trawl – Page 19 – NOAA Teacher at Sea Blog

September 20, 2008April 2, 2021

Marilyn Frydrych, September 20, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters
Date: September 20, 2008

Weather Data from the Bridge
42.53 degrees N, 67.51 degrees W
Cloudy, wind out of the E at 11 knots
Dry Bulb Temperature: 15.2 degrees Celsius
Wet Bulb Temperature: 14.0 degrees Celsius
Waves: 1 foot
Visibility: 10 miles
Sea Surface Temperature: 16.9 degrees Celsius

Science and Technology Log

We did a CTD with an attached water bottle and then deployed a net. We backtracked today and redid the sites we found yesterday which had good herring potential. About 10:30 in the morning we collected about 1/3 of a clothesbasket of fish. Most of that were herring and mackerel, with the usual small butterfish, goosefish or lumpfish, red hake fish, small jellyfish, and Ilex squid. The catch included an unknown two inch fish which Mike, the chief scientist, conjectured had gotten caught in a warm eddy off the Gulf Stream and ended in the wrong part of the ocean much like the jet stream blows birds off course. Part of sorting the fish involved gutting one to three each of the different lengths of herring to determine their sex, age, and what they had been eating. With practice and much patience on Robert and Jacquie’s part I learned to recognize the stomach and sex organs of the fish. None of the herring today had anything in their stomachs, while those of two days ago had lots, mostly krill. With two of us working it took about 45 minutes to measure the length and weight of each herring. They varied When we finally collected the net we had 3 basketsful of redfish, half a basket of silver hake, 4 herring, one large goosefish about a foot long, and a rare Atlantic Shad about 2 feet long.

To measure our fish we used the magnetized pointer in the upper right hand corner of the picture. It looks like a cigarette. We lined up the fish’s head against the black backstop. Then we stretched the body straight out. When we pressed the pointer against the end of the fish’s body an electrical circuit closed and the computer automatically recorded the fish’s length. The fish are silver hake. — To measure our fish we used the magnetized pointer. We lined up the fish’s head against the black backstop and stretched the body straight out. When we pressed the pointer against the end of the fish’s body an electrical circuit closed and the computer automatically recorded the fish’s length. The fish are silver hake.

We froze samples which we’d opened up for Mike and then one ungutted sample from each of the nine categories for the University of Maine. We did another CTD about 11:30 and deployed the net again. All did not go well this time. The sonar showed that the net was twisted and the opening blocked. The fishermen were called upon to bring it in and straighten it. The first thing they did was to take the two 400 pound chain weights off. Then they sent the net back out hoping it would straighten itself. Alas, they had to bring it in and send it out a couple more times as they manually untangled all the lines. It was very strenuous work and took them about 45 minutes. As a result we steamed about 3 miles past the point where we intended to fish.

We’ve sorted a smaller catch on the measuring board. We measured and weighed these fish, but never opened them to determine their sex. We did that only for herring. The scale is under the gray container on the right. We only had to press a button for the computer to record the weight. — We’ve sorted a smaller catch on the measuring board. We measured and weighed these fish, but never opened them to determine their sex. We did that only for herring. The scale is under the gray container on the right. We only had to press a button for the computer to record the weight

September 18, 2008April 2, 2021

Marilyn Frydrych, September 18, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters
Date: September 18, 2008

Weather Data from the Bridge
41.27 degrees N, 70.19 degrees W
Partly Cloudy
Wind out of the W at 19 knots
Dry Bulb Temperature: 26.0 degrees Celsius
Wet Bulb Temperature: 20.9 degrees Celsius
Waves: 9 feet
Visibility: 10 miles
Sea Surface Temperature: 21.6 degrees Celsius

Science and Technology Log

We suspended operations. The seas were from 8 to 9 feet for the next day and a half. Conditions were unsafe for the fishermen to work. Everyone spent the day reading, playing board games, watching movies, or typing on the three computers provided for everyone’s use. Erin Earley, the engineer wiper, took the opportunity to show Jacquie and me the engine room. She took us through all the portals marked, “Do Not Enter”. They all had ladders under them leading to the bowels of the ship. The engine area was compartmentalized and was entered from different spots from above. Erin showed us the ubiquitous colored handles which turned the various valves on and off.

There were yellow handles for transmission oil pipes, green for seawater, orange for hydraulic fluid, red for emergency fire hose water, blue for drinking water, and brown for engine oil. We headed down under the galley where we passed next to the 12-cylinder Detroit Diesel engine which powered the screw. It was about ten times the size of a good-sized pickup engine. Erin explained the importance of placing all this heavy machinery so that the weight is evenly distributed within the ship. The engine being so heavy is usually near the center of the ship. This necessitates a huge long drive shaft connecting it to the screw. The drive shaft, spinning away at high speed, was out in the open just under and alongside the catwalk. One slip would be catastrophic. Most of what we saw was large 5’ by 5’ or larger rectangular tanks for fuel, distilled water, black water, gray water, and used oil. The black water from the toilets is stored in a tank with “bugs” or a bacteria in it which eat the refuse and in effect clean up the water. The gray water is from the sinks and showers and contains soap which kills the bugs. The gray water has to be saved in tanks separate from the black water. All this is dumped into the sea in designated areas. Only the used oil is saved to be offloaded back at the dock.

Erin Earley pointing out hydraulic fluid pipes.

We saw two workshop areas, a storeroom with all the parts that might be needed for any possible repair, an extra emergency generator, and the Engine Control Room (CERC), where Engineer Chris O’Keefe was standing watch. The CERC room contained all the gauges to monitor all the engine systems. By the end of the tour Jacquie and I were totally impressed with how clean and organized everything was and how much knowledge the engineers needed. The four of them had to be experts in heating and cooling, in welding, in diesel engine repair, in electrical repairs, and hydraulics. Each of them had either mastered these fields or was in an apprenticeship with that as their goal. Usually people master one of these fields in a lifetime. We were also impressed with how many safety features were built in everywhere. It seemed everywhere we went there were three foot CO2 bottles which would automatically spray everywhere if a fire were to occur.

Personal Log

Sleeping was difficult for me that evening. I did succumb to seasickness Friday morning, but was fine after downing a sea sickness pill. We frittered away the rest of the day. Robert Gamble, second scientist under Mike Jech, got out his game called Hive and taught three or four of us how to play. Otherwise I read, did Sudoku, rode the exercise bike, and ate.

The food was tremendously good. All of it was prepared from scratch. The two cooks were at least four star cooks. They not only cooked, they also cleaned up their own mess, did the dishes, and cleaned up the dining area. They appeared the hardest workers on board. For both lunch and dinner they prepared two entrees, three veggies, homemade soup, and two salads. They baked two luscious desserts as well. So far we have sampled lamb chops, salmon, lobster bisque, crab ravioli, pork chops with a luscious applesauce, and grilled swordfish.

September 17, 2008April 2, 2021

Marilyn Frydrych, September 17, 2008

NOAA Teacher at Sea
Marilyn Frydrych
Onboard NOAA Ship Delaware II
September 15-25, 2008

Mission: Atlantic Herring Hydroacoustic Survey
Geographical area of cruise: New England Coastal Waters

Date: September 17, 2008

Weather Data from the Bridge
41.27 degrees N, 70.19 degrees W
Partly Cloudy
Wind out of the W at 19 knots
Dry Bulb Temperature: 26.0 degrees Celsius
Wet Bulb Temperature: 20.9 degrees Celsius
Waves: 2 feet
Visibility: 10 miles
Sea Surface Temperature: 21.6 degrees Celsius

Science and Technology Log

The third day out was much like the second day. Our first job was to fish with the big net. This time the chief scientist wanted to know what some small vertical echoes on the echogram were. He guessed that they were shrimp or krill. The acoustic echogram used three frequencies: 18 kHz, 38 kHz, and 120 kHz. If dots appeared in all three then he was pretty sure it was fish and most likely herring. These particular vertical dots appeared only in the 18 kHz echogram. He guessed they were very small fish, but wanted to determine if the signature belonged to opening were huge metal doors. They looked like doors, but in fact never closed. They were actually more like the front edge of an airplane wing. Their purpose was to stay parallel to each other and keep the net open. The net was rolled up on a large roller, which sat at the center back of the fantail. It was about 250 ft long. When it was time to deploy, the fishermen used a winch to unwind the net. The person at the helm had to be extremely careful that the boat kept at a steady headway of about 3 to 4 knots. The doors were stored at the very end of the stern. With the help of their own hydraulic winches they were lifted to a spot where they could be attached to the net. There was a place on each side of the net where the side wire changed to a chain link. The metal doors were clasped on these links and then dragged into the sea. Another link in the wire was for heavy chains. Their weight of about 400 pounds each held the sides of the net down.

Fishermen setting up the recorder which is sent outwith the net. — Fishermen setting up the recorder sent outwith the net.

The night crew, on from 6:00 pm to 6:00 am were busy Wednesday night and on into the morning. They did two CTD’s and three net deployments. They left us about 50 herring and silver hake to observe in the morning. Richie Logan, one of the fishermen, used these to write a birthday note to his daughter. Here’s his picture. Each time we sent out a net we were hoping for about half a clothes basketful of fish. Last night they filled 30 baskets. Only about 1/3 of a basket is ever measured and weighed. The rest are tossed back. Our chief scientist said he can remember processing enough to fill 60 baskets. So far most of the biomass in the basket has been krill. Mixed in with the krill are small anthropoids maybe a half inch square, jelly fish about twice that size, Illex squid from 2 to 6 inches long, baby silver hake, butterfish, or red hake. These last three are all in the neighborhood of 1 inch long.

This morning we pulled up a lamprey eel about 2 feet long and a couple two inch lumpfish in the evening. Most of the fish were dead when we got to them. We had to wait until the fishermen were totally finished with winding the net and had dumped the net’s contents onto the deck before we were allowed on the fantail. Then we sorted the large fish into clothes baskets and the smaller ones into small trays. Wednesday Jacquie Ostrom, another volunteer from Colorado Springs, noticed that two 3-inch lumpfish were moving. She added some water to our rectangular sorting pan and a piece of clear hard plastic we had thought was some molt or litter also started to move. No one seemed to know what the “plastic” was. After a quick reference to the Internet we learned it was the larva of the spiny lobster.

Richie Logan making a Happy Birthday email for his daughter.

Personal Log

We must have passed by the north-south migration path of the whales. We didn’t spot any today. The work load is really light compared with teaching. We work two or three hours cataloguing the catch after each trawl, clean up with the saltwater deck hose, and then wait for the next trawl maybe three or four hours later. A 20 minute CTD deployment every now and then is the only other work we are expected to do. The cruise is turning out to be very relaxing. I spend quite a bit of time just staring out at the sea, immersing myself in its gentle rhythm.

Seven basketsful of herring from a haul in the deep waters near Georges Bank.

The piece of “plastic” turned out to be the larva of a spiny lobster.

June 7, 2008April 2, 2021

Sue White, June 7, 2008

NOAA Teacher at Sea
Terry Welch
Onboard NOAA Ship David Starr Jordan
May 27 – June 7, 2008

Mission: Juvenile Rockfish Assessment
Geographical Area: Central California Coast
Date: June 7, 2008

Weather Data from the Bridge for Sat. 06-07-08 19:00 GMT

The DAVID STARR JORDAN Deck crew watches from the bow

Science and Technology Log

Heading for San Francisco!

The weather has again had an effect on the scheduled research tasks. As the week went on the weather deteriorated so that some nights we could only do one trawl before the waves crashing over the aft deck made it too dangerous to be out there. Safety was the primary issue in everyone’s mind on the ship – bridge officers and the scientists discussed weather conditions and forecasts and the deck crew were careful to point out safety concerns involving equipment or wearing protective clothing. Even with the ship feeling like it was doing a wild tango at one point, I felt very secure. Last night was a complete wash as far as doing the scheduled work. By evening the ship officers decided to stay out the night in Drake’s Bay since the peninsula would give some shelter from the wind and waves. We used the time to prepare for a new group to come aboard in San Francisco, cleaning our staterooms and doing laundry.

I sorted through notes and organized the dozens of photos taken over the last 12 days. Here are some squid facts Ken Baltz, the cruise leader told me about earlier in the cruise:

The Humboldt squid we caught were probably around 5 months old and will only live about 1 year
These squid are one of the fastest growing organism
They have a very rapid metabolism, eating about 20% of their body weight daily vs. our human requirement of 0.5 to 1%

Keith not only can tell you the scientific name of this big cephalopod, he can identify an incredible number of ocean animals

The bongo plankton tow ties in with the squid sampling in an interesting way. It shows how all of the research coordinated on the DAVID STARR JORDAN this cruise (and really all NOAA projects) is working towards understanding what life is like in the ocean and how the distribution of organisms is changing. One plankton sample from each bongo tow was preserved in ethanol. The other sample was preserved in formalin (a formaldehyde solution). The rationale behind this was that formalin denatures or destroys the structure of an organism’s DNA. The ethanol sample could be used to do genetic testing. When the samples are examined back in the lab, the researchers are hoping to find paralarvae of the Humboldt squid in the same location as the adults collected this cruise. This would give credence to the idea that they are now breeding off the coast of California, rather than in the tropics as has been the accepted understanding. Bill and Robert (two of the volunteers on this leg of the cruise) had great questions while Ken was explaining this part of his research. Bill (and the others) had been using a fluorescent lure to “jig” for squid. Squid are attracted to the bioluminescence found in some ocean animals, like the “headlights” on a California Headlight fish.

NOAA Teacher at Sea Sue White shows how gripping life at sea can be.

He asked if the squid are caught in the nets because they are hoping to feed on the small fish being concentrated there. His hypothesis was to see if luminescent lures in the net would increase the number of squid caught. Robert asked about using radioactive isotopes to label squid and then look for the radioactive label in the paralarvae as a way to see patterns in breeding. Such intriguing thinking. I was not alone in wanting to be awake for our entry into San Francisco Bay. We enjoyed a hot breakfast for the first time in days (and for some the first time ever on the ship!) and were invigorated by bright sunshine. Well, the sun seemed bright through the San Francisco haze after being on the night shift! Everyone was outside by the time land was sighted and we enjoyed watching the Golden Gate Bridge get closer. For days I had not noticed much traffic at sea (especially at night) so it felt like driving into a major city in that the traffic kept increasing the closer we got to the Bay. Huge shipping barges and small personal sailboats were all out on a beautiful Saturday morning.

The map distance from Drake’s Bay was not far, but our speed entering the bay was such that it took several hours to get around the bend and in to where the piers are in San Francisco. Just as in leaving San Diego, the ship officers were busy piloting the ship to its place at the pier. Staff from the Santa Cruz lab were waiting to help offload specimens, some ship personnel were already off duty and looking forward to a day in the city, and my husband was patiently waiting on the pier to hear my stories of life at sea.

Personal Log

After almost two weeks at sea it was interesting to adjust to life on land. I did feel the ground moving as I walked and especially felt phantom ocean waves when I tried to sleep or take a shower (no grab bars to steady yourself on land though!). The sounds were so different too with less of the ongoing sound of the ship engine or the air system in my stateroom and more collective noise of traffic and airplanes. I had missed the simple sounds of my backyard birds, but did not notice this until I realized how wonderful the familiar can sound. I am brimming with new information and connections to make with classroom labs and activities. I (and my husband) can hardly wait until school starts so I have a new audience for my Teacher at Sea stories.

Challenge Yourself

Think about the area where you live. How many people in your neighborhood can you name? List the types of dogs that live in your neighborhood, too.
Name any of the birds that may fly into your area. (Is this naming business getting harder?)
Name any other wildlife that may inhabit your neighborhood. (Remember that wildlife can be small and not all will be mammals!)
How many insects can you identify? Can you name specific types of one kind of insect? In other words, can you tell the difference between a monarch and swallowtail butterfly? What about a skipper and a sulfur butterfly?
Scientists, from experience, can name an incredible number of organisms. Often they can even give the scientific name for exactly one species that differs only slightly from another. You can also increase your naming ability with practice… what would you like to become an expert in identifying???

A unique view below the Golden Gate Bridge

“We can only sense that in the deep and turbulent recesses of the sea are hidden mysteries far greater than any we have solved.” ~Rachel Carson

What mysteries will I see next?

Sue

June 1, 2008April 2, 2021

Sue White, June 1, 2008

NOAA Teacher at Sea
Terry Welch
Onboard NOAA Ship David Starr Jordan
May 27 – June 7, 2008

Mission: Juvenile Rockfish Assessment
Geographical Area: Central California Coast
Date: June 1, 2008

Weather Data from the Bridge for Sun. 06-01-08 04:00 GMT

Joao Alves treats us to squid and salsa, Brazilian style.

Science and Technology Log

It’s shrimp night! We continue on up the coast of California. The transect schedule for tonight is off Point Reyes, north of San Francisco. The catch tonight surprised us (again) by being completely unique from earlier trawls. Usually the largest part of what we sort is krill. The first night it was very strange to see all of those eyes, but now the krill just seem like background to look past as you see other colors and textures. When we spread the catch out on our trays tonight, it was an orange pink instead of the typical brownish color. The nets were loaded with market shrimp! Joao took off with some after we sorted and came back later with boiled shrimp and cocktail sauce. This was the second time he had acted as a seafood chef for everyone. Friday night Joao brought down the squid he had saved from Tuesday and Wednesday night. He had been marinating it in his special recipe and spent the time before his shift sautéing squid strips for us. He had also made some salsa that was perfect with it . . . and the saltine crackers some of us were needing tonight due to the waves. It brought to mind this passage from John Steinbeck’s introduction to The Log from the Sea of Cortez: “…we could see the fish alive and swimming, feel it plunge against the lines, drag it threshing over the rail, and even finally eat it.”

Vlad Zgutnitski, Sam Brandal, and Jose' Coito ready to do a trawl — Vlad Zgutnitski, Sam Brandal, and Jose’ Coito ready to do a trawl

We have a pattern down for the nights now. The scientists, deck crew and bridge are seamless in their coordination of a trawl. Everyone knows their job now and down to who turns the deck lights off once the nets are in the water seems to be done intuitively. As soon as the nets are brought in, the sorting starts. Big fish, or worse the big jellyfish, are caught as the nets are being rolled up. Some fish and the jellies are measured and added to a database by location. Jellyfish are especially hard on the nets because of their weight. If they become too plentiful, trawls can be cancelled to keep the nets from being destroyed.

Looking for rockfish - Gabe, Ben, Keith, Bill, and Robert (left to right) — Looking for rockfish – Gabe, Ben, Keith, Bill, and
Robert (left to right)

Here is my count from one tray of catch tonight:

38 Myctophid (fish)
22 Californian Headlight (fish)
8 Sergestid ( tiny red dot shrimp)
5 Black Smelt (fish)
3 Black-tip (squid)
1 Blue Lantern (fish)
1 Gonatus (squid)

The fish are more familiar by now. The Myctophid and Headlight fish looked so similar at first, but now I can see the two bioluminescent dots between the eyes on the Headlight fish. With more experience, it became even more obvious that there were many differences differences, but harder when they are hidden behind the more generic krill, or in the case of tonight’s haul, the pinkish shrimp. The rockfish (Fig. 4) also have to been identified as separate from other fish also similar in size and color. Side by side it is easy to see that these fish that are both dark in color.

Personal Log

The waves just keep getting rougher as the cruise progresses. The motion onboard varies with different activities. The bars to grasp in the shower and at various places around the ship are very practical, to say the least. Sleep is an interesting process where you can wake up with tired muscles from trying to keep yourself in place! Those with more experience have said that it is physically tiring to be onboard and that we should expect to need more sleep. It is amazing how I have adjusted to sleeping during the day now. The volunteers have been great to work with. They are now bringing their music down to play as we sort the catch from each trawl.

Unsorted catch (krill, Sergestid shrimp, fish, squid)

It is fun to hear the eclectic playlists they have. I have also been impressed with how well-read they are. We have been able to talk about books that range from Steinbeck to environmental awareness. They also enjoy the oddities we find on our sorting trays… anything with suckers must be stuck on your finger to see how long it will hold on (little squid or octopi require peeling off!) One night we had double tailed fish. Somehow several of the fish that night managed to get one head caught in the other’s to the point that it looked like the head was in the center with a tail going off each side.

Challenge Yourself

Look at Figure 6 above. How many different types of animals do you see? (Hint: Different colors are easy to spot, but also look for different eyes since some of the animals we found were transparent! )
Can you find any animals that are not fish? We found tiny squid and octopi most nights. Squid tended to have really big eyes for their overall size. Most of what you see in Figure 2 is krill.
Describe what makes the juvenile rockfish different from the sand dab shown above.

“We can only sense that in the deep and turbulent recesses of the sea are hidden mysteries far greater than any we have solved.” ~Rachel Carson

What mysteries will I see next?

Sue