rockfish survey – NOAA Teacher at Sea Blog

NOAA Teacher at Sea

Charlotte Sutton

Aboard NOAA Ship Reuben Lasker

June 7 – June 18, 2024

Mission: Rockfish Recruitment and Ecosystem Assessment Survey (RREAS)

Geographic Area of Cruise: Pacific Ocean; U.S. West Coast

Date: June 11th, 2024

Weather Data from the Bridge

Date: Tuesday, June 11, 2024
Latitude: 35.42 °N
Longitude: 121.22 °W
Sea Wave Height: 4-5 ft
Wind Speed: 4 knots
Air Temperature: 57 ° F
Sky: Foggy / light rain

Science Log

Arriving on the Lasker

We’re off! After landing in San Francisco and driving down to Santa Cruz, I arrived on the NOAA Ship Reuben Lasker by way of small boat transfer. The Lasker was anchored in Monterey Bay, and sent a small boat to pick up myself and some of the science team and crew to be taken aboard. We boarded the small boat, the “RL-2 Shark,” then traveled to the side of the Lasker where we were hoisted up via a winch. I then got a full tour around the ship, and the opportunity to meet many people who work on the Lasker, including members of the science team, NOAA Corps, and Lasker crew.

Teacher at Sea Charlotte Sutton poses for a photo on board the small boat RL-2 Shark. She's wearing a life vest and a hard hat and holding in her hands a jacket with neon yellow reflective coloring. Behind the small boat, we can see the Santa Cruz harbor. — Charlotte boards the RL-2 Shark in Santa Cruz

a view up the portside of NOAA Ship Reuben Lasker, facing the aft deck, as seen from the small boat the water's surface. Winch cables and a frame have been lowered off the side of the large vessel. We can see a davit arm toward the aft. — Charlotte boards the RL-2 Shark in Santa Cruz

The Night Shift

Running a ship like the Lasker is a 24-hour-a-day operation. At all times there are some groups of people sleeping and others who are working. The majority of the science crew works at night, so my day typically begins with dinner at 5:00 pm and then working with the science team from approximately 9:30 pm until 6:30 am. As a morning person this was very difficult at first! But after two nights working, I’m finally adjusting to our new schedule.

What is the Goal of the Survey?

The main scientific focus of the upcoming mission is the Rockfish Recruitment and Ecosystem Assessment Survey (RREAS). This survey has been conducted since 1983, and collects data on rockfish and other organisms in their ecosystem.

Rockfish are a very important fish commercially and recreationally in California and on the West Coast. One of the primary purposes of the survey is to use the data collected to help provide additional information about the management of commercial and recreational fisheries off the west coast.

CTD Operations

On the ship's deck at night, a man stands facing away from the camera, looking down a large apparatus nearly the height of his shoulder. Inside a round metal frame are gray cannisters arranged in a circle (the "rosette"), surrounding a scientific probe mounted in the center. A cable extends from the top of the appartus out of sight. The man wears a hard hat, a life vest, and sunglasses and grasps a gray rope looped through a rung of the rosette. Another man, also wearing life vest and hard hat, is seen at a distance beyond the apparatus. It's nighttime. — CTD rosette, ready to be deployed into the ocean.

I began my first night shift by observing a CTD deployment. CTDs are instruments that measure Conductivity, Temperature and Depth (CTD). CTD measurements are conducted approximately 5-6 times a day, and twice at night. The CTD descends down into the ocean to a depth of up to 500 m . There are other instruments and sensors attached to the CTD that measure things like chlorophyll levels and oxygen levels. The data taken from the water column serves as a foundation for scientists to understand the ocean environment.

All of the CTD data, and all the data that the Lasker collects, is free and available to the public.

Trawling

a hand-drawn diagram of a trawl net in two positions: net while fishing (on top) and net deployment and retrieval (bottom.) The lines are all labeled: we see the headrope (with buoys) at the top of the net, the footrope (small buoys) at the base of the opening, the bridle lines, door leg and transfer lines, the doors, and lines "to trawl winch" and net "to cod end." — Hand-drawn diagram of trawl net, courtesy of scientist Tanya Rogers.

When do we trawl?

The reason the science team trawls at night because there is net avoidance during the daytime, meaning the fish will see the net coming during the day and swim away from it. Other creatures migrate towards the surface at night. In a pattern called vertical migration, these mesopelagic species migrate to shallow waters to feed during the night, while spending day hours at depth.

Having more diverse species to study is useful for the Rockfish Recruitment and Ecosystem Assessment Survey (RREAS). The more data that is collected on rockfish and other species helps scientists to better understand the heath of different fish species, and make predictions and assessments of ocean trends.

How does trawling work?

Each night, the Lasker crew, NOAA corps officers, and science team work together to trawl for different fish species.

“Trawls, which are nets towed behind a boat to collect organisms, have been used by fishers for centuries. Trawls can be divided into three categories based on where they sample the water column: surface, midwater, and bottom.” (NOAA Ocean Exploration)

In our Rockfish Recruitment and Ecosystem Assessment Survey, the science team conducts midwater trawls, at approximately 30m depth to target the fish and other ocean organisms that are targeted for the study.

The last few days we’ve averaged 5 trawls per night. The process begins by deploying the trawling net behind the ship into the midwater section of the water column, and trawling for fish for either 5 or 15 min. After the net is brought in, the contents of the trawl are sorted, measured, and recorded by the science team. This data will be later analyzed to help better understand the ocean ecosystem.

Charlotte stands at a large white bin, about three feet long, containing a pile of small silver-colored fish. She uses two hands to hold up a plastic pitcher filled with a sample of the fish - two other empty pitches rest in the bin. Charlotte wears a coat, orange grundens (fishing overalls), long orange gloves, and her Teacher at Sea beanie hat. — Teacher at Sea Charlotte with the catch of a trawl.

Six people stand three to a side along a long metal table and face the camera for a photo. They are wearing heavy fishing overalls and long orange gloves, and each grasps a pair of tweezers in one hand. On the metal table, white plastic trays contain subsets of the catch; in the foregroud, two of these plastic trays contain organisms that have already been sorted and neatly arranged. — The science team sort fish and other organisms from the trawl.

Personal Log

NOAA Ship Reuben Lasker: My New Home at Sea

NOAA Ship Reuben Lasker (photo courtesy of NOAA)

My new home for my time at sea is the NOAA Ship Reuben Lasker. The Lasker is a NOAA fisheries vessel, with a home port located in San Diego, CA.

“The ship’s primary objective is to support fish, marine mammal, seabird and turtle surveys off the U.S. West Coast and in the eastern tropical Pacific Ocean” (NOAA Office of Marine and Aviation Operations).

During my time at sea, the Lasker will be sailing off the coast of California, sailing out of Santa Cruz and back into port in San Diego.

Living on the ship reminds me a lot of my college dorm room. On the ship most people have roommates, and we all have shared spaces like the mess (cafeteria), science labs, outside decks and places to relax. Everyone aboard the ship has been extremely welcoming and kind, always answering any questions I might have and teaching me about life aboard a ship. I am happy to call the Lasker home over my trip at sea!

a bulletin board housed in a case with sliding glass doors, titled OUR CREW. The background of the display is a nautical chart of the California coast around the Channel Islands, though it is mostly obscured. Photos of the crew members are cut out and pinned all over the chart. There's also a magazine article about Reuben Lasker, the ship's namesake. — There are three major teams working and living as a cohesive unit aboard the *Lasker*. The *Reuben Lasker* crew, NOAA science team, and NOAA Corps officers each have distinct roles and work together each day to accomplish various science projects.

view of a sunset over a calm sea — Sunset aboard the *Lasker*.

Did you know?

Adjusting to working the night shift (approximately 9:00 pm – 7:00 am) as a typical morning person has meant sleep is often on my mind. Chatting before our second night shift, scientist Ily Iglesias shared with me how dolphins sleep. Both dolphins and whales sleep much differently than most mammals. Known as unihemispheric sleep, dolphins

“only rest half of their brain while the other half stays awake to breathe. Also, most whale and dolphin respiratory and digestive tracts are completely separate, so they don’t get water in their lungs when feeding underwater.” (NOAA Fisheries).

NOAA Teacher at Sea

Kimberly Godfrey

Aboard NOAA Ship Reuben Lasker

May 31 – June 11, 2018

Mission: Rockfish recruitment and ecosystem assessment survey

Geographic Range: California Coast

Date: June 10, 2018

Data from the Bridge

Latitude: 36° 39.980′ N

Longitude: 122° 33.640′ W

Wind: 30.87 Knots from the SE

Air Temperature: 12° C

Waves: 2-3 feet with 6-8 foot swells

Science Log

As you may have gathered from my previous blogs, I spent my time working with the night scientists. However, there was a lot happening during the daylight hours that I would like to highlight. There was a separate team assigned to the day shift. Some of their tasks included analyzing water samples, fishing, and surveying marine mammals and seabirds.

Catching fish during the day allowed them to see what prey were available to diurnal predators, and they could also compare their daytime catch to the evening catches. They used a different net called a MIK Net, which is a smaller net used for catching smaller and younger fish.

MIK Net — The MIK net used by the day time scientists to catch juvenile fish.

The day shift is also the best time for spotting seabirds and marine mammals. Some of the bird species spotted included brown pelican, common murre, terns, black-footed albatross, shearwaters, and at least 1 brown booby. The marine mammals we spotted included humpback whales, fin whales, blue whales, common dolphins, and sea lions.

I had an opportunity to speak with Whitney Friedman, a postdoctoral researcher with NOAA, and she explained to me some of the goals of their marine mammal survey. Many may recall that there was a time when whale populations, especially humpback whales, were in significant decline. Today, humpback whales are considered a success story because of rebounded populations. The concern now is monitoring the success of their food sources. Humpback whales feed on krill and fish like anchovies. However, it is possible that when these sources are less available or as competition increases, they may feed on something else. The question is, what is that something else? During this survey, one goal was to collect whale scat for analysis. Studies have found that some seabirds feed on juvenile salmon incidentally when their preferred local prey is limited, and they move inshore to feed on anchovy. Is it possible that whales might do the same? What else might they be foraging on? Unfortunately, we did not have much luck catching whale scat this time around, but they will try again in the future, and hopefully will find the answers they are looking for.

As previously mentioned, we also did water quality tests and took water samples using the Conductivity, Temperature, and Depth (CTD) Rosette. This instrument has multiple functions. As the initials suggest, it detects conductivity (the measure of how well a solution conducts electricity) and temperature at any given depth. Salinity (the amount of dissolved salts and other minerals) and conductivity are directly related. By knowing the salinity and temperature, one can determine the density. Density is one of the key factors that drives the ocean currents. Many species depend on the ocean currents to bring in nutrients and food. It all comes full circle.

CTD Rosette used to capture conductivity, temperature, and depth. We also used this to take water samples at specified depths.

The CTD is lowered into the water by a winch with the assistance of the deck crew.

When we lowered the CTD we could also take water samples at any given depth. This allowed scientist to test for various parameters. For example, we filtered various water samples to determine the amount of chlorophyll at certain depths. This can help scientists estimate the growth rates of algae, which in the open ocean are called phytoplankton. One of the scientists collected water to analyze for environmental DNA (eDNA). This is DNA that might be left in the air, soil, or water from feces, mucus, or even shed skin of an organism. In her case, she was trying to find a way to analyze the water samples for sea turtle DNA.

I’ve heard of eDNA, but I have never actually understood how they collected and analyzed samples for this information. My understanding is that it can be used to detect at least the presence of an extant species. However, when collecting these samples, it is likely to find more than one species. Scientists can use previously determined DNA libraries to compare to the DNA found in their samples.

Personal Log

We started trawling again on the evening of June 7^th. By then we settled ourselves into the protection of the Monterey Bay due to the weather getting bad. While we still had some off-shore stations, we tried our best to stay close to the bay because of the wind and swells. We had some interesting and challenging trawls in this area: lots of jellyfish. Some of the trawls were so full we had to actually drop the catch and abort the trawl. If not, we risked tearing the net. We tried to mitigate the overwhelming presence of jellies by reducing our trawls to 5 minutes instead of 15 minutes, and we still had similar results. One night, we had to cancel the final trawl to sew up the net. I’ve been told that sewing a fish net is an art form. Our deck hands and lead fisherman knew exactly what to do.

Let me tell you my experience with jellyfish during the survey. As you may recall, someone must be on watch for marine mammals on the bridge. This is the ship’s control room that sits on the 5^th level above water.

The Bridge of the *Reuben Lasker* is where we do inside Marine Mammal Watch. This is where the main controls of the ship are located.

From here you can see the surface of the water quite well, which makes it a great spot for the marine mammal watch. It was also great for watching hundreds of moon jellies and sea nettles float right by. It was one of the coolest things to watch. It was somewhat peaceful, especially hanging your head out of the window, the cool air blowing against your face, and the occasional mist of sea spray as the ship’s hull crashes against some of the larger swells. However, that same peaceful state disappears the moment you realize, “I’m gonna have to lift, count, and sort all those jellies!” I wasn’t too concerned about being stung; we had gloves for the sea nettles and the moon jellies were no real threat. However, the sea nettles (Chrysaora fuscenscens) smelled AWFUL, and the moon jellies (Aurelia spp.) are quite large and heavy. I’m honestly not sure how much they weighed; we did measure up to 20 per haul, some of them measuring over 400 mm. Even if they weighed about 5 pounds, lifting 50-60 of them consecutively until the count is complete is enough to get the muscles burning and the heart rate elevated. It was a workout to say the least. I was literally elbows deep in jellyfish. I also wore my hair in a ponytail most of the time. Anyone that knows me knows well enough that my hair is long, and definitely spent some time dipping into the gelatinous goop. I smelled so bad! HAHAHAHA! Nonetheless, it was still one of the most intriguing experiences I’ve had. Even though the jelly hauls proved to be hard work, I enjoyed it.

In those last few days, I felt like I became integrated into the team of scientists, and I felt comfortable with living out at sea. I had a few moments of nausea, but never really got sea sick. I still couldn’t walk straight when the ship rocked, but even the experts wobbled when the ship hit the big swells. Then, that was it for me. By the time I got the hang of it all, it was time to leave. I wish there were more hours in the day, so I could have experienced more of the day time activities, but I still got to see more than I thought I would, and for that I am grateful.

Did you know…

NOAA offers many career options. As a scientist, here are some things one might study:

track and forecast severe storms like hurricanes and tornadoes; monitor global weather and climatic patterns
Research coastal ecosystems to determine their health, to monitor fish populations, and to create policies that promote sustainable fisheries
Charting coastal regions and gathering navigational data to protect the ship from entering unsafe waters

NOAA Corps allows one to serve as a uniformed officer, commanding a ship or piloting aircraft. On NOAA Ships, they need engineers, technicians, IT specialists, deck hands, fishermen, and even cooks (The Reuben Lasker had two of the best, Kathy (Chief Steward) and Susan (second cook)). There are many opportunities available through NOAA, and there is a longer list of amazing experiences one can have working for this organization. If you want to explore in more detail, visit http://www.careers.noaa.gov/index.html

Tag: rockfish survey

Charlotte Sutton: Learning the Lasker, June 11, 2024

Kimberly Godfrey: Night time..Day time! June 10, 2018