mvanarsdale2018

September 19, 2018October 4, 2018

Mark Van Arsdale: Estuaries, September 19, 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 19, 2018

Weather Data from the Bridge

Clear skies, calm seas

60.25N, 145.5 W (Middleton Island Line)

Science Log

Estuaries

Water chemistry for the Middleton Transect Line

Estuaries are semi-enclosed bodies of water where fresh and saltwater mix. By this morning, we had moved into the Copper River Estuary and the salinity reading at the surface showed nearly fresh water. Estuaries can be sites of incredible biological productivity, but in Alaskan high rates of water flushing due to rain and glacial melt along with low rates of plant decay (and almost zero use of agricultural fertilizers) mean that may not be the case. Close to the Copper River, light may also become a limiting factor as the glacial sediments increase turbidity and decrease water clarity. Along this line, we did see a narrow band of higher productivity (seen as Fluorescence on the graph above) about fifty kilometers out where water clarity had improved.

Estuaries tend to be shallow with lots of tidal movement. This creates ideal conditions for plankton growth, and our nightly plankton tows did see more algae than we had in previous tows. We also started to see juvenile pink shrimp and salmon smolt. Much to our surprise, we were still catching jellies well into the freshwater area. For most oceanic species, fresh water is a stressor. Dealing with the constantly changing salinity is a challenge for any estuarine species. An inflowing tide brings in denser saltwater, which moves along the bottom. Freshwater flows in from rivers at the surface. Depending on the conditions of the estuary, that can create either well mixed brackish water or distinct salt and freshwater wedges.

Bird biologist Dan Cushing entering data along the Middleton Line.

Estuaries across the world have historically been centers of intensive human development. In the U.S., New York, San Francisco, Baltimore, and Seattle are just a few examples of large urban areas sitting along large and important estuaries. For historically developing cities, estuaries meant easy to access food and oceanic transportation, as well as the benefits of fresh water for drinking and the outflow of sewage waste. Sixty percent of North America’s estuaries are considered to have significantly degraded habitat. However, the Copper River Estuary remains a largely undisturbed gem. There are no dams on the Copper River and very little development along its watershed.

Personal Log

Human Connections

When the sun came up in the morning we could see the heavy glacial silt of the Copper River. There were sightings of ducks and other water fowl. The water was grey and murky, but the peaks surrounding the Copper River water shed were sensational, and I found myself wishing I could stay awake. As we get further east and into areas that I am completely unfamiliar with, there is so much to see, and I find myself wishing I did not have to sleep through the mornings.

At this point we were just a few miles away from the town of Cordova. Although I did not, many people on board had cell service this morning. When I woke up after five hours of sleep it was impossible to walk around the boat without seeing someone looking down at their phone. Scientists at sea are very work focused, but even hard core scientists miss their human connections. People wanted to talk to spouses or kids, and get updates on their friend’s social media. There were also murmured discussions about what news we had missed over the last eight days, much of it ominous. Our human connections are life sustaining points of encouragement, our twenty-four-hour news cycle maybe not so much. By afternoon we were headed far back out to sea working on the Middleton line. Because of the zig-zag nature of our day-night work, we have had a clear view of Middleton Island several times now. Those who were here last year recall such torrential rains that they never saw the island once. Our weather continues to be remarkably good. We hope to complete the Middleton Line tomorrow and head further east to Cape Suckling after that. Ironically, the good weather seems to be leaving the captain and crew slightly ill at ease. It can’t last forever, and they seem to be wondering when the other shoe will drop. I just hope that if and when the weather goes bad, it’s during the last leg of our trip when we have moved into the protected waters of Prince William Sound.

September 18, 2018October 4, 2018

Mark Van Arsdale: Sightings from the Flying Bridge, September 18, 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 18, 2018

Weather Data from the Bridge

Clear skies, calm seas

59.30 N, 146.15 W (Middleton Island Line)

Science Log

Sightings from the Flying Bridge

We finished up night work on the morning of the 17^th in a bit of swell. Our last casts of the Methot and the Bongo nets were bumpy. It was hard to stand up, and hard to keep objects from shifting dangerously. But the swell didn’t last, and by time I woke up mid-morning it was a picture-perfect day, clear and calm. The day shift finished up sampling the Kodiak line by dinner, and we began a twenty-four-hour transit from the Kodiak line to Middleton Island east of Prince William Sound. I got the night off, and with it my first solid night of sleep since the trip started. I felt like a whole new human.

Sunfish (Mola mola) with diver
© Tomas Kotouc
Tomas Kotouc
Sladkova 331/II, Jindrichuv Hradec, 377 01, Czech Republic

The transit allowed me to spend most of the day in the flying bridge and it was a good day for it. We sighted fin whales in the morning, numerous sea birds, another Mola mola (ocean sun fish), and two pods of Risso’s dolphins in the afternoon. The last two sightings are really interesting. That was the third Mola mola spotted on the trip. The Mola mola is the largest bony fish in the ocean. They can grow up to four meters long and three thousand pounds, eating almost exclusively jellies. They are a bizarre looking fish. They have no true caudal (tail) fin, thin elongated pectoral fins, and a body shaped like more like a giant head than a fish. They also swim (if you can call it that) on their side. The interesting thing is that the Mola mola is a sub-tropical fish and should not be seen in the North Gulf of Alaska – but here they are.

The Risso’s dolphins were another unusual sighting. We saw them in groups of twenty or so. Fast swimmers and acrobatic in their movements, you could see their characteristically white faces and scratched backs as they jumped out of the water. None of the crew or scientists on board had ever seen them and we went through three books trying to get a solid ID. Very little is known about this species, and confirmed sightings at sea are limited. It’s likely that this will be the farthest north sighting of Risso’s dolphins recorded.

In the last few years, unusual sightings of species have become more common and not just on the surface. Plankton tows are revealing copepod species more commonly associated with the California Current than the Gulf of Alaska. It’s possible that these sightings represent observational bias – we are just paying more attention. But it seems likely that species in the Gulf of Alaska are on the move.

The North Gulf of Alaska changes seasonally, it changes based on your depth and location, and it changes with weather and currents, but it seems obvious that it is also experiencing long term climactic change. How will that change affect the stability of this rich ecosystem? How will it affect the large slice of the Alaskan economy that depends on the wealth of fish brought out of the Gulf? Already this summer, the Gulf of Alaska cod fishery closed due to lack of fish. A disaster to some of fishermen in Kodiak, and a heavy hit to the Kodiak Island economy. By tomorrow morning we will be at the outflow of the Copper River. Copper River salmon are famous for their rich flavor, high prices, and dependable arrival, but this summer, fishing for Copper River king and sockeye salmon was also closed for much of the summer. Fish were coming back small or not at all.

Personal Log

Middleton Island

Good weather has left us a bit ahead of schedule, and the captain and chief scientists decided we could make an excursion to Middleton Island. When I get home I plan to do some more research on the Island, but it seems to have an interesting, albeit short history. The island is just a few thousand years old, brought up out of the ocean by the tectonic movements of the Pacific and North American plates. Much of the island is a flat plateau, surrounded by a series of shelves descending down to the water. Some of the shelves are quite new, the latest edition came during the 1964 Alaska Good Friday Earthquake, as the island was force 12 feet up from the ocean.

Abandoned air force buildings and the newly remodeled kittiwake tower.

The island was once home to a World War II Air Force base. It was believed that its moderate climate would make an ideal early warning site, but the base was abandoned some time ago. Middleton is currently home to an FAA weather station and an immense number of nesting seabirds. At some point the disintegrating air force buildings were taken over by those nesting sea birds. Scott Hatch, a U.S. Fish and Wildlife biologist, saw an opportunity and over the years has turned the old Air Force tower into an observation and study center for nesting black legged kittiwakes. Over a thousand birds have nests on the outside of the tower, and each one now has a one-way glass window at its back. The nesting birds can be observed and studied by budding biology students from inside the tower. Studies have been done on their diets, metabolism, behaviors and numerous other details of their private lives. We got to meet Scott and his wife, who were just finishing up some end of the season work on the sight. They gave us a bit of a tour and showed us where they had built facilities for students and observation sites for nesting common murres, as well as burrow digging sea birds like rhinoceros auklets and puffins. The sea birds were all gone, having fledged their young and returned to the ocean a few weeks before, but it was fun to imagine what the island looked and sounded like with thousands of sea birds on it.

The day off and a shore excursion seemed to leave everyone more relaxed that they have been for the last week. People smiled and joked and enjoyed the unusually warm September day. Feeling recharged, I was even looking forward to my night shift.

Cool Moment of the Day

We start working most nights just after the sun goes down. Last night I noticed there was a bird following us just overhead. It was an osprey, and it followed us for more than two hours as we worked through the night. The bird undoubtedly thought we were a fishing vessel and was looking for handouts, but in the middle of the night it was an amusing distraction to look up at the rapture silhouette against the clouds.

Animals seen today

Fin whales
Harbor porpoises
Risso’s dolphins
Another Mola mola
Lots of sea birds including puffins, auklets, shearwaters, cormorants, fulmars, petrels, a merlin, an osprey

September 18, 2018October 4, 2018

Mark Van Arsdale: Kodiak, September 17, 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 17, 2018

Weather Data from the Bridge

This morning 25 knot winds from the NE, waves to 8ft, tonight calm seas variable winds, light rain

58.14 N, 151.35 W (Kodiak Line)

Science Log

Kodiak

My wife and I have traveled to Raspberry and Kodiak Islands twice. The island’s raw beauty, verdant colors, and legendary fishing make it one of my favorite places on Earth. Its forests are dense, with huge hemlocks and thick growths of salmon berries. The slopes are steep and covered with lush grasses. Fish and wildlife abound. As we moved our way down the Kodiak line, getting closer and closer to land, that richness of life was reflected in waters surrounding the Island. In just fifty nautical miles we moved from a depth of a few thousand meters to less than one hundred. Seabirds became more abundant, and we saw large groups of sooty and Buller’s shearwaters, some of them numbering in the thousands. Sooty shearwaters nest in the southern hemisphere and travel half way across the planet to feed in the rich waters surrounding Kodiak. Fin whales were also abundant today, and could be seen feeding in small groups at the surface. Our plankton tows also changed. Deep sea species like lantern fish and Euphausiids disappeared and pteropods became abundant. We caught two species of pteropods that go by the common names – sea butterflies and sea angels. Sea butterflies look like snails with clear shells and gelatinous wings. Sea angels look more like slugs, but also swim with a fluttering of their wings. Pteropods are an important part of the Gulf of Alaska Ecosystem, in particular to the diets of salmon.

Sooty shearwaters as far as you can see.

In the last decade, scientists have become aware that the ocean’s pH is changing, becoming more acidic. Sea water, like blood, is slightly basic, typically 8.2 on the pH scale. As we have added more and more CO2 into the atmosphere, about half of that gas has dissolved into the oceans. When CO2 is dissolved in sea water if forms carbonic acid, and eventually releases hydrogen ions, lowering the waters pH. In the last decade, sea water pH has dropped to 8.1 and is predicted to be well below 8 by 2050. A one tenth change in pH may not seem like much, but the pH scale is logarithmic, meaning that that one tenth point change actually represents a thirty percent increase in the ocean’s acidity. Pteropods are particularly vulnerable to these changes, as their aragonite shells are more difficult to make in increasingly acidic conditions.

A nice introduction to Pteropods

Personal Log

I chose teaching

We have been at sea now for one week. I feel adrift without the comforts and routines of family, exercise, and school. There are no distractions here, no news to follow, and no over-scheduled days. There is just working, eating, and sleeping. Most of the crew and scientists on board seem to really enjoy that routine. I am finding it difficult.

There was a point in my twenties where I wanted nothing more than to become a field biologist. I wanted to leave society, go to where the biological world was less disturbed and learn its lessons. I see the same determination in the graduate students aboard the Tiglax. When working, they are always hyper focused on their data and the defined protocols they use to collect it. If anything goes wrong with tow or sampling station, we repeat it. You clearly need that kind of focus to do good research. Over time, cut corners or the accumulation of small errors can become inaccurate and misleading trends.

When I was in graduate school hoping to become a marine biologist, I was asked to be teaching assistant to an oceanography class for non-science majors. Never having considered teaching, the experience opened my eyes to the joys of sharing the natural world with others, and changed my path in ways that I don’t regret. I am a teacher; over the last twenty years it has come to define me. On this trip, they call me a Teacher at Sea, yet the title is really a misnomer. I have nothing to teach these people, they are the experts. Really, I am a student at sea, trying to learn all that I can about each thing I observe and each conversation I have.

Bowler's shearwater, photo credit Callie Gesmundo. — Buller’s shearwater, photo credit Callie Gesmundo.

Animals seen today

Fin whales
Lost of shearwaters (mostly sooty but also Buller’s), along with puffins, auklets, skua

September 17, 2018October 4, 2018

Mark Van Arsdale: What Makes Up an Ecosystem? Part IV – Jellies, September 16, 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 16, 2018

Weather Data from the Bridge

Mostly cloudy, winds variable 10 knots, waves four to six feet during the day, up to eight feet at night

57.27 N, 150.10 W (Kodiak Line)

Science Log

What Makes Up an Ecosystem? Part IV Jellies

Ever seen a jellyfish washed up on the beach? Ever gotten stung by one? Most people don’t have very favorable views of jellyfish. I’m getting to spend a lot of time with them lately, and I am developing an appreciation. We have a graduate student on board studying the interactions between fish and jellies. Her enthusiasm for them is infectious.

Graduate student Heidi photographing a phacellophora (fried egg) jelly

Jellyfish really aren’t fish. They belong to a group called Cnidarians, along with corals, sea anemones, and hydras. It’s one of the most primitive groups of animals on the planet. Ancient and simple, Cnidarians have two tissue layers, a defined top and bottom, but no left and right symmetry and no defined digestive or circulatory systems. Jellies have simple nerves and muscles. They can move, but they are unable to swim against oceanic currents and therefore travel at the whim of those currents. Jelly tissue is made of a collagen protein matrix and a lot of water. I have heard one scientist call jellies “organized sea water.” That’s really not too far off. Seawater has a density close to one kilogram per liter, and when you measure jellies, their mass to volume ratio almost always approaches one.

Despite their simplicity, jellies are incredible predators. When we scoop them up with the Methot net, they often come in with small lantern fish paralyzed and dangling from their tentacles. Jellies possess one of the more sophisticated weapons in the animal kingdom. Located in their tentacles are stinging cells, called cnidocytes. These cells contain tiny, often toxic harpoons, called nematocysts. The nematocysts are triggered by touch and can deploy as fast as a rifle bullet, injecting enough venom to kill small fish or to give the person weighing the jellies a nasty sting.

Me holding a Chrysaora (sea nettle) jelly. — Holding up a Chrysaora (sea nettle) jelly.

Jellies have not been thoroughly studied in the Gulf of Alaska, and the work onboard the Tiglax may take us closer to answering some basic questions of abundance and distribution. How many jellies are there, where are they, and are their numbers increasing in response to increasing ocean temperatures?

In order to sample jellies each night, four times a night we deploy a Methot net. The Methot net is a square steel frame, two and a half meters on each side and weighing a few hundred pounds. It is attached to a heavy mesh net, ten meters long. Even in relatively calm seas, getting it in and out of the water takes a lot of effort. We have already deployed it in seas up to eight feet and winds blowing 20 knots, and that was pretty crazy. The net is attached by steel bridle cables to the main crane on the Tiglax. As the crane lifts it, four of us guide it overboard and into the water. We leave it in the water for 20 minutes, and it catches jellies – sometimes lots of jellies. On still nights, you can sometimes see jellies glow electric blue as they hit the net.

As we retrieve the net there are a few very tense moments where we have to simultaneously secure the swinging net frame and lift the jelly-filled cod end over the side of the boat. A few of the hauls were big enough that we had to use the crane a second time to lift the cod end into the boat.

Smaller ctenophores (comb jellies) caught in the Methot net.

Once on board, the jellies have to be identified, measured, and weighed. Assuming catches stay about the same, we will measure over one thousand jellies while on this cruise. I don’t know how all of this data compares with similar long-term ecological projects, but on this trip the trend is clear. Jellies are true oceanic organisms, the further we go offshore the larger and more numerous they get. Go much beyond the continental shelf and you have entered the “jelly zone.”

Personal Log

Seasick teacher

Last night was tough. During our transit from the Seward line to the Kodiak line, things got sloppy. The waves got bigger, and their periods got shorter. To make things more uncomfortable, we were running perpendicular to the movement of the waves. I retreated to my bunk to read, but eventually the motion of the ocean got the better of me and I made my required donations to the fishes. The boat doesn’t stop for seasick scientist (or teacher) and neither does the work; at 11:00 last night I dragged myself from bed and reported for duty.

The work on the Tiglax is nonstop. The intensity of labor involved with scientific discovery has been an eye-opener to me. We live in a world where unimaginable knowledge is at our fingertips. We can search up the answer to any question and get immediate answers. Yet we too easily forget that the knowledge we obtain through our Google searches was first obtained through the time and labor of seekers like the scientists aboard the Tiglax.

The goal of this project is to understand the dynamics of the Gulf of Alaska ecosystem, but one of the major challenges in oceanography is the vastness of its subject. This project contains 60-70 sampling stations and 1,800 nautical miles of observational transects, but that is just a few pin pricks in a great wide sea. Imagine trying to understand the plot of a silent movie while watching it through a darkened curtain that has just a few specks of light passing through.

“Pinpricks in the ocean,” Transect lines for the North Gulf of Alaska Long-term Ecological Research Program.

Did You Know?

Storm petrels periodically land on ships to seek cover from winds or storms. They are one of the smaller sea birds, at just a few ounces they survive and thrive in the wild wind and waves of the Gulf of Alaska.

Last night we had a forked-tailed storm petrel fly into the drying room as I was removing my rain gear between zooplankton tows. A softball-sized orb of grey and white feathers, it weighed almost nothing and stared at me with deep black and nervous eyes as I picked it up, wished it well, and released it off the stern of the boat. It was a cool moment.

Animals Seen Today

Fin whales
Lots of seabirds including Storm Petrels, tufted puffins, Laysan and black-footed and short-tailed albatross, flesh footed shearwater, and an osprey that followed the boat for half the night
Mola mola (ocean sunfish), which was far north of its normal range

September 15, 2018October 4, 2018

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

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.

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

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.

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