots for bongo or going 11 knots to steam to the next station. It’s amazing.

Bridge:

The bridge is equipped with numerous dedicated systems including:

Hydrographic ES60 SONAR system, and ME70 multibeam system
Dynamic positioning and auto pilot system
X- and S-band Sperry Bridge Master RADARs
Transas ECDIS Navigation system
DGPS receiver
GMDSS communications suite including weather fax, satellite telephone, MF/HF and VHF radios
MTN internet communications system
SCS remote console and master clock display
Doppler speed log and depth sounder
Sperry primary and secondary gyro compass

Nearly all of these systems are solely controlled from the bridge, allowing scientific and operational systems to be totally independent. All scientific and fishing systems can be monitored from the bridge via remote consoles or SCS interfaces.

Layout of the bridge. Photo by DJ Kast

Laura Gibson charting on the navigational chart. Photo by DJ Kast

Depth Profiler. Photo by DJ Kast

Multi-beam bottom sounder. Photo by DJ Kast

Gibson letting me steer the ship. That is fear in my eyes. Photo by Laura Gibson

Starboard steering Console that lets you control the ship while the bongos or CTDs are deployed from the side sampling station. Photo by DJ Kast

Radar with four contacts! Photo by DJ Kast

Electronic Chart Photo by DJ Kast

LT Gibson checking on operations in the bridge. Photo by DJ Kast

Control and status indicator of watertight doors. Photo by DJ Kast

Navigation Light switches. Photo by DJ Kast

Cool Events on the Ship

Care Package Delivery:

The XO's friend that is "Rowing for Peace" to Turkey. The XO delivered ice cream, ship hats, and a pineapple. Photo by DJ Kast

The CO’s friend that is “Rowing for Peace” to Turkey. The CO delivered ice cream, ship hats, and a pineapple. Photo by DJ Kast

Emergency Drills:

The Bigelow values safety and to make sure that everyone knows what to do in an emergency they do quiet a few surprise drills to keep everybody on their toes.

Door sign with information on where to go for each person during each of the type of drills that occur on the ship. Photo by DJ Kast

Station card with information on where to go for each person during each of the type of drills that occur on the ship. Photo by DJ Kast

The first one was a Fire Drill and an Abandon Ship Drill on Wednesday May 20th, 2015.

Photo of me in a survival suit after the abandon ship drill was announced. Photo by Megan Switzer

Practicing the PLT gun (Pneumatic Line Throwing Gun): This is a gun that is used to help rescue people who have fallen overboard and it is also used to pass lines to other boats. It has a projectile connected to a long line that can travel far distance and connect an overboard victim to the boat.

Here is a video of it being shot:

A picture of me preparing the PLT gun for launch. Photo by Dennis Carey

Photo by Marjorie Foster.

Hydrophoning Acoustic Buoys!

While we were on the southern part of Georges Bank, the boat used a Hydrophone and geometry to pick up an Autonomous Multi-Channel Acoustic Recorder (AMAR) mooring in Lydonia Canyon. The ship sent signals to it with the hydrophone and the signals it received back were indications of where to send the boat next.

The application of the Pythagoreon Theorum in terms of acoustic sound distances to the buoy to help during retrieval. Oh the applications of MATH! Photo by DJ Kast

The application of the Pythagorean Theorem in terms of acoustic sound distances to the buoy to help during retrieval. Oh, the applications of MATH! Photo by DJ Kast

Geoff Shook sending out messages on the hydrophone. Photo by DJ Kast

Geoff Shook preparing to send out messages on the hydrophone to not only find it but also cause it to release to the surface since it was hundreds of meters down. Photo by DJ Kast

Successful retrieval of the acoustic buoy. Photo by DJ Kast

The back of the shirt that the crew and chief Scientist Jerry gave me. Photo by DJ Kast

The back of the shirt that the crew and chief Scientist Jerry Prezioso gave me. I’m having everyone sign it so that I can hang it up when I get home. Photo by DJ Kast

All of the crew have been absolutely amazing and have definitely made this the trip of a lifetime. Thank you all so much. -DJ

Last selfie of the trip. Photo by DJ Kast

Alex Miller: Smooth Sailing So Far, May 31, 2015

Posted on May 31, 2015 by millercommaalex

NOAA Teacher at Sea
Alexandra (Alex) Miller, Chicago, IL
Onboard NOAA Ship Bell M. Shimada
May 27 – June 10, 2015

View of the Hatfield Marine Science Center and NOAA dock as the Shimada pulled away.

Mission: Rockfish Recruitment and Ecosystem Assessment
Geographical area of cruise: Pacific Coast
Date: Sunday, May 31, 2015

Weather Data:

Air Temperature: 11.1°C
Water Temperature: 11.8°C
Overcast skies
Wind Speed (kts) and Direction: 15, SSE

Science and Technology Log

Last of the bridge we’ll see for some time.

We finally weighed anchor and set sail at 1032 Friday morning. Fog blanketed the shores of Newport as we passed below the Yaquina Bay Bridge and out into the channel created by the North and South Jetties. One of our last sights from shore was Chief Scientist Ric Brodeur’s wife, who had come to see us off. The fog was so thick that before we had even reached the end of the jetty her lime green jacket was hidden from view.

Emily and I and several of the other scientists watched our departure from the flying bridge, the highest observational deck on board the ship. It provides an almost unobstructed 360-degree view of the surroundings—making it perfect for Amanda’s surveys—but it’s also right next to the foghorn, which had to be blown every two minutes until we reached greater visibility. Needless to say, we all found somewhere else to watch the waves.

Visibility was low as we left Newport.

Once the ship had moved farther offshore, some of the fog cleared but the moisture in the air was still enough to cause concern for the computers so Amanda went to the bridge, an enclosed deck that houses the navigational instruments that the captain and other officers use to drive the ship. Here she began setting up her survey equipment.

Up to this point, I’d been getting a lot of great advice about handling the first few hours on board the moving ship. Some people suggested I lay down, but the go-getter in me wanted to work. Using a program that is linked to the ship’s GPS, Amanda taught me how to code the observations she was making of the seabirds and marine mammals. As she kept her eyes glued on the 90-degree quadrant made by making a quarter port (while facing the front of the ship, counter clockwise or left, for you digital folks) turn from the bow (front of the ship) (in the image at the top of this post, you can see a panoramic view of quadrant I, the port bow of the ship), she would call out codes for the species, distance from the ship and behavior of the bird she observed. If she were to spot any marine mammals–pinnipeds (pin-eh-peds) (seal and sea lions) or cetaceans (ceh-tay-shins) (dolphins and whales)–that gets entered in a separate database.

Amanda surveying from the flying bridge.

Amanda has to be prepared to work alone as she is the only ornithologist on the ship, but with a Teacher at Sea and other volunteers on board willing to learn and help out, she’s able to rely on us to share some of the work. She and I were working as quite the well-oiled machine for a solid 20 minutes before I made peace with the fact that I did not have my sea legs. To my great relief, it’s something you can sleep off.

__________________________

While at sea, the most important thing to remember is to be safe, so once we had been underway for a few hours, the ship’s crew and team of scientists went through drills to practice safety protocols for two of the three significant events that could happen at sea. A 10-second blast on the horn sounded the alarm for the fire drill, and all crew and scientists mustered (gathered) in their assigned locations. Next, 7-short, and 1-long blast signaled the start of the abandon ship drill. The need to abandon ship is highly unlikely, but out at sea you need to be prepared for anything. Most importantly, you need to know how to get into your survival suit, and fast.

Emily and I decided to practice since we were both first-timers to these impressive red neoprene onesies. Since they’re designed to be large enough to fit over your shoes and warm clothes, they can be awkward to put on, especially when you get to the zipping part. And who cares how they look when the water is 8-10° Celsius, a temperature that could cause hypothermia or fatal loss of body temperature.

Emily and I managed to get the survival suits on!

__________________________

Saturday was spent sampling a little bit of everything. Of course I paid a visit to Amanda up on the flying bridge to hear about how the birding (and marine mammal-ing) was going. Often, I find Emily there assisting with data entry. Since Amanda can only survey when the ship is traveling faster than 7 knots, traveling from station to station gives her time to look, but sometimes these distances are short and our time at the stations, releasing the various equipment needed for different scientists’ data collection, can be long. This is when Amanda goes off effort (not collecting data) for longer periods of time and during these times, Emily and I have taken to teaming up to check out what’s going on in the wet lab.

Jaclyn releases the neuston tow into the water.

Home to most of the science crew, the wet lab is wet. Initially, I thought foul weather gear was meant for, well, foul weather, but between the hauling in, spraying down and rinsing of the samples caught in the nets, everyone in the wet lab is wearing theirs full-time. Also, everyone must wear hard hats and PFDs (personal flotation devices, also known as life jackets) when out on deck as the equipment is being released or hauled in. Safety first, as always!

My cabin mate, Jaclyn Mazzella, and Phil White, are the two survey technicians on the Shimada. They help release and monitor the nets and equipment that are being used on this research cruise. More on these two interesting cats later.

Emily and I working hard to haul in the CTD.

While in the wet lab, Emily and I witnessed the CTD being hauled in. CTD stands for conductivity, temperature and depth. Conductivity is a measurement of salinity, or how salty the ocean water is. The way it works is by passing an electric current through the water and measuring how fast it travels. This is connected to how salty the water is because when salt is dissolved in water, it separates into ions, these particles carry a charge and allow electric current to pass through. More conductive water will be salty, less conductive water will be less salty or fresh.

We know that temperature provides a measurement of how hot or cold something is. In this case, we’re measuring the temperature of the water. It is mostly cold off the Oregon coast, though the scientists on board have been discussing a recent unexplained area of warmer water, dubbed the “warm blob.” Biologists aim to discover if the warm blob is going to have an impact on the fisheries.

As the CTD is lowered and raised, it can take measurements of these and other factors which allow biologists to compare the diversity and number of species they collect in their nets to the data collected. One of those nets is the neuston tow, a net that skims the surface of the water. It is one of several nets that are being used to collect samples from different layers of the ocean. The scientists on board expect to find jellies and larvae of different species in this net.

Curtis filters the cod-end of the neuston and finds a whole bunch of Vallela vallela.

Curtis filters the cod-end of the neuston and finds a whole bunch of Vellela vellela.

I got a chance to see the neuston being released. After it was hauled in, Dr. Curtis Roegner, a fisheries biologist with NOAA, detached the cod-end–a small container at the bottom of the net that collects everything the net caught–and filtered out the contents. Inside were a bunch of beautiful blue jellies! These guys are commonly known as by-the-wind sailors thanks to their interesting sail adaptation that allows them to harness the power of the wind to aid in their dispersal (scattering) throughout the ocean. I helped Sam Zeman, a biologist with the University of Oregon, Tyler and Curtis measure the diameter–the length at the widest point–of the bodies of the jellies.

Vellela vellela, by the wind sailors.

Curtis, Tyler and I working to measure and record the lengths of the sails on the Vallela vallela. (Thanks to Sam for taking this picture!)

Curtis, Tyler and I working to measure and record the lengths of the sails on the Vellela vellela. (Thanks to Sam for taking this picture!)

Personal Log

The more time I spend on the Shimada, the more determined I am to figure out how time travel works so I can go back and thank my September 2014 self for putting in the Teacher At Sea application. I’ve been on the ship for three days now and I love being able to go anywhere, day or night, and be able to observe and assist in research and data collection, but also just sit and talk with people who have all followed many different paths that led them to this ship, for these two weeks.

You might think my biggest struggles right now would be seasickness (which I’m not!) or missing my friends and family, but honestly, the hardest part is keeping the blog down to a readable length. There’s an enormous amount more happening here than I have the room to tell you but I will try and cover everything before our time is up.

Lastly, it’s true, I miss my friends and family, a lot, but there are certain creature comforts here that help ease the transition from land to sea. NOAA certainly knows how to keep morale and productivity up, with a well-stocked kitchen open 24 hours, meals prepared on site by talented cooks, and a TV lounge for socializing with a selection of over 500 movies, it’s easy to feel at home. And when finding a work-life balance is not possible, it’s necessary, all of this helps.

Well, that’s all for now, catch the next installment coming soon to a computer screen or mobile device near you!

Acknowledgements

Special thanks to Prof. Mary-Beth Decker consulting on the spelling of Vellela vellela and Brittney Honisch for teaching me a good way to remember port vs. starboard. When facing the front of the ship, port is left and both words have four letters.

DJ Kast, Drifter Buoy! May 29, 2015

Posted on May 30, 2015 by dkast2015

NOAA Teacher at Sea
Dieuwertje “DJ” Kast
Aboard NOAA Ship Henry B. Bigelow
May 19 – June 3, 2015

Mission: Ecosystem Monitoring Survey
Geographical area of cruise: George’s Bank
Date: May 29, 2015, Day 11 of Voyage

Drifter Buoy!

My buoy and I- ready to deploy! Photo by Jerry Prezioso

My buoy and me ready to deploy! Photo by Jerry Prezioso

NOAA has an Adopt a Drifter program! The program is meant to work with K-16 teachers from the United States along with international educators. This program provides teachers with the opportunity to infuse ocean observing system data into their curriculum. This occurs by deploying or having a research vessel deploy a drifter buoy. A drifting buoy (drifter) is a floating ocean buoy equipped with meteorological and/or oceanographic sensing instruments linked to transmitting equipment where the observed data are sent. A drifting buoy floats in the ocean water and is powered by batteries located in the dome. The drifter’s sea surface temperature data are transmitted to a satellite and made available to us in near real-time. The teachers receive the WMO number of their drifting buoy in order to access data online from the school’s adopted drifter. Students have full access to drifting buoy data (e.g., latitude/longitude coordinates, time, date, SST) in real or near real-time for their adopted drifting buoy as well as all drifting buoys deployed as part of the global ocean observing system. They can access, retrieve, and plot as a time series various subsets of data for specified time periods for any drifting buoy (e.g., SST) and track and map their adopted drifting buoy for short and long time periods (e.g., one day, one month, one year).

I am receiving one from the Chief Scientist onboard the NOAA Ship Henry B. Bigelow so the students in all my programs can access it, and this will be helpful to convey modeling of currents, and can help build models of weather, climate, etc .I was so excited when I found out that the chief scientist would be giving me a drifter for me and my students to follow. I decorated the buoy with programs that have inspired me to apply to the Teacher at Sea Programs, the current programs I am working for at USC (JEP & NAI), my family, and my mentors.

Representing the USC Readerplus Program that hosts my Wonderkids Programs. Photo by Jerry Prezioso.

Quick change into my NOAA Teacher at Sea Shirt. Thank you so much for all these opportunities. Photo by Jerry Prezioso.

Special recognition to JEP, USC Dornsife, and my Young Scientist Program & NOAA TAS! Photo by DJ Kast

USC Wonderkids and USC Seagrant Logos. Photo by DJ Kast

Thanks to NMEA and the USC Wrigley Institute, USC Catalina Hyperbaric Chamber for continuously supporting my ocean going adventures. Photo by DJ Kast

Thanks to NMEA (National Marine Educators Association) and the USC Wrigley Institute, USC Catalina Hyperbaric Chamber for continuously supporting my ocean going adventures (Plus my favorite gastropod, Spanish Shawl Nudibranch for color). Photo by DJ Kast

Representing Rossier, USC QuikSCience, and the NOAA Henry B. Bigelow Ship. Photo by DJ Kast

Representing Rossier, USC NAI, USC QuikSCience, and the NOAA Ship Henry B. Bigelow Ship. Photo by DJ Kast

Important family that have always supported me with my science education career. Photo by DJ Kast

My list of ocean educators that inspire me to always strive for more. Photo by DJ Kast

My list of ocean educators that inspire me to always strive for more. Plus a shout-out to the Level the Playing Field Institute, and their USC (Summer Math and Science Honors) SMASH program. Photo by DJ Kast

Special thanks to the schools participating in the USC Young Scientist Program and USC Wonderkids Programs. Photo by DJ Kast

JEP HOUSE and Staff!

JEP House and Dornsife Represent! Photo by DJ Kast

Important JEP People’s.
I forgot to take a final picture of this but this included Brenda, Adrienne, and Mandy. Photo by DJ Kast

I am teaching a marine biology class this summer for the USC Neighborhood Academic Initiative program. I am so excited to be following the drifter buoy # 39708. It was launched at 8:53 EDT on May 28th, 2015 and its first official position is: 41 44.8 N 065 27.0 W. I will definitely be adapting a few of the lesson plans on the following site and creating my own to teach my students about weather, climate, and surface currents.

http://www.adp.noaa.gov/lesson_plans.html

Deployment:

To deploy the buoy, you literally have to throw it overboard and make sure it hits nothing on its way down. When it is in the water, the cardboard wraps dissolve away, and the cloth drogue springs open, filling with water and causing the buoy to drift in surface water currents instead of wind currents. The tether (cable) and drogue (long tail that is 15 meters long) will unwrap and extend below the sea surface where it will allow the drifter to float and move in the ocean currents

Photo of the drogue deployed in the water. From the NOAA Adopt a Drifter Program website.

Deploy the Buoy! Photo by Jerry Prezioso

My buoy in the Water! The cardboard wraps will dissolve away, and the cloth drogue will spring open and fill with water allowing the buoy to drift in surface water currents instead of wind currents. Photo by DJ Kast

Since I was now an expert drifter buoy deployer, I was also able to deploy a buoy from the St. Joseph’s school in Fairhaven, Massachusetts. This drifter buoy’s tracking number is: 101638 and launched on May 28th, 2015 at 8:55 EDT and its first official position is: 41 44.9 N 065 27.0 W

Photo of me with the St. Joseph buoy that will also be deployed. Photo by Jerry Prezioso.

Ready to deploy. Photo by: XO LCDR Patrick Murphy

Tracking the buoy (from Shaun Dolk):

The easiest way to track these buoys in real-time is to use the Argos website https://argos-system.clsamerica.com/cwi/Logon.do.

Guest account: Username: BigeloTAS and Password: BigeloTAS.

Once logged in, select the “Data access” tab on the top left side of the screen.
Select “Mapping”; a pop-up window will appear.
Ensure “by ID numb. (s)” is selected from within the “Platform:” option (top left).
Enter your desired ID number in the search field at the top of the screen.
Enter the number of days for which you’d like data (20 days is the maximum).
Select “Search” to generate a trajectory plot for the given parameters.

**Please note, because you can only view the 20 most recent days of data, you’ll need to save the data if you wish to view the entire track line!**

To save data into Google Earth format, simply click on the Google Earth image (second tool from the right on the map settings bar, found just below the “Search” tab). You’ll need to save data at least every 20 days to ensure no interruptions in your final track line. Of course, to view the track line in its entirety, open Google Earth and ensure all of the data files are selected. If you desire to look at the data, not the track lines, go to “Data access”, then “Messages”, and enter your desired ID numbers. Again, data is only accessible for the most recent 20 days, so if you’d like to download the data for archival purposes, go to “Data access”, then select “Message download”. From here, you’ll want to save the data in .csv, .xls, or .kml format.

My buoy 39708 is transmitting properly and providing quality data! Below are some of the maps of its early trajectory and its current movement so far.

Early Trajectory! Photo sent by Shaun Dolk

Photo sent by Shaun Dolk

PS for Science- Otoliths

While we were deploying the buoys one of the engineers named Rahul Bagchi brought over a strainer that is attached to the water intake pipe. The strainer was covered in Sand Lances.

Sand Lances on the inside of the strainger. Photo by Dj Kast

Sand Lances on the inside of the strainer. Photo by DJ Kast

Sand Lances on the outside of the strainer. Photo by DJ Kast

Fortunately, there are another two scientists on board that need sand lance samples for their research purposes and they were collected. My research scientist friend Jessica needs the otoliths or fish ear bones for part of her research on cod, since sand lances are eaten cod. Otoliths are hard, calcium carbonate structures located behind the brain of a bony fish. Different fish species have differently shaped otoliths. They are used for balance and sound detection-much like our inner ears. They are not attached to the skull, but “float” beneath the brain inside the soft, transparent inner ear canals. The otoliths are the most commonly used structure to both identify the fish eaten by consumers up the food chain, and to age the fish itself.

Otoliths and time scale. Photo by NOAA NEFSC

Otoliths with the winters pointed out. Photo by: Bedford Institute of Oceanography

The otoliths also have daily growth bands. Alaskan Fishery scientists manipulate the daily growth bands in salmon larvae creating an otolith tag that identifies where the fish came from by controlling the growth rate of their fish populations.

Photo of a tagged otolith from the Sawmill Bay fishery in Alaska. Photo from: Alaskan Fisheries

New material (protein and calcium carbonate) is added to the exposed surface of the otolith over time, showing a fish life history (otolith start growing at day 1 even in larval stages). The lighter zones have higher calcium deposit which is indicate summers, while darker zones have higher protein levels which indicate winter. One pattern of a light and dark zone indicate a year and is consequently how the fish is aged.

Tiny white speck is the sand lance otolith. Photo by DJ Kast

The sand lances Jessica and I were dissecting for otoliths. Photo by DJ Kast

She also took a base of the tail for her research as well. Photo by DJ Kast

She also took a white muscle sample from the dorsal surface of the fish for her research as well. Photo by DJ Kast

Jessica Lueders-Dumont is using the otoliths for three main purposes in relation to her Nitrogen Isotope work.

1. She is hoping to see the changes from year 1 to the adult years of the fish to give an accurate fish life history and how they relate to the rest of the Nitrogen isotopes in the area’s food chain.

2. To see how current nitrogen isotopes compare to the archeological otoliths found in middens or sediment sites, since otoliths can be preserved for hundreds of years.

3. She is trying to create a baseline of nitrogen 15 in the Gulf of Maine so that she can see biogeochemical evidence of the N15 she finds in plankton in higher trophic levels like fish.

I will definitely be dissecting some fish heads with students to check for otoliths and using a microscope to age them.

PSS for Science:

The chief scientist and I decided we should put some Styrofoam Cups under pressure. This polystyrene foam is full of air pockets. This is important because the air pockets (volume) shrink with increasing pressure, essentially miniaturizing the cups.

I have done this before using the help of Karl Huggins at the USC Wrigley Institute’s Catalina Hyperbaric Chamber. We had a TA that wanted to teach about SCUBA diving so we had her students decorate Styrofoam cups and a head and placed it in the chamber. Apparently the Styrofoam was too good of a quality because it re-expanded on the way back up. http://www.youtube.com/watch?v=f6DDBFovht0

Also, I also found out you can do this with a pressure cooker- oh the experiments I will do when I get back. 😀

Before photos:

Front view of my NOAA TAS cup. Photo by DJ Kast

Back side of the NOAA TAS cup. Photo by DJ Kast

Just wanted it to say how amazing it has been on the NOAA Henry B. Bigelow. Photo by DJ Kast

Just wanted it to say how amazing it has been on the NOAA Ship Henry B. Bigelow. Photo by DJ Kast

I made a cup for my programs as well. Photo by DJ Kast

USC Wonderkids Program on a Styrofoam cup before shrinkage. Photo by DJ Kast.

Saying hi to all of my students from inside one of the cups. Photo by DJ Kast

In the mesh bag, and attached to the Rosette for shrinkage. Photo by DJ Kast

After Photos: the Styrofoam cups went down to 184 m or 603 ft on the Rosette/ CTD in South George’s Basin.

Shrunken Cups in the Mesh bag attached to the Rosette. Photo by DJ Kast

Shrunken Cups in the Mesh bag attached to the Rosette. It went down to 184 m or 603 ft Photo by DJ Kast

Look at these tiny cups! Photo by Jerry Prezioso

Cups compared to the original size (front). Photo by DJ Kast.

Cups compared to the original size (back). Photo by DJ Kast.

Alex Miller: Delayed but Still Determined, May 28, 2015

Posted on May 29, 2015 by millercommaalex

NOAA Teacher at Sea
Alexandra (Alex) Miller, Chicago, IL
Aboard and Inport NOAA Ship Bell M. Shimada
May 27 – June 10, 2015

Mission: Rockfish Recruitment and Ecosystem Assessment
Geographical area of cruise: Pacific Coast
Date: Thursday, May 28^th, 2015

Personal Log

A panoramic view from Yaquina Point, gray whales can often be seen from the Point on their migration route, one of the longest in the animal kingdom.

Greetings from NOAA Ship Bell M. Shimada!

From my time onboard I have learned it takes a lot of people to run a ship this size, which helps explain why, due to a staffing issue, we have been delayed until tomorrow, Friday, at 1000. All scientists and crew are being asked to assemble on deck at 0800 for a briefing where I imagine we will go over responsibilities and safety precautions before heading out to sea.

Our run has changed its course slightly since cutting down to 13 DAS (days at sea); we will now cruise between Southern Oregon and Gray’s Harbor, WA, with all the same mission objectives. While we haven’t gone anywhere yet, this time in port is affording me the opportunity to explore Newport and assist in and observe research that is being done by the scientists on land.

Newport has a considerable number of marine science facilities and most of the scientists I will be working with have or will have labs here in which they process the data they collect while in the field—the field can either be the sea or the land, depending on the study—and while the various organizations at the Hatfield cooperate and share research findings (as all good scientists do), there are distinctions in terms of what each scientist studies and, essentially, who pays them to do it.

The lighthouse at Yaquina Head.

Let’s start at the beginning. Most of the scientists going on this cruise of the Shimada are biologists. Biologists are scientists who study living things (bio-life, ology-study of) and so far I have met two kinds. Amanda’s specific field of biology is ornithology (making her an ornithologist), which specializes in the study of birds. Will Fennie, among others who you will hear more about, is an ichthyologist, a scientist who studies fish. For both, they will work at sea and on land to first collect and then process the information or samples (known as data in the scientific community). As I mentioned before, Amanda works with the Seabird Oceanography Lab at Oregon State University and starting in the fall semester, Will will begin his Ph.D. studies there as well. Other scientists on board are affiliated with other schools, like University of Oregon and Yale University, and some NOAA employs directly. You’ll meet some of them later on.

So, while I may not be at sea, I’m taking every opportunity I can to learn about how these scientists work, what their lives are like on and off the ship and what the significance of their research is. Yesterday, I rode with Amanda up to the Yaquina Head Outstanding Natural Area (it’s a beautiful name, really, but hereafter I will refer to it as Yaquina Head). Yaquina Head is home to Oregon’s tallest and second oldest lighthouse, one of a series that were built along the coast to guide fisherman home. It also happens to be home to a unique nesting site, also known as a colony, for many species of seabird, including the western gull and common murre.

Common murres return to their nesting sites once the eagles are out of sight.

We were there to try and adjust an antenna that was meant to pick up VHF signal (very high frequency, just one of several different radio signals that can be used) for a common murre she and her lab mates had previously tagged. Scientists use trackers (or “tags”) for a variety of reasons because they allow them to collect information on the birds’ location. This information will be put into a computer program that can then organize it so scientists can look for trends. Trends are patterns in data, which scientists analyze to gain new understanding or develop theories (ways to explain why these trends exist). For example, maybe the data will show a trend of no pings at the colony for several hours and scientists might theorize that eagles came to hunt during that time, scaring the murres away.

All of that was just hypothetical, but in fact, eagles had been hunting at Yaquina Head earlier that morning so thousands of murres were off the colony and sitting in the water. If you click on the first image in this post and zoom in you can see what look like black dots in the water. Each one is a seabird. As Amanda and her lab technician, Ian, worked to try and get the signal to come in clear without static, I wandered and watched for birds. I was also hoping to spot a spout, the tell tale sign of a whale or dolphin, but, alas, no luck.

In the end, the antenna issue was not resolved. Amanda said another member of her lab would be able to come out and take a look at it, another upside of being able to work in collaboration with others. At sea, she will mostly work solo, keeping a careful watch for various seabird and marine mammal species, but she’s already recruited me for data entry so that while she watches, I can help keep track of which species are spotted, what they were doing when they were spotted, and which direction they were traveling. All of this will be GPS stamped and stored to create a database of information, which will be shared among labs and researchers at different universities and institutions. When it’s operating at its best, science is a collaborative endeavor with the end goal being better understanding of our world.

Amanda and Ian adjust the VHF antenna to try and catch 24-hour presence-absence data for a tagged common murre.

Amanda and Ian adjust the VHF antenna to try and catch 24-hour GPS data for a tagged common murre.

________________________________

Today, I wanted to hike on the South Jetty to get a bit of exercise so I caught a ride with Will who was heading out to surf. If you choose to be an oceanographer or marine biologist, odds are you’ll end up living most of your life by the ocean, so if, like Will, you enjoy being in the water, it’s certainly something to consider.

A panoramic view of the South Jetty and the beaches of Newport.

Hiking out on the South Jetty, the path is easy-going for the first 150 feet or so, after that the distances between the rocks require a more careful eye and take up a bit more of your attention. Every now and then I would stop and try to catch a decent close-up picture of some of the seabirds that were constantly flying overhead.

A cormorant flies by me.

The sheer number of animals that live off the Oregon coast can keep your head turning for hours, which is good because I was trying to split my time between watching the horizon for spouts and snapping photos of the gulls, cormorants and murres. My eyes may have been playing on tricks on me—I really, really want to see a whale—but I swore I saw a spout. A big part of me wanted to take off running down the jetty to get a closer look, but that was a near impossibility unless I wanted to run the risk of jumping from rock to slippery, yellow-lichen covered rock. I did however manage to get a few of the types of photos I was hoping to get.

A flock of what appear to be cormorants.

After a quick coffee run, Will and I decided to check out the Oregon Coast Aquarium. While it can boast being a member of the top-10 best aquariums in the country, I think its real claim to fame is its former celebrity resident, Keiko the orca (killer whale), star of Free Willy, the 90s film that launched a generation of children who wanted to grow up and become marine biologists.

The aquarium focuses on education about the different marine life native to the Oregon coast, with exhibits on sea otters, harbor seals and California sea lions as well as the mysterious giant Pacific octopus. We were lucky to catch the rotating exhibition on shipwrecks, which focused both on the process by which archaeologists discover, unearth and study artifacts from shipwrecks in order to learn the story of their demise and how they become teeming centers of life, functioning as artificial habitat, once they make their way to the ocean floor.

________________________________

For our last night in port, Ric wanted to bring together as many of the scientists and crew as he could to give everyone an opportunity to get to know each other a bit before we made way. I met Tyler Jackson, a marine biologist from Oregon State University who is studying crab populations and Emily Boring, an undergraduate from Yale University. She’s just finished her freshman year, and she’s taking advantage of her summer to learn a bit more about a career she’s been interested in since she was in fourth grade. I would say that Emily is making a great choice to learn more and she’s definitely getting a head start if a life of research is what she ends up wanting.

________________________________

In darkness, we drove across the Yaquina Bay Bridge for the last time, the lights from restaurants and homes outlined the coast and traced down the docks, drawing our eyes to the Shimada, illuminated and waiting for us to take to the sea.

Good night Shimada.

Did You Know?

Giant Pacific octopus are highly intelligent and have such sophisticated camouflage that they can mimic color and texture of their surroundings, allowing them to hide and then pounce on their prey.

Correction:

You were told there would be seabirds in that panoramic picture and unfortunately, there are not. There are seabirds in this picture below.

Heidi Wigman: Bandit Reels, CTDs, and Camera Drops . . . Oh My! May 29, 2015

Posted on May 29, 2015 by hwigman

NOAA Teacher at Sea
Heidi Wigman
Aboard NOAA Ship Pisces
May 27 – June 10, 2015

Mission: Reef fish surveys
Geographical area of Cruise: Gulf of Mexico (29°38.27’N 087°19.31’W)
Date: May 29, 2015

Weather: 81° @ surface, SE winds @ 8-13 knots, seas 2-3ft, chance of showers, average depth 92m

Science and Technology Log:

The science operations aboard the Pisces is an around the clock event. For 12 hours each day (0700-1900) we are involved in a series of survey drops at predetermined reef sites, contained within blocks of 100 sq. Nautical Miles. At each, randomly chosen 0.1sq. Nm site, a set of deployment operations commences. The first piece of equipment that goes over the side is the camera rig. This circular housing (diameter/height) contains 4 cameras that take pictures and video. This rig “soaks” on the bottom for about 40 minutes, capturing the life on the reef, which will later be analyzed by the team, looking for the commercially important species. One lucky camera is chosen, with the criteria being that there are no obstructions in the frame, and that it is looking at the reef. From the footage of this camera the scientist will determine the fish abundance and types at the location. This data is shared with outside agencies for assessment and review of the reef health.

Camera rig waiting deployment

1/4 cameras - 2 lenses for stills and 1 for video

1 of 4 cameras – 2 lenses for stills and 1 for video

A second deployment at the reef site is the CTD (Conductivity, Temperature, Depth) probe (diameter= 1m/ height=144cm). This probe is lowered over the side, and does a quick calibration soak just below the surface. After about 3 minutes, it is lowered to within 2m of the ocean floor and captures data on the descent and ascent that measures conductivity (salinity), temperature, depth, oxygen levels, and turbidity.

CTD (Conductivity Temperature Depth) probe on deck

The third, and most fun, of the deployments are the bandit reels. This is when we try to entice fish to be the test subjects of the reef site. Baited with mackerel, each 10 hook bandit reel is placed along the starboard side at 3 points (forward, aft, and stern. Each of the reels has a different hook size on (small, medium, large)) and is lowered to the bottom for a 5 minute soak. Any fish that are caught, are brought aboard, and dissected to determine rate of growth and reproductive cycle. The otoliths, or ear bone, is extracted to determine the age based on the lines that appear across the surface — much like the rings of a tree to determine its age.

getting ready to bait up some mackerel

Amberjack from the last bandit reel of the day.

Math at Sea: When I was up on the bridge this morning to hang out with am watch we did some math to determine at what distance the Pensacola Lighthouse would be visible to us. Lucky for us, there is a math formula to determine this! To determine the geographic range (in nautical miles) you would first need to know 2 variables: height of beacon (h1) (above sea level) and observer’s height-of-eye (h2) above sea level. geographic range = 1.17√[(h1)+(h2)] {the product of 1.17 and the square root of the sum of the two heights} Math question of the day: at what distance would a sailor be able to spot a 119′ high beacon from a 36′ height-of-eye (if weather conditions were clear)? Up next . . . A closer look at the Science, Technology, Engineering, and Mathematics of the sidescan sonar

Heidi Wigman: The Trigonometry of Navigation, May 29, 2015

Posted on May 29, 2015 by hwigman

NOAA Teacher at Sea
Heidi Wigman
Aboard NOAA Ship Pisces
May 27 – June 10, 2015

Mission: Reef Fish Surveys on the U.S. Continental Shelf
Geographical Area of Cruise: Gulf of Mexico (29°30.456’N 87°47.246’W)
Date: May 29, 2015

Weather: 80°, wind SE @ 8-13 knots , 95% precipitation, waves 2-3 @ 3 sec.

Science and Technology Log

During my time aboard the Pisces, I wanted to focus on the use of mathematics in the day-to-day shipboard operations, and during science ops. I have been lucky to find math everywhere – even down to the amount of pressure it takes to open a water-safe door (which is a lot). As the officers navigate the Pisces through the Gulf of Mexico, special attention needs to be on the vast number on oil rigs in the area, as well as getting the scientists to the designated drop points. As a course is charted through the water, environmental effects (current and wind) can alter its final outcome. Basically, this is where trigonometry comes in to play – a real-life application, and answer, to the notorious “when am I ever going to use this?”

Suppose that the Pisces is traveling at a cruising speed of 15 m/sec, due East, to get to the spot of deployment for a camera rig. The ocean current is traveling in a Southern direction at 10 m/sec. These values are the “component vectors” that, when added, are going to give a resultant vector, and will have both magnitude and direction. If you think of the two forces acting upon each other as the legs of a right triangle, and the resultant vector as the hypotenuse, then using the Pythagorean Theorem will allow you to compute the resultant velocity. Use a trig function (invTAN) to find the angle at which the Pisces needs to travel to get to its drop point.

Personal Log

Time goes by slowly at sea – and that’s a good thing for me! I miss my family and friends, but this is an experience that I am enjoying each minute of. Thanks Pisces crew for being awesome!

Coming next . . . Bandit Reels, CTDs and AUVs – oh my!

am shift (0400-0800) plotting our course

AM watch (0400-0800) plotting our course

Pisces cruising the Gulf of Mexico

Navigation tools of the trade

DJ Kast, Interview with Megan Switzer and the Basics of the CTD/ Rosette, May 28, 2015

Posted on May 28, 2015 by dkast2015

NOAA Teacher at Sea
Dieuwertje “DJ” Kast
Aboard NOAA Ship Henry B. Bigelow
May 19 – June 3, 2015

Mission: Ecosystem Monitoring Survey
Geographical area of cruise: Gulf of Maine
Date: May 28, 2015, Day 11 of Voyage

Interview with Student Megan Switzer

Megan Switzer and her sampling collecting. Photo by: DJ Kast

Chief Scientists Jerry Prezioso and graduate oceanography student Megan Switzer

Chief Scientist Jerry Prezioso and graduate oceanography student Megan Switzer

Megan Switzer is a Masters student at the University of Maine in Orono. She works in Dave Townsend’s lab in the oceanography department. Her research focuses on interannual nutrient dynamics in the Gulf of Maine. On this research cruise, she is collecting water samples from Gulf of Maine, as well as from Georges Bank, Southern New England (SNE), and the Mid Atlantic Bight (MAB). She is examining the relationship between dissolved nutrients (like nitrate and silicate) and phytoplankton blooms. This is Megan’s first research cruise!

In the generic ocean food chain, phytoplankton are the primary producers because they photosynthesize. They equate to plants on land. Zooplankton are the primary consumers because they eat the phytoplankton. There are so many of both kinds in the ocean. Megan is focusing on a particular phytoplankton called a diatom; it is the most common type of phytoplankton found in our oceans and is estimated to contribute up to 45% of the total oceanic primary production (Yool & Tyrrel 2003). Diatoms are unicellular for the most part, and a unique feature of diatom cells is that they are enclosed within a cell wall made of silica called a frustule.

Diatom Frustules. Photo by: 3-diatom-assortment-sems-steve-gschmeissner

Diatom Frustules. Photo by: Steve Schmeissner

Diatoms! Photo by: Micrographia

The frustules are almost bilaterally symmetrical which is why they are called di (2)-atoms. Diatoms are microscopic and they are approximately 2 microns to about 500 microns (0.5 mm) in length, or about the width of a human hair. The most common species of diatoms are: Pseudonitzchia, Chaetocerous, Rhizosolenia, Thalassiosira, Coschinodiscus and Navicula.

Pseudonitzchia. Photo by National Ocean Service

Thalassiosira. Photo by: Department of Energy Joint Genome Institute

Photo of Coscinodiscus

Diatoms also have ranges and tolerances for environmental variables, including nutrient concentration, suspended sediment, and flow regime. As a result, diatoms are used extensively in environmental assessment and monitoring. Furthermore, because the silica cell walls are inorganic substances that take a long time to dissolve, diatoms in marine and lake sediments can be used to interpret conditions in the past.

In the Gulf of Maine, the seafloor sediment is constantly being re-suspended by tidal currents, bottom trawling, and storm events, and throughout most of the region there is a layer of re-suspended sediment at the bottom called the Bottom Nepheloid Layer. This layer is approximately 5-30 meters thick, and this can be identified with light attenuation and turbidity data. Megan uses a transmissometer, which is an instrument that tells her how clear the water is by measuring how much light can pass through it. Light attenuation, or the degree to which a beam of light is absorbed by stuff in the water, sharply increases within the bottom nepheloid layer since there are a lot more particles there to block the path of the light. She also takes a water sample from the Benthic Nepheloid Layer to take back to the lab.

Marine Silica Cycle by Sarmiento and Gruber 2006

Megan also uses a fluorometer to measure the turbidity at various depths. Turbidity is a measure of how cloudy the water is. The water gets cloudy when sediment gets stirred up into it. A fluorometer measures the degree to which light is reflected and scattered by suspended particles in the water. Taken together, the data from the fluorometer and the transmissometer will help Megan determine the amount of suspended particulate material at each station. She also takes a water sample from the Benthic Nepheloid layer to take back to the lab. There, she can analyze the suspended particles and determine how many of them are made out of the silica based frustules of sinking diatoms.

This instrument is a Fluorometer and is used to measure the turbidity at various depths. Photo by: DJ Kast

She collects water at depth on each of the CTD/ Rosette casts.

Rosette with the 12 Niskin Bottles and the CTD. Photo by DJ Kast

Up close shot of the water sampling. Photo by DJ Kast

CTD, Rosette, and Niskin Bottle basics.

The CTD or (conductivity, temperature, and depth) is an instrument that contains a cluster of sensors, which measure conductivity, temperature, and pressure/ depth.

Here is a video of a CTD being retrieved.

Depth measurements are derived from measurement of hydrostatic pressure, and salinity is measured from electrical conductivity. Sensors are arranged inside a metal housing, the metal used for the housing determining the depth to which the CTD can be lowered. Other sensors may be added to the cluster, including some that measure chemical or biological parameters, such as dissolved oxygen and chlorophyll fluorescence. Chlorophyll fluorescence measures how many microscopic photosynthetic organisms (phytoplankton) are in the water. The most commonly used water sampler is known as a rosette. It is a framework with 12 to 36 sampling Niskin bottles (typically ranging from 1.7- to 30-liter capacity) clustered around a central cylinder, where a CTD or other sensor package can be attached. The Niskin bottle is actually a tube, which is usually plastic to minimize contamination of the sample, and open to the water at both ends. It has a vent knob that can be opened to drain the water sample from a spigot on the bottom of the tube to remove the water sample. The scientists all rinse their bottles three times and wear nitrile or nitrogen free gloves to prevent contamination to the samples.

On NOAA ship Henry B. Bigelow the rosette is deployed from the starboard deck, from a section called the side sampling station of this research vessel.

The instrument is lowered into the water with a winch operated by either Adrian (Chief Boatswain- in charge of deck department) or John (Lead Fishermen- second in command of deck department). When the CTD/Rosette is lowered into the water it is called the downcast and it will travel to a determined depth or to a few meters above the ocean floor. There is a conducting wire cable is attached to the CTD frame connecting the CTD to an on board computer in the dry lab, and it allows instantaneous uploading and real time visualization of the collected data on the computer screen.

CTD data on the computer screen. Photo by: DJ Kast

The water column profile of the downcast is used to determine the depths at which the rosette will be stopped on its way back to the surface (the upcast) to collect the water samples using the attached bottles.

Niskin Bottles:

Messenger- The manual way to trigger the bottle is with a weight called a messenger. This is sent down a wire to a bottle at depth and hits a trigger button. The trigger is connected to two lanyards attached to caps on both ends of the bottle. When the messenger hits the trigger, elastic tubing inside the bottle closes it at the specified depth.

Todd with the manually operated Niskin Bottle. Photo by: DJ Kast

Todd holding a messenger to trigger the manually operated Niskin Bottle. Photo by: DJ Kast

Todd with the manually operated Niskin Bottle. Photo by: DJ Kast

Manual CTD fully cocked and ready to deploy. Photo by DJ Kast

Here is a video of how the manual niskin bottle closes: https://www.youtube.com/watch?v=qrqXWtbUc74

The other way to trigger Niskin bottles is electronically. The same mechanism is in place but an electronic signal is sent down the wire through insulated and conductive sea cables (to prevent salt from interfering with conductivity) to trigger the mechanism.

Here is a video of how it closes electronically: https://www.youtube.com/watch?v=YJF1QVe6AK8

Conductive Wire to CTD. Photo by DJ Kast

Photo of the top of the CTD. Photo by DJ Kast

Photo of the top of the CTD showing the trigger mechanism in the center. Photo by DJ Kast

Top of the Niskin Bottles to show how the white wires are connected to the top.

Top of the Niskin Bottles shows how the lanyards are connected to the top. Photo by DJ Kast

The pin on the bottom is activated when an electronic signal is sent through the conductive sea cables. Photo by DJ Kast

Using the Niskin bottles, Megan collects water samples at various depths. She then filters water samples for her small bottles with a syringe and a filter and the filter takes out the phytoplankton, zooplankton and any particulate matter. She does this so that there is nothing living in the water sample, because if there is there will be respiration and it will change the nutrient content of the water sample.

Filtering out only the water using a syringe filter. Photo by DJ Kast

Syringe with a filter on it. Photo by: DJ Kast

This is part of the reason why we freeze the sample in the -80 C fridge right after they have been processed so that bacteria decomposing can’t change the nutrient content either.

Diatoms dominate the spring phytoplankton bloom in the Gulf of Maine. They take up nitrate and silicate in roughly equal proportions, but both nutrients vary in concentrations from year to year. Silicate is almost always the limiting nutrient for diatom production in this region (Townsend et. al., 2010). Diatoms cannot grow without silicate, so when this nutrient is used up, diatom production comes to a halt. The deep offshore waters that supply the greatest source of dissolved nutrients to the Gulf of Maine are richer in nitrate than silicate, which means that silicate will be used up first by the diatoms with some nitrate left over. The amount of nitrate left over each year will affect the species composition of the other kinds of phytoplankton in the area (Townsend et. al., 2010).

The silica in the frustules of the diatom are hard to breakdown and consequently these structures are likely to sink out of the euphotic zone and down to the seafloor before dissolving. If they get buried on the seafloor, then the silicate is taken out of the system. If they dissolve, then the dissolved silicate here might be a source of silicate to new production if it fluxes back to the top of the water column where the phytoplankton grow.

Below are five images called depth slices. These indicate the silicate concentration (rainbow gradient) over a geographical area (Gulf of Maine) with depth (in meters) latitude and longitude on the x and y axis.

Depth slices of nitrate and silicate. Photo by: This is the type of data Megan is hoping to process from this cruise.

Depth slices of nitrate and silicate. Photo by: GOMTOX at the University of Maine
This is the type of data Megan is hoping to process from this cruise.

NOAA Teacher at Sea Blog

Monthly Archives: May 2015

DJ Kast, NOAA Ship Henry B. Bigelow, May 31, 2015

Alex Miller: Smooth Sailing So Far, May 31, 2015

DJ Kast, Drifter Buoy! May 29, 2015

Alex Miller: Delayed but Still Determined, May 28, 2015

Heidi Wigman: Bandit Reels, CTDs, and Camera Drops . . . Oh My! May 29, 2015

Heidi Wigman: The Trigonometry of Navigation, May 29, 2015

DJ Kast, Interview with Megan Switzer and the Basics of the CTD/ Rosette, May 28, 2015