Ecosystem Responses to El Niño

Month: May 2016 (page 1 of 2)

De-Mobilization Days

We demobilized, or unloaded the ship, on Thursday May 12.

  • First we packed everything up back in the boxes they came in.

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  • Then we swept the labs and cleaned the counters. There was so much dried salt everywhere!

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  • We put our linens in bags in the hallway. The Sikuliaq crew took care of them for us. Thanks guys!


  •  Then we were ready to come in. But the ship needed a little help. The bow thruster had gone out, and so a tug boat met us in the harbor to push us in.

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We made it in safely and unloaded everything by Friday. Overall we had a very  successful and productive cruise. Thanks for reading!


The Barbeau Lab’s Benthic Boundary Layer Study

The Barbeau lab is spending the day testing the benthic boundary layer just off the coast of the Vandenberg Air Force Base.  The benthic boundary layer (BBL) is thought to be a layer of sediment mixing very near the bottom of the seafloor, that upwells trace metals.

The Barbeau lab samples the BBL by first dropping a CTD profile to see if there is a benthic boundary layer at a station location, and then sampling it with a 30L go-flow bottle on their plastic-coated winch.


The bottle is open on deck and cocked close in the air. It is weighted down and dropped very slowly.



When the bottle is under 10-15m of water, the pressure of the water opens the bottle, which we see at the surface by air bubbles escaping. Then we send the bottle to within 5m of the bottom. To close it Sarah sends a messenger down the line to close it. Sara, Maitreyi and Ethan are holding the wire to feel the sensation of it tripping closed.


Then we bring up the bottle and it is carried into the trace metal van to filter the water for trace amounts of iron and ligands. Measuring trace amounts of iron in the BBL allows the Barbeau lab to potentially find the riverine source of iron to the California Current.

Yelp Review: R/V Sikuliaq’s Galley

R/V Sikuliaq’s Galley


Location: Somewhere in the Ocean

Contact Info: 241 on the ship phone

Ask for Mark or Susan


Price Range: $$$$$$$$$ or ____ (depending on if you’re paying the grant or not)

Hours: 715-815



7 days a week

(Coffee and leftovers 24 hours a day)


Take-out Yes

Accepts Credit Cards No

Accepts Apple Pay No

Parking Walk-Up Line Only

Outdoor Seating Deck Seating Available

Wi-Fi Spotty

Takes Reservations 2 years out, through NSF



The music playing always matches the food for the day, and the blue non-skid tablecloths really bring the outdoors in. The TV is always playing my favorite channel, “The Back Deck.” The porthole windows always have a beautiful view outside. And the food is amazing of course!



I never thought the first place I would have bison or quail eggs would be on a ship. I’ve eaten here every meal for 24 days and haven’t had a repeat yet! And Mark and Susan are always so friendly when they’re serving us in line. And the mess attendant Ed is the nicest, even if we make him wash dishes 12 hours a day.



Order the green curry. It’s amazing. Or if you go in the morning, get all the banana bread.



Do I like Mark’s cooking or his Mohawk more? It’s a tossup. But the rack of lamb was seriously a culinary experience not to be missed. Just sad the restaurant is dry so we couldn’t enjoy it with a nice glass of red.



Slept through lunch? Shame on you… but no worries Mark and the galley crew bring desserts to you down in the main lab



Celiac friendly! Best gluten free menu around! Mark and Susan are happy to accommodate dietary restrictions and say they enjoy the challenge. Check in at every meal to see what they have cooked up.



One day you are dining on wild Alaskan King Salmon and the next you are sampling the Cuisine of the Orient, each prepared with the same level of enthusiasm and care. Even the ship’s electrician is schooled in the culinary arts. Best midnight snacks ever.



Just a short stone’s throw from your stateroom door, the location cannot be beat. For any hour of the day, the employees are sure to keep the coffee stocked- feel free to fill that fifth cup. Just a half star off of five for the damn TV: it’s always on the same channel!

The CCE cruise, according to Maitreyi

Maitreyi Nagarkar has been writing letters to her friends and family while on the cruise, and she has been drawing pictures in the letters. She’s letting me use some of the diagrams for the blog! Hopefully some of these awesome drawings will help clarify what we’re doing out here!

Maitreyi first drew the back deck. This is where all the main operations happen:


She also drew the sediment traps and plankton nets:

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But Maitreyi spends most of her time working on the CTDs with the other chemists and the trace metal team.

Here is the main CTD rosette:


And how we deploy and recover it (bonus points for Maitreyi drawing herself in safety gear on the deck):

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As it deploys, the CTD measures the temperature at multiple depths:


And at different depths, the Niskin bottles “fire,” which means that they close, containing water at that distinct depth.

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The tuna crabs are here!

Bellineth Valencia had the first tow of Cycle 4, and her ring net tow was defined by two things: thousands of tiny Calanus copepods, and tuna crabs! The tuna crabs (genus Pleuroncodes) are not common in these waters; they are normally off of Baja California. But last summer, with the abnormally warm waters in this region [colloquially called “The Blob”], we caught them by the hundreds. And now, with the warm waters of El Niño, we expected to see them again. What is surprising is that we are only 20 nautical miles from Cycle 3, that was crabless, and here we have tons! You can see them swimming at the surface at night as well.

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The ring net in action. It’s weighted down so it sinks vertically into the water.

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Belli preparing her tow-collecting bucket, that was soon full of tuna crabs. She was only looking for Calanus copepods for a grazing experiment, so the crabs had to be taken out into another bucket.

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Close-ups of the tiny crabs.


There are sometimes multiple ways of measuring the same phenomenon at sea. Mark Ohman’s MVP (moving vessel profiler) has an LOPC (laser optical particle counter) on it that scans plankton as it dives through the water. It records pixelated shapes of the plankton as they pass through it.

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The blue oblong shapes on the right of the screens showed up on the LOPC on every dive between 30-10 m, right where the highest concentration of doliolids was.

Tristan Biard’s UVP (underwater vision profiler) takes photos of plankton as the CTD (conductivity, temperature, depth sensor) descends on each dive. It does this by illuminating a flat plane of water that the camera focuses on as the CTD descends, and it takes pictures of all plankton in that plane of light. The photos are then sorted by a computer algorithm in to categories of animals that Tristan then re-sorts manually.


Left: The UVP attached to the CTD rosette. The red bars emit the light that create the flat plane of light. Right: Dr. Biard hard at work analyzing images.

As we have been going through the doliolid plankton bloom, we wanted to see if the UVP and MVP were both detecting the bloom at the same depth and in similar amounts. We drove the ship in a circle to sample the same water parcel, and we first did five CTD dives to sample the UVP, then five MVP casts, then five more UVP tests. [Also, sorry scientists love acronyms!] Then we preserved the water from the CTD bottles of the last UVP cast, to see if there were doliolids in the actual CTD bottles. The CTD is only at each depth for a few seconds as it closes each bottle, so to catch doliolids in the bottles would mean the density is very thick.


Preserving the bottles.

The CTD water, the MVP LOPC, and the UVP all saw the same thing – doliolids at the same concentration at the same depth. But we can’t truly compare the results of how they recorded the bloom until Tristan manually checks all the images. And that will take many days. Like so many things we do at sea, there is a lot of analysis on the backend after the instrument comes on board. So until then, we wait and wonder how all our instruments compare. On to Cycle 4!


It’s Friday Night! And no one cares.

When you’re out at sea, the things that determine how you spend your day are whether you are steaming to a location to do research, the weather, and whether your equipment is working.

If all those things are working, then what determines how you spend your day (on this cruise at least) is what day of the Cycle you are on, and how many replicates of each experiment you need to do at that Cycle. Our cycles last three days, and are spatially determined by where the sediment traps and drifters take us.

What else determines how you spend your day is whether you need to take your samples during the day or at night, every 6 or 12 hours, or right at sunrise and sunset as the plankton migrate from the bottom to the top of the water column.

What doesn’t determine when you work is what day of the week it is.  There’s no sense of the weekend, or a 40 hour work week. So it’s Friday night, but no one cares. There’s still science to be done.

Spotlight on: Seaver Wang’s Research

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I’m Seaver Wang, a graduate student in Dr. Nicolas Cassar’s research group at Duke University’s Division of Earth and Ocean Sciences. In my research, I am interested in measuring rates of marine carbon and nutrient cycling and relating these processes to the microbial diversity of the surface ocean. In addition to this project examining El Niño and the California current, I am also studying nitrogen and phytoplankton activity and taxonomy in the Sargasso Sea, a region of the western North Atlantic. My project aboard the Sikuliaq involves operating an instrument designed to measure “net community production” in the surface ocean using a method called equilibrator inlet mass spectrometry, or EIMS.

Net community production, or NCP, is the balance between biological rates of photosynthesis and respiration taking place in the upper, well-mixed portion of the sea. For instance, if photosynthesis exceeds total respiration, the resulting positive NCP represents an overall uptake of carbon by marine biota. Using a mass spectrometer, I analyze dissolved gases from seawater collected continuously from an intake near the ship’s keel. The instrument measures the ratio of oxygen—which is consumed and produced by biological activity—to argon. Argon is a relatively inert compound that has similar solubility characteristics to oxygen gas but goes completely unused by marine biota, unlike oxygen. Therefore, differences in the ratio of oxygen to argon can largely be isolated to biological activity. Using the O2/Ar ratio measured via EIMS, I am able to calculate phytoplankton productivity, which we hope to compare to measurements of photosynthetic pigments, zooplankton grazing, particle sinking, and microbial community composition that are being conducted by other teams aboard the Sikuliaq.

Doliolids for Days

Today we pulled purple grape juice up from the ocean – gallons and gallons of it.

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Upon closer inspection, it was actually seawater full of thousands of blue-and-red doliolids. They had apparently been growing like crazy in the surface waters surrounding our boat. Not many other creatures were in our nets, which keeps us wondering where did they come from, and how long will they last? Only more sampling over the next few days will tell us the development and fate of this mysterious mass of creatures.

Perhaps you’re wondering what a doliolod is. Picture this: a small, clear, gelatinous barrel shape, slightly larger than a pencil eraser, with eight to nine purple-blue muscle bands circling its girth like hoops. The gut and gonads form a pair of red dots inside, producing the blend of colors that give our net tows their intriguing purple goo. Because of their watery gelatinous composition, doliolids are often mistaken for jellyfish. Surprisingly, however, doliolids are not very closely related to jellyfish, and are actually some of humanity’s closer relatives. Within the kingdom Animalia, humans are in the phylum Chordata, meaning that we have certain developmental characteristics such as a notochord and gill slits as embryos. It turns out that doliolids have several of these same characteristics, making them more similar to us than to things like sea stars and jellyfish.

Doliolids are rather mysterious ocean creatures. They are usually present in very low abundances within the zooplankton community, but every couple of years, without warning, they bloom and completely dominate surface waters. When we were sampling in offshore waters for Cycle 2 this past weekend, we saw a fair number of larval doliolids and pyrosomes, and wondered if a bloom would materialize. As we moved closer inshore and began sampling in a higher-productivity nearshore upwelling zone for Cycle 3, our nets became absolutely clogged with doliolids. Every net we’ve brought up yesterday and today, day and at night, has been dripping with doliolids. Our post-processing time has also increased dramatically. Usually, the three filtering processes that we put a Bongo net sample through take an hour to complete, combined. This morning’s Bongo net took four hours to complete, with everyone in our lab (four graduate students plus two volunteers) filtering nonstop (in addition to deploying our daytime MOCNESS net, running through a weekly ship fire drill, and taking 10-minute shifts for lunch). Other experiments happening onboard have also been swamped with doliolids. One of my labmates, Cat Nickels, looks at egg production in female copepods (a type of small crustacean generally present in high numbers). Her copepod sorting over the past two days has slowed down significantly, as she shuffles through hundreds of doliolids to find a few stray copepods that she can use for her experiments. Another member of our cruise, Mike Stukel, deploys sediment traps at several depths in the water column at the beginning of each of our three-day sampling cycles. These traps collect particulate matter and dead plankton that rain down through the water column. When we haul the sediment traps up at the end of the cycle tomorrow night, they may be completely full of dead doliolids.

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Normally each bongo sample takes 5 dishes. This one took 28!


We had to split the top MOCNESS sample in half to get it to a manageable size to preserve.

Despite the nuisance of doliolids to our sampling efforts, they are an incredible study opportunity. Little is known about what causes doliolids and salps to rapidly reproduce into water column-dominating ‘blooms’, and they can be very hard to find and study because of our inability to predict when and where they will occur. The current high numbers of doliolids that we are finding may give us clues as to what physical ocean conditions favor these blooms. If we can better understand what constitutes good conditions for these organisms, we may also be able to use future blooms in turn as indicators of variations in ocean conditions.

What will tomorrow’s sampling bring? That’s the question that keeps us going as we throw nets into the ocean several times a day (including middle-of-the-night MOCNESS deployments). Processing takes a lot of extra time and effort, but sailing into the middle of an event like this reminds us that we have to take advantage of this rare glimpse into the secrets of the sea.


This post written by Laura Lilly, our filterer extraordinaire.

Polar Bear Update

The hunt for polar bears is officially on!

I found one on top of the clock in the electronics lab while on MVP watch. Megan noticed one on the clock in the main lab. All the clocks on the ship have local and UTC time.

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Two of the paintings in the ladderwell have them, and a painting right outside the galley. A polar bear on a plaque of a polar bear!

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When we finally ventured inside the sauna we found one, between the D and P of this road sign.


There’s one on the fire dampening control box on the way to the winch shack.


And one in the communal head (shipspeak for restroom).



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