midwater trawl – NOAA Teacher at Sea Blog

July 13, 2023July 19, 2023

Lisa Carlson: Where Did You Come From, Where Did You Go? July 13, 2023

NOAA Teacher at Sea

Lisa Carlson

NOAA Ship Bell M. Shimada

July 5, 2023 – July 19, 2023

Mission: Fisheries: Pacific Hake Survey (More info here)

Geographic Region: Pacific Ocean, off the coast of California

Date: July 13, 2023

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Weather Data from the bridge:

July 11 (1200 PT, 1500 EST)
Location: 37° 46.7’ N, 123° 26.6’ W
43nm (50mi) West of San Francisco, CA

Visibility: 2 nautical miles
Sky condition: Overcast, fog
Wind: 20 knots from N 250°
Barometer: 1015.2 mbar
Sea wave height: 2-3 feet
Swell: 6-7 ft from NW 320°
Sea temperature: 12.2°C (57.2°F)
Air temperature: 12.7°C (57.9°F)
Course Over Ground: (COG): 270°
Speed Over Ground (SOG): 10 knots

July 12 (1200 PT, 1500 EST)
Location: 38° 06.8’ N, 123° 01.6’ W
7nm (8mi) North of Point Reyes Lighthouse, Inverness, CA

Visibility: 2 nautical miles
Sky condition: Overcast, fog
Wind: 12 knots from N 350°
Barometer: 1016.0 mbar
Sea wave height: 1-2 feet
Swell: 3-4 ft from W 280°
Sea temperature: 11.0°C (57.2°F)
Air temperature: 11.5°C (57.9°F)
Course Over Ground: (COG): 270°
Speed Over Ground (SOG): 10 knots

July 13 (1200 PT, 1500 EST)
Location: 38° 17.3’ N, 123° 06.1’ W
2.5nm (4mi) Southwest of Bodega Bay, CA

Visibility: 3 nautical miles
Sky condition: Few clouds, fog
Wind: 13 knots from NW 300°
Barometer: 1015.9 mbar
Sea wave height: 1-2 feet 1-2
Swell: 3-4 ft from NW 300°
Sea temperature: 10.7°C (51.3°F)
Air temperature: 13.7°C (56.6°F)
Course Over Ground: (COG): 340°
Speed Over Ground (SOG): 10 knots

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In my July 6 post, I explained how NOAA Ship Bell M. Shimada is equipped to collect acoustic data in the form of echo grams and therefore find fish to trawl for. In my July 10 post, I explained how we get the fish onboard, and what we do with the sample once it is collected from the net. These entries described what work is done in the Acoustics Lab and the Wet Lab, but there is one more Lab onboard to explore and explain: the Chemistry Lab.

view down the starboard side of NOAA Ship Bell M Shimada shows a wooden nameplate (reading Bell M Shimada) on a railing, the fast rescue boat mounted aftward, and the Golden Gate Bridge in the background. — NOAA Ship *Bell M. Shimada* leaving Pier 30/32 in San Francisco, CA on July 5, 2023. (Just a nice photo taken by me that I wanted to include)

Science and Technology Log

Each morning after breakfast, we usually gather in the Acoustics Lab, determine what transect we are on, if we are inshore or offshore, and in some ways: hurry up and wait. Once certain patterns and blips show up on the echo grams, the Acoustics team talks with the bridge and may request to turn around and attempt a trawl. After all marine mammal observations are completed, the net is retrieved, and the samples are brought to the Wet Lab, we sort and collect data on the samples. These operations usually take place between 0800 and 2000. (8am to 8pm)

So what happens at night? In the Chemistry Lab, scientists work with the Deck and Surveys Departments to deploy a collection of electronic instruments and 12 Niskin bottles (open bottles used to collect and hold water samples, about one meter long) secured to a cylindrical frame called a rosette. It is deployed from the side sampling station instead of the stern. Scientists onboard NOAA Ship Bell M. Shimada use the instruments and collection of water samples in two ways: measuring Conductivity, Temperature, and Depth (CTD) within a water column to study oceanography, and collecting environmental DNA (eDNA).

photo of a large piece of sampling equipment on deck. a large white metal cylindrical frame houses a ring of perhaps ten tall gray canisters - the Niskin bottles. The bottles circle the conductivity, temperature, and depth probe, which is barely visible. Behind the frame, past the ship's rail, we see vivid blue water with a few white caps and a coastal mountain range beyond.

CTD Niskin bottles arranged on a circular rosette frame.

“Nighttime operations primarily consists of deploying the Conductivity-Temperature [-Depth] (CTD) rosette which gathers oceanographic data such as conductivity, temperature, dissolved oxygen, and chlorophyll fluorescence. The CTD can also be triggered to collect water at specific depths.”
NOAA Fisheries: “eDNA Part 2: There’s a Lot of Water in the Sea – and the Chemistry Lab”

NOAA Ocean Exploration: “What does “CTD” stand for?”

Conductivity, Temperature and Depth: CTD

CTD stands for conductivity (ability to pass an electrical current), temperature, and depth. Scientists use the rosette frame, which is attached to the ship by cables, and has the CTD and 12 Niskin bottles attached, to collect electronic data and multiple water samples.

“A CTD device’s primary function is to detect how the conductivity and temperature of the water column changes relative to depth. Conductivity is a measure of how well a solution conducts electricity and it is directly related to salinity. By measuring the conductivity of seawater, the salinity can be derived from the temperature and pressure of the same water. The depth is then derived from the pressure measurement by calculating the density of water from the temperature and the salinity.”
NOAA Ocean Exploration: “What does “CTD” stand for?”

Senior Survey Technician Elysha Agne gives commands to the Deck Department running the winch and cable to the rosette, and ensures quality data is being collected at each sampling depth.

“For more detailed analyses back in the lab, each of the large gray bottles captures a water sample at a different depth. The data provide scientists important information about the local aquatic environment.”
NOAA: “Photo story: Virtually cruise aboard a NOAA ship for a fish trawl survey”

Depending on the depth at which the vessel is currently operating, the rosette will descend to one to five predetermined depths (50m-500m) for sampling. For example, if the vessel depth reads 400m, water samples will occur at 50m, 150m, 200m, and 300m (more information in Table 1 below). A water sample is also taken just below the ocean surface using a through hull fitting, which allows seawater to be collected via a hole in the hull that feeds directly to the Chem Lab.

Table 1. Sample depths for eDNA. Two independent samples should be taken at each depth. The total ocean depth of location for the CTD cast determines the depths at which water samples will be collected. The rows of the table are labeled Sampling Depth (m) and the columns are labeled Topography depth of CTD cast. — Table 1 in Protocol manual, written by Chem Lab member and eDNA scientist Abi Wells.

While the rosette descends, data is recorded from multiple sensors and are later used by scientists to compare with Acoustic and Wet Lab data and compile and categorize new information from the survey. Pressure, depth, temperature, conductivity, salinity, oxygen, fluorescence, and turbidity were all being recorded during this leg of the survey mission.

photo of a computer screen displaying data. two graphs depict depth (m) on the y-axis and salinity or dissolved oxygen on the x-axes. — Program displaying data collected from the CTD rosette in real time.

Environmental DNA: eDNA

During the day, Hake stay in deeper waters, averaging around 200-350m, but at night the nocturnal feeders start their daily migration through the water column to shallower depths. They feed primarily on zooplankton, shrimp, myctophids (Lanternfish), and even young Hake at this depth. As Hake move throughout the water column, they leave behind DNA in the water that can be collected later as sort of a signature of their presence in that location. The collection, filtering, and preservation of sampled water in the ocean environment is categorized as collecting eDNA. This environmental DNA can be in the form of gametes (reproductive cells), fish scales, feces, etc.

Collecting water samples at different depths in the same vertical column can show what marine life was present at that location, and what depth they were at. I relate it to reviewing school security cameras or talking to other teachers at the end of the school day, to determine where a student was at a certain time and why.

Chem Lab member and eDNA scientist Abi Wells collecting a 2.5L water sample from a Niskin bottle after a successful CTD deployment.

When the rosette is back on deck, scientists use gloves and new collection bags called Whirlpacks, to collect approximately 2.5L of water from each 10L Niskin bottle. This process is conducted with a great emphasis on sterility, including wiping the bottle spigot with DNAway to remove any contaminants, using new materials, and not allowing fingers or the spigot to touch the collection bag.

White paper is taped down on a bench in the wet lab. On it are rows of water filtering cups mounted on gray horizontal pipes attached to hoses. Each filter cup is topped with a paper filter. Two have funnels attached; additional funnels, still sealed, line the workbench behind the filtering cups. — Sterile work site being set up to pour water samples into the cups and strain through the filters.

blue gloved hands pour water from a clear plastic bag into a funnel attached to a filtering cup. nearby, three plastic pitchers serve as holders for open plastic bags will filled with water. — Sterile work site being set up to pour water samples into the cups and strain through the filters.

Once the collection bags are filled and brought to the Chem Lab, filtration occurs using 1.0 micron filters. Although this size of filter, compared to smaller filters, allows some cells to pass through and not be collected, it is faster and results in less breakage of cells and loss of DNA. After 2.5L of the water sample is poured through individual filters for each depth sample, they are placed in pre-labeled (location and depth information) tubes with 2mL of preservative buffer. The tubes are stored at room temperature and away from UV light until NOAA Ship Bell M. Shimada is back in port and the samples can be further researched in on-land laboratories. Results from additional studies help to compile lists of marine life that was present in the water column and can be compared to acoustic data and species caught and logged in the Wet Lab.

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Personal Log

So, there you have it. Three Labs onboard that conduct very different research, but fit together in the puzzle of Hake development, migration, diet, niches, ecosystem, biomass, and supporting sustainable commercial fisheries. Each additional piece of data; whether it be echo sounds, physical samples, eDNA, or CTD information, strengthens the others and helps to create a cohesive summary of the data.

This was a lot to learn in the first few days, but as I’ve said before, all of the crew has been welcoming, supportive, and educational. Having a strong team that works together is priceless, and thoroughly noticed and appreciated.

A few days into the mission my Mom asked me what the best part of my day was. I had three answers and haven’t had a day yet with only one answer. I replied that it was the great salmon dinner, clean clothes, and seeing Risso’s Dolphins for the first time.

Video taken by me of Risso’s Dolphins surfacing for air. (Plays on loop)

We are now a little more than halfway through the mission and it has truly flown by. We’ve shared riddles and daily Final Jeopardy questions. We’ve laughed over daily experiences and the faces Hake fish make. We’ve played music and watched baseball during dinner. We enjoy watching marine life and breathe in the salt air while strengthening our sea legs. Sometimes we just drink coffee and snack and enjoy this opportunity with each other, and that makes every part of the day the best part.

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Did You Know?

Although Hake are occasionally cannibalistic, they are not at the top of their food chain. Humboldt Squid (Remember those 15 foot long tentacles in my Wet Lab post?), Dogfish Sharks, and marine mammals are all predators, as well as commercial fishing.
Today well over 100 Spiny Dogfish Sharks were inadvertently caught in the trawl, in the same location as the baskets of Hake we sampled from.
Maybe there were baby Hake fish in the sharks’ stomachs… we didn’t attempt to find out.

a white plastic basket of small sharks — Basket one of Spiny Dogfish

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New Terms/Phrases

Although I had learned the terms a few days earlier, I got to help Wet Lab Lead Ethan Beyer collect otolith and stomach samples for the first time from a sub-sample of Hake the other day.

I watched and learned, then helped scan barcodes of otolith sample bottles, add 95% ethanol that is diluted 50/50 with water, and delicately pick up the ear bones with tweezers and place them in the bottle.

Additionally, each Hake in the sub-sample has its weight recorded, along with length, sex, and developmental stage. From that sub-sample, five stomachs are removed for later analysis, and five have their stomachs opened and their diet is recorded. We often find Lanternfish (Myctophids), Krill (Euphausiidae) and small Hake.

Two orange-gloved hands reach toward a fish on an electronic scale. the ichthystick measuring board is on the table in front of the scale. To the right, in the foreground of the photo, is a large styrofoam case holding small glass sample bottles upright. about two thirds are capped with black caps, while the rest are empty. — Wet Lab Lead Ethan Beyer weighing a Hake sample. Otolith tubes are in the foreground, those with lids have samples inside them and have been scanned into the database with other measurements and samples data from the Hake.

July 10, 2023July 19, 2023

Lisa Carlson: One Fish, Two Fish, Rockfish, Hake fish! July 10, 2023

NOAA Teacher at Sea

Lisa Carlson

NOAA Ship Bell M. Shimada

July 5, 2023 – July 19, 2023

Mission: Fisheries: Pacific Hake Survey (More info here)

Geographic Region: Pacific Ocean, off the coast of California

Date: July 10, 2023

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Weather Data from the bridge:

July 7 (1200 PT, 1500 EST)
Location: 36° 00.4’ N, 122° 05.9’ W
16nm (21mi) West of Big Sur, CA

Visibility: 10 nautical miles
Sky condition: Overcast
Wind: 20 knots from NW 330°
Barometer: 1013.1 mbar
Sea wave height: 3-4 feet
Swell: 6-7 ft from NW 320°
Sea temperature: 14.0°C (57.2°F)
Air temperature: 14.4°C (57.9°F)
Course Over Ground: (COG): 323°
Speed Over Ground (SOG): 10 knots

July 8 (1200 PT, 1500 EST)
Location: 36° 34.5’ N, 122° 05.3’ W
17nm (20mi) Southwest of Monterey, CA

Visibility: 10 nautical miles
Sky condition: Few clouds
Wind: 19 knots from NW 330°
Barometer: 1013.8 mbar
Sea wave height: 5-6 feet
Swell: 6-7 ft from NW 330°
Sea temperature: 14.0°C (57.2°F) 13.7
Air temperature: 14.4°C (57.9°F) 14.3
Course Over Ground: (COG): 089°
Speed Over Ground (SOG): 10 knots

July 9 (1200 PT, 1500 EST)
Location: 37° 06.8’ N, 123° 00.5’ W
30nm (35mi) West of Pigeon Point Light Station, Pescadero, CA

Visibility: 10 nautical miles
Sky condition: Overcast
Wind: 13 knots from NW 332°
Barometer: 1016.0 mbar
Sea wave height: 2-3 feet
Swell: 4-5 ft from NW 310° 4-5
Sea temperature: 14.3°C (57.7°F)
Air temperature: 15.2°C (59.4°F)
Course Over Ground: (COG): 093°
Speed Over Ground (SOG): 10 knots

July 10 (1200 PT, 1500 EST)
Location: 37° 26.7’ N, 123° 06.4’ W
32nm (37mi) West of Pescadero, CA

Visibility: 8 nautical miles
Sky condition: Overcast, fog in vicinity
Wind: 20 knots from NW 330°
Barometer: 1015.9 mbar
Sea wave height: 2-3 feet
Swell: 3-4 ft from NW 320°
Sea temperature: 14.5°C (58.1°F)
Air temperature: 13.6°C (56.5°F)
Course Over Ground: (COG): 314°
Speed Over Ground (SOG): 3 knots

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Science and Technology Log

Lisa poses for a photo in the wet lab with a hake fish. She's wearing heavy-duty orange overalls and large orange gloves. With her right hand, she grasps the fish by its open mouth, and her left hand holds on to the tail. We can see metal tables and equipment in the background. — Me holding a Hake before sorting. After observation, we determined this was a developmentally mature female, measuring 50cm (20in) long!

In my July 6 blog post, I explained how NOAA Ship Bell M. Shimada is equipped to collect acoustic data in the form of echo grams. The acoustics team uses the data to determine if there are enough return signals to suggest fish are present and attempt a trawl. In this blog post, I will explain how we get the fish onboard, and what we do with the sample of marine life once it is collected from the net.

One question I had after learning about the acoustics and environmental DNA (eDNA) pieces of the survey mission was, “How does physically collecting and researching Hake samples fit into the puzzle of understanding their ecosystem and supporting sustainable fisheries?” (NOAA Fisheries quick facts and video here)

“While echosounders are useful, they do not provide certain quantitative data that researchers need to understand the ecology of these organisms and the midwater zone. To collect quantitative data, such as biomass, length and weight, and age class distributions, researchers must gather representational samples and take direct measurements of them. The best way to do this is by employing trawls.”
NOAA Ocean Exploration: “Trawls”

So, although acoustics and eDNA research is important to the overall survey, they are only pieces of the puzzle, and the puzzle is not complete without conducting trawls and physically researching samples. NOAA Ship Bell M. Shimada uses a midwater trawl net that is deployed from the stern over the transom, and towed behind the vessel. As the name suggests, midwater trawls occur in the middle section of the water column, versus surface and bottom trawls. The net is conical in shape and uses two metal Fishbuster Trawl Doors, and two sets of heavy chain links called Tom weights, in order to keep the trawl in the middle of the water column.

a simple and stylized monochrome illustration of a fishing vessel towing a midwater trawl behind it. The net in tow is conical, attached at four points to two bars that hold the opening apart, and these bars are attached to lines (ropes) extending back from the vessel. This net is capturing two fish and missing a third. — NOAA Fisheries: “Fishing Gear: Midwater Trawls”

“The midwater region is especially important because the creatures that inhabit it constitute the majority of the world’s seafood. Understanding the ecology of midwater organisms and their vast environment can provide us with better information to manage these important natural resources and prevent their overexploitation.”
NOAA Ocean Exploration: “Trawls”

Deck department assisting in recovering the trawl net after a successful deployment.

Two deck crewmembers work with an orange and white fishing net on the aft deck of NOAA Ship Bell M. Shimada. They are wearing foul weather gear, life vests, and hard hats. At right, one leans over the net, searching for remaining captured fish. The other approaches from the left, looking down at the net, to assist. We can see a cloud-capped mountain range in the distance beyond the water.

Once the net is onboard, the net is emptied one of two ways depending on the size of the sample. For large samples, marine life is deposited into a hopper and subsequent conveyor belt. For smaller samples, the Hake will be put into a large basket then divided into smaller baskets of approximately 100 Hake each. Any other marine life like Salps, Myctophids, Pyrosomes, Rockfish, King of the Salmon, and small bony fish, etc. are recorded in the database and returned to the ocean.

“The ship’s wet lab allows scientists to sort, weigh, measure and examine fish. The data is entered directly into the ship’s scientific computer network.”
NOAA Office of Marine and Aviation Operations (OMAO): “Bell M. Shimada”

a large black plastic bin filled with fish - mostly hake, but a few splitnose rockfish (eyes bulging from the pressure change) stand out for their red color. An orange-gloved hand reaches toward the basket from the upper left corner of the image.

Large basket containing a sample of Hake with a few (red) Splitnose Rockfish.

a view of NOAA Ship Bell M. Shimada’s Wet Lab with multiple scales, Ichtystick electronic measuring boards, trawl camera, vials for otolith (ear) bones, disposal chute, and tools including scalpels, tweezers, and knives. — NOAA Ship *Bell M. Shimada’s* Wet Lab with multiple scales, Ichtystick electronic measuring boards, trawl camera, vials for otolith (ear) bones, disposal chute, and tools including scalpels, tweezers, and knives.

Maddie, in the wet lab, holds a hake fish up for a photo. She is wearing a long-sleeved shirt, heavy-duty orange overalls, and large orange gloves. Her hair is tied back in two double braids and topped with a teal bandana. She holds the fish in two hands, horizontally, at the level of her mouth, so we cannot see her smiling, but we can see her arch her eyebrows as she looks straight at the camera. — NOAA Ship *Bell M. Shimada’s* Wet Lab with multiple scales, Ichtystick electronic measuring boards, trawl camera, vials for otolith (ear) bones, disposal chute, and tools including scalpels, tweezers, and knives.

With our boots and bright orange rubber pants and gloves on, our first task is to distribute the sample of Hake into baskets of about 100 each. Based on how many baskets we fill, a random selection of baskets will be kept, and the others will be returned to the ocean. With the remaining groups of Hake, we determine their sex and length.

In order to do this, we use a scalpel to make an incision on the underside/belly of the Hake. Once open, we are able to examine their organs, including the gonads to determine if the fish is male or female, and if they are developmentally immature or mature. Young Hake are difficult to sex, and it takes practice to get over any initial fears of cutting into an animal; let alone being able to locate and identify the gonads. Hake usually spawn in early winter, so many of the smaller Hake we sample from during the summer are age one or younger.

Our largest Hake thus far was a developmentally mature female, measuring 50cm (20in). In order to accurately and consistently measure the length of the sample, we use a waterproof, magnetic plastic board with metric (centimeter and millimeter) markings called an Ichthystick (think: high-tech meter stick). The fish is placed on the board with its mouth touching the black board at 0cm, then a magnetic stylus is placed at the fork of the fish’s tail. Once the magnetic stylus is placed on the board, the length to the nearest millimeter is displayed on the LCD screen and automatically entered into the database program. The length data is grouped with the date, time, and identified sex for later observation and comparison.

Additional information, abstracts and outline about Ichthystick here

Ichthystick’s LCD display, motherboard, magnetic board, and magnetic stylus. Digital scale in background.

An even smaller subgroup is then selected and examined to record weights of individual Hake, collect ear bones called Otoliths for aging, stomach samples for diet, liver for RNA, and ovaries for maturity development. Otolith bones help determine the age of the Hake because they grow a new “layer” of bone each year, similar to coral structures and annual tree rings. Organs and bones removed from the Hake are sent to NOAA Fisheries centers for analysis and included in databases with the date, identified sex, length, weight, and location in which they were collected.

This data is used to build more of the puzzle, along with acoustical information, water samples, and eDNA data in order to further understand the ecosystem, biomass, diet, and

“support sustainable populations of Pacific hake on the West Coast.” (…)
“It provides vital data to help manage the migratory coastal stock of Pacific hake. The hake survey, officially called the Joint U.S.-Canada Integrated Ecosystem and Pacific Hake Acoustic Trawl Survey, occurs every odd-numbered year.”
NOAA Fisheries: “Joint U.S.-Canada Integrated Ecosystem and Pacific Hake Acoustic Trawl Survey”

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Personal Log

Although this subtopic of explaining the Integrated Ecosystem and Pacific Hake Acoustic Trawl Survey is a bit easier to understand than my July 6 Acoustics Lab post, it certainly does not mean it’s an easy task!

When I had a tour on July 4, I remarked how clean and organized the Wet Lab is. I hadn’t see it in action yet, but noticed how everything had its place and use. On July 6 we conducted our first trawl and collected a sample of 11 baskets of Hake (approximately 1,100 Hake since we group about 100 Hake together in each basket.) From that sample, we kept four baskets and counted, sexed, and measured 541 Hake.

Five of us were working together in the Wet Lab for that haul. I’ll admit I probably didn’t sex 100+ Hake. It took a few minutes of watching the others carefully and swiftly cut into the underside of a fish, open the two sides, and know what to look for to determine the sex of very young Hake. Eventually I found the courage to slice in and take a look. By the fourth or fifth Hake, the uneasiness had subsided and I found the process very interesting and educational. Although young samples are hard to sex as they are often undeveloped, the others encouraged me and answered my questions and guesses with enthusiasm and support.

While working on measuring the lengths of our samples, one Science Team member paused and remarked how beautiful he found the fish. Although they do not have vibrant, bold colors, shimmering scales, or anything else particularly remarkable, he found the beauty in them. He digressed into a conversation of their role in the ecosystem, how they are living and breathing creatures, and how they probably all have their own personalities and slight physical differences. I noticed some of their eyes were shiny and sparkling, and how their faces and expressions were noticeably unique the more you looked. That “down to earth”, heartfelt discussion was very special and demonstrated how the crew respects the process of catching and sampling Hake, while keeping each other and marine mammals safe.

From the NOAA Corps Officers, to the deck department, to the engineers, electronics, science team, survey team, galley crew, volunteers, and everyone in between; the crew on NOAA Ship Bell M. Shimada is special. They take pride in their vessel and job, and always seem to have a smile and kind greeting. Being away from land and loved ones for weeks and months at a time will certainly take a toll on the body and mind, but this team is there for each other. To all of the crew, thank you for making me feel so welcomed and appreciated. We’re almost halfway through the mission, and as tired as I may get after (sometimes) 12+ hour days, I sleep well knowing the crew trusts their vessel and each other; and look forward to learning and becoming more and more acquainted each day with the people that make this mission possible. Thank you!

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Did You Know? (FAQs)

1. Are you finding schools of them?

We’ve had seven successful trawls out of nine attempts for Pacific Hake fish. They often come with pyrosomes (Sea Pickle) myctophids (Lanternfish), and salps in the net too. Some trawl attempts are successful without a hitch, but more often than not we have to restart our Marine Mammal watches a few times before deploying in order to keep our ocean life safe and not get tangled in the net. Two trawl attempts have been abandoned because of the amount of persistent marine mammal life and playfulness near the ship. (I think they know we’re watching and show off for our cameras.)

2. What’s your average depth?

The transects (Set and numbered longitudinal east-west lines NOAA Ship Bell M. Shimada navigates on while collecting acoustic data) usually range from 50m – 1,500m (164ft – 4,921ft) in depth.

However, right now one of the displays in the Acoustics Lab, the depth reading is 3,240m which is about 10,630ft or just over two miles deep!
This depth is only 1,870ft shallower than the wreck of the RMS Titanic!
(We were on a long transect, we do not often see depths this great.)

3. Have you gotten seasick? Seasickness should subside after about 3 days.

I’ve never gotten seasick thankfully! Knock on wood and all the other premonitions, please.

4. What is the Hake role in the ecosystem?

More info on this coming in later posts after explaining our Chemistry lab and technology aboard!

However, as predators, they can be cannibalistic towards their own kind.
As far as their role in human consumption: They are often used as a substitute for Cod and Haddock, and in fish sticks and imitation crab meat.

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Animals seen July 5-July 10:

Mammals: Sea Lions, Harbor Seals, Dall’s Porpoise, Risso’s Dolphins, Pacific White-Sided Dolphins, Northern Right Whale Dolphins, Humpback Whales

Birds: Gulls, Black-Footed Albatross

Bony Fish: Hake, Lanternfish (Myctophid), Flatfish, King of the Salmon, Split Nose Rockfish, Chili Pepper Rockfish

Other Marine Life: Giant or Humboldt Squid (15 foot tentacles in trawl), Spiny Dogfish Shark, Shrimp, Plankton, Krill, Sea Pickle (Pyrosome), Salp, Eel Larva

a spiny dogfish - a species of small shark - placed on a fish measuring board atop a metal table. a scale is visible next to the measuring board. — Spiny Dogfish Shark (42cm or 16in long)

three impressively long squid tentacles laid out on the floor; they are orange-brown on top, and white underneath, lined with white suckers (suction cups) of varying size — Spiny Dogfish Shark (42cm or 16in long)

June 1, 2012August 11, 2021

Scott Davenport: Heading to Sea, May 21, 2012

NOAA Teacher at Sea
Scott Davenport
Aboard NOAA Ship Bell M. Shimida
May 21-May 27, 2012

Mission: Rockfish Survey
Geographical area of cruise: Eastern Pacific, off the California coast and next to the Mexican Border
Date: May 21, 2012

Personal Log

Hi, my name is Scott Davenport and I am excited to be a part of NOAA’s Teacher at Sea Program. It is going to be great. I teach at Paul T. Albert Memorial School located in scenic Tununak, Alaska. It is a Yup’ik village on the Bering Sea. Most families practice subsistence living. My subject is junior high generalist, meaning I teach everything. Last year, I had a great group of seventh and eighth graders. It was my first year in Alaska and as a full-time teacher. Everyone learned a lot.

Jr High Class — Tununak Seventh and Eighth Graders. Can you tell it is the last day of school?

Teacher at Sea intrigued me because it opens wide array of possibilities. A consistent issue at our school is what comes next? Graduation is a celebration, but it also brings apprehension and uneasiness. There are not a wide range of jobs in the village. It is normally limited to fishing, teaching, being a cashier, store stocker, or bush pilot. A NOAA boat offers a wider range of careers. My experience on the ship will help my students make connections to new possibilities. The long cruises followed by long breaks fit with subsistence living. They can have the time to go on a two week moose hunt and not miss work. Being located on the sea, most of my students are acclimated to spending time on the water. My experience will open eyes.

While on board the Bell M. Shimada, we have seven objectives. Objective #1: Sample the epi-pelagic micronekton. That means–thanks to Cynthia explaining it to me–we are going to see what is living in the upper water column. The specific fish we are looking for are the juvenile rockfish. We will also survey Pacific whiting, juvenile lingcod, northern anchovy, Pacific sardine, market squid and krill. Objective #2: Characterize prevailing ocean conditions and examine prominent hydrographic features. Objective #3: Map the distribution and abundance of krill. Objective #4: Observe seabird and marine mammal distribution and abundance. Objective #5: Collect Humboldt squid. Objective #6: Conduct deep midwater trawls to examine mesopelagic specimen. Finally Objective #7: Examine feeding habits of jellyfish. My personal objective is to not vomit at sea.

The three things I am looking forward to most are meeting new people, witnessing scientific research, and learning new, unexpected items. My three biggest concerns are falling overboard at night into a never-ending dark abyss, the food, and making sure I contribute to the work/use my time wisely. I am also excited to have a break from snow.

Shoveling Snow — In the fall, the stairs went down.

June 20, 2010April 15, 2021

Tanya Scott, June 20, 2010

NOAA Teacher at Sea
Tanya Scott
Onboard NOAA Ship Miller Freeman
June 16 – 21, 2010

Mission: Ecology of Juvenile Fishes
Geographical Area: Central Oregon/Washington Coast
Current Location: 35 miles offshore, steaming to Seattle, WA
Date: Sunday, June 20, 2010

Today is my last full day aboard the Miller Freeman. It is currently 4:00 pm and I have just woken up! I find that being on a ship rocks me to sleep. Or, could it be that I was up until 6:00 am this morning? Either way, I am fully rested and ready to rinse and store all of the scientific equipment in preparation for our departure tomorrow morning. We are currently steaming towards Seattle, Washington where we will depart the ship.

Our work on Saturday turned out to be very interesting. While pulling the midwater trawl, a small pod of Pacific Whitesided dolphin became interested in our tow. They swam very close to the net for a time and had everyone worried that they may become entangled. Luckily, they lost interest and swam away. If they had become entangled in the net there are many protocols that would have been implemented. The marine mammal stranding unit in Washington would have been called, a representative would have been sent to meet the ship, and many photographs taken as documentation. It is always a concern that marine mammals may become entangled in nets but fortunately, this time was not one of those cases.

scott_log3 — Krill brought in from the midwater trawl.

The catches from our midwater trawl brought up the familiar species of krill, purple lanternfish, rockfish, and hake. Since the depth of this trawl does not target adult fish, we have been dealing almost exclusively with juvenile and larvae fish. Our last haul produced more larvae rockfish than usual, which is good for the scientists conducting this survey. They are, however, trying to determine where the largest concentrations of juvenile rockfish are during the season. Rockfish are an important species in the Pacific Northwest. It would be easy for you to think of how important flounder are in our area. Rockfish are harvested for sale in fish markets and therefore are threatened by over harvesting. It is important to monitor their movement and habitat in order to determine when and where Pacific Hake regulations should be put in place. Another commercially important species is the Pacific Hake. This fish is deboned and sold as fish sticks in the grocery store. I’m sure that most of you have eaten a Pacific Hake and didn’t even know. These fish are commonly caught by fisherman and, just as the rockfish, their populations are threatened by over harvesting. When Pacific Hake are caught in the midwater trawl, their length is measured, recorded, and the fish are returned to the ocean. All of the data collected by the scientist involved in this study will help to ensure the survival of these commercially viable species. More importantly, keeping their populations stable will mean that the food web remains intact. Just as we have discussed in class many times, everything on earth has its place. Something else always depends on it for food, shelter, survival, and well being.

Since today is the last full day on board we will be preparing the equipment for transport back to Newport, Oregon. It is important that everything is rinsed with freshwater to prevent corrosion. After being rinsed and dried, we will package everything in boxes. Our bunks will be stripped, our lockers emptied, and staterooms cleaned. Although my time on board is coming to an end, I know that I will have many memories and experiences to share with you when I return.

Tanya Scott

June 18, 2010April 15, 2021

Tanya Scott, June 18, 2010

NOAA Teacher at Sea
Tanya Scott
Onboard NOAA Ship Miller Freeman
June 16 – 21, 2010

Mission: Ecology of Juvenile Fishes
Geographical Area: Central Oregon/Washington Coast
Date: Friday, June 18, 2010

Science and Technology Log
Before telling you about my experiences in the last day or so, I’d like to give a little more information about the experiments being conducted by Oregon State University (OSU). The title of this study is: The Stock Assessment Improvement Program (SAIP) Ecology of Juvenile Fishes off Oregon/Washington. The primary purpose of this study is to assess the ecology and population of juvenile fishes between Willapa Bay, WA and Heceta Head, OR as part of a NOAA Fisheries Stock Assessment. Scientists are trying to gain a better understanding of the direct and indirect linkages between oceanographic conditions and fish survival in the marine environment. This is becoming more important as the need to manage fish stocks increases. Scientists collect data concerning biotic and abiotic conditions and assess the relationship between these factors and fish populations.

As many of you already know, there is a very similar need in NC for such studies. If you recall, our scallop season was closed for two years and only opened briefly last year for harvest. Such closures and limitations are put on species such as scallop in order to give populations time to recover from over harvesting. Similar problems are also encountered on the west coast with many species that fisherman harvest for sale to the public. One important thing to remember is that the food you order in a restaurant had to be harvested from someone, somewhere. Another good example is shrimp, which many of you love to eat! Fisherman harvest shrimp to sell in markets which in turn, are sold to restaurants and grocery stores. If fisherman take shrimp without regard for their population then problems eventually arise. It is the goal of scientists to monitor issues such as population and species health before they become a problem. Monitoring is the goal of the SAIP project being conducted by OSU and NOAA.

One of the challenges of this trip has been adjusting to the work/sleep schedule. Most of the samples collected by OSU scientists are done during the night. There are 4 stations a night that must be sampled and there is about an hour of transit time between each station. After catching up on a bit of sleep yesterday, I awoke around 2 am this morning to assist with the last two stations.

When a station is reached, three instruments are deployed and data is recorded. Below is a description of each:

1. CTD: I discussed this in the previous log. This instrument is used to collect data including salinity, temperature, density, turbidity, dissolved oxygen, and florescence. It is important to know what abiotic factors affect the population of juvenile fish. Bknowing what factors affect their movement, scientists are better able to determine where and wpopulations can be found. For example, the average water temperature is 12.9 Celsius where our samples are taken.

2. Bongo Tow: This interesting piece of equipment is deployed when the ship slows to about 1-2 knots. We usually travel at a speed of about 12 knots on average. When the Bongo goes over, everyone knows because we all slow down! The Bongo Tow consists of two nets that are lowered into the water at a depth of 100 meters. The Bongo Tow collects a small sample of the water column at this depth and is then brought back to the surface. My job has been to rinse the Bongo tow once it is onboard, collect any organisms that were caught in the nets, and preserve them. These samples are then taken back to the OSU lab where scientists examine the contents under a microscope. They are looking for tiny organisms called zooplankton and phytoplankton. These organisms are an important food source for juvenile fish and scientists want to know what food is available where fish are found. In addition to zoo and phytoplankton we have captured krill and Dungeness crab larvae.

scott_log2 — Here I am before deploying the CTD. We are required to wear a life jacket, hard hat, and foul weather gear when working.

3. Midwater trawl: This is the most exciting part of each station rotation. This net is towed from the aft (back) of the ship for 15 minutes at a depth of around 30 meters. The purpose of this trawl is to capture juvenile fish to be counted and measured. Once onboard, scientist work to separate all species found in the net. Below is a list of the species caught this morning as we sorted:

scott_log2-1 — I am holding a juvenile squid that I’ve sorted from the trawl.

Flatfish larvae (very similar to our flounder), Pacific Hake, Squid, Rockfish larvae, Whitebait Smelt, Juvenile King-of-the-Salmon, Popeye blacksmelt, Slender barracudina, and blue lanternfish.

Today, we are steaming ahead to our first station about 11 miles off the coast of southern Washington. We will begin sampling tonight at 7:00 pm once we reach the station and continue to sample the remaining 3 stations. The work is usually completed around 5:00 am so I am off to catch up on sleep again as I will be up into the wee hours of the morning! One thing that I do enjoy about being up at these odd hours is watching the sunrise on the open ocean. What a beautiful way to greet each day!
Until tomorrow…
Tanya Scott