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.

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.

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

Patty McGinnis: San Francisco–Home to Alcatraz, Angel Island, and Sea Lions, May 22, 2013

NOAA Teacher at Sea
Patty McGinnis
Aboard R/V Ocean Starr
May 20 – 29, 2013

Mission: Juvenile Rockfish Survey
Geographical Area of Cruise: San Francisco
Date: May 22, 2013

Personal Log

Early Monday I flew out of Philadelphia and landed a few hours later on the west coast—a trip that would have taken the pioneer settlers a half a year or more to accomplish. The first leg of my flight landed in Los Angeles, followed by a short hop up north to San Francisco. The plane followed the California coastline nearly the entire time. I found myself mesmerized by the Pacific Ocean as it hugged the shoreline as if to embrace the homes that dotted the land. I had spent many years of my youth growing up in San Diego, and watching the water brought back many memories of lazy summer days complete with gritty sandwiches and sunburned skin.

My first night in San Francisco was spent in a hotel near the airport; yesterday morning I took an expensive (nearly $60!!!) taxi cab to my current accommodation. I was lucky—the hotel had a room free early in the morning so I dumped my bag and went exploring. It was only a short walk to Fisherman’s Wharf—the place where San Francisco fisherman have historically unloaded their catch—most notably the Dungeness crab. The crab gets its name from a town in Washington where it was first harvested (although I didn’t have an opportunity to taste the crab, I wondered how it compares to the Chesapeake Blue Crab).

Although the sun was out, I found it was a mere deception once I got close to the water. The air temperatures were in the 50’s and the wind was blustery at times. Up and down the waterfront are numbered piers; I walked down to Pier 33 in hopes of buying a ticket to Alcatraz Island. Alcatraz, or the “The Rock” is quite visible from the Fisherman’s Wharf area. Although many know it as a famous prison, it has also been a Civil War fort and was home to the first lighthouse on the west coast. The only way to get onto the island, which is managed by the National Park Service, is by purchasing a ticket through a ferry company. Despite it being midweek and not quite summer, all the tickets had been sold out for the entire day.

Alcatraz
Alcatraz Island doesn’t seem that far away from San Francisco but cold, rough water means few prisoners escaped

Disappointed, I trudged down towards Pier 39—a famous tourist attraction. I settled for a tour of the bay, which included a good look at both the Golden Gate Bridge and the San Francisco-Oakland Bay Bridge. Both are engineering marvels. The Bay Bridge, which opened in 1936, is actually a double-decker bridge that is part suspension bridge and part cantilever bridge. Originally the top deck was for cars and the bottom deck was for trains and trucks but now cars can travel on both levels. The Golden Gate Bridge is a suspension bridge that opened in 1937. It is possible to walk across the bridge and today was no exception. As our boat passed under the bridge, I could see people waving at us from high above. Our boat had a loud speaker that provided interesting information about the history of San Francisco, but the noise from the wind made it difficult to make out what was being said. Our boat was rocked around by the wind and swells, making me wonder what the water outside the relative shelter of the bay was doing. I do know that rough seas have changed the location where I’ll be boarding the Ocean Starr. Later today I’ll be picked up and driven to Santa Cruz, a town south of here that lies along the Monterey Bay.

On the water with the Golden Gate Bridge in the background
On the water with the Golden Gate Bridge in the background

While on the tour of the San Francisco Bay, I learned about Angel Island—a quiet wildlife area that is a California state park only accessible by ferry. I found the lure of visiting a relatively uninhabited area after the hustle and bustle of Fisherman’s Wharf too strong to ignore. Interested in doing a little hiking, I grabbed an afternoon ferry over to the island and was delighted by the unusual plant life and the opportunity to listen to waves crashing against the shore (check out the Angelcam for a view from the Visitors center). During my walk, I spied numerous succulents, as well as some beautiful (and unidentifiable by me) trees with bark reminiscent of the sycamore.

The bark on this tree reminded me of the sycamore
The bark on this tree reminded me of the sycamore

Angel Island has a fascinating history. Although it is a California park today, at one time it served as an immigration point for nearly a million immigrants, most of whom were Chinese. Unlike European immigrants who passed through Ellis Island, however, the Chinese immigrants were detained until they could prove that they had family in the United States (a process that often took years). Angel Island was also at one time the home of a U.S. Army base called Fort McDawgell and served as a quarantine station to prevent the spread of illness to San Francisco.

It was late afternoon when I returned to Fisherman’s Wharf, where I spent quite a bit of time at Pier 39 observing the resident colony of California sea lions. The sea lions, the majority of which are male, reminded me of some middle school students I know. Although many napped in the sun, others jostled and pushed each other around and off the docks and some brayed loudly as if to say “look at me.” Sea lions have always been present in the bay, but using the docks as a haul out for sunning has only been occurring since 1989. Researchers aren’t sure what prompted the animals to begin using the dock as a habitat, but plentiful food and an absence of predators are two reasons that the animals stay around. Yesterday nearly all the dock space was packed with wall-to-wall sea lions who crowded near each other as they slept. This behavior of seeking out physical contact is known as positive thigmotaxis. The sea lion numbers evidently fluctuate in response to food availability and mating season as many of the “bachelors” head off in search of a girlfriend. You can check out their antics on the Sea Lion webcam.

Look who took over Pier 39!
Look who took over Pier 39!

These sea lions are displaying positive thigmotaxis when they lie on top of each other
These sea lions are displaying positive thigmotaxis when they lie on top of each other

As I finish my writing, I think about the adventure ahead. I’ll soon be picked up soon by two scientists and driven to Santa Cruz, where we will board the Ocean Starr. I worry a bit about the rough seas and the likelihood of seasickness. I also wonder what it will be like to conduct night trawling. I’ve been assigned to the 8:00 p.m. to 6:00 a.m. shift; why is it that trawling is done at night? Are fish feeding at that time and more likely to be caught? Does night trawling reduce by-catch (organisms that are caught unintentionally)? Or perhaps it is because you catch more at night? I guess I will soon find out. In the meantime, I better study the picture below so I can help identify the fish we catch!

Which fish would you buy at the supermarket?
Which fish would you buy at the supermarket?

Jennifer Fry, July 17, 2009

NOAA Teacher at Sea
Jennifer Fry
Onboard NOAA Ship Miller Freeman (tracker)
July 14 – 29, 2009 

Mission: 2009 United States/Canada Pacific Hake Acoustic Survey
Geographical area of cruise: North Pacific Ocean from Monterey, CA to British Columbia, CA.
Date: July 17, 2009

Hake are unloaded into holding containers, soon to be weighed and measured
Hake are unloaded into holding containers, soon to be weighed and measured

Weather Data from the Bridge 
Wind speed: 20 knots
Wind direction: 340°from the north- north west
Visibility: foggy
Temperature: 15.2°C (dry bulb); 13.0°C (wet bulb)

Science and Technology Log 

Each day I observe the NOAA scientists using the scientific process.  These are the same process skills we learn in the classroom. The scientists determine what they want to find out and state it in a question form. These are some of the questions/hypotheses that they are trying to answer.

  • What and where are the populations of hake?
  • In what environments do the hake best thrive?
  • When do they migrate?
  • What do they feed on?
  • What feeds on the hake?

Once the hake are observed on the sonar, the trawl net is dropped into the water.  The fish are hauled out onto the deck where they are emptied into huge holding bins.  Scientists want a good sampling of hake for the survey, not too much and not too little.  Getting a good sample is important to the scientists; both for their research and the environment.  The scientists don’t want to take too many hake each time they fish, doing this might diminish the hake population. 

Collecting Data: Observing – Using the senses to collect information.

Classifying – Sorting or ordering objects or ideas into groups or categories based on their properties.

Measuring – Determining dimensions (length/area), volume, mass/weight, or time of objects or events by using instruments that measure these properties.

Otoliths—fish ear bones—are extracted and placed in vials (test tubes) for later study.
Otoliths—fish ear bones—are extracted and placed in vials (test tubes) for later study.

The scientists then collect their data. Fish are separated by species or classified.  All hake collected are then weighed. A certain number of them are measured in length, and their sex is determined.  Scientists observe; dissect a group of hake, and collect the fish’s ear bones, called the otoliths, (2 white oval shapes pictured above). Otoliths are stored in small vials, which are like test tubes, for later study. The test tube has a serial number which is fed into a computer as well. Later, scientists will observe the otoliths under a microscope.  The otolith helps determine the age of the fish. When observed under a microscope, the otolith, or ear bone has rings similar to rings of a tree. The more rings, the older the fish.  The age of the fish or data is then recorded in a computer spreadsheet.

Communicating – Using pictorial, written, or oral language to describe an event, action, or object.

Making Models – Making a pictorial, written or physical representation to explain an idea, event, or object.

Recording Data Writing down the results of an observation of an object or event using pictures, words, or numbers.

As data is collected, it is recorded into a computer database, then scientists create tables and graphs from information in this database.

Inferring  – Making statements about an observation that provide a reasonable explanation.

Predicting – Guessing what the outcome of an event will be based on observations and, usually, prior knowledge of similar events.

Interpreting Data – Creating or using tables, graphs, or diagrams to organize and explain information.

The otoliths look like small oval “winglike” structures.
The otoliths look like small oval “winglike” structures.

Once all the data is in the computer, scientists can analyze or figure out the answers to these questions.

  • What and where are the populations of hake?
  • In what environments do the hake best thrive?
  • When do they migrate?
  • What do they feed on?
  • What feeds on the hake?

Scientists use the data to infer or make a statement about the data that gives a reasonable explanation.  Scientists also make predictions by guessing what the outcome might be based on the data/observations.

Marine Mammal Watch – NOAA Fisheries instructs the scientists to conduct a “marine mammal watch” prior to a fishing trawl. This is to protect the marine mammals, such as dolphins, whales, sea lions, and seals.  When the nets go into the ocean, the curious sea lions want to see what’s going on and play around the nets.  This can prove dangerous for the animals because if they get tangled in the net, they cannot come up for air, and being mammals, they need air.  As it happened, a half a dozen sea lions were spotted around our trawl net. To protect the inquisitive animals we found another spot in which to put our net.

California sea lion
California sea lion

Personal Log 

Everyone aboard the Miller Freeman is a team.  It’s an amazing working environment.  The ship runs like a well oiled machine.  The crew is always so helpful and are dedicated to their work.  The scientists are incredibly dedicated to their specific field and are committed to helping the world and the ocean’s biome. Everyone is so patient with all my questions.  I am so grateful and honored to be part of this hake survey which is so scientifically important in determining the health of our ocean.

Animals Seen Today 
California sea lions
Hake Myctophidae: lantern fish

Mary Anne Pella-Donnelly, September 10, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 10, 2008

Weather Data from the Bridge 
Latitude: 3736.6398 N Longitude: 12336.2210 W
Wind Direction: 220 (compass reading) SW
Wind Speed: 11.3 knots
Surface Temperature: 14.638

This moon jelly was captured with the mid-water net.  Its bell was 35.5 cm wide.   The purplish pattern represents the gonads, which the turtles love to eat.
This moon jelly was captured with the mid-water net. Its bell was 35.5 cm wide. The purplish pattern represents the gonads, which the turtles love to eat.

Science and Technology Log

The mid-water net was just deployed.  This is a new net for the research team to use.  On the trip north, during the first part of this cruise, the last net became mangled during use.  A new, larger net was obtained and the crew is working out how best to deploy it.  After three tries, they seem to have determined the best way to lay it out, release it, and winch it back in. The David Starr Jordan is now heading over to the off shore area outside of Point Reyes, where the plan will be to deploy it for only one to two minutes.

The jellyfish there are usually so numerous that they will fill the net immediately.  Leatherbacks eat jellyfish of many kinds, but they love the types in the Pelagiidae family.  These are the types with long hanging arms, which the turtles snack on until they get up into the body cavity. The jellyfish are then eaten from the insides, with a soft-bodied bell left behind. The bell-shaped body of this family can be as large as 55 cm.    The favorite of leatherback, so the one we will hope to find in abundance, is the Sea nettle, Chrysaora fuscescens. These are most numerous in August and September in specific locations off the California coast, so it can be anticipated that leatherbacks will also be found there.  The predictability of this occurrence is the reason leatherbacks have evolved to travel the Pacific Ocean from Asia every year. 

Unidentified songbird, hopping a ride aboard the Jordan.
Unidentified songbird, hopping a ride aboard the Jordan.

The ship, David Starr Jordan, was built in 1965, so is among the oldest of the fleet of NOAA research ships.  The age can be found in the cabinet design, the flooring material and little features. Never the less, it has been built for sustained trips at sea for up to 23 days in length. There is a steward on board who creates elaborate lunches and dinners daily. Last night’s dinner included Filet Mignon, shrimp in butter sauce, two soups, sautéed vegetables, and at least four other hot dishes. There is always a salad bar set up and 24-hour hot beverages, cereal, toast, ice cream, yogurts and fruit. Everyone eats well.

In the crew’s lounge, drawers of over 200 current films are stored, including new releases. They have been converted to 8 mm tape to accommodate the video system on board.  There is also a small gym with a treadmill, stationary bicycle and bow-flex machine.  A laundry room completes the ‘home’ environment. At least three showers are available.  The ship has a system to desalinate water, which is a slow process, so water conservation is suggested.  This means:  wet yourself down, turn off the water, soap up and scrub, then turn the water on and rinse off.  Repeat if necessary. There are no water police, but we all have an interest in enough water being available.

Although the food has looked great, I have found that until I get my ‘sea legs’ I need to stay away from most food.  Yesterday evening, I discovered that the lunch and dinner I ate; did not look as good coming out as it did going down.  Today is better, but I will stick to yogurt, oatmeal, and tea for a bit.

Animals Sighted Today 
Sea nettle jellies Chrysaora fuscescens
Moon jellies Aurelia aurita
Egg yolk jellies Phacellophora camtschatica
Ocean sunfish Mole mole
Humpback whale Megapterea novaeangliae
Blue whale Balaenoptera musculus
Common murre Uria aalge
Black phoebe Sayornis nigricans
Red phalarope Phalaropus fulicaria
Buller’s shearwater Puffinus bulleri
Sooty shearwater Puffinus griseus
Brown pelican Pelecanus occidentalis
Brandt’s cormorant Phalacrocorax penicillatus
Dall’s porpoise Phocoenoides dalli 

Questions of the Day 

  1. What type of data is considered ‘oceanographic’ data?
  2. What types of organisms produce chlorophyll in the ocean?

Mary Anne Pella-Donnelly, September 10, 2008

NOAA Teacher at Sea
Mary Anne Pella-Donnelly
Onboard NOAA Ship David Jordan Starr
September 8-22, 2008

Mission: Leatherback Use of Temperate Habitats (LUTH) Survey
Geographical Area: Pacific Ocean –San Francisco to San Diego
Date: September 10, 2008

Weather Data from the Bridge 
Latitude: 3737.3158 N Longitude: 12337.1670 W
Wind Direction: 234 (compass reading) SW
Wind Speed: 9.7 knots
Surface Temperature: 14.638

Deck crew setting up the mid-water net to be deployed off the back deck.
Deck crew setting up the mid-water net to be deployed off the back deck.

Science and Technology Log 

Two consistent methods of data collection on the survey include netting and collecting oceanographic data. Up to three times a day a mid-water net is carefully dropped off the back, and towed at the surface. The last two times the net has been pulled in one or two moon jellies have been caught. Each specimen is weighed and measured, then tossed back. Every evening, two hours after sunset, a bongo net is deployed off the side of the boat. With weights added, it is designed to drop as far as 300 m below the surface. Since there are two nets collecting, the scientists are able to retrieve and preserve the contents of one, to be analyzed for species composition later, and examine the second here on the boat.  This is done two hours after sunset since many organisms come much closer to the surface after dark, when their predators are less likely to find them.

Another important tool that is used to collect oceanographic data is the CTD.  This CTD has eight chambers and can collect samples from eight different water depths.  It is carefully dropped down to 500 m (or more if needed), and then a chamber is opened at intervals determined by the scientist collecting the samples. Every waking hour the temperature of the ocean is sampled using a XBT “gun” that shoots out a 760 meter long copper wire. XBT stands for Expendable Bathy thermograph. The weighted wire is kept in the ocean until a stable reading is obtained.  This gives an indication of the temperature gradient from the surface down to 760 meters in the immediate area. 

Personal Log 

Two Dall’s porpoise gliding next to the ship.
Two Dall’s porpoise gliding next to the ship.

The first 24 hours were smooth sailing through overcast but calm seas.  We have had two visits by common dolphins who have seen the boat, told their 4 or 5 best buddies, and come over to ‘ride the bow.’ They glide under the surface, leap up through the waves and glide some more.  They are having a blast. The second time was less convenient for the research, since the mid-water net could not be deployed with marine mammals in the area. And the dolphins wouldn’t leave!! So deployments had to wait 45 minutes for the dolphins to get tired and go find another playground. Yesterday a net drop deployment was almost postponed again, for a large pod of white-sided dolphins spotted behind the boat. They swam perpendicular to the ship however, and stayed a good distance away. It was estimated that there were

180 of them! That was it for yesterday. The first afternoon, we saw one humpback whale spouting and then it showed its fluke as it went under.  Another four were seen in the distance. We are all looking forward to more sightings.  The primary job that I and another ship visitor have, is to act as observers up on the flying bridge, one half hour before the net is scheduled to be dropped, and stay until the net is retrieved.  Because of the Marine Mammal Protection Act, all activity that could put these animals at risk must not be done if any marine mammals are in the area. So I sit up on the highest deck, and watch.  There is a walkie-talkie next to me, a computer set to log any sightings of interest, including jellies that float by and high-powered binoculars to scan the surface.  With snacks and beverages always handy in the mess hall, I can be quite cozy.

Animals Seen So Far 
Humpback whale Megapterea novaeangliae
Common dolphin Delphinus delphis
Pacific white-sided dolphin Lagenorhynchus olbiquidens
California Sea lion Zalophus californianus
Moon jelly Aurelia labiata
Egg yolk jelly Phacellophora camtschatica
Sooty shearwater Puffinus griseus
Buller’s Shearwater Puffinus bulleri  

We also have a few lost, confused song birds on board-who are happily eating up insects for us Western tanager Piranga ludoviciana Townsend’s warbler Dendroica townsendi 

Questions of the Day 

  1. What is the purpose of scientific names in international research?
  2. To become a marine scientist, what fields of science are required as background?