Gulf of Alaska Ecosystem Research Blog

Lower Trophic Level Cruise in Southeast Alaska on the Oscar Dyson

Dyson in the Gulf of Alaska

Morgan Ostendorf authored this blog. Morgan does oceanographic chemistry lab work for JISAO in the EcoFOCI project at NOAA Pacific Marine Environmental Lab. This was her first research cruise.

The NOAA Ship Oscar Dyson's April 2013 cruise off southeastern Alaska is part of the Lower Trophic Level Studies for the GOA-IERP, an integrated ecosystem research program sponsored by the North Pacific Research board. From 2010 to 2014, oceanographers, fisheries biologists and modelers are looking at the gauntlet faced by commercially important young-of-the-year groundfishes, specifically walleye pollock, Pacific cod, Pacific ocean perch, sablefish and arrowtooth flounder in both the eastern and western gulf. The factors that most affect the survival of these fish as they travel from offshore areas where they are spawned to nearshore nursery areas will be identified. The Oscar Dyson's cruise will study the hydrography, nutrients, chlorophyll, and primary production, as well as sampling the zooplankton and larval fish abundance.

April 2, 2013

Everyone has made it to Seward safe and sound for the GOAIERP-LTL Spring cruise on the NOAA Ship Oscar Dyson. Some of us were a little worried we weren't going to make it when the pilot announced that we were going to have to land in Fairbanks and take a bus down to Anchorage because of ash coming from a volcano. Thankfully it was just an April Fools joke. At the moment, almost everything has been loaded onto the ship and we are in the process of setting up lab spaces and tying everything down. We plan to depart Thursday for our research area off southeast Alaska. So far the weather has been beautiful and I'm hoping that the weather continues to cooperate.


Seward, AK (Photo: Morgan Ostendorf)

Morgan B. and Lisa are setting up a microscope in the lab

Morgan B. and Lisa are setting up a microscope in the lab (Photo: Morgan Ostendorf)

Ana and Marie are setting up the clean area for measuring iron dissolved in seawater

Ana and Marie are setting up the clean area for measuring iron dissolved in seawater (Photo: Morgan Ostendorf)

April 4-5, 2013

We left port around 1330 today and the weather couldn't have been better. As we made our way to the first station, we saw some dall's porpoises.

We decided to do a test cast at GAK1, which is located about 45-60 minutes from the port in Seward. Scientists have been taking measurements and samples at GAK1 since 1970, so it was a good spot to practice. The CTD rosette, which measures temperature, conductivity, pressure, oxygen concentration, light transmission and PAR (photosynthetically active radiation), was launched. Niskin bottles are mounted on the rosette in order to collect water samples. The rosette is lowered into the water until it is about 10 meters from the bottom. As the rosette is brought back to the surface, Niskin bottles are closed electronically by an operator at certain depths. Once the rosette is back on the deck, scientists start taking all the samples they need. I was able to help take some water samples for measuring chlorophyll, which is related to the amount of phytoplankton in the water.

Peter and Dennis deploying the CTD at GAK1 (Photo: Morgan Ostendorf)

Since this is my first time ever being out at sea, I have been pretty excited. Thankfully, the weather and the seas have been cooperating so far. I quickly learned that the ship has no bias with the direction that it rolls; sometimes it feels like it is rolling in a circle. I am still in the process of getting my sea legs, but everyone has been nice and given me helpful hints about how to stand and walk on the ship. Personally, I like to employ the philosophy of holding onto the ship with at least one hand at all times. So far I have felt fine and have enjoyed my time so far, but we will see if that changes when the weather isn't so nice.

April 6-7, 2013

Just north of Cross Sound, we encountered a spring bloom with higher concentrations of chlorophyll than anything we saw in 2011. This is good news because one of the goals of the spring LTL (Lower Trophic Level) cruises is to investigate the spring bloom. In 2011, we never saw a spring bloom during the May cruise or in the satellite data later in the season.

Copepods and Euphausiids (krill) (Photo: Morgan Ostendorf)

Neuston net in the water (Photo: Morgan Ostendorf)

Morgan B. identifying fish larvae under the microscope at XS1 (Photo: Morgan Ostendorf)

Capelin (a forage fish, or a fish that other fish like to eat) (Photo: Morgan Ostendorf)

April 12, 2013

This morning we saw a dozen or so humpback whales breaching in Sitka Sound. We saw them feeding by using their pectoral and caudal (tail) fins to splash the water. There were multiple humpback whales doing this in order to corral either small fish (pacific herring) or euphausiids (krill) to eat. It was a great start to the day.

Mt. Edgecomb (A volcano located in Sitka Sound) (Photo: Morgan Ostendorf)

This evening I had the chance to help deploy and recover the CTD (it was my first time). When deploying the CTD, the main goal is to make sure the CTD doesn't bang into anything on the deck. A CTD costs over $100,000, so we don't want the electronics to be ruined. Also, if you are deploying or recovering the CTD, you have to wear a safety belt and be hooked to a safety line. This is done for safety reasons because we don't want anyone to fall in the water. When recovering the CTD, you have to help pull the CTD onto the deck to where it gets set down.

Morgan O. and Nancy deploying the CTD just outside of Sitka Sound (Photo: Morgan Busby)

Greenling from the bongo net (Photo: Morgan Ostendorf)

Pelagic (mid-to-surface water) Shrimp from the bongo net (Photo: Morgan Ostendorf)

Octopus larva from the bongo net (Photo: Elizabeth Chase)

April 13, 2013

Adult Lantern Fish from a bongo net (Photo: Morgan Ostendorf)

April 15, 2013

Larry helping Ana and Marie fix their fish that they use to collect iron (Photo: Dave Kachel)

April 18, 2013

Last night (and this morning), I finally witnessed bioluminescence in person for the first time; it was amazing! The first time I saw it was when I was filtering chlorophyll samples. As I folded over the filter, I saw a blue light flash. I wasn't sure if my eyes were playing tricks on me or if I was actually seeing bioluminescence.

I started the cruise with a list of things that I was hoping to see while we were out at sea, sort of like a wish list. Earlier in the evening, I was talking with Nancy, telling her that since I was able to check off seeing whales from my wish list, the next thing I really wanted to see was bioluminescence. She had told me not to get my hopes up as this isn't really the time of year to see bioluminescence, especially as far as phytoplankton go. Less than an hour later, I found myself proding the filter with tweezers, with a bright blue flash occuring every time. I was overwhelmed with excitement and at the same time, I was having a hard time believing what I was seeing.

I spent some time talking to other scientists about bioluminescence. The most common color to see for bioluminescence is blue. This is because of the chemical reaction that takes place between luciferin and luciferase in the photophores of living organisms. Lisa told me that some copepods are bioluminescent. After telling Dean what I saw on the filters, he said if I was to look at the filter in the light, I might be able to see a small copepod on the filter. I also learned that some bacteria are bioluminescent. As far as phytoplankton go, it is the dinoflagellates that produce bioluminescence.

After the excitement from witnessing bioluminescence on the filter, things went back to normal and I started to analyze the chlorophyll samples that I collected the previous night (after filtering the chlorophyll samples, we let them sit in a freezer for 24 hours befor analyzing them). After a few minutes had passed, Peter came in and asked if I was able to take a quick break (I had learned earlier that I could actually put the samples in the fridge after I had removed the filters and centrifuged them). I placed the samples in the fridge, put on my float coat and followed him to the aft (back) of the ship. I looked at the water and saw flashes of light in the water. All I could do was stand there in awe and wonder. Peter told me that this was the first time he saw bioluminescence so far on this cruise. I couldn't believe that after being told that it was unlikely to see bioluminescence on this cruise, I had seen it three different times, all in one night! After an exciting night/morning of unexpected surprises, I am happy to say that I can check seeing bioluminescence off of my wish list for this cruise.

Marie collecting Iron samples from the fish (Photo: Morgan Ostendorf)

Lisa taking the wire angle for the bongo net (Photo: Chrissy Jump)

Dennis, Lisa and Sigrid recovering the bongo nets (Photo: Chrissy Jump)

Dennis, Lisa and Sigrid recovering the bongo nets (Photo: Chrissy Jump)

April 19, 2013

Octopus larva from the bongo net (Photo: Morgan Ostendorf)

Calm seas in the morning (Photo: Morgan Ostendorf)

April 24, 2013

We made it back to port after being out at sea for 21 days. The cruise was successful and lots of samples were collected. Overall, we did 112 CTD casts (oxygen, salt, nutrient, chlorophyll, iron samples and production experiments), of which 18 were trace metal (iron) casts. We also deployed the neuston net 115 times and the bongo nets 116 times. In addition, we deployed a multinet 5 times and released 7 ARGOS-tracked drifters. We also encountered a spring chlorophyll bloom, which was a big relief because the GOAIERP-LTL cruise to southeast Gulf of Alaska in 2011 never encountered it and the bloom is a focus of the program. While we did encounter some rough seas/weather, the weather was great for the majority of the cruise.

Everyone has been busy packing and offloading gear in order to make room for the next cruise (a mooring cruise), which should start April 29th. Although it has been a little windy while we are offloading, the sun is shining and there are very few clouds in the sky.

Overall, I had so much fun on the cruise. I was able to interact with other scientists and learn so much in such a short period of time. While I mainly collected chlorophyll samples, I was still able to help collect nutrient samples, run the oxygen system and to see what we were catching in the nets. I was able to achieve a new level of understanding of the research the labs are involved in and why we collect so many samples. I can't wait to go back out to sea!