One way scientists assess the health of our ocean’s ecosystems is to take samples of zooplankton and ichthyoplankton (fish eggs and larvae), both on the surface of the water and at depth. Observations of these plankton can inform us greatly about productivity at the bottom of the food chain, spawning location and stock size of adults, dispersal of larval fish and crabs to and away from nursery areas, and transport of ocean currents.
The Newport Hydrographic (Newport Line) is an oceanographic research survey conducted by NOAA’s Northwest Fisheries Science Center and Oregon State University scientists in the coastal waters off Newport, Oregon.
Researchers have collected physical, chemical, and biological oceanographic metrics along the Newport Line every two weeks for over 20 years. This twenty-plus year dataset helps us to understand the connections between changes in ocean-climate and ecosystem structure and function in the California Current.
Data from the Newport Line are distilled into ocean ecosystem indicators, used to characterize the habitat and survival of juvenile salmonids, and which have also shown promise for other stocks such as sablefish, rockfish, and sardine. These data also provide critical ecosystem information on emerging issues such as marine heatwaves, ocean acidification, hypoxia, and harmful algal blooms.
Newport line
Barometer of ocean acidification and hypoxia in a changing climate
Global climate models suggest future changes in coastal upwelling will lead to increased incidence of hypoxia and further exacerbate the effects of ocean acidification. The Newport Line time-series provides a baseline of biogeochemical parameters, such as Aragonite saturation state—an indicator of acidic conditions. Researchers can compare this baseline against possible future changes in the abundance of organisms (e.g., pteropods, copepods and krill) sensitive to ocean acidification and hypoxia.
Equipment used
Vertical/half meter net
Getting the vertical net in the water
Vertical net deployed vertically in the water from a research vessel
A vertical net is a ring net with a small mesh width and a long funnel shape. At the end, the net is closed off with a cylinder (cod-end) that collects the plankton. It is deployed vertically in the water from a research vessel. It is mostly used to investigate the vertical/diagonal stratification of plankton. This allows the abundance and distribution of mesozooplankton to be determined.
Bongo net
Washing the sample down the bongo net
A bongo net is drawn horizontally through the water column by a research vessel
A bongo net consists of two plankton nets mounted next to each other. These plankton nets are ring nets with a small mesh width and a long funnel shape. Both nets are enclosed by a cod-end that is used for collecting plankton. The bongo net is pulled horizontally through the water column by a research vessel. Using a bongo net, a scientist can work with two different mesh widths simultaneously.
Assisting Toby with Isaacs-Kidd net
Isaacs-Kidd midwater trawl
Isaacs-Kidd midwater trawl dimension
Isaacs-Kidd midwater trawl collects bathypelagic biological specimens larger than those taken by standard plankton nets. The trawl consists of the specifically designed net attached to a wide, V-shaped, rigid diving vane. The vane keeps the mouth of the net open and exerts a depressing force, maintaining the trawl at depth for extended periods at towing speeds up to 5 knots. The inlet opening is unobstructed by the towing cable.
What we got?
Samples from vertical netSamples from bongo net
Isaacs-Kidd sample
Krill from the Isaacs-Kidd
Personal Log
SHARK ATTACK!
That’s right, our underway CTD was attacked by a shark.
R.I.P.
On a bright and sunny day, the science team decided to launch the underway CTD, but things didn’t go as planned! Retrieving the uCTD back to the ship we saw a big dorsal fin zigzagging close to the uCTD, until we noticed that the uCTD was no longer attached to the line, therefore we had no choice that to cancel the uCTD. You should have seen all of our faces; we couldn’t believe what we saw. We think it could have been a:
White sharkSalmon shark
underway CTD (what the shark ate)
CTD stands for conductivity (salinity), temperature, and depth and it enables researchers to collect temperature and salinity profiles of the upper ocean at underway speeds, to depths of up to 500 m. Ocean explorers often use CTD measurements to detect evidence of volcanoes, hydrothermal vents, and other deep-sea features that cause changes to the physical and chemical properties of seawater.
Weather at 1300 Pacific Standard Time on Monday 15 July 2019
We’re slowly coasting through a dense patch of fog. I can see about 20 meters off the deck before the horizon tapers to a misty, smoky haze. Then my eyes are affronted with a thick wall of white. It’s like we’re inside a room covered in white felt wallpaper – one of those rooms in a funhouse where the walls keep closing in on you as you walk through it. For safety, the ship keeps sounding a loud horn at least once every 2 minutes to announce our position for other boats in the area. It’s been like this for an hour now. It’s a little spooky.
PERSONAL LOG
On a brighter note, we saw whales earlier this morning! We were one mile off the coast of southern Oregon, and ahead of us we saw the backs of a few whales peeking out of the surface. I was able to grab a pair of binoculars sitting next to me on the bridge, and with those I could clearly see their dark bodies in the water! Every once in a while one would gracefully lift its tail above the surface as it prepared to dive. They were so cute!
Eventually we got closer to them and we started to see more whales on either side of the ship. I spent probably 15 minutes moving from one side of the bridge to the other with my binoculars to get a better look. I’m lucky the NOAA Corps officers are so accommodating! Otherwise I think my constant fluttering from one area to another could’ve been construed as a pain.
The officers like to see whales too, so they were happy to share what they knew with me. It turns out we were most likely watching Humpback Whales. LT Dave Wang, Operations Officer on the ship and trained as an ichthyologist (fish biologist), said most whales have a distinctive blow pattern, tail shape, and dorsal fin size that makes it easier to identify which kind he’s looking at. I had no idea before today that there were so many different species of whales. I knew Orca – Free Willy, Humpback, and maybe something called a Blue Whale? But that would’ve been the extent of it. In the marine mammals identification guide housed on the ship, there are 45 types of whales in the table of contents! And that’s probably not a complete list of all whale species.
At one point today, eventually, once the fog lifted, we were 36 miles off shore and started seeing shoals of coastal pelagic species all around the ship. We could pick them out easily because each shoal looked like a dark, churning, rippled inkspot on the otherwise smooth-as-glass surface. While the low wind conditions are partly what left us in a thick layer of fog all afternoon, it is what also kept the water smooth enough to pick out the shoals. So I guess not all was lost. We saw even more whale activity around these shoals than we saw this morning, and they were a lot closer to the ship!
One of the whales just off the starboard bow left a footprint. Larger whales like the Humpback produce larger footprints, and the calm sea state today allowed us to see them! It looked like a smooth patch of water in the center of concentric circles.
I’ve been trying to see whales and other marine mammals the whole trip. I saw a sea lion the other day, just one glimpse of it before it went under the water and we left the area, but now having seen the whales I feel pretty content. The Commanding Officer of the ship also told me that seals or sea lions like to hang out on the pier that we’ll be docking at in San Francisco, so there’s still hope yet!
THE SCIENCE
If you’ve ever been whale watching on a boat, the type of whale you probably saw was a Humpback Whale. They can often be seen near the shore since they like to stay within the continental shelf, and they spend a lot of time near the surface compared to other whales. Not all whale species exhibit this same behavior. If whales had a personality, I would call the Humpback Whales the Jersey Shore cast of the sea. They do things that come across as attention-seeking behaviors to the outside observer – slapping their unusually long flippers on the surface of the water, smacking their tails against the water in agitation, flipping their tails in the air before diving, and sometimes breaching the surface with their whole bodies. Of course, they’re not doing it to get our attention. But it makes for easy and exciting observation!
All Humpback Whales have unique patterns of coloration and texture on their flukes, so scientists can use photos to track specific animals as they migrate or go about their regular activities in a similar fashion to how we use fingerprints to uniquely identify people.
They also have the advantage of something called countershading. One of the whales I saw today had a silvery-shiny underside to its fluke that glistened in the sunlight and contrasted greatly with the dark, almost black color of its back. A lot of fish and marine mammals like whales and porpoises use countershading to help camouflage them by having naturally darker backs (dorsal side) and lighter stomachs (ventral side). This way when something is looking down at the creature, it blends in with the dark depths of the ocean, and when something is looking up at the creature, it blends in better with the lighter, sunlit layer of water near the surface.
Anything from krill to small fish are fair game for Humpback Whales when they’re hungry. Sometimes a group of Humpback Whales will work together as a team to catch fish. One way they do this is by bubble net feeding. It’s rare to witness, but a bubble net is a pretty sophisticated way to catch fish. It reminds me of the trawling we do each night from NOAA Ship Reuban Lasker except in this case the whales use a circular pattern of bubbles to corral a bunch of fish into one area… then they thrust forward aggressively, quickly, to scoop up the masses. We use a trawl net to corral the little critters into a codend instead of swallowing them whole.
Photo of Humpback Whale Using Bubble Net to Catch Anchovies. Photo by LT Dave Wang, taken earlier this year
Quart Jar Filled with Krill Collected in a Bongo Tow
Baleen whales, like the Humpback, have a unique mouth that is hard to explain. If you can visualize a pelican’s beak, it looks a bit like that from the outside. These whales gulp a whole mouthful of water – including zooplankton, krill, and small fish – into their mouths, but they don’t swallow it down outright and they don’t exactly chew their food either. With all that saltwater and prey in their mouths, they use long rows of baleen attached to their upper jaw like a fine-toothed comb. And just like we would use a cheesecloth to strain the moisture off of runny yogurt, Humpback Whales filter the water out of their mouths through the baleen and keep the fishy goodness for themselves.
TEACHING CONNECTIONS
Watching the whales all day kept drumming up images in my mind from when I read Grayson by Lynne Cox. I wrote a review of Grayson in July 2014 on the Pennsylvania Council of Teachers of English and Language Arts (PCTELA) blog. This book, by far, is one of my favorite recommendations to read aloud to students.
If you’re not an English teacher, you probably didn’t spend a lot of late nights in college reading novels to cram for a test. It wasn’t part of your major. But you’re missing out! There are so many ways to use novels and literary nonfiction across the content areas. Grayson, for example, is artfully written. In the book review I wrote it tells Lynne’s “account of meeting a baby whale in the ocean during one of her early morning training swims. This lonely whale, separated from its mother, stays close to Lynne in the water while fishermen search for the mother. This true yet almost unbelievable story is hauntingly beautiful.”
Taking 15 minutes of class time to read an excerpt from this book aloud could enrich any classroom. There are many instances when she writes about wanting to give up and swim back to shore. The baby whale is ultimately not her responsibility. It was very cold. She’d been out there in the ocean for hours with nothing but her own strength and experience to keep her afloat. She hadn’t eaten all day. But she stayed with the baby whale. She resolved to see it through to the very end. Any teacher can use her stick-with-it attitude as an example to encourage students to work through academic challenges.
One of my friends, blogger Allyn Bacchus, is a middle school social studies teacher. He uses historical fiction in his class every year. He writes, “My 8th grade U.S. History class covers a unit on Industry and Urban Growth in the late 1800’s and early 1900’s. I have supplemented our unit with the historical fiction novel Uprising written by Margaret Peterson Haddix. It covers the story of 3 teenage girls and their involvement in the Triangle Shirtwaist Factory in New York in 1911. The author brings to life the living, working, and social conditions of the time period and allows my students to experience this unit through the eyes of girls who are living in it.”
Through the eyes of girls who are living in it. This is something a textbook cannot do.
No one knows your discipline, your students, and your intended classroom environment better than you. Take an hour to fall down the Amazon rabbit hole! Search for a topic you find interesting and relevant to your curriculum, read the book review, click on the comparable book recommendations… you get the point. Most of the time you can find a book preview to check out the text before purchasing – is the font too small? Too complicated? Too boring? Choose a short excerpt from a text you like for your first attempt at using literature in the classroom and build from there.
TEACHING RESOURCES
Since we’re talking about literature today, I’ll narrate the resource list.
We can search online for other educators who have already blazed the trail for us. Here is a blog post written by Terry McGlynn titled Assigning Literature in a Science Class. The post itself is well written, and if you take the time to read through 54 comments below it, you will find lots of other text recommendations for a science classroom. This article written by Kara Newhouse titled How Reading Novels in Math Class Can Strengthen Student Engagement shows why two math teachers read books in their high school classrooms. One of those teachers, Joel Bezaire, wrote a blog post with suggestions for other novel studies in math class. The other teacher, Sam Shah, shares a student example to explain how powerful it can be to use literature in a math class. It gets students to understand abstract and often elusive mathematical concepts.
I’ve written four nonfiction book reviews to accompany this NOAA Teacher at Sea experience and PCTELA is posting one review each week in July to the new media platform on their website. If not Grayson, then maybe you’ll find useful one of the books I read and reviewed to prepare for this trip. They include Gone Tomorrow: The Hidden Life of Garbage, Blind Man’s Bluff: The Untold Story of American Submarine Espionage, The Hidden Life of Trees: What they Feel, How They Communicate – Discoveries from a Secret World, and Biomimicry: Innovation Inspired by Nature.
And finally, I would be remiss to end this post without steering you toward The Perfect Storm written by Sebastian Junger about a small fishing vessel and crew caught in an Atlantic storm and In the Heart of the Sea: The Tragedy of the Whaleship Essex by Nathaniel Philbrick – a captivating true story about the whaling industry which is thought to be the inspiration for Moby Dick.
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.
Mission: Pelagic Juvenile Rockfish Recruitment and Ecosystem Assessment Survey
Geographic Area of Cruise: Pacific Ocean off the California Coast
Date: June 8, 2017
TAS David Amidon with a tray of sorted catch
Different Rockfish species caught 6/8/17
Science and Technology Log
The main scientific research being completed on the Reuben Lasker during this voyage is the Pelagic Juvenile Rockfish Recruitment and Ecosystem Assessment Survey and it drives the overall research on the ship during this voyage. Rockfish are an important commercial fishery for the West Coast. Maintaining healthy populations are critical to maintaining the fish as a sustainable resource. The samples harvested by the crew play an important role in establishing fishery regulations. However, there is more happening than simply counting rockfish here on the ship.
How does it work? Let me try to explain it a bit.
First, the ship will transfer to a specific location at sea they call a “Station.”
Collection stations off the California Coast that the Reuben Lasker trawls annually.
For a half hour prior to arrival, a science crew member will have been observing for Marine Mammals from the bridge area. When the station is reached, a new observer from the science crew will take over the watch outside on the deck. The fishermen on the boat crew will then unwind the net and launch it behind the boat. It must be monitored from the deck in order to ensure it is located 30 m below the surface. Once everything is set, then the ship trawls with the net at approximately 2 knots. Everything must be consistent from station to station, year to year in order to follow the standardized methods and allow the data recorded to be comparable. After the 15 minutes, then the crew pulls the net in and collects the sample from the net. This process is potentially dangerous, so safety is a priority. Science crew members can not go on the deck as they have not received the proper training.
Timelapse video of the fishermen bringing in a catch. 6/7/17 (No sound)
Once the sample is hauled in, the science personnel decide which method will be used to establish a representative sample. They pull out a sample that would most likely represent the whole catch in a smaller volume. Then we sort the catch by species. After completing the representative samples, they will eventually stop taking counts of the more abundant organisms, like krill. They will measure the volume of those creatures collected and extrapolate the total population collected by counting a smaller representative sample. Finally, we counted out all of the less abundant organisms, such as squid, lanternfish and, of course, rockfish. After the sample is collected and separated, Chief Scientist Sakuma collects all of the rockfish and prepares them for future investigations on shore.
A selection of species caught off the coast of San Clemente. These include Market Squid, Anchovies, Red Crab, King-of-Salmon (the long ribbonfish), and Butterfish, among others.
NOAA has used this platform as an opportunity. Having a ship like the Reuben Lasker, and the David Starr Jordan before that, collecting the samples as it does, creates a resource for furtAher investigations. During the trawls we have catalogued many other species. Some of the species we analyzed include Sanddab, Salp, Pyrosoma, Market Squid, Pacific Hake, Octopus, Blue Lanternfish, California Headlightfish and Blacktip Squid, among others. By plotting the biodiversity and comparing the levels we recorded with the historic values from the stations, we gain information about the overall health of the ecosystem.
What happens to the organisms we collect? Not all of the catch is dumped overboard. Often, we are placing select organisms in bags as specimens that will be delivered to various labs up and down the coast.
Collecting subsets for classification
This is a tremendous resource for researchers, as there is really no way for many of these groups to retrieve samples on their own. Rachel Zuercher joined the crew during this survey in part to collect samples to aid in her research for her PhD.
Along with the general species analysis, the team specifically analyzes the abundance of specific krill species. Krill forms the base of the marine ecosystems in the pelagic zone. They are a major food source for many species, from fish to whales. However, different krill species are favored by different consumers. Therefore, an extension of the Ecosystem Assessment involves determining the abundance of specific krill species. Thomas Adams has been responsible for further analyzing the krill collected. He counts out the representative sample and use microscopes to identify the species collected based on their physical characteristics.
Additionally, at most stations a Conductivity, Temperature and Depth cast (CTD) is conducted. Basically, bottles are sent overboard and are opened at a specified depth.
The apparatus for collecting water during CTD casts
Then they are collected and the contents are analyzed. Often these happen during the day prior to the Night Shift taking over, with final analysis taking place after the cruise is complete. This data is then connected with the catch numbers to further the analysis. Ken Baltz, an oceanographer on the ship, uses this information to determine the production of the phytoplankton based on the amounts of chlorophyll detected at depth. This is an important part of the food web and by adding in this component, it makes the picture below the surface clearer.
NOAA Corps’ Ryan Belcher completing the CTD collection for a station.
Finally, there are two more scientific investigations running as we cruise the open seas during the daylight hours. Michael Pierce is a birdwatcher from the Farallon Institute for Advanced Ecosystem Research who is conducting a transect survey of Seabirds and Marine Mammals. He is based on the Flying Bridge and catalogs any birds or marine mammals that pass within 300 meters of the ship’s bow. Although difficult, this study attempts to create a standardized method for data collection of this nature. As he explained, birds are more perceptive than we are – what looks like open ocean really varies in terms of temperature, salinity and diversity below the surface. Therefore, birds tend to favor certain areas over others. These are also important components of the food web as they represent upper level predators that are not collected in the trawl net. Also, on the bottom of the ship transducers are installed that are able to gather information through the EK60 Echosounder. This sonar can accurately identify krill populations and schools of fish underwater. Again, adding the data collected from these surveys help create a much more complete understanding of the food web we are analyzing out on the open sea.
Sonar data from the EK60
Personal Log
Sunday, June 4
The waves were very active all day. Boy am I glad I’m wearing the patch. There was so much wind and the waves were so high, there was a question if we were even going to send the net out. High wind and waves obviously add an element of concern, especially for the safety of the boat crew working the net.
I spent some of the day up on the Bridge- the section of the boat with all of the navigation equipment. The Executive Officer (XO) gave me an impromptu lesson about using the map for navigation. They have state-of-the-art navigation equipment, but they also run a backup completed by hand and using a compass and straightedge just like you would in math class. Of note – the Dungeness Crab season is wrapping up and many fishermen leave traps in the water to catch them. When the boat is passing through one of these areas, someone will act like a spotter so the boat can avoid getting tangled up. When I was looking with him, we saw some whale plumes in the distance.
We did launch the net twice Sunday night, collecting a TON of krill each time. In the first batch, we also caught some squid and other small prey species. The second trawl was very surprising. Despite cutting it down to a 5 minute trawl, we caught about the same amount of krill. We also caught more squid and a lot of young salmon who were probably feeding on the krill.
That is a ton of krill!
Monday, June 5
I am getting used to the hours now – and do not feel as guilty sleeping past 2PM considering we are up past 6 in the morning. It will make for a tricky transition back to “the real world” when I go home to NY!
During the day, spent some time just talking with the science folks and learning about the various tasks being completed. I also spent some time up on the Flying Bridge as they said they had seen some Mola, or Giant Ocean Sunfish (although I did not see them). I did have a chance to make a few videos to send to my son Aiden’s 3rd grade teacher back in NY. It did not work out as well as I had hoped, but considering we are out in the middle of the ocean, I really can’t complain about spotty wi-fi.
Once we started the night shift, we really had a good night. We completed work at 5 stations – which takes a lot of time. We saw a LOT of biodiversity last night – easily doubling if not tripling our juvenile rockfish count. We also saw a huge variety of other juvenile fish and invertebrates over the course of the night. We finally wrapped up at 6:30 AM, what a night!
Tuesday, June 6th
We found out today that we will need to dock the ship prematurely. There is a mechanical issue that needs attention. We are en route straight through to San Diego, so no fishing tonight. However, our timing will not allow us to reach port during the day, so we will get a chance to sample the southernmost stations Wednesday night. Thus is life at sea. The science crew is staying on schedule as we, hopefully, will be back on the water this weekend.
Wednesday, June 7th
After a day travelling to San Diego, we stopped at the stations near San Clemente to collect samples. Being much farther south than before, we saw some new species – red crabs, sardines and A LOT of anchovies. Closer to shore, these counts dropped significantly and krill showed up in numbers not seen in the deeper trawl. Again, I am amazed by the differences we see in only a short distance.
More from our anchovy haul- the bucket contains the entire catch from our second trawl, the tray shows how we analyzed a subset. Also on the tray you find Red Crab, Salps, Mexican Lanternfish and Krill.
Mission: Pelagic Juvenile Rockfish Recruitment and Ecosystem Assessment Survey
Geographic Area of Cruise: Pacific Ocean off the California Coast
Date: June 4, 2017
Science and Technology Log
All of the work for the Juvenile Rockfish Survey is completed at night – we probably will not even get going most nights until after 9 PM. Wonder why so late? Any guesses?
This is a night time operation because we are focused on collecting prey species – we are not catching full grown rockfish, only juveniles which are less than a years old (YOY = Young of the Year). As Keith Sakuma, the Chief Scientist for the Reuben Lasker, explained – this survey gathers information about the juvenile rockfish so that NOAA can pass information onto the states in order to establish a sustainable fishery. This could lead to changes in fishing regulations based on the abundance of the juvenile stocks, which would be adults down the road. They trawl at night for two main reasons- during the day time, the rockfish would simply see the net and swim away. Also, many of the other creatures being catalogued are prey species that hide in the depths during the day to avoid predators, rising to the surface as the night moves on.
The night shift includes the science personnel and the crew of the boat. The boat crew not only operates the ship, but the fisherman also send out the trawl net and bring it back in. While the boat crew rotates on a specified schedule, the night-time science group keeps going until the work is done. However, these two groups are very much in sync and really work well together. This blog entry will be my introduction into the procedures and initial results of our work from the first couple nights. I will provide much more detail in later posts.
The science personnel for this leg of the voyage includes myself and Chief Scientist Sakuma as well as Cherisa and Ryan, who are members of the NOAA Corps; Thomas, an undergrad student from Humboldt State; Rachel, a PhD student at UC-Santa Cruz; and Maya, a Hollings undergraduate scholar from UNC-Wilmington.
The Night Crew at work separating species during the shrimp haul. Photo by Keith Sakuma.
The Juvenile Rockfish Survey, boiled to its simplest terms, consists of a midwater trawling net behind the ship, meaning it does not float and it never touches the bottom. Anything caught will be sorted and analyzed by the science crew. In reality, it is a bit more complicated.
First of all, net operations take place at specified stations that the ship revisits periodically and have been used for some time. The stations for a night run on the same latitude line, running west away from the coast.
Before sending the net out, we need to run a Marine Mammal Watch from the bridge for 30 minutes. If a marine mammal, such as a sea lion, dolphin or whale, is spotted, then they make efforts to avoid getting them tangled in their nets, or alter their behavior in any way. Sometimes the trawl for that station has to be abandoned due to wildlife activity, although we have not seen any marine mammals during our investigation so far.
Getting ready for my shift on the Marine Mammal Watch
Once the ship arrives at a station, the boat crew sends out the net. After it reaches the depth of 30m, they trawl for a 15 minute interval. A science crew member is also sent outside on deck to continue the marine mammal watch for the duration of the trawl. Finally, after the time is up, they bring in the net and empty its contents into buckets, which are then transferred to the science crew.
This is when our work began. While we are on the lookout for rockfish, we actually found very few of these. A majority of our catch consisted of pyrosomes and krill. The science crew employed a number of measures to estimate the numbers of these creatures, as counting them one-by-one would have taken a long, long time to do. We did volume approximations and analysis of representative samples for these creatures. When we found fish or other species of note, we would pull the individuals out, classify them and record their lengths. Samples were frozen for use by researchers working at other locations on the West Coast.
Measuring the mantle of a Market Squid. Photo by Rachel Zuercher.
Some examples of the species we collected:
Juvenile Rockfish collected off the “Lost Coast”
Sample of other species collected and catalogued, including: Medusa Fish, Gonatus Squid, Thetys and California Headlight Fish
We worked solid through four stations on the first night, wrapping up just before 6 AM. We will be at it again, if weather permits, every night of the voyage.
Personal Log
Thursday, June 1st
This was a very long day. I left my house in Syracuse, NY at 6 AM, flying out of the airport around 8 AM. After a quick transfer in Chicago, I flew in a Boeing 737 all the way to San Francisco. I then made it to Eureka, California around 4 PM (West Coast time) for an overnight stay. Fortunately, I met up a few of the science personnel for dinner who were also headed to the Reuben Lasker in the morning. Eureka was beautiful, surrounded by oceans and redwoods.
Sunset in Eureka, CA
Friday, June 2nd
In the morning, we caught a transfer boat at the public marina out to the Reuben Lasker, anchored a few miles away off the coast. Once the passage was done, we settled in and met some of the crew. I even shared a coffee with the CO- or Commanding Officer. Everyone onboard has been so open and welcoming – you can tell they enjoy their work.
Transfer boat that to us to the Reuben Lasker
After dinner, we finally got down to sciencing. (That’s my word – I’m sticking to it.) I was impressed by how different the catch was from each station, even though they are only a few miles apart. You can try to start telling a story right there. That’s kind of the point to this whole survey. To try to tell a story about the overall health of the pelagic ecosystem based on representative samples. Piece by piece, year by year, data points can turn into meaning when connections are made. I think it is science in the purest form -gathering data for the sake of having information. By having a long-term data base of information about all of the other creatures collected, not just the rockfish, we can decipher meaning by analyzing population trends and collating them with other phenomena, such as weather, fishing or pollution.
Saturday,June 3rd
I am getting adjusted to the day/night pattern of the Night Shift. I got to sleep around 6:30 AM and woke up close to 2 PM. I was able to grab a quick cereal from the Galley and then started in on some work. Dinner was served at 5 PM – filet mignon with crab legs? The cooks, or stewards, Kathy & Patrick do an amazing job. They also save meals for people running the late schedule. For the next week and change, lunch is served around midnight and breakfast will be close to 6 AM, before we head to sleep.
Today, the wind picked up and the waves kicked up with it. We cruised around the “Lost Coast” and ran two stations at night. We were scheduled for more, but the waves got larger the further the ship is off the coast. Today’s word is shrimp – we hauled in more shrimp than you could count. We also found a number of rockfish in one of the stations, although there were very few found in our second trawl.
NOAA Teacher at Sea Dana Chu On Board NOAA Ship Bell M. Shimada May 13 – 22, 2016
Mission: Applied California Current Ecosystem Studies (ACCESS) is a working partnership between Cordell Bank National Marine Sanctuary, Greater Farallones National Marine Sanctuary, and Point Blue Conservation Science to survey the oceanographic conditions that influence and drive the availability of prey species (i.e., krill) to predators (i.e., marine mammals and sea birds).
Geographic area of cruise: Greater Farallones, Cordell Bank, and Monterey Bay National Marine Sanctuaries
Date: Tuesday, May 17, 2016
Weather Data from the Bridge Clear skies, light winds at 0600 increased to 18 knots at 0900, 6-8 feet swells
Science and Technology Log
Ahoy from the Bell Shimada! Today, I will explain three of the tools that are deployed from the side deck to obtain samples of the water and the ocean’s prey species.
First off we have the Harmful Algal Bloom Net, also known as the HAB Net, which is basically a 10-inch opening with a 39-inch fine mesh netting attached to a closed end canister. The HAB net is deployed manually by hand to the depth of 30 feet three consecutive times to obtain a water sample. The top fourth of the water collected is decanted and the remaining water (approximately 80ml) is transferred to a bottle which is then sealed and labeled with the location (latitude, longitude), date, time, vertical or horizontal position, and any particular comments. The samples will eventually be mailed off to California Department of Health Services lab for analysis for harmful toxins from algae that can affect shellfish consumers.
Next we have the hoop net, which is pretty much similar in design to the HAB net, except for a larger opening diameter of 3 feet (think hula hoop) and a net length of nine feet. The net tapers off into a closed container with open slits on the sides to allow for water drainage. The purpose of the hoop net to collect organisms that are found at the various depth levels of the deployment. The hoop net is attached to a cable held by the winch. The hoop net is lowered at a specific angle which when calculated with the speed of the vessel equates to a certain depth. The survey crew reports the wire angle sighting throughout the deployment.
Every time the hoop net is brought back up there is a sense of anticipation at what we will find once the canister is open. Coloring is a good indicator. Purple usually indicates a high concentration of doliolids, while a darker color may indicate a significant amount of krill. Phytoplankton usually have a brownish coloring. Many of the hoop net collections from today and yesterday include doliolids and colonial salps, neither are very nutrient dense. Yesterday we also found pyrosomes, which are transparent organisms that resemble a sea cucumber with little bumps and soft thorns along their body. The smallest pyrosome we came upon was two and a half inches with the largest over six inches long. A few small fish of less than one inch in length also showed up sporadically in these collections as well.
The Scientific team is looking for the presence of krill in the samples obtained. The Euphausia pacifica is one of the many species of krill found in these waters. Many tiny krill were found in the various hoop net deployments. On the last hoop net deployment for today and yesterday, larger sized krill of approximately 1 inch) were found. This is good news because krill is the dominant food source for marine mammals such as whales. Ideally it would be even better if the larger krill appeared more frequently in the hoop net samples.
Finally, we have the Tucker Trawl, which is the largest and most complex of the three nets discussed in today’s post. The Tucker Trawl consists of three separate nets, one for sampling at each depth: the top, middle, and bottom of the water column. Like the hoop net, the tucker trawl nets also have a canister with open slits along the side covered with mesh to allow water to drain. All three nets are mounted on the same frame attached to a wire cable held by the winch. As the Tucker Trawl is towed only one net is open at a time for a specific length of time. The net is closed by dropping a weight down along the tow. Once the weight reaches the net opening, it triggers the net to shut and sends a vibration signal up the cable line back to the surface which can be felt by the scientist holding the cable. The net is then towed at the next depth for ten minutes. Once the last net tow has been completed, the Tucker Trawl is brought back up to surface. Similar to the hoop net, the survey tech reads the wire angle throughout the deployment to determine the angle the cable needs to be at in order for the net to reach a certain depth. This is where all the Geometry comes in handy!
As mentioned already, with three nets, the Tucker Trawl yields three separate collections of the nutrients found within the top, middle and bottom of the water column. Once the nets are retrieved, each collection container is poured into a different bucket or tub, and then into a sieve before making it into a collection bottle. If there is a large quantity collected, a subsample is used to fill up a maximum of two bottles before the remainder is discarded back into the ocean. Once the samples are processed, an outside label is attached to the bottle and an interior label is dropped inside the bottle, formalin is added to preserve the sample organisms collected so that they can be analyzed later back in the lab.
Personal Log
It is so good to finally get my sea legs! I am glad I can be of use and actively participate. Cooperative teamwork is essential to getting everything to flow smoothly and on time. The Bell Shimada’s deck crew and NOAA team work hand in hand with the scientists to deploy and retrieve the various instruments and devices.
In the past two days I am getting a lot of hands on experience with deploying the HAB net to assisting with processing samples from the HOOP Net and Tucker Trawl. It’s always exciting to see what we might have collected. I can’t wait to see what the rest of the week may bring. I wonder what interesting finds we will get with the midnight Tucker Trawl samples.
Lesson Learned: Neatness and accuracy are imperative when labeling samples! Pre-planning and preparing labels ahead of time helps streamline the process once the samples are in hand.
Word of the Day:Thermocline – This is the depth range where the temperature of the water drops steeply. The region above the thermocline has nutrient depleted waters and while the region below has nutrient rich waters.
