food chain – NOAA Teacher at Sea Blog

April 30, 2019May 3, 2019

Katie Gavenus: Thinking Like A Hungry Bird, April 28, 2019

NOAA Teacher at Sea

Katie Gavenus

Aboard R/V Tiglax

April 26-May 9, 2019

Mission: Northern Gulf of Alaska Long-Term Ecological Research project

Geographic Area of Cruise: Northern Gulf of Alaska – currently on the ‘Middleton [Island] Line’

Date: April 28, 2019

Weather Data from the Bridge

Time: 1715
Latitude: 59^o 39.0964’ N
Longitude: 146^o05.9254’ W
Wind: Southeast, 15 knots
Air Temperature: 10^oC (49^oF)
Air pressure: 1034 millibars
Cloudy, no precipitation

Science and Technology Log

Yesterday was my first full day at sea, and it was a special one! Because each station needs to be sampled both at night and during the day, coordinating the schedule in the most efficient way requires a lot of adjustments. We arrived on the Middleton Line early yesterday afternoon, but in order to best synchronize the sampling, the decision was made that we would wait until that night to begin sampling on the line. We anchored near Middleton Island and the crew of R/V Tiglax ferried some of us to shore on the zodiac (rubber skiff).

This R&R trip turned out to be incredibly interesting and relevant to the research taking place in the LTER. An old radio tower on the island has been slowly taken over by seabirds… and seabird scientists. The bird biologists from the Institute for Seabird Research and Conservation have made modifications to the tower so that they can easily observe, study, and band the black-legged kittiwakes and cormorants that choose to nest on the shelfboards they’ve augmented the tower with. We were allowed to climb up into the tower, where removable plexi-glass windows look out onto each individual pair’s nesting area. This early in the season, the black-legged kittiwakes are making claims on nesting areas but have not yet built nests. Notes written above each window identified the birds that nested there last season, and we were keen to discern that many of the pairs had returned to their spot.

Gavenus1Birds — Black-legged kittiwakes are visible through the observation windows in the nesting tower on Middleton Island.

Gavenus2Birds — Nesting tower on Middleton Island.

The lead researcher on the Institute for Seabird Research and Conservation (ISRC) project was curious about what the LTER researchers were finding along the Middleton Line stations. He explained that the birds “aren’t happy” this spring and are traveling unusually long distances and staying away for multiple days, which might indicate that these black-legged kittiwakes are having trouble finding high-quality, accessible food. In particular, he noted that he hasn’t seen any evidence they’ve been consuming the small lantern fish (myctophids) that generally are an important and consistent food source from them in the spring. These myctophids tend to live offshore from Middleton Island and migrate to the surface at night. We’ll be sampling some of that area tonight, and I am eager to see if we might catch any in the 0.5 mm mesh ‘bongo’ nets that we use to sample zooplankton at each station.

The kittiwakes feed on myctophids. The myctophids feed on various species of zooplankton. The zooplankton feed on phytoplankton, or sometimes microzooplankton that in turn feeds on phytoplankton. The phytoplankton productivity is driven by complex interactions of environmental conditions, impacted by factors such as light availability, water temperature and salinity as well as the presence of nutrients and trace metals. And these water conditions are driven by abiotic factors – such as currents, tides, weather, wind, and freshwater input from terrestrial ecosystems – as well as the biotic processes that drive the movement of carbon, nutrients, and metals through the ecosystem.

Scientists deploy CTD — This CTD instrument and water sampling rosette is deployed at each station during the day to collect information about temperature and salinity. It also collects water that is analyzed for dissolved oxygen, nitrates, chlorophyll, dissolved inorganic carbon, dissolved organic carbon, and particulates.

CTD at sunset — When the sun sets, the CTD gets a break, and the night crew focuses on zooplankton.

Part of the work of the LTER is to understand the way that these complex factors and processes influence primary productivity, phytoplankton, and the zooplankton community structure. In turn, inter-annual or long-term changes in phytoplankton and zooplankton community structure likely have consequences for vertebrates in and around the Gulf of Alaska, like seabirds, fish, marine mammals, and people. In other words, zooplankton community structure is one piece of understanding why the kittiwakes are or are not happy this spring. It seems that research on zooplankton communities requires, at least sometimes, to consider the perspective of a hungry bird.

Peering at a jar of copepods and euphausiids (two important types of zooplankton) we pulled up in the bongo nets last night, I was fascinated by the way they look and impressed by the amount of swimming, squirming life in the jar. My most common question about the plankton is usually some variation of “Is this …” or “What is this?” But the questions the LTER seeks to ask are a little more complex.

Considering the copepods and euphausiids, these researchers might ask, “How much zooplankton is present for food?” or “How high of quality is this food compared to what’s normal, and what does that mean for a list of potential predators?” or “How accessible and easy to find is this food compared to what’s normal, and what does that mean for a list of potential predators?” They might also ask “What oceanographic conditions are driving the presence and abundance of these particular zooplankton in this particular place at this particular time?” or “What factors are influencing the life stage and condition of these zooplankton?”

Copepods in a jar — Small copepods are among the types of zooplankton we collected with the bongo nets last night.

As we get ready for another night of sampling with the bongo nets, I am excited to look more closely at the fascinating morphology (body-shape) and movements of the unique and amazing zooplankton species. But I will also keep in mind some of the bigger picture questions of how these zooplankton communities simultaneously shape, and are shaped by, the dynamic Gulf of Alaska ecosystem. Over the course of the next 3 blogs, I plan to focus first on zooplankton, then zoom in to primary production and phytoplankton, and finally dive more into nutrients and oceanographic characteristics that drive much of the dynamics in the Gulf of Alaska.

Personal Log

Life on the night shift requires a pretty abrupt change in sleep patterns. Last night, we started sampling around 10 pm and finished close to 4 am. To get our bodies more aligned with the night schedule, the four of us working night shift tried to stay up for another hour or so. It was just starting to get light outside when I headed to my bunk. Happily, I had no problem sleeping until 2:30 this afternoon! I’m hoping that means I’m ready for a longer night tonight, since we’ll be deploying the bongo nets in deeper water as we head offshore along the Middleton Line.

While on Middleton Island, we marveled at a WWII shipwreck that has been completely overtaken by seabirds for nesting.

Shipwreck filled with plants — Inputs of seabird guano, over time, have fertilized the growth of interesting lichens, mosses, grasses, and even shrubs on the sides and top of the rusty vessel.

Did You Know?

Imagine you have a copepod that is 0.5 mm long and a copepod that is 1.0 mm long. Because the smaller copepod is half as big in length, height, and width, overall that smaller copepod at best offers only about 1/8^th as much food for a hungry animal. And that assumes that it is as calorie-dense as the larger copepod.

Question of the Day:

Are PCBs biomagnifying in top marine predators in the Gulf of Alaska? Are there resident orca populations in Alaska that are impacted in similar ways to the Southern Resident Orca Whale population [in Puget Sound] (by things like toxins, noise pollution, and decreasing salmon populations? Is it possible for Southern Resident Orca Whales to migrate and successfully live in the more remote areas of Alaska? Questions from Lake Washington Girl’s Middle School 6^th grade science class.

These are great questions! No one on board has specific knowledge of this, but they have offered to put me in contact with researchers that focus on marine mammals, and orcas specifically, in the Gulf of Alaska. I’ll keep you posted when I know more!

May 28, 2015August 21, 2021

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

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

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: — 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 by: — 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

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.

July 16, 2014August 21, 2021

Andi Webb: The Chance of a Lifetime: Oregon II: July 16, 2014

NOAA Teacher at Sea
Andi Webb
Aboard NOAA Ship Oregon II
July 11 – 19, 2014

Mission: SEAMAP Summer Groundfish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: July 16, 2014
Science and Technology Log

Do you ever wonder sometimes how people are so generous with their time and talents? That’s how I feel onboard the Oregon II with a crew that is simply amazing at their work. The thing is, though, they make it seem like it’s not work to them. Oh, it’s hard work-that’s certain. But they all seem to enjoy it. There is passion for the ocean here, for the environment, for honing your craft. I feel certain I’m among some of the best scientists, NOAA Corps Officers, Deck Crew, Engineers-you name it. As if that weren’t enough, you can’t beat the food in the Galley! Who knew you could get French Silk Pie on a Groundfish Survey? Shhh….We’ll just keep that a secret!

Many people like to write about the scientific facts of NOAA in their blogs and there’s certainly nothing wrong with that. I mean, this is science in action, right? Me, however? I like to write about how people make me feel. The people of the Oregon II make me feel welcome. They make me feel happy I’m here. I asked one of the scientists today to please tell me, without worrying about political correctness, if the crew really enjoys the teachers being on board. She readily answered, “I love for teachers to be here. You’re all so excited to learn and that makes it fun for us!” How refreshing. As I write this, someone just knocked on my door and told me they put my clothes in the dryer for me. Really? Does it get much better than this? Teacher at Sea is about learning what scientists do but to me, it’s also about immersing yourself in the work and the friendship on board. As I work the noon to midnight shift each day and the trawls come in, we “haul back” together. Brittany, Michael, and Mark know so much and I learn more and more each day. I’m thankful for them. Kim is sharing items I can use in my classroom. They’ve included me in what they do, they’re teaching me, and I’m making friends. For that, I am thankful.

She's an amazing ship. Something I've heard on board is that she's "a good 'ole girl." — She’s an amazing ship. Something I’ve heard on board is that she’s “a good ‘ole girl.”

The beautiful blue ocean today~Blue skies and blue waters in the Gulf of Mexico.

Brittany, Michael, and Mark share their wisdom with me as I learn about all the creatures of the sea. It's truly magnificent to see so many different types of animals. — Brittany, Michael, and Mark share their wisdom with me as I learn about all the creatures of the sea. It’s truly magnificent to see so many different types of animals.

It takes everyone working together to get the job done.

There are beautiful creatures like this every day here.

Well, they have beautiful qualities, too!

March 2, 2012August 11, 2021

Dave Grant: Fast, Flat and Flying Fishes, March 1, 2012

NOAA Teacher at Sea
Dave Grant
Aboard NOAA Ship Ronald H. Brown
February 15 – March 5, 2012

Mission: Western Boundary Time Series
Geographical Area: Gulf Stream waters
Date: March 1, 2012

Weather Data from the Bridge
Position: 26.30N Latitude – 79. 23W Longitude
Wind speed: Calm
Wind direction: Calm
Air Temperature: 76E F
Atm Pressure: 1013. mb
Water Depth: 750 meters
Cloud Cover: 20%
Cloud Type: Cumulus

Personal Log

Our most persistent travel companions on the cruise are the flying fish and today they are the most abundant in the entire trip. Sit at the bow while we are plunging into the swells and it is impossible not to be mesmerized by what issues from the sea surface when old Triton blows his wreathed horn.

Over the eons, fishes have experimented with many different avenues of escape from predators and competition, and soaring out of the water is arguably the most dramatic and effective. There are scores of species in the family Exocoetidae, which comes from Greek roots and refers to “sleeping outside” – which was logical to ancient mariners who believed the flying fishes left the ocean to sleep on the shoreline. I check the Ron Brown’s deck each morning, hoping one has inadvertently landed on it, but without luck so far.

We flush them from both sides of the ship while underway. Like birds of a feather flocking together, some escaping groups are about a foot long with a wing span (Oversized pectoral fins to be exact) about the same spread. Juveniles in other schools look no larger than the silver dollar George Washington threw across the Delaware River(Or did he skip it for greater distance like these little fishes do off the crests of waves?).

Between the sky, sea and sunsets, I thought I had seen all the shades of blue on this cruise, up to the moment we had a perfect view of a flying fish that soared past the railing and then steered off towards the horizon. Flying fish exhibit all the colors of the near end of the spectrum as their attitude and altitude change in flight. Taking advantage of the mesoscale winds generated between swells, the fishes launch off wave crests and can soar farther than a football field; sustaining the flight time by sweeping their tail laterally in the water.

Flying fish are harvested throughout the warmer waters of the ocean by man and beast, and are an important staple to island cultures. Barbados – to our south – is called the “land of the flying fish” and on the reverse side of a dollar coin that I kept after a Caribbean trip, one finds the fish in flight. When we are closer to land, I hope to see one of their main aerial opponents flying out to meet us – frigate birds.

Impossible to photograph, for the time being, I’ll be content to admire their flights during the day, and at night, watch them dodge the attacks of mahi-mahi under the ship’s lights.

Flying fish off the bow!

Mahi-Mahi

Our British colleagues remembered to bring fishing poles and the mahi-mahi is the most sought after and elusive creature out here when the ship is “on-station” doing sampling. Fishes and squid routinely come to the surface and congregate under the stern lights, and occasionally a large mahi will lurk in the shadows and dart in close to us chasing prey.

Also called dolphin-fish, our fishermen have learned only that the Hawaiian name Mahi-Mahi (Many Polynesian words are repeated) means “strong” since the hooked fishes have broken their fishing lines and escaped.

Mahi is popular in restaurants and is a light, mild tasting fish. Swimming under the lights they look pale and eel-like, but when landed in a boat they exhibit a range of shades from blue and green that fades to golden – hence the Spanish name Dorado.

A Mahi rises to the surface alongside the Ron Brown

Fish ON!

Finally the fishermen had some luck and landed a jack – but without a fish guide, that’s as far as I can go in identifying it (Although the term “tuna” is loosely applied to most things that swim by.) Fortunately, I was able to get off an email and photo to Jeff Dement of the American Littoral Society (www.littoralsociety.org).

When not fishing, Jeff runs the largest independent fish tagging program in the country; distributing tags to recreational fishermen and analyzing their thousands of returns to document where fishes migrate to and how fast they grow.
His quick analysis directs us towards the lesser amberjack (Seriola fasciata) “based upon the shape of the snout, and the eye stripe length.”

Fast swimming and hard fighting, the amberjacks are popular gamefish on the line and in the skillet. Like most fish, they are tasty fried, broiled, baked, or grilled (I like fried…my doctor demands boiled, baked or grilled)

Like barracudas and some other apex predators of the reef, amberjacks are implicated in Ciguatera poisoning in humans. They acquire contaminants from eating herbivorous reef fishes that have ingested and accumulated Ciguatoxins produced by Dinoflagellates attached to marine algae they have been grazing upon. Harmless to the fishes, the poison is a neurotoxin in humans who are exposed to a concentrated dose from a top predator like the amberjack through the process called bioaccumulation. This is the same process that concentrates Mercury spewing into the atmosphere from coal-fired power plants, into the sea, then into plankton and forage fishes, and finally tuna.

An amberjack gets a close look at people before returning to the sea.

“You strange astonished-looking, angle-faced,
Dreary-mouthed, gaping wretches of the sea,
Gulping salt-water everlastingly,
Cold-blooded, though with red your blood be graced,
And mute, though dwellers in the roaring waste…
What is’t you do? what life lead? eh, dull goggles?
How do ye vary your dull days and nights?
How pass your Sundays? Are ye still but joggles,
In ceaseless wash? Still sought, but gapes and bites,
And drinks and stares, diversified with boggles.”

(Leigh Hunt – The Man to the Fish)

It pays to be clear.

For me, the catch of the day is a leptocephali – a larval fish as long as my index finger, that I almost overlooked in the samples.

A number of species go through this inconspicuous stage as zooplankton, and the most famous and intensely studied are the eels. American eels spend a year drifting to East Coast estuaries from their birthplace in the Sargasso Sea. The European species takes a more leisurely two-year tour of the North Atlantic on the Gulf Stream.

(Images from the Ron Brown, by Dave Grant)

August 26, 2011April 28, 2021

Kevin Sullivan: Bering Sea Bound, August 22, 2011

NOAA Teacher at Sea
Kevin C. Sullivan
Aboard NOAA Ship Oscar Dyson
August 17 — September 2, 2011

Mission: Bering-ALeutian Salmon International Survey (BASIS)
Geographical Area: Bering Sea
Date: August 22-24, 2011

Weather Data from the Bridge
Latitude: N
Longitude: W
Wind Speed: 20-23kts Tue,Wed. seas 9′ Thu 8/25 = calm
Surface Water Temperature: C
Air Temperature: 55F
Relative Humidity: 70%

Science and Technology Log

We are on Day II of our travels to get to our first sampling station located in the SE Bering Sea. We will begin our fishing operations today! We have had decent weather thus far although we did just go through Unimak Pass (see picture below of location) which is a narrow strait between the Bering Sea and the North Pacific Ocean. This passage offered a time of heavier seas. I’m guessing that like any strait, the currents may become more funneled and the seas “confused” as they squeeze through this area. It’s kind of analogous to it being more windy in between buildings of a major city vs. suburbia as the wind is funneled between skyscrapers. I also imagine this to be a popular crossing for marine mammals as well.

Interesting to think that both marine mammals and humans use this passage to both get to the same things: a food source and a travel route. It’s a migratory “highway” for marine mammals, and a heavily-trafficked area for humans in international trade and commercial fisheries.

Anyway, the Bering Sea is a very unique body of water. It really is the way that I imagined it. It is as though you are looking through a kaleidoscope and the only offerings are 1000 different shades of grey. It is rainy, foggy, and windy. I can appreciate how this sea has been the graveyard for so many souls and fishing vessels in the past who have tried to extract the bounties it has to offer.

As of Wednesday, the 24th, we have finished 4 stations of the 30 that have been planned for Leg I of this study (Leg II is of similar duration and goals). I was involved with helping the oceanographic crew with their tasks of collecting and evaluating various parameters of water chemistry. To do this, an instrument called a “CTD”– an acronym for Conductivity, Temperature, and Depth — is lowered. This instrument is the primary tool for determining these essential physical properties of sea water. It allows the scientists to record detailed charting of these various parameters throughout the water column and helps us to understand how the ocean affects life and vice-versa.

One aspect that I found very interesting is the analyzing of chlorophyll through the water column. All plant life on Earth contains the photosynthetic pigment called chlorophyll. Phytoplankton (planktonic plants) occupy the photic zone of all water bodies. Knowing that we live on a blue planet dominated by 70% coverage in water, we can thank these phytoplankton for their byproduct in photosynthesis, which is oxygen. Kind of strange how you often symbolize the environmental movement with cutting down of the rainforests and cries that we are eliminating the trees that give us the air we breath. This is true, but proportionately speaking, with an ocean-dominated sphere, we can thank these phytoplankton and photosynthetic bacteria for a large percentage of our oxygen. Additionally, being at the base of the food chain and primary consumers, these extraordinary plants have carved a name for themselves in any marine investigation/study.

The procedure to measure chlorophyll involves the following: water from the Niskin Bottles (attached to the CTD, used to “capture” water at select depths) is filtered through different filter meshes and the samples are deep-frozen at -80F. To analyze chlorophyll content, the frozen sample filter is immersed in a 90% solution of DI (Distilled Water) and acetone which liberates the chlorophyll from the phytoplankton. This is then sent through a fluorometer.

Filtering water from CTD for Chlorophyll Measurements

Fluorescence is the phenomena of some compounds to absorb specific wavelengths of light and then, emit longer wavelengths of light. Chlorophyll absorbs blue light and emits, or fluoresces, red light and can be detected by this fluorometer.

Amazing to think that with this microscopic plant life, you can extrapolate out and potentially draw some general conclusions about the overall health of a place as large as the Bering Sea. Oceanographic work is remarkable.

Personal Log

The crew aboard the Oscar Dyson have been very accommodating and more than willing to educate me and take the time to physically show me how these scientific investigations work. I am very impressed with the level of professionalism. As a teacher, I know that most often, the best way to teach students is to present the material in a hands-on fashion…inquiry/discovery based. This is clearly the format that I have been involved in while in the Bering Sea and I am learning a tremendous amount of information.

The food has been excellent (much better than I am used to while out at sea). The seas have been a bit on the rough side but seem to be settling down somewhat (although, I do see a few Low Pressure Systems lined up, ready to enter the Bering Sea…..tis the season). Veteran seamen in this area and even in the Mid-Atlantic off of NJ, know that this is the time of year when the weather starts to change). On a side note, I see that Hurricane Irene has its eyes set on the Eastern Seaboard. I am hoping that everyone will take caution in my home state of NJ.

Lastly, it’s amazing also to think of the depth and extent of NOAA. With oceans covering 70% of our planet and the entire planet encompassed by a small envelope of atmosphere that we breathe, it is fair to say that the National Oceanic and Atmospheric Administration is a part of our everyday lives. I am in the Bering Sea, one of the most remote and harsh places this planet has to offer and across the country, there are “Hurricane Hunters” flying into the eye of a hurricane that could potentially impact millions of people along the Mid Atlantic………..Both operated and run by NOAA!

Sunset on the Berring Sea 08-24-11 — Sunset on the Bering Sea 08-24-11