Latitude: 58º 28.54 N Longitude: 154º 46.05 W Wind Speed: 16.8 knots Wind Direction: 190º Air Temperature: 11º Celsius Barometric Pressure: 102
Science and Technology Log
Scientists aboard NOAA
Ship Oscar Dyson are estimating the numbers and biomass
of walleye pollock in the Gulf of Alaska.
They use acoustics (sound data) to help them do this.
Acoustic representation of fish in the area
Acoustic representation of fish in an area
Echo sounders send an acoustic signal (ping) into the water. The sound bounces off objects that have a different density than the surrounding water (such as the swim bladder in a fish) and returns back to the echo sounder. Using the speed of sound, this technology can determine how deep the fish are in the water column.
How much sound each object reflects is known as the target strength. The target strength is dependent upon the type of fish and the size of the fish. A bigger fish will give off more of an echo than a small fish will. A fish’s swim bladder is primarily what reflects the sound. Smelt and krill do not have swim bladders. As a result, they do not reflect as much sound as a pollack would. Even though a big fish gives off more sound energy than a small fish of the same species, it is possible that a return echo could indicate either one big fish or several smaller fish clumped together. A big fish of one species could also give off similar sound energy to a big fish of a different species. For that reason, actual fish are collected several times a day in the nets described in a previous blog.
From a net sample, scientists determine the number of each species in the catch as well as the length and weight of individuals of each species.
Measuring pollock
Additionally, scientists also determine the sex and age of the pollock. The catch data is used to scale the acoustic data, which in turn allows scientists to estimate how many pollock there are of various size and age groups in a given area. These numbers help scientists determine the sustainability of the pollock population, which in turn allows the North Pacific Fishery Management Council to set catch quotas.
Counting krill
Krill Fun Facts:
Krill (aka
euphausiids) are small crustaceans (a couple of millimeters long) of the order Euphausiacea. The word “krill” is a Norwegian word meaning “a
small fry of fish.” Krill are found in every ocean and are a major food source.
They are eaten by fish, whales, seals, penguins, and squid, to name a few. In Japan, the Phillipines, and Russia, krill are
also eaten by humans. In Japan, they are
called okiami. In the Phillipines and
Russia, they are known as camarones. In the Phillipines, krill are also used to
make a salty paste called bagoong. Krill are a major source of protein and
omega-3 fatty acids.
There are many kinds of krill. Thus far, in the Gulf of Alaska, we have been seeing mostly Thysanoessa enermis, which measure approximately 1/2 inch in length.
PersonalLog
People often refer to New York as the city that never sleeps. The same can be said for the NOAA Ship Oscar Dyson. Life onboard the Oscar Dyson carries on 24 hours a day, 7 days a week. There is never a time that the ship is not bustling with activity. Everyone on the boat works 12-hour shifts, so someone is always working while others are sleeping (or doing laundry, exercising, or watching a movie in the lounge before they go to sleep.) Most people on the boat work either the noon to midnight shift or the midnight to noon shift. However, the science team works 4 a.m. to 4 p.m., or 4 p.m. to 4 a.m. I am in the latter group. It was easier to get accustomed to than I had imagined, although it is sometimes confusing when you look at your clock and wonder whether it is 5 a.m. or 5 p.m. since the sun is shining for most of the day. Kodiak has only 4-5 hours of darkness now, and the sun sets at approximately midnight. Therefore, it does not really feel like nighttime for much of my shift.
The view from NOAA Ship Oscar Dyson
Views (and sunsets) like these make it easy to work the night shift!
Last night I fell asleep, twice, at the lab bench in between trawls, since I am still adjusting to being on the night shift. We worked from 9:00 P.M. to 6:30 A.M. After the shift I had a nice hot shower and slept a solid 9 hours from 7:00 AM to 4:00 PM. Hopefully, I will be less drowsy tonight!
Upon waking, I went to the galley and grabbed some Raisin Bran and coffee and took it up to the flying bridge to hang out with Ornithologist Brian Hoover. Our current location is in the middle of the Channel Islands, an area I know something about because my friend Evan Morrison, mentioned in my first blog, helps with the Channel Islands Swimming Association, and I would like to swim between these islands one day. Lauren Valentino, Flora Cordoleani, Ily Iglesias and I congregated on the flying bridge and decided we should exercise. We joined Flora in her squat challenge (80 squats on this particular day), followed by 5 minutes of planking and a bit of erging. Half of female members of the fish sorting team are avid rock climbers. They did lots of pull-ups using the rock ring climbing training holds that are installed there.
It felt nice and warm when the ship stopped for deployment of the Conductivity, Temperature and Depth (CTD) Rosette, and it got chilly again as the wind picked up when the ship started moving again. We saw a few whale spouts in the distance and at 5:30 P.M. we went down to the galley for a delicious meal of steak and mashed potatoes. I am beginning to really appreciate how nice this whole experience has been in terms of amenities. The NOAA Reuben Lasker first set launch in 2014 and is a state of the art fisheries vessel with a sophisticated acoustics lab, fish lab, dynamic positioning system, CTD, etc., but is ALSO equipped with creature comforts including a movie lounge, an ice cream cooler loaded with ice cream sandwiches, snickers, fruit pops, you name it, and my personal favorite – a coffee bar where all coffee is freshly ground, an espresso machine, and all varieties of milk and creamers, including Reese’s cup whipped cream. The mattress in my stateroom bunk is quite comfortable and the shower gets hot within seconds! I doubt it can get much better than this for a research experience at sea?
Game Plan and Trawling Line: Point Sal line with five 15 minute hauls.
I am familiar with the sorting protocol now. The catch is dropped from the net into the bucket by members of the deck crew and survey tech, with the oversight of Keith Sakuma, Chief Scientist and NOAA Operations Officer Keith Hanson. The bucket is immediately placed in the fish lab and this is when the fish sorting team starts our work.
Dropping the catch from the Cobb Trawl net into the bucket.
A volume of fish just placed on a sorting tray. This catch has a lot of anchovies, krill, and California smoothtongues.
Separating the krill from the myctophids, Northern anchovies, and California smoothtongues.
Team Red Hats sorting fish. NOAA’s Keith Hanson in the rear left side.
SORTING AND COUNTINGMETHOD
We start by carefully picking through a 2000 mL or 5000 mL volume of the harvest, depending on Keith Sakuma’s initial assessment of the species density and volume in the bucket. The first volume of catch to be sorted is evenly dispersed onto four white sorting trays arrayed on the main lab bench. Once you have a pile of the catch on your tray, you start to separate them into piles of different types of organisms, such as Northern anchovies, ctenophores, krill, salps, pyrosomes, Californian smoothtongues, squid, rockfish, myctophids, and young of year (YOY) fish. I prefer to use my hands for sorting while others use forceps. Once sorted, we count the number of individuals for each species. If we have difficulty identifying an animal that we have not yet seen, we ask Keith Sakuma or a more experienced team member to help with identification. YOY fish, some in larval form, are particularly difficult for me.
Once sorted and counted, we verbally call out the common name and number of organisms to Keith Sakuma who manually records the data in a 3-ring binder for the lab hard-copy. For smaller organisms, such as krill or salps, or in hauls with a high number of any particular species, it would be quite tedious to pick out and count each individual in the total haul. This is why we start with a small subsample volume or 0.5, 2 or 5L, count the individuals in that small volume, establish the ratio for the number of individuals in that volume, and then extrapolate and calculate by the total volume of the haul. For example, if we counted 97 pyrosomes in the initial 5L sort, and we collected a total of 1000L, then we can say that there are 19,400 pyrosomes in the haul.
Chief Scientist Keith Sakuma recording the data from a haul during sorting.
Once 20 individuals of each species have been called out, we no longer have to count that species since the ratio for this catch has already been established and to expedite sorting the rest of the volume. Following sorting, the length of the twenty representatives of each species is measured using electronic calipers and the values populate on an Excel spreadsheet. After measuring, specimens requested by various research institutes including Scripps Institution of Oceanography, Moss Landing, and Monterey Bay Aquarium Research Institute (MBARI) are collected, labelled and frozen.
Flora Cordoleani keeping track of which specimens are to be preserved for various research groups.
Keith Sakuma bagging specimens to send to collaborators.
Creature(s) feature: Salps and Pyrosomes.
Salps What are these strange gelatinous organisms in our catch that look like little puddles of clear jelly with a red, green, yellow, and brown digestive organ in the center? They are goopy, small and slippery making them difficult to pick up by hand. They float on the sea surface and are ubiquitous in our hauls BUT NOBODY KNOWS ABOUT THEM.
These creatures are called salps and belong to the subphylum Tunicata. Tunicates have a notochord in their early stage of life which makes them members of the phylum Chordata, to which humans also belong. Having a transparent body is a way escape being preyed upon.
A group of salps. This species is dime to quarter sized and this number of salps occupies a volume of ~10-15 ml once placed in a beaker.
Salp digestive organs.
Salps are planktonic tunicates That can be found as individual salps or in long chains called blastozooids. The salps shown in the photo below were individuals and were notable in most of our hauls. Individual salps in this pile are dime to quarter sized and occupy a volume of ~10-15 ml. We measured the volume of salps in every haul.
While on the topic of salps, I will tell you about a cool 1 inch long salp parasite I found on my sorting tray (see image below). Keith Sakuma explained that it was a deep sea amphipod called Phronima which is a parasitoid that takes up residence inside of a salp’s body, eats the salp’s organs, and then lays its eggs inside of the salp. The King-of-the-salmon, Trachipterus altivelis, (which we are also catching) uses its protrusible jaw to get inside of the salp just to eat this amphipod!
Phronima amphipod – lives and reproduced in salp after eating the salp’s organs. King-of-the-salmon fish use their protrusible jaws to eat the amphipod.
King-of-the-salmon, Trachipterus altivelis
King-of-the-salmon, Trachipterus altivelis, who preys upon phronima living inside of salp, with jaw protruded.
A large haul full of salps.
Another type of salp we keep catching is Thetys vagina, a large solitary species of nektonic salp that feeds on plankton, such as diatoms, and is an important carbon sink in the ocean. Thetys has an external surface, or test, that is covered with bumps and ridges, as seen in the photo below.
Thetys vagina, the twin-sailed salp.
The internal filtering organ of Thetys vagina.
Kristin Saksa examining a larger Thetys vagina, or the twin-sailed salp. The dark colored tentacles are downward facing. This is the siphon where water enters the sac-filled body.
PyrosomesPyrosoma atlanticum are another type of planktonic tunicate which are very numerous in most of our hauls. Pyrosomes look like bumpy pink hollow tubes with openings on both ends. They are rigid in structure and easy to pick up by hand, whereas salps are goopy and difficult to pick up by hand. We have collected some pyrosomes that are 13 inches long, while most are in the 4-6 inch range. The small pyrosomes look like clear Tic Tacs, but they do not taste as such.
Pyrosoma atlanticum, with an ~6 inch specimen on the left and small pyrosomes on the right.
How can pyrosomes be so ubiquitous just 20 miles or so off of the Central California Coast, but I have never seen one that has floated up on the beach or while swimming?
Pyrosoma atlanticum are also planktonic tunicates, but are colonial organisms made up of many zooids held together by a gelatinous structure called the tunic. One end of the tube is wide open and filters the water for zooplankton and phytoplankton, while the other end is tighter and resembles a diaphragm or sphincter. The pyrosomes we harvested appeared in diverse array of pinks and purples. Pyrosomes are believed to harbor intracellular bioluminescent bacteria. Pyrosomes are drifting organisms that swim by beating cilia lining the branchial basket to propel the animals through the water and create a current for filter feeding.
Pyrosoma atlanticum assorted by color.
Moss Landing Graduate Student Kristin Saksa excited about the large haul of Pyrosoma atlanticum.
Current location/conditions: Evening August 13 – northwest of Icy Point Alaska
Air temp 34F, sea depth 45 m , surface sea water temp 42F
Calling in the Drones
We have not seen another ship or any other sign of civilization since we left Nome, until today when NOAA scientists coordinated an at sea meeting between the Healy and two saildrones. Saildrones are remotely piloted sailboats that roam the seas without anyone on board. A given route is programmed for collecting data and changes to the sailboat’s survey area can be given directly by satellite through the Internet. After not seeing anything on the horizon for many days when the sail drone came into view it was quite eerie for me. It was like a random floating traffic cone dropped in the Arctic. I was amazed that it did not tip over. The saildrone has a relatively large keel (the fin part of the boat you cannot see under water) to help it from tipping over. The boat itself is about 7 m long (23 ft) x 5 m tall ( 16.3 ft) x 2.5 m wide (8.2 ft) with a traveling speed of 3 to 5 knots.
The saildrone is a remotely piloted sailboat that contains many scientific instruments.
We collected surface water samples near the drone that will be tested to verify the accuracy of the drones reporting instruments.
The instruments on a saildrone measure weather conditions and ocean conditions and properties. The ocean data includes measurements for temperature, wave height, sea depth, currents, pH, salinity, oxygen, and carbon dioxide. Underwater microphones listen for marine mammals and an echosounder can keep track of fish that pass by. This is a wealth of information in an area of the world where there are so few ships to report back weather and sea observations to civilization.
Today’s Wildlife Sightings
We caught Thysanoessa inermis in the big Methot net today. I had to have Nissa Ferm, a fisheries biologist from Lynker Inc working under contract for NOAA, spell that word out for me. She wrote it down without hesitation. I found this amazing because even spell check doesn’t recognize those words. Nissa identifies many specimens we catch by eye and then verifies identification under a microscope. In general terms, Thysanoessa inermis is a type of organism often referred to as krill and is only about a centimeter in length.
Thysanoessa inermis, a species of krill
Thysanoessa inermis is a vital member of the bottom of the food chain and an animal that eats phytoplankton. Phytoplankton is a microscopic plant that lives in the sunlit layers of the ocean and gets energy from the sun. As with all plants, this is done through the process of photosynthesis. In the case of phytoplankton being an underwater plant, it uses carbon dioxide dissolved in the water in its photosynthesis process. Thysanoessa inermis helps gather this energy in by eating the phytoplankton and then becomes the prey of much larger creatures in the marine food chain such as fish and whales.
Now and Looking Forward
Although it was short lived, we saw our first snow flurry today. It was incredible to see snowflakes in August! I am looking forward to more snowflakes and continued cool weather.
Geographic Area of Cruise: North Pacific: Greater Farallones National Marine Sanctuary, Cordell Bank National Marine Sanctuary
Weather Data from the Bridge
Date
July 5 2018
Time
1100
Latitude
37 30.1’N
Longitude
123 08.5’W
Present Weather/ Sky
Cloudy
Visibility (nm)
12
Wind Direction (tree)
Light
Wind Speed (kts)
Variable
Atmospheric Pressure (mb)
1021.3
Sea Wave Height (ft)
<1
Swell Waves Direction (true)
270°
Swell Waves Height (ft)
1-2
Temperature Sea Water (C)
13.0°
Temperature Dry bulb (C)
Air Temperature
16.7°
Temperature Wet Bulb (C )
13.7°
Science and Technology Log
Krill are small crustaceans (think shrimp-like) that inhabit the world’s oceans. They are an essential component of marine ecosystems, residing near the bottom of the food chain. Krill are a staple in the diet of whales, squid, octopuses and fish. Understanding the variability of krill populations is an important way of monitoring ocean health. In order to track the krill population, scientists do two things; they use acoustics to estimate the biomass and use nets to verify the results from the acoustics.
Deploying the Tucker Trawl
Scientists use a large net mechanism called a “Tucker Trawl” to collect samples of krill and other zooplankton at various depths in the water column. A Tucker Trawl is a set of opening and closing cone shaped nets made of fine mesh (holes that are 333 microns in diameter). The unit we are using has three sections, each with a mouth diameter of 1 meter by 1.5 meters and a sample collector container on the bottom. Krill is collected by dropping the net in a specific location to a specified depth while the ship is slowly moving at a rate of approximately two knots per hour (2.3 mph). An onboard crane deploys and retrieves the mechanism using a heavy cable. On this cruise we’ve sampled to depths as much as 200 meters deep. The Tucker Trawl depth and when the nets are opened can be adjusted in order to sample several vertical positions in the water column during a single trawl.
Processing Samples
Once the samples are back onboard the nets are sprayed down and the collectors are carefully emptied into storage containers for later analysis onshore. The content analysis will count and identify the various species collected in the sample, as determining sex, size, lifecycle which vary by species. We’ve observed two different species in our samples; Euphasia pacifica (smallest and most abundant) and Thysanoessa spinifera (larger with a spiny back). Data collected via these Tucker Trawl sessions is used to construct models for assessing krill biomass using acoustic measuring technology.
Thysanoessa spinifera upclose
Loads of Krill
Personal Log
Tucker Trawling is wet business but really interesting. It’s a great learning experience working with Dr. Jaime Jahncke to deploy the nets and process the samples. We’re doing several trawls each day throughout the cruise- one session around noon and another set around midnight. I’ve adjusted my sleeping schedule to get a few hours of rest before we start the midnight shift and then I sleep a few hours after we finish working around 4:30 am. I’m tired but really happy to be here.
Did You Know?
The name “krill” is Norwegian for “small fry of fish”.
Geographic Area of Cruise: Pacific Ocean from Newport, OR to Port Angeles, WA
Date: 8/21/2017
Latitude: 49.48 N
Longitude: 128.07 W
Wind Speed: 10 knots
Weather Observations: Sunny
Science and Technology Log
Today was our first chance to use the Methot net, and it was a lot of fun! The Methot net is smaller than the net that we usually use, and it is used to catch smaller organisms. Today we were targeting euphausiids. We thought we saw a pretty good aggregation of them on the 120 kHz acoustics data, where they appear the strongest of the three frequencies we monitor. We needed to validate that data by trawling the area to find the source of the backscatter and make sure they really were what we thought they were. There are many scientists who use data on euphausiids, so this was a good opportunity to provide them with some additional data. Because we’ve been working mostly on larger organisms, I was excited for the chance to see what a Methot net would pull up.
The Methot net coming up with its haul
It was very exciting that when the net came up, we had TONS of euphausiids! (“Tons” here is not used in a literal sense…we did not have thousands of pounds of euphausiids. That would have been crazy). Although we did not have thousands of pounds of them, we did have thousands of specimens. I’m sure thankful that we only had to take data on a subsample of thirty! I got to measure the lengths and widths of them, and using the magnifying lenses made me look very scientific.
Measuring euphausiids
Along with euphausiids, we also found other species as well. We found tiny squids, jellies, and even a baby octopus! It was adorable. I’ve never considered that an octopus could be cute, but it was.
Baby octopus
We also measured volumes and weights on samples of the other specimens we found, and I used graduated cylinders for the first time since college. We would put in a few milliliters of water, add our specimens, and then calculate the difference. Voila! Volume. Good thing I remembered to call the measurement at the bottom of the liquid’s meniscus… I could have messed up all the data! Just kidding… I’m sure my measurements weren’t that important. But still – good thing I paid attention in lab skills. It was definitely a successful first day with the Methot net.
Personal Log
The big buzz around the ship today was the solar eclipse! I was even getting excited at breakfast while I ate my pancakes and made them eclipse each other. We got lucky with weather – I was nervous when I heard the foghorn go off early in the morning. Fortunately, the fog lifted and we had a pretty good view. We all sported our cheesy eclipse shades, and the science team wore gray and black to dress in “eclipse theme.” Even though we couldn’t see the totality here, we got to see about 85%. We’re pretty far north, off the coast of Vancouver Island in Canada. The mountains are beautiful! Seeing land is always a special treat.
Here are some eclipse pics:
Rockin’ our cheesy eclipse shades
Some science team members enjoying the eclipse
Eclipse!
The eclipse would have made the day exciting enough, but the excitement didn’t stop there! While the scientists and I were working in the wet lab, we heard that a pod of orcas was swimming within eyesight of the ship. We dropped everything and hurried to take a look. It was so amazing; we could see five or six surface at once. They must have been hunting. We only see orcas when we’re close to land because their prey doesn’t live in deeper waters. Deeper into the ocean we are more likely to see gray or humpback whales.
It’s almost time for dinner…we sure have been spoiled for food! Last night we had pork loin and steak. I’m not sure that our chef will be able to top himself, but I’m excited to find out. I have heard rumors that he is very good at cooking the fish we’ve been catching, and that really makes me wish I liked seafood. Unfortunately, I don’t. At all. Not even enough to try Larry’s fried rockfish. Luckily, he makes lots of other food that I love.
Tonight after dinner I think Hilarie, Olivia, and I are going to watch Pirates of the Caribbean 2. Last night we watched the first movie while sitting on the flying bridge. It was a pretty cool experience to feel the spray of the sea while watching pirates battle!
Movie time!
That’s all for now; I’ll be back with more scientific fun soon!
Did you know?
Krill (the type of euphausiid we studied) is one of the most populous species on earth. It basically fuels the entire marine ecosystem.
