Fishing nets like the ones used on the NOAA Ship Oscar Dyson or on commercial fishing boats can be very expensive. If one plans on doing a bottom trawl (fishing with a net that goes down to the sea floor) one wants to make sure that there are not rocks or other things that can snag or tear the net. If there are too many rocks or boulders or uneven topography, the area is considered “untrawlable”. While computer imagery can provide some guidance with regard to what lies deep beneath the surface, scientists onboard the NOAA Ship Oscar Dyson are hoping that video images taken with an underwater camera can provide a more complete picture and be the basis for a more precise computer model of what areas are in fact untrawlable.
Why is this important? Scientists onboard the NOAA Ship Oscar Dyson are surveying the fish that live in the middle of the water column. However, groundfish surveys need to account for all the fish living on the ocean floor. If the groundfish program can’t trawl in certain areas, then they don’t know what is there. For example, rockfish often live in untrawlable areas. If a groundfish survey can’t put a net in areas where rockfish live, then they won’t really “count” the correct numbers of rockfish in their survey. Data obtained using an underwater camera can help determine what species of rockfish are being underrepresented by the groundfish program.
One of the many perks of being on the 4 p.m. to 4 a.m. shift is that I get to watch the drop camera in action! The camera (with its attached light) is slowly lowered to the sea floor.
The drop camera
I have seen the camera take 4 minutes to reach the bottom or as long as 8 minutes depending upon the depth of the water being surveyed. The camera is then “driven” along the bottom (or right above it) for 15 minutes via a control box on the boat (similar to a tiny joystick). I even got to drive it a few times!
My turn to drive!
The images are recorded and also seen in real time on several computer screens on the boat. We have seen rocks, of course, but also jellyfish, sea whips, crabs, anemones, octopuses, sea stars, and a wide variety of fish. One night, there were thousands of sand dollars. It looked like we had come across a buried treasure! It is fascinating to see what is happening deep beneath the boat. It’s kind of like virtual scuba diving!
Sand dollars and brittle stars
Tiger Rockfish
Flatfish
Giant Pacific Octopus
ANOTHER Giant Pacific Octopus!
Kelp Greenling
Quillback
Drop Camera Elementary School Math Fun
If the stereo drop camera takes 8 minutes to reach the bottom when the water is 200 meters deep, how long might it take to reach the bottom if it was:
100 meters
deep? ____________
50 meters
deep? ______________
300 meters
deep? _____________
Personal Log
It’s time to come clean and admit that I suffer from Pareidola. Don’t worry, it’s not contagious, or even dangerous. In fact, I think it’s a lot of fun. You see, Pareidola is a psychological phenomenon where you see patterns. Quite often, people with Pareidola will see faces in objects where there really isn’t one, like on an electrical outlet.
Electrical outlets… do you think they look like faces?
My Pareidola
has reached a new level on the NOAA Ship Oscar Dyson as I am seeing not
just faces but ROBOTS like these:
Robot!
Robot!
Let me
know if you see any robots at your house, and I am on the lookout for more
here!
Mission: Sea Scallop Survey Geographic Area of Cruise: Northeast Atlantic Ocean Date: June 14, 2017
Weather Data from the Bridge Latitude: 41 31.54 N
Longitude: 70 40.49 W
Wind Speed 10 Knots (11.5 mph)
Air Temp 20.2 C (68.4 Fahrenheit)
Science and Technology Log
Contrary to the popular Rolling Stones song “Time is on my Side,” time is not on our side while we are taking survey of the scallop population in the Northeast Atlantic Ocean. This survey has been meticulously planned for months leading up to the actually event. There is no time budgeted to sit at a dredge station longer than you have to.
The Nobeltec Cruise Track for the 2nd and 3rd legs of the 2017 Scallop Survey. You can see this survey has covered 1000’s of nautical miles, and stopped at over 100 dredge stations.
For seven days our noon to midnight science crew has been working at a blistering pace to dredge the ocean floor or take pictures with the underwater camera, HabCam. We are on a tight schedule, and in a twelve hour period we are able to work through 10 dredge stations. There has been little down time, and because some of the dredge stations are so close together, there is no time to be unproductive while we are at a station. Because of this, there are often stations where we simply are not able to individually count all the organisms we collect. There are many situations where our crew must use the method of subsampling.
For you in the Midwest, imagine you wanted to know how many dandelions were in your yard. Now if you are anything like me, you have way too many to count. If you went to count them all individually, it would literally take you all day if not more. It is just not time efficient to do such a thing. But if we took a population sample of some random areas in the yard, we could come up with an answer of how many dandelions were in the yard, and get a very close answer to actually counting them individually.
A similar example I can give you is with a recent dredge catch that was full of sand dollars. In one of our massive dredge catches composed of about 99.5% sand dollars, I completed an estimate sand dollars in a similar manner. I filled 2 liter pail full of sand dollars. My count for that pail was 188 sand dollars per 2 liters. In this catch we had 46 baskets each with a volume of 46 liters. So at 94 sand dollars per liter with there being 2,116 liters total, you can estimate there are about 198,904 sand dollars in that dredge catch.
A dredge catch that was almost 100% sand dollars. These sand dollars are dripping with a green algae and cover our buckets and wet gear in a green coating.
We are faced with similar tasks while sorting through the dredge. When we face those situations, we turn to the method of sampling, and we take a representative sample of our catch. At most stations we are taking count of sea stars, crabs, waved whelks, all fish, and scallops. When we collect the dredge, most of the time it would not be time efficient to totally count up all the sea stars, so we turn to subsampling.
Here’s how subsampling works. Once we have sorted our dredge catch into various pails, we count up our specimens. For sea stars however we always take a subsample. To do that our watch-chief takes a scoop full of whatever is in our discard pails, and she does this randomly. She puts the random sample in a 4.5 liter pail. From here, she can begin to estimate the number of sea stars in our dredge catch. For example, if she goes through the 4.5 liter pail and finds six sea stars, and she knows there are four 46 liter pails of discard from the dredge, with a little math work she can figure out how many stars are in the dredge. If there are four 46 liter pails of discard, then there is a total of 186 liters of discard. She knows from her random sample that there are 6 sea stars per 4.5 liters which would come out to 1.3 sea stars per liter. By multiplying that number by 186, you can determine that an expanded estimate for the sea stars in the dredge collection would be 242 sea stars.
An example of our discard baskets from our dredge catches. This catch was sea star heavy, and this shows it would have taken too much time to count each sea star individually. Since many sea stars are predators of scallops, a count needs to be recorded.
We also use this method when we have a large catch of scallops. When we have an overly large scallop catch on the dredge, we are not able to count and measure every single scallop from the catch. In these cases we use a representative amount. In one case we caught 24 baskets of scallops, each basket able to hold 46 liters. If we were to measure all of those scallops we would be at that station far too long to move onto the next dredge. When we caught enough scallops to fill 24 baskets, we used 3 baskets of scallops as a representative amount. All of the scallops in the 3 baskets were measured for their shell height. We would then take a mean average from these scallops to represent the 21 other baskets. We are also able to estimate the number of scallops in the 24 baskets the same way I estimated the number of sand dollars in a dredge catch.
A large catch of scallops from one of our dredge stations. In this case a representative sample of shell heights was taken.
Representative samples and population estimations through sampling are valuable tools that scientists use to collect a lot of data in a more efficient amount of time. From this data, mathematical models and predictions are developed. By implementing these methods, we are able to get more data from more locations.
Personal Log
It has been 9 days since I arrived in Woods Hole, Massachusetts to be a part of this journey. As I shared in my last blog, it is hard to be away from home, but many of the people here are gone more than 100 days per year. There is one thing that makes that time away easier….eating! Here on the Hugh R. Sharp, I would imagine I’ve put on some extra pounds. Most days I feel like a cow grazing. There are so many snacks on board, that it is so easy just to walk by the galley and grab a mini candy bar, chips, pop, or ice cream. I have discovered there is no better candy bar than a Baby Ruth. On top of the snacks and sweets, the cook, Paul, cooks up some mean dinners. Though I miss my wife’s home cooking, Paul’s cooking is a good substitute.
Lots of candy and snacks and some good dinners is probably leading to some extra poundage! There are two drawers always full of candy, and a freezer always full of ice cream. Pictured on the left is the ship’s cook, Paul.
Outside of eating, there is not much recreational time on the ship. I do try to get up a couple hours before our shift begins to just enjoy being out on the ocean. I haven’t been able to make myself get up yet for sunrise at 5:05 AM. After working a twelve hour shift sorting dredge catches, there’s not much you want to do but sleep. Sleeping on the boat has been good. Probably some of the deepest sleep I’ve had since our kids were born. I’ve gotten used to the motion of the boat, the sound of waves hitting the bow, and the boat stabilizers which sound like a giant snoring. I’m a sleep walker, so that was a concern coming in that I would find myself on deck, sleep walking. But I’m sleeping so sound, I don’t think it’s possible. However I did warn my roommates to stop me if they saw me up in the middle of the night.
Part B of the survey has started, and with that most of my crew got off the ship, and I will have a new crew starting today. It was a great group of people to work with.
Part A of the survey the day crew from left to right: Crew chief Nicole, myself, Dylan, Sue, and Nancy. Then the night crew of Lauren, John, Jill, Han, and crew chief Mike.
Did You Know?
Living in Illinois, there are not many times where knowing your parts of a ship come in handy. However, as I have been living on the Hugh R. Sharp for over a week now I have picked up some terms. I did not know many of these coming on, so this is a “Did you know?” moment for me.
Front of the ship: bow
Back of the ship: stern
Moving to the front of the ship: forward
Moving to the back of the ship: aft
The left of this picture is port, and the right is starboard. It took me awhile to figure out what our turn would be like if we were making a turn to starboard.
If you were on the bow, your left would be the: port
If you were on the bow, your right would be the: starboard
Fathom: 6 feet
A heading of zero: North, a heading of 90: East, a heading of 180: South, a heading of 270: West
Heading to a location quickly: steam
Kitchen (where I constantly graze in between dredge stations): galley
Location of the ship’s navigational equipment is: bridge
Bathrooms: the head
NOAA Teacher at Sea Janet Nelson Huewe Aboard R/V Hugh R. Sharp June 13 – 25, 2012
Mission: Sea Scallop Survey Geographic Area: North Atlantic Monday, June 25, 2012
Weather Data from the Bridge: Latitude: 41 24.21 North
Longitude: 069 54.98 West
Wind Speed: 13.7 kt
Air Temperature: 17 C
Final Log:
We are steaming for home. Woods Hole, MA that is. In the past ten days we have conducted 71 scallop dredge tows and processed 15, 979 scallops. We also took over 4 million images with the HabCam in 691 nautical miles of this leg. We have been a little busy.
A tow of scallops
This morning (0600 hrs.) we mustered in the dry lab and began our assignments, ranging from swabbing the decks to vacuuming our state rooms. Tonight I will be in Boston and then on my way back to Minnesota. I am ready to go home, but I know I will think back fondly on a few things. The rocking of the boat when I’m going to sleep. Meals prepared for me. The sound of waves and water. The hum of the engines. Seeing what comes up in the scallop dredge. Being on deck and on the bridge. A hap chance at seeing whales or dolphins. New friends and fun banter. Even though this journey began with an unpleasant introduction, it is ending with fond feelings.
Me and a barn door skate!
Being on this boat has been interesting for several reasons. I have learned new things about ocean life that I can take back to my classroom as well as a few souvenirs. I can honestly say I have never seen more scallops in my life, not to mention sand dollars and sea stars! I am looking forward to sharing this experience with my family, students, and friends. As I write this last blog, I am thinking of what a privilege it has been to be a member of this team of researchers. I am honored to learn from them. To my team: Jon, Nicole, Mike, Jess, Alexis, Ted, Nick (TG), and TR, thank you!! This experience would not have been the same without you! I will remember you fondly for many, many days to come.
NOAA Teacher at Sea Janet Nelson Huewe Aboard R/V Hugh R. Sharp June 13 – 25, 2012
Mission: Sea Scallop Survey Geographic Area: North Atlantic Wednesday, June 20, 2012
Weather Data from the Bridge: Latitude: 41.03.21 North
Longitude: 071 32.79 West
Air temp: 21 C
Wind Speed: 15.6 kt
Depth: 135.2 feet
Science and Technology Log:
I came on shift yesterday at noon with three back to back dredge tows (we have done 30 dredges thus far on Leg II). We are off the coast of Long Island. Most of the dredges around here have been filled with sand dollars and sea stars. In total, we have processed and counted on this leg of the survey 5, 366 scallops, 453 skates, and 58 Goosefish, a very interesting fish that buries itself in the sand and uses a filamentous lure to attract prey and engulf them. In addition, we have counted 132, 056 sea stars (wow!) and 590 crabs. The HabCam had some glitches yesterday but we began running the vehicle on our shift at approximately 1245 hrs. It made a run for approximately three hours and 57 minutes, with approximately 22.387 nautical miles of pictures before we dredged again.
While looking at the images of the HabCam, it astounds me at seeing prior dredge track marks from commercial scallopers and clamers. By looking at the side scan sonar, some of the dredges are very deep and very invasive. It reminds me of strip mining and clear cutting in terrestrial ecosystems. It is also evident, by observing the images, that little is left in those areas but shell hash. With that said, there are still some interesting species that get photographed, such as jelly fish and sea stars in patterns you would think they orchestrated.
We are working our way toward Georges Bank and will be there, from what I’m told, sometime late this afternoon or evening. All equipment is running well and what time we lost with the late departure has mostly been made up. It’s amazing what technology can do!
Personal Log:
As of yesterday, I have been away from home with little to no contact for six days, so when I was told yesterday morning prior to coming on shift that we had cell phone signal, I immediately went up on deck and called my husband! Although I only got an answering machine, it was good, and familiar, to hear his voice.
We then had a fire drill at noon and after that, set to work. It was nice to be outside working for the next 4 hours. I think I finally have my sea legs. However, the seas have also been cooperating with only 1-3 foot swells, at best. When they are higher, I sometimes feel like the Scarecrow in “The Wizard of Oz”. It’s a good thing I can laugh at myself when I look completely ridiculous while tripping through a door or, with no warning whatsoever, bump into a wall! From what I understand, this ship has a flatter bottom than most so every wave and swell catches it and tosses it in whatever direction that wave is going, despite having just gone in the opposite direction! I am hoping the sea remains calm when we get to Georges Bank.
I am learning a great deal about the critters that live in the ocean around here. It is so strange to have at times hundreds upon hundreds of sand dollars being pulled up in the dredge at one location and then to have mostly sea stars pulled up at another location. My favorite, however, are the hermit crabs! They are so cool! They will begin to crawl out of their shells, see you coming to pick them up and immediately crawl way back inside and stare at you. I actually think I saw one blink at me. Not really, but my imagination does run away at times.
Those are also the times someone, usually me or the watch chief (chief scientist is guilty of this too!), bursts into song or starts quoting a movie line, and then half the crew is joining in. I have gotten more proficient at using the technology equipment on board that does the recording of the measurements of the specimens, and also at cutting/shucking the scallops. Never thought I would know how to do that! I have a feeling there are a few things I never thought I would do before this cruise is over. I have five more days at sea. Anything is possible!
Side note: Today is beautiful for being at sea! Clear sky, moderate winds, and sea legs that are working!!
NOAA Teacher at Sea
Jessie Soder
Aboard NOAA Ship Delaware II
August 8 – 19, 2011
Mission: Atlantic Surfclam and Ocean Quahog Survey Geographical Area of Cruise: Northern Atlantic Date: Wednesday, August 12, 2011
Weather Data Time: 12:00
Location: 41°47.405N, 67°21.702W
Air Temp: 18.4°C (65°F)
Water Temp: 17°C (63°F)
Wind Direction: South
Wind Speed: 8 knots
Sea Wave height: 1 foot
Sea Swell: 2 feet
Science and Technology Log
TK holding a monkfish caught in the dredge
When I was a little girl I was always excited to pull the minnow trap up from the end of the dock to see what oddities I had caught accidentally while trying to trap minnows. I am reliving this excitement on a much larger scale on this research cruise. The dredge we are using to fish for ocean quahogs and surfclams is 5ft x 20ft, weighs 2500lbs, and is pulled for ¼ nautical mile each time it is towed. (That means it covers an area of about 9000 square feet.) As you might imagine it accidentally catches things besides the ocean quahogs and the surfclams that we are fishing for.
The dredge is lowered into the water off the back of the ship. Once it hits the ocean floor a powerful jet of water is sprayed into the ocean floor in front of it to “liquefy” the sand or mud on the ocean bottom. This loosens the clams and suspends them in the water, just above the bottom. (Ocean quahogs and surfclams aren’t far below the bottom; just a few inches.) Then, while they are suspended in the water the dredge scoops them up. The dredge is brought back up to the ship and dumped and we sort through the catch. The ocean quahogs, surfclams, and a few other species are kept to weigh and measure. Below is a video of the dredge being hauled back on the back deck of the ship.
After three watches I am getting pretty good at identifying ocean quahogs and surfclams. What is the difference between an Atlantic surfclam and an ocean quahog? Well, they are very similar! They are both bi-valve mollusks, which means that they have two shells covering a soft body. They both burrow into the sand so that only their siphon sticks out. Both of them filter their food, algae and plankton, through their siphon. One of the biggest differences between them is in the way that their shells connect, or hinge together. Another difference is their lifespan. The ocean quahog lives for more than 150 years and the Atlantic surfclam lives for approximately 30 years. Their size and shape are different too. Ocean quahogs are rounder than the Atlantic surfclams, which have a triangular shape. The Atlantic surfclam also grows larger than the ocean quahog.
Ocean Quahog (left) Atlantic Surfclam (right)
Just like I was excited as a kid to find crayfish and bullheads in my minnow trap I am excited to see what the dredge brings up each time. So far our biggest catch was 4400 quahogs! Conversely, our smallest catch was just three quahogs! Sometimes the dredge is filled with empty shells, or empty shells and sand dollars, or thousands of clams, or sometimes it is really sandy. Each time it is a surprise and it gives you a brief glimpse of what the bottom looks like.
Personal Log
Empty shells and sand dollars
There are many potential dangers that you can face every day while working on a ship. In fact, since being aboard we have run three drills; man overboard, fire, and abandon ship. These drills are run on every trip so that everyone knows exactly what to do.
I think that there is something about being at sea on a ship that heightens your awareness of yourself. I have experienced that same sort of feeling when I am sea-kayaking in big water, or hiking on a bear trail. It is the feeling that there is something out there that is bigger than you are. You sense things in a much clearer and acute way.
This evening the sun was going down on the starboard side of the ship and the moon was coming up on the portside. We could see for miles and miles. Earlier today we watched a school of tuna swim past and dolphins in the distance. It was a beautiful clear and sunny day and we were 140 miles from land. We are lucky.
Questions to Ponder
The clams and quahogs are collected on this research cruise from the sea floor using a hydraulic dredge. The dredge is lowered and run along the seafloor for about 5 minutes in order to pick up the clams and quahogs. Each time this is done it is called a “tow.” How many people do you think are needed to conduct (operate the machinery and collect the data) one tow for clams and quahogs? How many different jobs are there during one tow?
