Mark Van Arsdale: Gelatinous Fireworks, September 21, 2018

NOAA Teacher at Sea

Mark Van Arsdale

Aboard R/V Tiglax

September 11 – 26, 2018

 

Mission: Long Term Ecological Monitoring

Geographic Area of Cruise: North Gulf of Alaska

Date: September 21, 2018

Weather Data from the Bridge

Partially cloudy skies, variable winds, calm seas to three feet

59.27 N, 143.89 W (Cape Suckling Line)

 

Science Log

Gelatinous Fireworks

 

CTD (water chemistry) data visualized along the Cape Suckling Line.

CTD (water chemistry) data visualized along the Cape Suckling Line.

Last night, we traveled between the Middleton Island line and the Cape Suckling line, providing us with a change in pace from our regular routine of zooplankton and jelly collecting.  Still, it wasn’t a night off, and at midnight, while still in deep waters, we stopped to do a special Multi-net tow. At 800 meters (almost 2500 feet,) this was our deepest tow of the trip.  A tow that deep takes almost two hours to get down to depth and back up again.  This tow was looking for unique organisms for later genetic analysis, and most of the stuff that came up I had previously only seen in movies.  Deep red shrimp, giant copepods almost a centimeter in length, big-eyed lantern fish, comb jellies, and amphipods that looked straight out of the movie Aliens.

Lanternfish from a deep water (800 m) Multi-net tow.

Lanternfish from a deep water (800 m) Multi-net tow.

We had a couple of hours break until we reached the outermost Cape Suckling station, so naturally I slept.  We did our first Methot net jelly tow at five am. We were in deep water, 2500 fathoms (~15000 feet), and far enough off shore that the jellies were abundant.  In fact, as we were putting the net in the water we noticed that there were more jellies than we had previously seen at any sampling station.   After putting the net in, we turned off the ships lights and lay witness to a fireworks show in the water.  So many jellies, and each time one hit the net there was an explosion of blue green light.  Jellies, particularly the glass jellies, are super fragile with long delicate tentacles.  When they hit the net, their tentacles break apart and they release a plume of glowing bioluminescence.  The normal in-water time for this net is twenty minutes, but after seeing such dense concentrations of jellies we decided to pull it early.  As we pulled it out of the water, the net nearly bursting at its seams, we had to attach an extra line and bring the cod end out of the water with the crane.  We measured jellies for a long time, and watched the sky glow red as the sun came up over the rugged peaks of Cape St. Elias and the Bering Glacier.

The Scientists

Yesterday, I talked about the Crew of the Tiglax. Today I thought I would say a bit about the scientists on board.  Excluding myself, there are thirteen scientists on board.  Of those thirteen, ten are women and three are men.  The group includes four graduate students, three research technicians, two wildlife biologists, two primary investigators/professors from UAF, one investigator/professor from the University of Hawaii, and one semi-retired UAF research staff.  Aside from the wildlife biologists and the researcher from the University of Hawaii, they are all physical oceanographers.  Physical oceanographers look at the ocean almost as if it is an equation waiting to be solved.  If you have the right physical drivers, wind and currents may combine nitrates and iron at the surface.  If you have the right nutrients mixed with light near the surface, you get phytoplankton growth.  If you have oxygen and phytoplankton with the right physical conditions to stay near the surface, you can grow and sustain zooplankton. They build ecosystems as if by Lego blocks, each piece critical to the final outcome.

Ask any one of them how they get paid and you will inevitably get the response – it’s complicated.  Most of the salaries are funded through grants in what they describe as “soft money.”  Grants for research are funded by a variety of agencies, in this case, the largest being the National Science Foundation.  Writers of the grants list the number of positions required and the dollar figure attached to those positions.  Once the grant is awarded it gets managed by The University of Alaska accounting department.  For the grad students, these trips are certainly a learning opportunity, and one that a lot of schools could not offer.

Personal Log

Autonomy

The back and forth nature of the way we sample stations is at times dizzying.  We make progress slowly, sample four stations at night, drive back to where you started in the morning, then sample the same four stations during the day.  At sunset, start at the next station down the line.  Much of the conversation aboard revolves around what station we are on and what test is being run.   The acquisition of data is slow, tedious, and deliberate work.

Today we are closer to Canada than we are from the town of Seward where we left. When you are part of a research cruise one hundred miles off shore, you can’t just go home because you’re tired, or because something happens at home, or because you just want a break. If something breaks, you have a spare, or you try to fix it.  If a schedule gets altered because of waves or weather, you just sleep when you can and work later.  There is no phone and no internet, so you can’t call your kids to wish them goodnight.  There is just work, and I have found myself in many ways ill prepared for its single-minded focus.

I have come to realize how much I take for granted the autonomy I have to do or go where I want.  Out here, you have no autonomy.  You go where the boat goes, you eat what and when the chef says, you work when the chief scientist says to work, and you do exactly what they say.  This of course, is driven by the sheer expense of doing research at sea as well as the tremendous travel times it takes to get out this far.

Northern Fulmar, notice it's "tube nose."

Northern Fulmar, notice it’s “tube nose.” photo credit Callie Gesmundo.

Did you know?

Many seabirds have a structure on the tops of their beaks that looks like the air intake on a muscle car.  These birds are known as “tube-nosed” birds and they make up the order Procellariiformes.  The group includes albatross, fulmars, petrals, and shearwaters.   The tube hides two nasal glands that help them concentrate and remove excess salt from their blood.  The glads allow them to drink saltwater without suffering dehydration.

 

Animals seen today

  • Minke whale
  • Lots of sea birds including puffins, auklets, shearwaters, albatross, fulmars, petrels, and gulls

Mark Van Arsdale: What Makes Up an Ecosystem? Part III – Zooplankton, September 15, 2018

NOAA Teacher at Sea

Mark Van Arsdale

Aboard R/V Tiglax

September 11 – 26, 2018

 

Mission: Long Term Ecological Monitoring

Geographic Area of Cruise: North Gulf of Alaska

Date: September 15, 2018

Weather Data from the Bridge

Mostly cloudy, winds southerly 20 knots, waves to eight feet

57.56 N, 147.56 W (in transit from Gulf of Alaska Line to Kodiak Line)

Science Log

What Makes Up an Ecosystem? Part III Zooplankton

The North Gulf of Alaska Long-term Ecological Research Project collects zooplankton in several different ways.  The CalVET Net is dropped vertically over the side of the boat to a depth of 100 meters and then retrieved.  This net gives researchers a vertical profile of what is going on in the water column.  The net has very fine mesh in order to collect very small plankton.  Some of these samples are kept alive for later experiments. Others are preserved in ethanol for later genetic analysis. One of the scientists aboard is interested in the physiological details of what makes copepods thrive or not.  Copepods are so important to the food webs of the Gulf of Alaska, that their success or failure can ultimately determines the success or failure of many other species in the ecosystem.  When “the blob” hit the Gulf of Alaska in 2014-2016, thousands and thousands of sea birds died.  During those same years, copepods were shown to be less successful in their growth and egg production.

Chief Scientist Russ Hopcroft prepping the Multi-net

Chief Scientist Russ Hopcroft prepping the Multi-net

The second net used to collect zooplankton is the Multi-net.  We actually use two different Multi-nets.  The first is set up to do a vertical profile.  In the morning, it’s dropped vertically behind the boat.  Four or five times a night, we tow the second Multi-net horizontally while the boat moves slowly forward at two knots.  This allows us to collect a horizontal profile of plankton at specific depths.  If the water depth is beyond 200 meters, we will lower the net to that depth and open the first net.  The first net samples between 200 and 100 meters, above 100 meters we open the second net.  As we go up each net is opened in decreasing depth increments, the last one being very close to the surface.  Once the net is retrieved, we wash organisms down into the cod end, remove the cod end, and preserve the samples in glass jars with formalin. In a busy night, we may put away twenty-five pint-sized samples of preserved zooplankton.  When those samples go back to Fairbanks they have to be hand-sorted by a technician to determine the numbers and relative mass of each species.  We are talking hours and hours of time spend looking through a microscope.  One night of work on the Tiglax may produce one month of work for technicians in the lab.

 

Underwater footage of a Multi-net triggering.

The last type of net we use is a Bongo net.  Its steel frame looks like the frame of large bongo drums.  Hanging down behind the frame is two fine mesh nets, approximately seven feet long terminating in a hard plastic sieve or cod end.  Different lines use different nets based on the specific questions researchers have for that transect line or the technique used on previous years transects.   To maintain a proper time series comparison from year to year, techniques and tools have to stay consistent.

A cod end

A cod end

I’ve spent a little bit of time under the microscope looking at some of the zooplankton samples we have brought in. They are amazingly diverse. The North Gulf of Alaska has two groups of zooplankton that can be found in the greatest abundance: copepods and euphausiids (krill.)    These are food for most other animals in the North Gulf of Alaska.  Fish, seabirds, and baleen whales all eat them.  Beyond these two, I was able to observe the beating cilia of ctenophores and the graceful flight of pteropods or sea angels, the ghost-like arrow worms, giant-eyed amphipods, and dozens of others.

Deep sea squid, an example of a vertical migrator caught in our plankton trawls

Deep sea squid, an example of a vertical migrator caught in our plankton trawls

By far my favorite zooplankton to watch under the microscope was the larvae of the goose neck barnacle.  Most sessile marine organisms spend the early, larval stage of their lives swimming amongst the throngs of migrating zooplankton.  Barnacles are arthropods, which are defined by their exoskeletons and segmented appendages.  Most people would recognize barnacles encrusting the rocks of their favorite coastline, but when I show my students videos of barnacles feeding most are surprised to see the delicate feeding structures and graceful movements of this most durable intertidal creature.  When submerged, barnacles open their shells and scratch at particles in the water with elongated combs that are really analogous to legs. The larva of the goose neck barnacle has profusely long feeding appendages and a particularly beautiful motion as it feeds.

We have to “fish” for zooplankton at night for two reasons.  The first is logistical.  Some work needs to get done at night when the winch is not being used by the CTD team.  The second is biological.  Most of the zooplankton in this system are vertical migrators.  They rise each night to feed on phytoplankton near the surface and then descend back down to depth to avoid being seen in the daylight by their predators.  This vertical migration was first discovered by sonar operators in World War II.  While looking for German U-boats, it was observed that the ocean floor itself seemed to “rise up” each night.  After the war, better techniques were developed to sample zooplankton, and scientists realized that the largest animal migration on Earth takes place each night and each morning over the entirety of the ocean basins.


One of my favorite videos on plankton.

Personal Log

The color of water

This far offshore, the water we are traveling through is almost perfectly clear, yet the color of the ocean seems continuously in flux.  Today the sky turned gray and so did the ocean.  As the waves come up, the texture of the ocean thickens and the diversity of reflection and refraction increases.   Look three times in three directions, and you will see three hundred different shades of grey or blue.  If the sun or clouds change slightly, so does the ocean.

The sea is anything but consistent. Rips or streaks of current can periodically be seen separating the ocean into distinct bodies.  So far in our trip, calm afternoons have turned into windy and choppy evenings. Still, the crew tells me that by Gulf of Alaska standards, we are having amazing weather.

Variations in water texture created by currents in the Gulf of Alaska.

Variations in water texture created by currents in the Gulf of Alaska.

 

Did You Know?

The bodies of puffins are much better adapted to diving than flying.  A puffin with a full belly doesn’t fly to get out of the way of the boat so much as butterfly across the surface of the water.  Michael Phelps has nothing on a puffin flapping its way across the surface of the water.

 

Animals Seen Today

  • Fin and sperm whales in the distance
  • Storm Petrels, tufted puffins, Laysan and black-footed and short-tailed albatross, flesh footed shearwaters