A few days ago we deployed three moorings in our study area. These complicated contraptions hold instruments in place in the ocean’s water column, strung on a line between a bottom anchor weight and surface (or subsurface) flotation. Big excitement for Team Phytoplankton because the instruments (if they work AND survive the storms) will provide a continuous stream of data on the ocean’s temperature, salinity, subsurface light environment, chlorophyll and nutrient content, and many other wondrous things. Although they will only be sampling one point in space, this continuous time record will allow us to ask all kinds of questions about the timing of phytoplankton blooms and their relationship to ocean and atmosphere conditions. As you’ll see below, many other questions can be asked as well, by other members of our science team and the larger community.
It’s one thing to see theoretical diagrams of mooring design on paper and another to see these enormous and complex arrangements of gear being deployed off the stern of Sikuliaq. We first spent some hours surveying the bottom in the deployment area, using the ship’s multi-beam seismic survey instruments to fine-tune the deployment location. (The moorings were designed for a depth of 230 meters.) The flotation goes in first, and then the line is strung out behind the ship as it slowly steams along. Gear is added using shackles, pear links, winches, etc. to take tension off of the main line and allow the instruments to be attached. Finally the anchor weights (railroad wheels!) are lowered over the side, and with the whole 230 meter-long mooring now streaming out behind the ship, they are released using a snatch block. As the weights descend they briefly pull the surface flotation under and it is an adrenaline-charged moment to wait for that flotation to pop up again – did we really calculate that line length properly and find the right bottom depth for deployment???
Three moorings were deployed. One is a guard mooring with only a few low-cost instruments on it. The second has a ‘wire walker’ instrument package that travels up and down the mooring line twice per day measuring temperature, salinity and other properties from near the bottom to near the surface on each excursion. The third is filled with instrumentation in addition to the ‘standard’ oceanographic sensors, including ADCPs*; both passive acoustics (listening for marine mammals) and active acoustics (using sound waves to identify large zooplankton and fish); a sediment trap that collects sinking material and funnels it into a preservative-filled cup, rotating to fill a new cup every two weeks; and a particle imaging system. It is truly impressive to watch an expensive instrument the size of, say, a large fire hydrant being almost literally tossed into the ocean many miles (about 75) from shore. The skill of our mooring technician Pete, the ship’s bosun Paul, and the other crew involved in this all-day operation was incredibly impressive and the whole operation went flawlessly.
For the science nerds among you, some of the mooring data are being transmitted to shore and can be viewed on the Alaska Ocean Observing System (AOOS) web site. Check it out: we are the GEO moorings in the Gulf of Alaska section.
*Acronym of the day: ADCP = acoustic doppler current
Post by UAF
graduate student and honorary Team Phytoplankton member Annie Kandel
I’m not an official member of Team Plankton, but my advisor at University of Alaska Fairbanks, Dr. Ana Aguilar-Islas, works closely with Suzanne on these cruises. I’m also sharing a room with Kerri (Team Phytoplankton Super-Tech!) so that has to count for something. We’ve had a lot of good bonding moments, like the couple of times she nearly witnessed my death as I tried to climb down from the top bunk.
When I’m not falling out of bed, I spend a decent amount time with Ana and our other team member, Carrie, working in a plastic bubble we set up in Sikuliaq’s analytical lab. Most of our work on the LTER cruises is sampling for trace metals, and trace metal clean techniques can be kind of intense. Amazing care has to be taken to prevent contamination of seawater samples containing minute quantities of iron, on a ship that is literally made out of iron. Our bubble took the whole first day to set up and included building a frame out of line and wood, setting up a rack for our trace metal clean Niskin bottles (which spend as little time outside the bubble as possible), hanging HEPA* units and a lot of plastic, and then cutting windows in the plastic so that it doesn’t look quite so suspicious. Also, so that we can see the clock.
While we’re taking or processing samples, we wear sleeves as well as gloves to protect the samples from ourselves, and we also wear different shoes in the bubble. Since we’re working with naturally occurring metals such as iron and aluminum it’s really important to make sure we don’t get any hair, skin, or dust in the bottles. Iron is an important trace metal in the ocean, as it’s required by various enzymes for biological processes but is generally found in very small (nanomolar) concentrations. There are different forms of iron in the ocean and the fraction referred to as “dissolved” is the pool that is biologically available. Dissolved iron only constitutes about 1% or less of the total iron that is present in seawater, and in many areas of the ocean iron acts as a limiting nutrient for phytoplankton growth.
These waters are
called HNLC, which stands for high nutrient/low chlorophyll, and it means that the
chlorophyll levels are lower than would normally be expected given the amount
of available macronutrients, e.g. nitrate and phosphate. The discrepancy is
thought to be due to iron limitation. To investigate this, we’re performing an
iron addition experiment where we collect HNLC water and add iron both
naturally, by mixing it with water from the Copper River plume, as well as
artificially, by spiking samples with an iron(III) chloride solution. The
experiment was set up a couple of days ago after many hours of searching for
HNLC water. We are taking samples daily to see how the plankton community
composition and physiology changes under these conditions.
The last time
Ana and Suzanne performed this experiment their bottles had been sitting in
acid for 10 years, a cleaning procedure that is excessive even by trace metal
standards. This time around I was in charge of cleaning them and only had about
two months, so keep your fingers crossed!
*Acronym of the
day: HEPA = High Efficiency Particulate Air. These filter units remove dust and
other particles that could carry iron into the seawater samples being
The other day I was asked by Kat, our NOAA Teacher-At-Sea
for this cruise, what I want members of the general public to take away from my
work studying iron limitation of phytoplankton. Though I can provide her a
superficial answer to my research question immediately, the motivations for my
work go much deeper than answering “How does a micronutrient affect
There are two main levels at which I want to
answer Kat’s question:
1. Proximal: Though phytoplankton are microscopic, they have
2. Philosophical: Why bother in the quest for such knowledge?
Level 1: The Macroscopic Impacts of a
Both human societies and phytoplankton communities are impacted by global climate change. Globally, humans are realizing the need to combat carbon emissions and mediate the effects of increasing global temperatures. Consequences of global climate change for us include mass emigration as sea levels rise, and increased frequency of extreme weather events (e.g. droughts, wildfires). As a result, humans are racing to bridge political divides between countries, develop sustainable energy, and manage natural disaster response. Phytoplankton, too, must respond to global climate change. As sea surface temperatures rise, phytoplankton will have to adapt. Excess CO2 that enters seawater from the atmosphere – increasing as humans burn ever more fossil fuel – can remove the precious materials some plankton use to make their “shells” and take away their protection. Dissolved CO2 can also alter the ability of micrograzers to swim and find food! Melting glaciers are a double-edged sword. Glacial flour (finely ground rock) in freshwater runoff brings in vital nutrients (including iron) through the Copper River Plume and phytoplankton love their iron! But freshwater also works to trap phytoplankton in the surface layers. When all the nutrients are used up and you’re a phytoplankton baking in the heat of the sun, being trapped at the surface is super stressful! As global climate change accelerates in the polar regions, phytoplankton in the Northern Gulf of Alaska are in an evolutionary race against time to develop traits that make them resilient to their ever-changing environment. Phytoplankton crossing the finish line of this race is imperative for us humans, since phytoplankton help to mediate climate change by soaking up atmospheric CO2 during photosynthesis to produce ~ 50 % of the oxygen we breathe!
Phytoplankton also form the base of a complex oceanic food web. The fresh salmon in the fish markets of Pike’s Place (Seattle, WA), the gigantic gulp of a humpback whale in Prince William Sound (AK) and even entire colonies of kittiwakes on Middleton Island (AK) are dependent on large numbers of phytoplankton. When phytoplankton are iron limited, they cannot grow or multiply (via mitosis). In a process called bottom-up regulation, the absence of phytoplankton reduces the growth of animals who eat phytoplankton, the animals who eat those animals, and so on up the entire food chain. To illustrate this point, let us consider “The Blob”, an area of elevated sea surface temperature in the Gulf of Alaska in 2015-16. “The Blob” limited phytoplankton growth, thereby reducing the abundance of small, fatty fishes further up the food web. As a result, the population of kittiwakes on Middleton Island crashed as the birds could not find enough fish to provide them the nutrients and energy to reproduce successfully. In this way, the kittiwake population decline was directly attributable to a lack of phytoplankton production.
Not only are phytoplankton ecologically important, they are commercially important. For consumers who love to fish (and for the huge commercial fisheries in the Northern Gulf of Alaska), the base of the food web should be of particular interest, as it is the harbinger of change. Fisheries managers may use models of phytoplankton growth to monitor fish stocks and establish fisheries quotas. If sporadic input of iron from dust storms, glacial runoff, or upwelling stimulate phytoplankton to grow, fish stocks may also increase with the newfound food source. Because phytoplankton are inextricably linked to fish, whales, and seabirds, in years where nutrients are plentiful, you may well see more fish on kitchen tables across the U.S. and Native Alaskans may be able to harvest more seabird eggs.
Level 2: The Nature of Science
As a supporter of place-based and experiential learning, I
view myself as a student with a dual scientist-educator role. To succeed in
these roles, I have to be able to combine reasoning with communication and
explore questions like “How does science relate to society?” and “How do we
foster scientific literacy?” What better way to think about these questions
than embarking on a three-week cruise to the Pacific Subarctic?! Not only am I working
with amazing Principal Investigators in an immersive research experience, I am
able to collect data and think of creative ways to communicate my findings.
These data can be used to build educational curricula in an effort to merge the
classroom with the Baltic room (where the CTD is deployed). But what’s the
point of collecting data and sharing it?
Science is “a collaborative enterprise, spanning the
generations” (Carl Sagan) and is “the poetry of reality” (Richard Dawkins). The
goal of communicating my results in a way that touches the lives of students is
two-fold. One aim is to allow them to appreciate the philosophy of science-
that it is iterative, self-correcting, and built upon measurable phenomena. It
is the best way that we “know” something. The other aim is to allow students to
engage in scientific discourse and build quantitative reasoning skills. As the
renowned astrophysicist, Neil DeGrasse Tyson has said, “when you’re
scientifically literate the world looks very different to you and that
understanding empowers you.” Using phytoplankton to model the scientific
process allows students to enter into the scientific enterprise in low-stakes
experiments, to question how human actions influence ecosystems, and to realize
the role science plays in society. Ultimately, I want students to use my data
to learn the scientific process and build confidence to face the claims
espoused by the U.S. government and seen on Facebook with a healthy amount of
skepticism and an innate curiosity to search for the truth.
One of the first questions I often get, once people hear that I’m an oceanographer, is, “Do you scuba* dive?” I actually used to, way back in the day when I worked on corals as an undergraduate, but diving turns out not to be part of most oceanographic expeditions. So how do we get our samples out of the ocean?
Allow me to introduce the CTD, mentioned in previous posts but not really explained. The CTD (short for Conductivity, Temperature and Depth) is an instrument package surrounded by water collection bottles (called ‘Niskin’ bottles) that we put over the side of the ship multiple times per day to collect data about the water ‘column’ as well as water samples containing the dozens of things we’d like to measure directly: suspended particles like the ones coming in with the glacier-fed rivers, dissolved chemicals including the nutrients that sustain plankton growth, and the smallest members of the planktonic community including the myriad of species studied by Team Phytoplankton.
CTD packages come in all sizes and we have an impressively large one on Sikuliaq. It’s picked up off the deck by a winch and then boomed out off the side of the ship through a sort of garage door, making it possible to deploy even in fairly rough weather (which we haven’t had yet – it’s been Lake Alaska out here so far this cruise). On the smaller ships we sometimes use, the CTD deployment and recovery is much more ‘hands on’ and can get very exciting in rough seas.
One of the coolest parts of the CTD is the real-time data connection to computers on board, via a conducting cable that also acts as the tether to the ship (you don’t want to kink or break this one. . . tedious to repair and very expensive to replace). As the package of instruments and bottles descends through the water, data are fed up the cable, collected by a computer, and plotted for us to see. We can get information in real time about depths where the temperature, salinity and dissolved oxygen change sharply (marking potential changes in habitat for marine organisms). We can see chlorophyll fluorescence maxima, marking layers rich in phytoplankton. Other sensors we have measure nitrate (an important source of N for phytoplankton) and light (of obvious importance for photosynthesis!). We also have some very high-tech instruments that capture images of particles at different depths.
As the CTD is hauled up again, we stop it at depths of interest and ‘fire’ one of the sampling bottles by clicking a box on the computer screen. This sends an electrical impulse down the conducting cable, releasing the bottle’s top and bottom closure lids from a harness and allowing them to snap close and trap a water sample.
When the whole package comes on board we end up with an array of water samples collected from different depths. Everyone swarms in to drain them into a motley collection of bottles and bags. There are so many different properties being sampled on Sikuliaq that we have to make a ‘water budget’ allocating the 12 liters in each Niskin to each person who needs some, and even specifying the sampling order in some cases.
Our deepest casts on this cruise will be to 2,000 meters (more than 1 mile) deep, and will take several hours. You can see that a scuba diver would have to be mighty well equipped and extremely pressure-resistant to do the job of the CTD!
*Acronym of the day: SCUBA = Self-Contained Underwater
It was fun to read Delphina’s post yesterday, and look through the eyes of someone experiencing their first research cruise. Her post made me reflect on my past research cruises – although I am starting to lose count! How many times has it been…
It’s hard to describe what my job at sea is like, but someone sent me this meme that sums it up pretty well. Multitasking? You bet. We have a lot of wheels spinning in our lab. Team Plankton (aka the Strom Lab) is led by our fearless leader, Suzanne. She kindly gives me a lot of credit for holding things together, but her knowledge, leadership skills and sea-going abilities are impressive. Suzanne is one of the NGA LTER principal investigators (PIs). I am Suzanne’s research technician on the LTER project, and I conducted my graduate work in the Gulf of Alaska with her 15 (!) years ago. You’ve met our two graduate students, Clay and Hana. Both are off to a roaring start with their thesis projects. Rounding out our team is Delphina, who set up her first experiment just a few hours ago! Combining two new thesis projects, a REU project, intensive plume study sampling and experimentation, plus our “standard” NGA LTER sampling – we have our hands full. When the CTD hits the deck, there are a lot of things happening at once.
Problem Solving. As Delphina mentioned yesterday, there is no going to the store or supply closet. I pack doubles, triples, spares, extras of everything – while trying to anticipate the possible needs of all our research projects. Still, equipment malfunctions (the physical oceanographers are heroically trying to repair one major piece of sampling equipment as I type this), the cryovials are nowhere to be found, fragile glassware breaks…it all happens. Time passes quickly and there’s not a lot of room for error. This bring us to:
Requires Coffee. And chocolate. Teas of various sorts. Snacks – lots of snacks. We are all working hard. Long hours running 19+ days straight – we supply ourselves with the appropriate amounts of sugar and caffeine to keep us going.
Will Travel. Heck yeah! Shannon Point Marine Center in Anacortes, Washington –> SeaTac –> Anchorage –> Seward –> Prince William Sound –> Copper River plume in the eastern Gulf of AK –> Kodiak Island and 100 nautical miles south in the western Gulf of AK –> then back. In just 3 weeks!
All of the above adds up to a pretty exciting and interesting job as a member of Team Plankton. I enjoy working at sea, and my small boys think their mom has a super cool job.
P.S. Happy birthday, Jens. One of the
drawbacks to life at sea. I wish I were there to celebrate!
I’ve been at sea before, but never for a long time and never while researching. I’ve been out on dive boats and cruise ships, but neither experience gave me a sense of what a research cruise would be like. I’d never been out for longer than a week and never particularly far from shore. I knew what projects we’d be working on and that we’d be working a lot, but everything else was a mystery. What is the schedule like? How are the rooms? How much does the boat rock? What is the lab space like?
My first surprise was just how much equipment it takes to
run a lab. On land, you barely notice the closets of chemicals, drawers of
gloves and tubing, and shelves of empty bottles. But when you set up a lab from scratch, box
by box, you realize how many supplies are needed to run the experiments. This
is compounded by the need to bring extras and backups – there are no supply
runs at sea – and by the need for organizers to keep supplies secure but
accessible. As someone who stresses over remembering to pack enough t-shirts, I
have no idea how someone manages to pack an entire lab without forgetting
anything! The planning and organization involved in an operation like this is
staggering, especially considering that we are only one of a handful of lab
My next surprise was how high tech and comfortable the ship
was. I hadn’t pictured ceilings lined with outlets, monitors in every room, an
onboard crane, an elevator, and an RO water system. If you ignore the
portholes, the labs feel almost like any other land-based lab; they have
multiple sinks, fume hoods, freezers and enough space for all the scientists. In
terms of commodities, I had expected to be roughing it a bit, imagining short
showers and a bed reminiscent of my old dorm room. Instead, I was welcomed with
plenty of hot water, a memory foam mattress, and the biggest towel I’ve ever
One thing I knew about, but hadn’t really considered, was
how everything needs to be secure. In every room, there are tiny, ingenious
modifications to keep things from flying around in bad weather. Drawers latch
shut and tables have raised lips. In the mess, the coffee machines are bolted
down and the placemats are nonslip. The deck and the lab benches are fitted
with eyebolts so equipment can be tied down with ropes. And for the people there
are handholds everywhere, even the shower.
The science has so far been more what I expected. I’m ever more thankful to my lab classes for covering the basics, like opening a niskin bottle and vacuum filtering. But there are still a lot of new skills, like running a fluorometer and filtering size fractions. Staying organized is also a skill itself, keeping track of a large volume of samples and multiple experiments.
So far, a research cruise is a lot of work, especially since the rocking
motion makes me sleepy. But contributing to research that’s been ongoing for
decades feels amazing, like I’m part of something bigger than I realized.
During our downtime, it’s fun to hear about everyone’s work, both the
scientists and the crew.
Tomorrow we head to the plume and begin the experiment that’s the basis of
my REU (Research Experiences for Undergraduates) project. Stay tuned for more
information about this dilution experiment!
Wasn’t I just saying that it doesn’t do to get too attached to your daily agenda out here? Today the gremlins were out in force. Our morning started with a line wrapped around the ship’s propeller, a circumstance that arose during deployment of a sediment trap array (more on this in a later post). Needless to say this stopped science PDQ. After a tense hour or so, our incredibly able crew was able to get the line unwrapped by reversing the propeller slowly, while also launching the skiff to recover the rest of the array before it floated off into the sunrise. If you are getting the idea that oceanography depends as much on ships’ crews as it does on card-carrying oceanographers, you would be 100% correct!
On the positive side, We Found The Plume! At the inner end of our Middleton Island sampling line (a.k.a. the MID line), we encountered turquoise waters more reminiscent of a tropical lagoon than of subarctic seas. Glaciers grind rock into tiny particles (‘glacial flour’) which are carried into the Gulf of Alaska from glacier-fed rivers and provide an important source of the micronutrient iron (see post from June 24th). At 10 nautical miles offshore we were in water heavily influenced by the Copper River, with only a third of the salt content typical for the region. During our fine-scale survey, scheduled to start on Wednesday (but see top paragraph. . .), it looks like we’ll be mapping some highly complex and fascinating river plume features.
Team Phytoplankton completed yet more CTD sampling and experimental work. We found time to take a peek at some of the water samples we are collecting, and got a surprise – in waters 20 nautical miles offshore, there was a thriving community of tintinnid* ciliates. These single-celled organisms swim and feed using hair-like cilia at one end of the cell, and build a robust shell into which they can retract to escape predators. These particular tintinnids build their shells out of mineral grains found in the surrounding waters. We usually don’t see very many tintinnids in our study area, and are curious as to why they, and not the ‘typical’ ciliates, are so numerous here. These are the kinds of questions that get marine ecologists very excited – we’re an easily entertained bunch!
I have to go now – one of the ship’s cooks just came through the lab with a platter of warm chocolate chip cookies –
*”tintinnid” means “bell-like”. They are aptly named.