NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 23, 2008
Alison, Shrinky Cup Project Director, with the cups before being sent under.
Weather Data from the Bridge
Time: 1919(GMT)
Latitude: 4219.5N Longitude: 6812.5 W
Air Temp 0C: 20.7
Sea Water Temp 0C: 19.6
Science and Technology Log
The Shrinky Cup Caper
A trip to sea is not complete without the classic experiment on ocean depth and pressure— Styrofoam cup shrinking. Styrofoam cups are decorated with markers, and then lowered in a bag attached to the cable during a vertical cast. In our experiments, pressure is measured in decibars (dbar). This means that 1 dbar equals about 1 meter of depth. So 100 dbars = 100 meters; 1000 dbars =1000 meters. For every 10m (33ft) of water depth, the pressure increases by about 15 pounds per square inch (psi). At depth, pressure from the overlying ocean water becomes very high, but water is only slightly compressible. At a depth of 4,000 meters, water decreases in volume only by 1.8 percent. Although the high pressure at depth has only a slight effect on the water, it has a much greater effect on easily compressible materials such as Styrofoam.
Attaching the cups
Styrofoam has air in it. As the cups go down, pressure forces out the air. See the results of the experiment for yourself. The depth of the cast was 200 meters or about 600 feet. (You can now calculate the total lbs of pressure on the cups). Addendum: Alison discovered that putting one of the shrunken cups down a second time resulted in an even smaller cup. The cups were sent to 200 meters again. Below right is a photo of the result of reshrinking the cup. Apparently, time has something to do with the final size as well. Resources: NOAA Ocean Explorer Web site – Explorations; Submarine Ring of Fire. AMNH Explore the Deep Oceans Lessons.
Over they go!
Personal Log
There is a noticeable difference in the amount of plankton we pull in at different depths and temperatures. I can fairly well predict what we will net based on the depth and temperature at a sample site. I’ve also noticed that the presence of sea birds means to start looking for whales and dolphins. I assume that where there is a lot of plankton (food) there are more fish and other lunch menu items for birds and dolphins. A high population of plankton means we are more likely to see more kinds of larger animals.
Animals Seen Today
Salps
Krill
Amphipods
Copepods
Ctenophores
Chaetognaths (arrow worms)
Fish larvae
Atlantic White-sided Dolphins
Terns
Minke whales
Pilot whales
Mola mola (4)
The results of what happened to the cups at a depth of 200 meters. The white cups are the original size.Left, a cup shrunk 2 times; center 1 time; and right, the original size
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 22, 2008
Weather Data from the Bridge
Latitude: 4224.2 N Longitude: 6659.1 W
Sea Surface Temperature: 21.2 C
Depth: 202m
Becky proudly displays her drifter buoy before its deployment!
Science and Technology Log
It’s a buoy! Today has been busy—a vertical cast, baby bongos and the big bongos. But let me tell you about the other things. First of all, Alison and I deployed my very own buoy. NOAA has an Adopt-A-Drifter (buoy) program. Jerry Prezioso, our Chief Scientist, thoughtfully signed me up for it before we sailed. We deployed it today at George’s Bank, the deepest station we will reach.
The deployment consisted of picking up the basketball-sized buoy and throwing it over the side. There is a transmitter in the black float which will allow us to track the buoy’s motion for years. NOAA uses these buoys to assemble weather reports, monitor climate changes, etc. The buoy consists of the round ball with the transmitter and a “drogue” a long “tube” of cloth that fills with water. The purpose of the tube is to make sure it is the ocean current that moves the buoy, not wind.
With a little help, Becky gets ready to throw her drifter into the ocean
There is a diagram on the Adopt-A-Drifter site. The ball and drogue (sounds like an English pub) are attached to a metal ring which anchors the drogue and the ball. Here I am with the MSDE-decorated buoy. You can barely see the metal ring. The drogue is the green thing, folded up. You throw the whole thing overboard. The paper and tape dissolve and the drogue unfurls. It has to be kept tied up so you don’t go overboard with the drifter. NOAA’s Office of Climate Observation sponsors the “Adopt-A- Drifter” program. According to the Web site: “The “Adopt-A- Drifter” program (allows you to access) information about drifting buoys (drifters) that move with the ocean currents around the globe. The drifter floats in the ocean water and is powered by batteries located in the dome. The drifter data that are collected, including location with a GPS, are sent to a satellite and then to a land station where everyone can access the data.
And off it goes on its long journey
Drifters are continually being deployed from ships around the world. They last for a number of years unless they collide with something like an island in the middle of the ocean or a continent. Each drifter receives aWMO ID # (World Meteorological Organization Identification Number) so the data can be archived. The purpose of the drifters is to gather the information necessary for countries to: 1) forecast and assess climate variability and change, and 2) effectively plan for and manage response to climate change.”
This map indicates where the drifty buoy was deployed: where the Labrador Current, the Gulf Stream, and the North Atlantic current converge
We will release it in George’s Basin at 4224.2 N latitude; 6659.1 W longitude. This is an interesting area because of the way currents converge near this site. Above is a map of the area. Below it is a diagram showing the major currents.
A map showing the area where the drifter buoy was deployed from the Delaware II
As you can see, the buoy was deployed where the Labrador Current, the Gulf Stream and the North Atlantic Current encounter each other. There is a chance that the buoy will travel into the Gulf Stream or through the Northeast Channel into the North Atlantic Current. It might also just stay within the basin, caught in the large gyre within the Basin. You can get on-line and track the buoy to see what happens to it.
More from the Web site:
“The Adopt-A- Drifter program provides an opportunity for teachers to infuse ocean observing system data into their curriculum. An educational sticker from each school is adhered to the drifter before deployment and teachers and their students access sea surface temperature and/or sea surface pressure data from the drifter online. Students plot the coordinates of the drifter on a tracking chart as it moves freely across the ocean and make connections between the data accessed on line and other maps showing ocean currents and winds. Drifter data are used to track major ocean currents and eddies globally, ground truth data from satellites, build models of climate and weather patterns and predict the movement of pollutants if dumped or accidentally spilled into the sea. It is important for teachers and students to understand how the data are measured, how often data are downloaded, and what data are available for schools and the general public to access.”
Source: Modified from Follow the world’s ocean currents with NOAA’s Adopt a Drifter Program
Stanitski, D.M.; Hammond, J. OCEANS, 2005. Proceedings of MTS/IEEE
Personal Log
As we move further north, our nets started pulling in krill. I hoped that whales were not far behind. I was not disappointed. Yesterday we encountered dolphins on three separate occasions. One group came very near the ship and I have some good video of them “porpoising” through the waves. We also spotted a whale spout, but I could not see the whale. Later in the day, during our safety drill, I was looking out to sea just as a pilot whale leaped straight into the air. We were able to see that there were a number of these whales feeding in that area. Towards afternoon, we saw a group of Minke whales. In late afternoon, another spout was spotted and we saw a huge tail disappear under the water- probably a humpback whale.
Ocean Explorer related lesson: Islands in the Stream- How geologic feature(s) in the structure of the ocean floor may cause an eddy to form in the current above it
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 19, 2008
Weather Data from the Bridge
Latitude: 4000.7 N Longitude: 6931.5
Sea Surface Temperature: 21.2 C
Depth: 114m
The Delaware’s latest cruise track has taken it from Woods Hole, MA, south past the Outerbanks of North Carolina, and then north again toward Georges Bank
Science and Technology Log
We are heading east out to sea, right now at 4005 N latitude, 6942 W longitude. (Pull out those atlases). We will begin a turn north towards Georges Bank. Georges Bank is a large elevated area of the sea floor which separates the Gulf of Maine from the Atlantic Ocean and is situated between Cape Cod, Massachusetts and Cape Sable Island, Nova Scotia. Georges Bank is (was) one of the most productive North Atlantic fisheries (Grand Banks being the most productive). “Legend has it that the first European sailors found cod so abundant that they could be scooped out of the water in baskets. Until the last decades of this century these banks were one of the world’s richest fishing grounds… (Source: AMNH web site below).
This map shows the location of Georges Bank and the underwater topography.
Northeastern fishery landings are valued at approximately $800 million dockside, of which a large proportion is produced on Georges Bank. Recently, scientists of the U.S. Geological Survey (USGS) and NOAA’s National Marine Fisheries Service (NMFS) have undertaken an effort to document direct interactions between physical environmental factors and the abundance and distribution of fishery species. (Source: USGS below). This means that the water chemistry, temperature and other factors affect how many fish there are, how many kinds of fish there are, and where they are. The article from USGS explains that the sea floor sediments that form Georges Bank came from the time when glaciers scoured the area. Since that time, sea level has risen, covering the glacial sediments, and tides and currents are eroding the bottom. When this erosion happens, small sediment particles are winnowed out by tides and currents leaving larger gravel-sized sediments on the floor. This kind of surface is good for scallop larvae and other small animals so they can settle on the bottom and not get buried by sand. Thus, the type of sediment on the ocean floor helps determine what kinds of animals can live there.
This map shows the continental U.S. Exclusive Economic Zones (EEZs).
Interestingly enough, politics and international relations have affected our trip to Georges Bank. We have been waiting for clearance through the U.S. State Department working with the Canadian government, to get permission to go into Canadian waters. As Wikipedia explains below, part of Georges Bank is “owned” by the U.S. and part is “owned” by Canada. Our route is to take us through the eastern part of Georges Bank, the part owned by Canada. Unfortunately, due to the speed of processing the request, we just this morning found out we got clearance to go there. If the request had been denied, we would have had to sail around the Exclusive Economic Zone (EEZ) to avoid Canadian waters. Fortunately, we are now good to go.
From Wikipedia:
“During the 1960s and 1970s, oil exploration companies determined that the seafloor beneath Georges Bank possesses untold petroleum reserves. However, both Canada and the United States agreed to a moratorium on exploration and production activities in lieu of conservation of its waters for the fisheries.
The decision by Canada and the United States to declare an Exclusive Economic Zone (EEZ) of 200 nautical miles (370 km) in the late 1970s led to overlapping EEZ claims on Georges Bank and resulted in quickly deteriorating relations between fishermen from both countries who claimed the fishery resources for each respective nation. In recognition of the controversy, both nations agreed in 1979 to refer the question of maritime boundary delimitation to the International Court of Justice at The Hague in The Netherlands. Following five years of hearings and consultation, the IJC delivered its decision in 1984, which split the maritime boundary in the Gulf of Maine between both nations out to the 200 NM limit, giving the bulk of Georges Bank to the United States. Canada’s portion of the Gulf of Maine now includes the easternmost portion of Georges Bank.”
It’s been a very quiet day today. We had several station samples this morning. At the first one, around 6:30 a.m. one of the crew members spotted two whales. They were too far away to see what kind they were. I, unfortunately, was inside the ship at that time and missed it. However, we are heading north so maybe we will have a chance to see some.
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 16, 2008
Weather Data from the Bridge
Time: 1807 (GMT)
Latitude: 36.05.40 N Longitude: 75.24.30 W
Air Temp 0C: 25.3 0C
Sea Water Temp: 26.7 0C
On left: small barrel-shaped copepods; Center: white, arrow worms; Top right: amphipods
Science and Technology Log
The most common zooplankton we have seen so far are salps, amphipods, arrow worms and copepods. Pteropods (sea butterfly) have been in a number of samples but are not numerous. Salps look like clear, jelly-like marbles. We’ve encountered these animals in warm, shallow water. They are holoplanktonic relatives of sea squirts (Urochordata). Salps are filter feeders, using cilia to move suspended particles from the water. They feed by pumping water through a sieve to remove bacteria and nanoplankton, and are thus, a very important link in the food chain. Some species of salps form huge chains by budding. They show both sexual and asexual life stages. For more about salps and photos see this website.
Amphipods are also extremely common crustaceans. There is no carapace (shell-like covering), but their bodies are flattened side-to-side, much like a shrimp. Their bodies are segmented with 6 segments in the head, 8 in the thorax and 6 in the abdomen.1 They have a brood pouch on their thoracic limbs. They have a variety of limbs used for feeding, crawling or jumping. One group lives off a host, feeding on salp tissues. Some types live in tubes; others use their back legs to anchor themselves while they sway to and fro in the water column. Some species swim rapidly while others stay near the bottom of the ocean. Many will move vertically in the water column, moving near the surface during the day, and sinking again at night. The species we are catching has large compound eyes that can be seen by the naked eye. For more about amphipods, visit this website.
Becky examines the catch using a hand lens.
Copepods are very common crustaceans, with more than 200 species and 10,000 families. 2 We have found more of these than any other organism. Copepods are omnivorous. Some groups graze on microplankton; other groups of copepods prey on larger plankton, including other copepods. They are an important link in the food chain as well, moving carbon from a microscopic level to a larger trophic (feeding) level. They are eaten by jellyfish, fish, comb jellies and arrow worms. Copepods have “antennae” that have special sensors that detect water movement around them. They are able to move toward prey by contracting a muscle that runs in a circle around their bodies. For more about copepods, visit this website.
Arrow worms (Chaetognatha) are common along coasts, but we did not catch any out away from shore. Arrow worms are classified in their own group, distinct from Annelids (earthworms), round worms and flatworms, which are all separate groups of worms. They are predators, often waiting to ambush their prey. When their cilia detect prey, usually copepods, the arrow worm contracts 2 muscles that run dorsally and ventrally (top to bottom) to strike. Their mouths have spines that grab the prey and smaller “teeth” produce a venom that subdues the prey. The prey is swallowed whole. Arrow worms, in turn, are eaten by jellyfish, copepods and fish.2
Sea Butterflies were not common, but they are very interesting. Sea butterflies (pteropods) are holoplanktonic mollusks, related to snails. Basically, they are shell-less snails. Their foot is modified into winglike structures (ptero= winged) that they flap as they swim through the water. Their bodies are tube-shaped and clear. The bodies and wings of the species we have seen are an orange-pink color. They are predators and are preyed upon by fish, sea birds and whales.
Information for these paragraphs were modified and combined from the following sources: 1 Newell, G.E. and Newell, R.C.; Marine Plankton: A Practical Guide; 5th edition; 1977; Hutchinson & Co; London.2 Johnson, William S. and Allen, Dennis M.; Zooplankton of the Atlantic and Gulf Coasts: A Guide to Their Identification and Ecology; 2005; Johns Hopkins University Press.
Personal Log
This morning we saw dark clouds in the distance. You could see rain falling from the clouds. Nearby we could see the tail of a water spout disappearing into the clouds. We sampled our southern-most station and are now heading north along the coast just south of Chesapeake Bay. The samples we are pulling now have a lot of diatoms.
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 15, 2008
Weather Data from the Bridge
Latitude: 3846.7 Longitude: 7302.1
Temp 25.4 C
Bongo net
Science and Technology Log
In the last post, I explained WHY we are collecting zooplankton. This post will illustrate HOW the samples are taken.
The samples are collected using a device called a bongo net (Yes, like the musical instrument). You can see the metal rings and the nets hang from the metal rings. One net is marked with red and the other green. This allows you to tell the two nets apart. The samples from the red side will be used for the ichthyoplankton study. The samples from the green side will be used for the zooplankton study.
The white device is the CTD (Conductivity, Temperature, Depth). You attach it to the bongo net frame and turn it on. The CTD takes measurements on the way into the water and on the way out of the water. When the bridge clears you, the computer operator (inside) tells the hydraulics operator to start letting out the line and at what speed to let it out and bring it in. You calculate the amount of time in and out using a chart that is based on changing depth. You have to calculate it so you get at least a 5-minute tow.
The CTD
Now the bongo nets are raised on the A-frame. You can see the CTD above the bongos (right picture) and there is a lead weight beneath and between the nets. Next, the A-frame moves the nets over the side of the ship and they are lowered into the water. You cruise for at least 5 minutes. The idea is to get within 5 meters of the bottom, then start bringing the nets back in. The computer operator keeps track of where the bottom is. The idea is to stop the line going out in time so the nets don’t hit the bottom and pull up a bunch of sand. Then you just have to wait for the tow, and eventually for the nets to come back up.
The bongos are removed from the A-frame and brought into the wet lab. You use the hose to wash the plankton down to the bottom of the net. The bottom of the net is put into the sieve. When the net is hosed down to the sieve end, you untie the bottom of the net and let the plankton wash into the sieves. The mesh captures zooplankton, but lets smaller phytoplankton through. Finally you rinse the plankton from the sieves into a jar with 5% formalin for preservation. A label is put into the jar as well as on top of the jar, stating station number, date and time.
NOAA Teacher at Sea, Becky Bell, assists in deploying the bongo nets.
Personal Log
We had a fire drill and an “abandon ship” safety drill. In the picture to the right, I am wearing a survival suit, lovingly known as a “Gumby suit”. If you abandon ship, you have to run to the deck and put on this suit. It is one piece, with inflatable neck rest, whistle and flashing pocket light so you can be spotted. You have to lay the suit out on deck, and sit down in it. Feet go in first, then you stand up and pull the rest over your head, find the arms etc. Look at the look on my face. Not too sure about this! The front flap closes to show only your eyes–on me a little higher. You should try zipping the front zipper with thick rubber gloves that are too big for you. It reminds me of the astronauts trying to fix the space station. I have a new appreciation for how difficult it is too, like, HOLD anything. The best news yet–we get to practice next week again.
Deploying the Bongo netThe A-frameThe nets begin to emerge from the water.Waiting for the nets to come back up after the towBecky rinsing down the netThen she puts the plankton into a jar for preservationBecky dons her survival suit during a safety drill.
NOAA Teacher at Sea
Rebecca Bell
Onboard NOAA Ship Delaware II August 14-28, 2008
Mission: Ecosystems Monitoring Survey Geographical Area: North Atlantic Date: August 14, 2008
Weather Data from the Bridge
Time: 134628 (GMT)
Latitude: 40.33.06N Longitude: 72.47.36W
Air Temp 0C: 22.1
Sea Water Temp: 22.3 0C
NOAA Ship Delaware II
Science and Technology Log
We sailed from Woods Hole, MA on Wednesday, August 13, 2008 on the first of three legs as part of the Ecosystem Monitoring Program. There are two main objectives of the cruise. The first is to see how well the fish population is doing by sampling and counting fish larvae. The number of fish is important to the fisheries industry- those folks who bring cod and other fish to your table. The second objective is to monitor the zooplankton population. Fish feed on the zooplankton, so a healthy zooplankton population may mean a healthier fish population. We also are monitoring the physical properties of the water; in this case, salinity and temperature. These influence where fish larvae and zooplankton can survive and where and how far they can be dispersed.
There are 125-130 sites randomly selected for sampling. At each site, a pair of bongo nets are dropped and the two samples are collected side-by-side, for a total of 250-260 samples. One sample is designated for the ichthyoplankton (fish larvae) study, and the other for the study of zooplankton composition, abundance and distribution. Near-surface along-track chlorophyll-a fluorescence, which indicates abundance of phytoplankton (i.e. food for the zooplankton), water temperature and salinity are constantly measured with the vessel’s flow-through sampling system. We will also be collecting a separate set of samples as we approach the Chesapeake Bay. These will be used to study aging of fish larvae.
Zooplankton include both unicellular and multicellular organisms. Many can easily be seen with the naked eye. Zooplankton can be classified in a number of ways. One way is to classify them by life history. Holoplankton are those that are planktonic during their entire life cycle (lifers). Meroplankton refers to those plankton in a developmental stage, like eggs and larvae (shorttimers). These larvae will grow into larger organisms such as jellyfish, mollusks, fish, starfish and sea urchins, crustaceans, copepods and amphipods.
The term “plankton” comes from a Greek word for “wanderer” or “drifter”.1 This may imply that these organisms are passively moved about by currents. However, many can power around on their own, using several different methods such as cilia, muscle contraction, or appendages on the head, thorax or abdomen. They also move vertically in the water column, up toward sunlight during daylight hours and downward at night. Krill (whale food), on the other hand, do the opposite- travel downward during the day and up at night.
The first two samples contained a vast number of salps. A salp is holoplanktonic and is related to sea squirts (urochordates). They are filter feeders, catching bacteria and extremely small plankton in mucous-covered “nets” that act as sieves. Salps are an important part of the ocean food chain.
Samples 3-5 show a greater variety of organisms- comb jellies (ctenophores), arrow worms (Chaetognatha) fish larvae and amphipods. Samples 6-8 are dominated by copepods. There are salps, too, but not nearly as many (about 1/3 fewer) as we saw in the first 2 samples.
So I am looking at these results and wondering: Are there patterns to the distribution of these assemblages? Are salps found in warm water or cooler water? Does temperature matter at all? Do they like deeper water? Higher or lower salinity? Combinations of any of these? Are they found where another organism is found?
Personal Log
We began our first work shift today, er, last night, um, this morning at 3 a.m. I work the 3 a.m. to 3 p.m. shift. That means to bed around 7pm., rise and shine at 2:30 a.m. Well, rise, anyway. Not much shining till later.
As I sat on the deck in darkness, waiting to reach our first sample site, I spotted the light from another ship on the horizon. I watched as the light traveled up a wave, then down a wave then up, up, up, up, still up. I could not believe how high it was going, knowing we were doing the same thing. It’s a good thing it doesn’t feel like that. We are now heading south, back towards the Chesapeake Bay. It is getting hotter and muggier, just like home.
We saw dolphins today. A large leatherback turtle was spotted from the bridge. The 3pm- 3am. shift reported seeing flying fish.
NOAA Teacher at Sea
Laurie Degenhart
Onboard NOAA Ship Delaware II July 14-25, 2008
Mission: Clam Survey Geographical Area: North Atlantic Date: July 23, 2008
Weather Data from the Bridge
Winds at 170° at 23 knots
Sea temperature: 18.9° C
Air temp 22.6° C
Swells: 1
Atmosphere: Clear
Laurie and some fellow crewmembers are covered with clay and mud after climbing in the dredge
Science and Technology Log
The last two days have been less hectic. The scientists have had to make several repairs. The sensors on the dredge were having problems recording data. Sean Lucey, Chris Pickett, and TK Arbusto, as well as other scientists have spent several hours replacing sensors and making sure that the sensors were logging accurate data. In order for the survey to be reliable the scientists at sea and in the lab decided that the ship needed to return to previously tested sites to insure that the sampling techniques had not changed with the changes in the sensor.
We have sampled both Quahogs and Surf Clams today. It seems that some locations are dominated by the Quahogs, while others are mainly Surf Clams. The weather has been hot and humid. So far in the trip, the Delaware II has been able to avoid the storms farther to the south. Tonight however, the winds are starting to pick up. We may see rain! Today I climbed up in the dredge compartment when it was full of clay. Even though I knew that the dredge was very safe, I still worried that I might fall into the ocean. The clay was very dense with rocks. Sean Lucey, chief scientist, used a high pressure hose to loosen the majority of the mud, but it was still a big slippery muddy job. John, the Chief Bosun, told me that a full load of mud weighs almost 9000 pounds! There were very few clams in the load.
Personal Log
This shift has been very busy. The tows have been pretty much back to back. All the people on my shift have formed a great team. Though the work is hard we seem to be able to make it fun….
I continue to be impressed with the NOAA officers and scientists. The scientists have to have knowledge of oceanography, marine biology and statistics in order to execute accurate sampling. Another area of expertise is in trouble shooting all the scientific equipment… after all there is no running to the hardware store for spare parts. Today when the sensors broke the scientists, mechanical engineers, and the bosun had to work together to correct the problem.
Both the NOAA officers and the scientists have to be able to cope with volunteers (me included) that have no knowledge of life at sea. Each new crewmember has learn to fit in…I’m sure that this tries the patience of the seasoned crew. Being aware of all the ins and outs of life at sea is quite a learning process. For example, I went to the bridge after dark… it seemed to be pitch black…. actually the Executive Officer was “on watch” having the lights out made it easier for him to see both the ocean and the electronic equipment that he had to use in order to safely captain the ship.
One of my goals for the trip is to put together a collection of photographs that depicts all the aspects of life aboard the Delaware II. So far I have over 300 photographs. The crew seems quite pleased…many members ask if I can take more pictures.
During this voyage I have learned a great deal about how a ship runs. I am very pleased to have had the opportunity to work aboard the Delaware. I will create a DVD with the images and video clips that I have gathered. I want to share my experience with students, teachers, and student teachers. NOAA offers great resources for educators and a vast selection of careers for those who wish to live a life that is rewarding and exciting.
NOAA Teacher at Sea
Laurie Degenhart
Onboard NOAA Ship Delaware II July 14-25, 2008
Mission: Clam Survey Geographical Area: North Atlantic Date: July 20, 2008
Weather Data from the Bridge
Winds at 200° at 23 knots
Sea temperature: 24.2° C
Air temp 24.6° C
Swells: 0
Atmosphere: Clear
Science and Technology Log
Scientists and volunteers sort dredge materials.
We are now into day 7 of our clam survey. Everyone on the ship pulls together as a team to make each tow a success. Each location for a dredge site is called a station. The NOAA crew in charge of the ship must not only be at exactly the correct longitude and latitude, but the depth of the water, the speed of the tow, and the condition of the sea (waves and swells) must also be considered. There are three separate places on the ship where these decisions are made. The bridge controls the location of the ship and notes the conditions of the sea. The chief bosun controls the dredge towing. He manages the cables, depth, and length of the tow. The scientist in the lab choose the exact location of the tow and the depth. The scientists use sensors attached to the dredge to log data about the tow. The bosun reels the cable back to the ship and onto the platform. After the tow has been made the deck hands secure the dredge compartment where the catch is.
The scientific crew then measures and counts the clams. A scientist from the FDA, Stacey Etheridge, has the science crew shuck a certain number of clams. She then homogenizes them in a food processor to take back to the laboratory to test for possible toxins. The NOAA scientists collect data on the different types of clams as well as the size and weight. They are also trying to determine the age of the clam given the rings on the shell. In addition to the scientist on the Delaware II, there is an entire NOAA crew. There are engineers, ship’s officers, and fishermen. Everyone has specific assignments. The NOAA officers are at sea approximately 244 days a year. The NOAA careers website here.
Personal Log
The scientists must have many skills in order to keep the study going. Not only do they have to know about the clams, but also how to fix problems with the computer program and its sensors, as well as the mechanical operation of the dredge equipment.
The weather at sea has been very hot and humid. The hours are long. We do approximately 10 tows on a twelve-hour shift. Think about this… each tow gathers around 4 thousand pounds of material off the ocean floor. That makes 40,000 pounds. There are 7 people on our shift. That means each of us sorts and moves around 5700 pounds in a shift…. that’s as much as a small car! I guess I can have dessert with lunch today. The work is enjoyable.
Tina and I have shucked over 500 clams. We ROCK, or should I say CLAM, at shelling Quahogs. The Captain told me that we may feel the effects of tropical storm, Cristobol. I sure hope I don’t get seasick. I learned a new skill…swabbing the deck. It is amazing the range of tasks each crewmember has to have to keep the ship running smoothly.
Our Chief Scientist, Sean Lucey, oversees all of the roles of the scientists and volunteers. It’s a big job and he sets the tone for the rest of us. Everyone is positive and willing to do whatever is needed. Jakub, the Watch Chief, oversees the general operation of sorting and measuring the clams. Both Sean and Jakub are great at teaching me the ropes so that I can do my best. One time as I was on my way to my “station” Sean remarked, “I know you’ll be ready.” I thought that was great, sometimes I get anxious about doing the exact right thing at the right time.
I am starting to think about the lesson plans that I am going to write. I want to make a simulation of a clam survey for elementary students using Oreo Cookies to gather data. Sean is going to give me data from the trip to use in my lesson plans. One of my goals for my presentations is to go to various Vocational Classes to talk about all the facets of NOAA as a career path. I also want to develop a presentation about the roles of a scientist, showing the different aspects of the skills that they have.
Once again the meals have been great. I was told that the Stewards, John and Walter, have a reputation for providing the best food of all the NOAA ships. Sure seems right to me! We have had great meals. One night we had Sea Bass, another night we had lamb chops. There is always an abundance of vegetables and fruit. Then there is dessert… apple pie!
NOAA Teacher at Sea
Laurie Degenhart
Onboard NOAA Ship Delaware II July 14-25, 2008
Mission: Clam Survey Geographical Area: North Atlantic Date: July 15, 2008
Weather Data from the Bridge
Winds at 200° at 7 knots
Sea temperature: 20.7° C
Air temp 24.4° C
Swells: 160 4’ 12 sec.
Atmosphere: Clear
Science and Technology Log (Monday, July 14 – Thursday, July 17)
NOAA Teacher at Sea, Laurie Degenhart, gets ready to set sail on the DELAWARE II.
We set sail midday on Tuesday, July 15, 2008. Monday was spent with repairs. We heard a presentation by Dr.Larry Jacobson, the head of the Clam Survey Project. He explained that there was a general shift in the populations of Surf Clams and Ocean Quahogs.
This study is collecting data for his team to use in determining the changes and possible causes of the change. NOAA and the clam fishing industry enjoy a good relationship, working handin-hand to protect the clam population and promote clam fishing. We were taken to the NOAA storeroom and outfitted with our “foul weather gear.” We wear the gear on board to sort and shuck clams. We each were issued boots, yellow bib overalls, and an orange rain slicker….I look quite dashing.
Laurie dons a survival suit during a ship safety briefing.
Chief scientist, Sean Lucey, gave us a general description of the work that we would be doing. Sean stressed how important accuracy is in all the facets of the Clam Survey. There are several assignments. Each person is assigned a shift. My shift is from Noon until midnight. That’s 12 hours! We are not to return to our room until our shift is over, because the other women I share the room are on the opposite shift and will be sleeping. I am on a team with Jakub Kircun, as the Watch Chief. He is very patient and kind, even when I make a mistake. There are seven people on our team: four NOAA scientists, one graduate student who is studying plankton, one volunteer, and me, the Teacher at Sea.
General Description of a Clam Dredge
The back of the Delaware II has a large metal dredge (it looks like a giant square shifter-See photo.) The cage is lowered to the sea floor at pre-determined random locations and dragged by a special cable called a hauser for exactly 5 minutes. Then the dredge is hauled back to the boat and its contents are dumped on a platform. We all sort through the dredged material sorting out clams and other sea life, throwing the rest back out to sea. The clams are measured, weighed, and some meat specimens are taken for examination. Computers record a vast array of information for the scientists. Sean Lucey (Chief Scientist) is always making decisions where we go and provides the lab and other scientists information about the catch. The team does around 10 or so tows in a twelve hour shift.
First Assignment
I was assigned by, Jakub Kircun, Watch Chief, to record information about the tow a using computerized data collection system called SCS (Scientific Computer Systems). I go into a room on the bridge and listen to the deck department communicating with the bridge and I record when the dredge is on the bottom, towing, and back on deck. The information is tracked in SCS with button pushers. I also log information about wave height, swell direction, and swell height, which I receive from the officer on watch. I also need to record depth, time, and speed of the boat during a dredge tow. This provides accurate data for the scientists back on land to analyze. As soon as that part of my job is finished, I come down stairs to help sort and shuck the clams..
The clam dredge aboard the DELAWARE II
Personal Log
Holy Cow, a 12 hour shift….from noon until mid-night! I was worried, but the shift seems to fly by. There is always something that needs to be done. I was assigned by Jakub Kircun, Watch Chief, to record the sensors for the dredge itself. What a responsibility!!! Talk about pressure. Sean, Chief Scientist, has been really great. His sense of humor has helped ease my stress. I never realized how much computers are used aboard a ship to monitor experimental data. Not to mention the general running of the ship….. There are 31 computers in all. For each tow which Sean and Jakub call a station, I do the recording for the dredge then come down stairs…put on my boots and bib overalls and head out to sort the clams with the others on my team. It’s a big job…good thing I am used to working in the woods of Wyoming… otherwise, I don’t think I could keep up!!!
Laurie sorts clam on the fantail of the ship.
After we sort the clams, Tina, a graduate student from University of Connecticut, and I measure and weigh the clams using a special computerized machine called a Limnoterra Fish Measuring Board. Tina and I are becoming great clam shuckers. We need to weigh the clams both with and without the shell. Joe, the other volunteer, also helps weigh and shuck the clams. Sometimes they are sweet smelling… but sometimes not! They look nothing like Howard Johnson’s Clam Strips!
I have started a shell collection to bring back to my school. I will be working with the Science Coordinator to design science experiments that use data from our trip. The Chief Scientist, Sean Lucey, is working with me to develop lesson plans that use the data being collected. Just learning to find my way around the ship has been a challenge. I’ve learned to find the galley…. great food. Walt and John, the ship’s stewards, are fantastic chefs. Today we had crab cakes with lemon sauce, vegetables, and peach cobbler with whipped cream for dessert. I am telling myself that as much physical work as I am doing I can eat what I want….that’s my story and I am sticking to it!
All the crew has been welcoming and accepting. Richie and Adam, NOAA crewmembers, take care of securing the dredge. It looks like a dangerous job to me! They both have a great sense of humor.
NOAA Teacher at Sea
Robert Lovely
Onboard NOAA Ship Gordon Gunter March 31 – April 12, 2008
Mission: Reef Fish Ecological Survey Geographical area of cruise: Pulley Ridge and the West Florida Shelf, Gulf of Mexico Date: April 5, 2008
This sea anemone was part of a remarkably diverse community on Pulley Ridge at about 212 feet.
Weather Data from the Bridge
Visibility: 7-8 miles
Wind Direction: 140 degrees (SE)
Wind Speed: 13 knots
Sea Wave Height: 1-2 feet
Swell Wave Height: 2-3 feet
Seawater Temp.: 24.7 degrees C.
Present Weather: Clear
Science and Technology Log
Today we made three two-hour ROV dives on Pulley Ridge. We documented an impressive amount of biodiversity along three transects at depths that ranged from about 190 to 225 feet. Downward still images of the bottom were taken at regular four minute intervals; forward facing still shots were taken whenever something of interest presented itself; and a continuous forward-looking video recording was made of the entire transect.
Agaricia sp., reef-building coral we found at 215 feet.
The ideal cruising speed for the ROV video recording is a very slow one-half knot, which presents significant challenges for the people on the bridge. In fact the Commanding Officer, LCDR Brian Parker, remarked on how good a training exercise this cruise is for his team. Upon our return to port, and for weeks afterwards, fishery biologist Stacey Harter will analyze the video to derive density estimates for the fishes observed. She will determine the area covered by each video transect and count individuals of each species that intercepted our transect line. Abundance estimates then can be extrapolated per unit area. Others will use similar techniques to determine the aerial extent of living corals. These data, in turn, will be useful to authorities responsible for managing the fisheries. Pulley Ridge is a drowned barrier island system that formed about 14,000 years ago, when sea levels were lower because a larger portion of the Earth’s water was locked up in glacial ice. While the presence of photosynthetic corals, such as Agaricia spp. was patchy on our dives, we did encounter large fields of green algae in relatively high densities.
The green algae, Anadyomene menziesii, dominated large areas in the southern portion of Pulley Ridge.
This species no doubt is the Anadyomene menziesii described by Robert Halley and his group at the USGS. These striking seascapes resembled large fields of lettuce. At the southern end of Pulley Ridge this green algae dominated the seabed. As we moved northward from station to station, however, it occurred in much lower densities, and we began to see higher proportions of the calcareous green algae Halimeda spp. Various species of red coralline algae were also common on Pulley Ridge. Apart from the abundance of Anadyomene menziesii, the other striking observation one makes on this deep coral reef is the presence of conical-shaped mounds and pits. These structures are almost certainly constructed by fish, such as the sand tilefish (Malacanthus plumieri) and red grouper (Epinephelus morio). Sand tilefish in particular burrow into the coral rubble and pile it up for cover. Red grouper are also industrious excavators.
A red grouper at rest in a small pit on Pulley Ridge.
The mounds and pits introduce an element of topographic relief into an otherwise flat seascape along the top of Pulley Ridge. Because so many other species of fish are attracted to these structures, I would suggest that (at least among the fish) sand tilefish and red grouper represent keystone species in this unique ecosystem. The removal of these two species would have a significant impact on the rest of the community. Other fauna we observed today were typical of what one might encounter on a shallow-water reef, including sponges, tunicates, lobsters, bryozoans, amberjacks, angelfish, reef butterflyfish, snapper, barracuda, and a loggerhead turtle.
Personal Log
My favorite place on the ship is the boatswain’s chair way up on the bow. No one else seems to know about it, for I have yet to find it occupied when I want to use it. It is the quietest, most scenic spot on the ship. Whenever I get a chance, I sneak up there to watch the flying fish. They are flushed by the ship, and some of them can remain in flight for long periods, perhaps 20 seconds or more. If I am especially lucky, I also get to watch dolphins riding our bow. This is a real treat because they seem so playful.
Our ROV disturbs the nap of a loggerhead turtle (Caretta caretta).A pod of dolphins bow-riding the ship.
The Echo Integration-Trawl Survey of Walleye Pollock closed the season with a total of 74 Aleutian wing trawls (AWT mid-water trawls), 19 bottom trawls, 27 Methot trawls (plankton) and 81 ConductivityTemperature-Depth Sensor Package deployments (CTD water quality checks) collecting a wealth of biological and physical oceanographic data. The crew and scientists are excited to be headed back to shore but also there is a good feeling regarding the mission of the trip and the validity of the data collection. Of the 50,840 Kg of fish netted more then half was caught in the 44 AWT mid-water trawls executed this third leg of the survey. During this time we took the length of 16,761 individual pollock and identified 19 other species of fish.I spent some time looking at graphs of preliminary data to try and make sense of what was accomplished from the work done during the sail. This past winter had a higher incidence of sea ice relative to the previous years. Generally the colder and saltier the water, the greater the density and the deeper it sinks. Although this concept was illustrated in salinity measurements at different depths (deeper being saltier) we found this not to be true when looking at temperature profiles.
Basket star
In the sea, deeper does not always mean colder. The Bering shelf is influenced by more than one current system and we found the data taken from the northern parts of the transect along the shelf had colder water than the southern areas as expected but along the slope near the edge of the deep basin the water remained consistently warmer relative to the shelf water despite the latitude change, rarely dipping below 1°C. Generally, we found colder water near the bottom of the shelf between 50 and 100 meters then we did near the bottom of the deeper slope at 200 meters or more. This is mainly due to ice melt in the northern latitudes slowly moving cold water along the bottom of the shelf, where as the deep basin and slope are influenced by slightly warmer currents moving northwest from the Aleutian chain. As a teacher working on the water in the east I came out here assuming the deep areas would be colder but instead I was schooled on currents and their influence on water temperatures.
Leg 3 Transects of Pollock Survey Area: Fish symbols indicate trawl locations. Circles represent CTD readings and diamonds represent the line between Russian and US fishing grounds.
Through much of the cruise the lead scientists on shift spend enormous amounts of time monitoring the acoustic signal (echograms) from sounds waves beamed below the ship. When they find a significant mass of pollock they often would take a sample – go fishing. Using patterns on computer monitors scientists are able to hypothesize which signals indicate pollock. Both the length data taken from measuring fish and the acoustic estimates are used to come up with biomass numbers. In the echogram in figure 3 there is what appears to be a signal indicating mixed size pollock. We know that pollock schools tend to be homogeneous with respect to age and size. The strong blue layer at the top of the echogram represents plankton near the surface and in this instance the fish are mostly near the bottom with larger fish indicated in blue and more evenly dispersed, while dense schools of small fish show up as odd shaped clumps with lighter colors. When we sampled this water we found this to be true; we observed two groups of pollock, large adults and small two year old juveniles. The data in Figure 4 (histogram lengths) shows the two size groups. Cannibalism may be part of the reason the smaller fish stick together in separate densely packed schools.
Temperature Profile from CTD readingsConductivity (salinity) Profile from CTD readingsEchogram of trawl haulTrawl histogram
In the echogram, we see more evenly dispersed adult pollock. This is verified by the haul 92 histogram in figure 6 that shows that most of the pollock sampled where between 40 and 55 centimeters long. Looking at the distribution of pollock in our study area (Figure 7) shows a consistent band of greater incidence of fish near the slope particularly to the western parts of the study area. As the fishery scientists fine tune hydro-acoustic technology they hope to get a better understanding in zooplankton (Figure 8) trends that influence survivorship of young Pollock. A Krill Survey would be ambitious but by looking at the higher frequency acoustic waves, verified with Methot Trawls, one can estimate krill biomass in pollock regions. Environmental monitoring of chlorophyll concentration (phytoplankton measured from CTD water samples analyzed back on shore) and krill biomass (zooplankton) relative amounts from year to year can help create a better understanding of the resources necessary to support fish stocks.
FIGURE 7: Preliminary data of pollock distribution throughout the survey areaFIGURE 8: Preliminary zooplankton estimates throughout the pollock survey area
I would like to thank Chief Scientist, Paul Walline and B-Watch Chief ,Patrick Ressler for taking the time to explain to me the science of hydroacoustic survey analysis and sharing with me their preliminary data.
Chief Scientist, Paul Walline, monitoring the echogram from the bridge of OSCAR DYSON.
Bird of the Day:
The bird survey folks identified over 35 species on our trip. I became familiar at least 6 species of birds that I felt comfortable identifying on the fly. When there were hundreds of birds circling the boat there was sometimes one type of bird that stood out making identification a snap. The Auks are related to penguins and have rounder body shapes and unique flight patterns. Like penguins of the southern hemisphere, the denser body composition makes them excellent at swimming under water, but they less nimble taking off and flying in the air compared to sleeker less dense seabirds like the gulls. Unlike penguins all 13 species of auks in the northern hemisphere can fly. The two most abundant types observed onboard are the Murres and the Puffins. I was fortunate to see two species of puffin this trip, the Horned and Tufted Puffin, seemingly too exotic for the Bering Sea. Both have specialized large colorful beaks for carrying multiple prey items and attracting mates. As we sail southeast we are fortunate to be seeing more of them.
Personal Log:
Patrick, always with a smile, takes a break from the computer screens to look at the catch.
These last few days, despite the lack of fishing, have not been without excitement. The bottom-study video sled captured Dall’s Porpoises swimming under water as it was deployed off the stern. As we head southeast there seems to be more whales and clearer skies. This evening we saw dozens of fin whales and one pod was feeding so close that I was able to see baleen. The whales’ baleen is used to screen their plankton food. I learned the Right Whale has asymmetrical coloring on its baleen and the right side has a lighter off-white color, which we were able to see from the port side of the ship. I would like to take this opportunity to express my gratitude to the crew of the OSCAR DYSON for their help in getting acclimated to the Bering and to NOAA’s Teacher at Sea program for providing this amazing experience.
Question of the Day
Today’s question: What is next for the OSCAR DYSON? She is headed back out to the Bering to find rare Right Whales. Check out ship tracker at NOAA’s website or the OSCAR DYSON Web site for more info.
Previous Question: How much fish did we catch? 26,575 kilograms (summer extra credit – convert this number to pounds and metric tons)
Roy works with the deck crew to remove the “pea pod” from the trawl net.
Science and Technology Log: Special Operations
When a fully equipped research ship goes to sea everybody wants in. Any scientist doing work in a particular region needs access to that region to conduct their fieldwork. Fishery scientists often catch a ride with commercial vessels to do work at sea. A research vessel can be more desirable for certain projects and NOAA has a system for organizing request proposals and prioritizing work. Unfortunately, a boat is limited in the number of passengers, equipment, food and other resources it can carry. For example one scientist, who is not with us, has sent light meters onboard and requested we collect the data for him. The light meter mounts to our trawl net to study if light penetration affects the vertical distribution of walleye pollock. The pollock survey, the main project of the season, has a science team of 8 not including the birders, ship’s staff and Teacher at Sea. With this many scientists onboard the ship becomes a platform for an interesting mix of experimentation.
Measuring the fish
We finished the transects of the Pollock Survey and are now transiting southeast back towards Dutch Harbor. Tomorrow we launch “the sled”, a large metal-framed instrument equipped with an underwater video camera to record the sea bottom of a special study site. The purpose of the study is to assess the effect of bottom trawling on benthic habitats and measure recovery progress over time. The study site is an area that was bottom trawled back and forth around a month ago. The camera will be pulled in lines perpendicular to the tracks created by the trawling. I got a sneak peak at some of the video footage and the benthic habitat is flat and muddy with strange white sea pens poking upward around 5 feet. Crabs and flat fish scurry around while giant basket stars and sea anemones ornament the bottom. We will use some of our transit time to reflect on some of other side projects that occurred this trip, most of which were designed to refine and validate the survey methodology.
A late night course in net sewing
When the trawl catch is unloaded into the lab the sex, weight and length of individual fishes are recorded. To make the work more efficient, a new measuring board has been designed to length fish. This is the first time it was tested and it performed smartly. The board allows scientists to input digital length data by touching the sensor to the board at the end of the fishtail fork. NOAA Scientists, Rick Towler and Kresimir Williams, designed the instrument using magnetic sensors from scratch, and shared with me the details of their first project and how the length board evolved from an acoustic instrument through trial and error to the prototype we tested this year. When processing data from trawling, there is always a concern as to how to best represent biomass estimates. You should not count a fish that is 10 centimeters the same as you would a fish that is 40 centimeters. Although they would both qualify as one fish they have a different size and thus a different biomass. We know we cannot count every fish so we have different methods of estimating biomass.
Deck crew works to get fish out of the pocket nets
Not all fish are caught with the same efficiency; the retention of fish in a net must be taken into consideration. To compensate for this, an estimate as to fish escapement is often factored into the calculations for fish density. Fisheries Scientist, Kresimir Williams, wants to quantify fish escapement. He is using handmade “pocket nets” to study selectivity and sample escaped fish. In the evening we conducted experimental trawls to monitor escapement from our main trawl nets. We did this by attaching pocket nets to the outside of the trawl net in random placement and analyzing pollock caught in the smaller nets relative to the catch in the cod end. We have found that smaller fish (one year-old juveniles) more often escape the net from near the cod end as opposed to forward, where there is a larger mesh size. Although the data will not be analyzed until later, observations indicate this could be important in interpreting pollock survey results.
The “peas” are equipped with digital cameras
The most exciting project for me is the “Optical Pea Pod”, another Kresimir/Rick design. The pod houses 2 digital cameras, a timed circuit board and a strobe light that is lowered in the net to photograph fish at regular intervals. The setup is designed to produce calibrated stereo images of fish making it possible to measure fish length in deep water. Perhaps, in the future, the cod end can be left open allowing the fish to swim out safely as they are documented. The imaging data can possibly be used to verify the acoustic data that is currently used to estimate the population, reducing the need to handle fish on deck. I would like to thank my technical advisors, Kresimir and Rick, for involving me in their projects and for their support in my work as Teacher at Sea.
Bird of the Day
Adrienne and Travis test the peacameras for pressure down to 80 meters
The Albatross is a seabird steeped in maritime folklore. Mariners of yore would tell stories of the souls of dead sailors rising when they saw the white bird. Famous for being one of the largest seabirds they are a magnificent sight. The Wandering Albatross is capable of extremely long migrations, circumnavigating the globe for years before settling down to breed. Albatrosses, of the biological family Diomedeidae, have recently been reclassified (based on recent DNA evidence) and the number of genii and species is widely disputed. What is clear is that many species are in danger of extinction. The greatest impact to their populations is long line fishing although many were slaughtered for their feathers before being protected after the turn of the last century. Swordfish, monkfish and cod are fished with long-lines involving miles of baited hooks that can attract the birds and lead to their entanglement and subsequent drowning. We have seen two species on this cruise, the Laysan and the Short-tailed Albatross. It is estimated that there are only between 1500 and 2000 Short-tailed Albatrosses remaining the world. Many were harvested for feathers and a volcano eruption at their Japanese breeding grounds decimated the remaining adults. Fortunately juveniles at sea have returned to breed and hopefully with protection, the numbers will continue to rebound. We were lucky to have one spend a fair amount of time of our stern in calm waters the other day as we were stopped for water quality testing.
Rick spends most of the sail tweaking the electronics and the software for things to work. In an attempt to upgrade the failing batteries of the strobe light he designs a super-battery housed in a milk carton.
Personal Log
The Bering is a surprisingly lovely color of blue and if the sun would ever come out I am sure it would accent the aesthetic of the water’s color. When we stop to check the water quality the CTD instrument makes for a decent secchi disk and I have observed anecdotally that the visibility seems to be around 13 meters or 40 feet.On an unrelated topic, the other day Executive Officer LT Bill Mowitt let me in on his “lesson plan” for the weekly drill. We went into a fan room and created an electrical fire scenario. We also left clues around the area for the crew and fire fighter team to assess and react to. When it came time for the actual drill I had front row seats to watch the drill unveil and was then permitted to test the fire house of the leeward side the ship. All went well.
Question of the Day Today’s question: How much fish did we catch? Previous Question: How does one become a Golden Dragon?
The short answer is one sails across the 180-degree line separating the eastern and western hemisphere. We did this going steaming to Russian waters continuing our survey work in the Northwest Bering.
Kresimir and Rick send the final prototype of the pea pod down in the trawl netPollock in the net down below 80 meters – caught and measured on cameraAnother amazing in-flight shot by Tamara K. MillsAn Immature Short-tailed Albatross off the stern of the OSCAR DYSON (image by Mark Rauzon).Executive Officer Bill Mowitt sets up a Fire DrillFire team reacts
NOAA Teacher at Sea
Roy Arezzo
Onboard NOAA Ship Oscar Dyson July 11 – 29, 2007
Mission: Summer Pollock Survey Geographical Area: North Pacific, Alaska Date: July 23, 2007
Weather Data from Bridge
Visibility: <1 nm (nautical miles)
Wind direction: 220° (SW)
Wind speed: 8 knots
Sea wave height: <1 foot
Swell wave height: 0 feet
Seawater temperature: 9.8 °C
Sea level pressure: 1006.7 mb (millibars)
Air Temperature: 10°C
Cloud cover: 8/8, fog
Roy and Tamara get excited about birding on the bridge of the OSCAR DYSON
Science and Technology Log
Consumers became very aware of the issue of by-catch when the media reported the canned-tuna industry was killing dolphins in their nets nearly a decade ago. The industry responded by changing some of their fishing methods and marketing “dolphin-safe tuna”. NOAA monitors and sets catch limits for commercial fishing, regulating by-catch, among other things. The Coast Guard assists by also enforcing these fishing regulations. Some of the scientists working here on the pollock survey have worked as fishery observers on commercial vessels, monitoring by-catch in the Alaska fleets. The by-catch regulations vary based on the region, species and season. For example, on the Bering Sea none of the finfish outfits are allowed to keep any crab, they need a special permit to keep halibut and they need to keep cod if they are fishing for pollock. Commercial trawling for pollock results in typically low by-catch. Some environmental groups have listed pollock as a sustainable fish food compared to other seafood in that the harvest does not seem to significantly harm the environment or severely deplete fish stocks. The Marine Stewardship Council, an independent global nonprofit organization, has certified Alaskan pollock as a sustainable fishery.
NOAA Scientist Abby separates out a Chrysaora melanaster jellyfish.
Although we are not dealing with by-catch directly, I find the connection between by-catch, sustainability and fish stocks very interesting. The Echo Integration Trawl Survey uses acoustic data to estimate pollock populations. When we put out our nets we do so to obtain a sample of fish, detected by our acoustic instruments. Since we are conducting mid-water trawls we bring up mostly pollock. The non-pollock species that occasionally get caught in the net are important in verifying the acoustic data and to know what is in the water column with the target species. As a science teacher, the diversity makes for interesting fishing and I have been able to observe a few organisms that spend most of their time in deep water. I have shared some of my images of the unusual species below, all of which I had never seen before this trip. Many of the organisms we bring up go back into the water after we record the data but some of our catch makes it to the galley to be served up for meals.
More Invertebrates
Some type of sea penSmall squidFlathead Sole (Hippoglossoides elassodon). Flatfish tend to swim higher in the water column in the evening following the planktonGreenland Turbot (aka Greenland Halibut)Pacific cod (Gadus macrocephalus)Pacific Herring (Clupea pallasi)Great Sculpin (Myoxocephalus polyacanthocephalus)Smooth lumpsucker (Aptocyclus ventricosus)Shrimp from a night trawlKier, Chef and Assistant to the Chief Steward, makes a serious shrimp bisque.Catch of the day: Chief Steward Rick cooks up Pollock Fish and Chips
Bird of the Day: Turns out, there is no such thing as a seagull. This was passionately explained to me by birder who will remain nameless. You ask, why no seagulls? Simply the term is not used in the scientific community. There are seabirds and of this general group there are well over 100 species of gulls. Some gulls are found well inland. Some species of land-based gulls have become popularized due to their opportunistic feeding around humans. Many of the pelagic gulls I have seen this trip are not as well trained as the ones in NYC and stick to wild foods, not even accepting the occasional fish scraps I have tempted them with off the back deck. I had reported in a previous log seeing Kittiwake’s and some immature Herring Gulls. Today we saw a Slaty-back Gull. It is a handsome gull with striking contrasts of black, dark grey and white. They seem to turn up more each time we reach the northern end of a transect line (above 60° latitude). I also learned that the red spot on the beak is a sign of maturity in many adult gulls. I have a renewed appreciation for gulls and look forward to identifying the species back home.
Bottom trawls, conducted on the previous leg of this study, tend to have more diversity in the sample
Personal Log
We are approaching the northwestern edge of our transect field and the water is deeper and colder and we are finding less fish. I am lucky to find more time to spend on the bridge and witness the communication with Russian fishing vessels, jumping salmon and occasional marine mammal sightings. I have a little camera envy. Some of the folks aboard have the right lens and the right camera to catch the action out at sea. My little 4X zoom digital is looking mighty bleak on the deck and thus I need to rely on the serious photographers for images of some of these exciting finds; their generosity in sharing their images is most appreciated.
Slaty-Back Gull
Question of the Day
Today’s question: How does one become a Golden Dragon?
Previous Question: Why do pollock rise in the water column at night?
Much of the food eaten by pollock fluctuates in their vertical migration depending on light penetration. During the daylight hours many of the euphausiids (krill) can be found lower in the water column. It seems that by staying lower in the darker portions of the water column during the day, zooplankton may be more protected from their major predators. Near the surface, the phytoplankton (algae) uses the sun’s energy to produce food all day. As the light fades the zooplankton rise, feeding on algae, and the pollock follow their food source.
Krill from one of our nighttime raids with the Methot TrawlKrill (pollock food): Partially digested from inside the stomach of a pollockPollock gill rakers screen food from leaving the oral cavity as the water passes out of the gill slits, oxygenating the gills
NOAA Lieutenant Commander D. Zezula reading the chart of the North Bering Sea
Science and Technology Log:
I would like to thank David J. Zezula, Lieutenant Commander for NOAA and Alaska Region’s Navigation Manager, who spent over an hour showing me charts and resources for my school. David is serving as a relief officer of the deck aboard the OSCAR DYSON. Around our second Transect this leg we needed to break off from our line momentarily to avoid some shallow pinnacles listed on the chart. Of the three, one pinnacle is charted in deep water and the tall thin pinnacle seems an unlikely seafloor feature. I was surprised to learn that the information on the printed chart was different from the digital GLOBE program the scientists use to assess the bottom. It was indicated on the printed chart that these shallow regions were charted back before we started making seafloor maps using multi-beam sonar technology. The actual depth in that region is thus questionable and rather than sail over what seemed like deep enough water we cruised around it for safety precautions. Our draft is about 29 feet and all of sensors are located on the centerboard that extends down below the hull’s lowest point. As a research vessel we care very much about our sensors.
Long-tail Jaeger photographed off the bow of OSCAR DYSON by Tamara K. Mills
I asked David about this and he went to his files and was able to show me more information about the dates and background on that specific chart. Some of the archives he has access to were actually scanned from hand written charts created with lead lines back at the turn of the century. One of the main parts of his job back on land is to help prioritize what regions of Alaskan waters are to be updated with modern technology as part of NOAA’s Office of Coast Survey (the hydrographic and nautical charting division of NOAA). Obviously they focus on key ports and channels first but there is much water out there to chart and verify.
Bird of the Day: Today I was fortunate to see yet another “new to me” species. The Long-tail Jaeger (Stercorarius, longicaudus) is a pelagic seabird that rules the air. Although it probably eats some fish near the surface it is famous for its aerial piracy. It is a very muscular bird that is capable of upending flying birds forcing them to regurgitate their stomach contents to obtain a meal. This is currently their breeding time so it is early in the season for them to be found this far out at sea but soon mature adults and their grown offspring will be out on the Bering looking for food before their winter migration to the south. I keep missing the albatross sightings and hope that it will be my next bird of the day. Information provided courtesy of Mark Rauzon, birder, author, educator and friend.
OSCAR DYSON’s centerboard
Personal Log
Land! It was very exciting to see land for many reasons. First, the sun was out, a rare treat on the Bering. Many of the weather entries above will list the cloud cover as 8/8, which means out of 8 parts of sky all of it is covered by clouds. Also the visibility was good and the seas, which turned up with some high winds last night, had calmed down considerably. Lastly we were looking at Russia, many of us for the first time, which made sense since we were in the north part of our third transect line in Russian waters. It was also the first time we have seen land since we left Dutch Harbor. Cape Otvesnyy, at 860 meters high was visible from about 63 miles away. We all went outside the bridge to take photos and celebrate.
Question of the Day
Today’s question: Why do pollock rise in the water column at night?
Previous Question: How is the field of acoustics used in science?
OSCAR DYSON’S deck crew attaches an acoustic device (yellow) to the fishing gear
Acoustics is a huge area of technology that ranges from how we design theaters to the use of sonograms to view unborn children. Much of the acoustic technology used in science has to do with creating alternative ways to observe different environments. Light does not travel through water as far as sound (vibrations). Sound waves are the key to looking deep into water. Marine mammals know this and can find prey with echolocation, reading reflected sound waves they send out to locate food and communicate.
On OSCAR DSYON we use several types of acoustic instruments
The Simrad EK60 is our main fish counting instrument and it uses about a 7º beam to send out sound waves of different frequencies and receive echoes from organisms and objects of different sizes. It is mounted on the centerboard and reads information from 5 frequencies ranging from 18 to 200 KHz. As we run along our transect line the data that is received is used to estimate the fish density. The scientists onboard spend a fair amount of time checking to see that the echoes actually represent pollock.
The ME70 Multi-beam is mounted to the ship’s hull and is a powerful tool in creating a wide swath three-dimensional image of what is below the ship. This is especially useful in hydrographic work that involves charting and mapping the seafloor bottom but it may be used for the fish survey in the future. The Acoustic Doppler Current Profiler (ADCP) is also connected to the centerboard and uses the Doppler Effect (the change in frequency and wavelength of a sound pulse as perceived by an observer moving relative to the source of the sound) to estimate current and fish speed.
We place a Net Sounder (FS70, affectionately known as the turtle) on to our fishing n each time we trawl. Like scientists, commercial fishermen often use this instrument to monitor the shape of the net opening and the amount of fish entering the net. It does this by sending a 200 kHz frequency beam across the opening of the net and transmits data along a cable for the team to see on our monitors. Along with the turtle we send down a Simrad ITI, which is smaller and wireless but a lower resolution net sounder that is used as backup in the event we have trouble with our cable.
The DIDSON (Dual Frequency Identification Sonar) is an instrument that has been developed for divers in low visibility water and has many industrial applications. It creates an image typical to the one seen on sonogram tests. It uses a high frequency beam (up to 1.8 MHz) to achieve a short-range image (up to 50 meters). It has been applied to salmon return rate studies and has well enough resolution to make out the shape of a moving fish. The pollock survey team has been experimenting with it as a way to monitor fish escapement from the net and how fish behave within the net.
In our survey work most of our mid-water trawls occur between 17 and 700 meters. The acoustic technology is vital to verify fish at these depths.
Science and Technology Log: Why fish pollock? What do pollock fish? Pelagic Food Webs of the Bering Sea
Surveying pollock on the Bering shelf provides the data needed to set catch limits to manage the fishery. Catch limits for American fishing fleets are to be decided soon for next year. The pollock survey I am part of as Teacher at Sea is technically known as the Echo Integration Trawl Survey been an annual tradition of NOAA since 1971! The OSCAR DYSON, and before her the MILLER FREEMAN, use traditional trawling gear to achieve this goal. The fishing gear tends to be smaller then the larger fishing vessels since we don’t need to catch as many fish to estimate population trends. Like commercial operations we are interested in where the fish are in the water column and their geographic distribution. We also are concerned with their age composition. Although we primarily use acoustic sensors to detect fish, by trawling we can see how the technology used to locate fish in the water matches with what is being caught in the net. We also monitor by-catch organisms to observe what is mixed in with pollock when trawling.
Aleutian Islands
Dutch Harbor, AK, according to the National Fisheries Service continues to be the No. 1 port by weight for seafood landings. In 2005, 877 million pounds of seafood passed through port, in 2006 it was more. In terms of seafood value only New Bedford, Mass., surpasses Dutch Harbor mostly due to the increase in the scallop market and decrease in crab populations. Dutch Harbor is known for its king crab industry in the winter and finfish year round, including hake, cod and salmon. Although shrimp is American’s most popular seafood item in terms of sales, finfish occupy much of the top five. Canned tuna is second highest for sales in the U.S., salmon is third and then pollock and tilapia; however if you factor in the global market, the amount of pollock being harvested and the sales for food products such as frozen whitefish foods, filets and surimi (Asian fish paste used in foods such as artificial crab) make it the largest seafood industry in the world (Anchorage Daily News). In addition Pollock are seasonally fished for roe. Commercially, fishing pollock is a good business venture due to its large schools and typically low by-catch. According to the National Marine Fisheries Service approximately 307 million dollars in pollock sales was made in the U.S in 2005. More than 3 million tons of Alaska pollock are caught each year in the North Pacific from Alaska to northern Japan. Of that the U.S. is responsible for about half. The population of Pollock in the Bering alone was estimated at 10 million metric tons early this decade and the catch limit was set around 10 –15% of the population size. Last year the survey team found a significant decline in populations and thus the catch limit was lowered but anecdotally there are preliminary signs of good recruitment with many young pollock being identified in this summer’s survey.
Assorted diatoms
We are clearly at the top of the food web and consuming a large amount of pollock. The pollock are part of a very complex ecosystem. They are fragile fish and short lived but fast growing and quick to reproduce. The pollock population seems to be greater in number then most other harvestable finfish in the Bering, possibly due to a decline in Pacific Ocean perch, and shows interesting fluctuations in population density in response to global climate changes and sea current patterns. The Bering Sea lies between the Arctic Ocean to the north and the North Pacific to the south but remains a unique ecosystem exhibiting some characteristics of each of its neighbors.
Jellyfish found in the plankton net – large plankton!
The food web of the pelagic zone of open water in the cold Bering Sea is contingent on movement of nutrient rich waters. The main source of nutrients for the upper shelf region where one finds pollock seems to be influenced by the flow of the Alaskan Stream near shallower coastal waters which flows east across the Aleutian chain. Some of the water flows up through passes and becomes parts of currents like the Aleutian North Slope Current that feed the shelf. The Bering Sea is an extremely large and a relatively shallow body of water making it very different and it is this nutrient flow between shallow waters of the coast and shelf and deep basin/trenches to the west and south that account for its high biodiversity. In addition to currents ice melt and water temperature greatly affects nutrient flow and productivity. The nutrient rich water enables phytoplankton to flourish and reproduce in otherwise cold barren water. In turn zooplankton feed on the phytoplankton which transfers the organic carbon foods from producers to other levels of the food web. Invertebrates (ex. crabs, shrimp and jellyfish), small birds, small fish and baleen whales feed on the zooplankton. Seals, sea lions, skates, larger seabirds, porpoises and toothed whales feed on the fish and invertebrates. A substantial portion in the diet of larger pollock is made of plankton such as krill. This is the same food baleen whales filter out of the water when feeding. Krill is the common name of shrimp-like marine invertebrates belonging to the order of crustaceans called the Euphausiids. Adult Pollock also dine on smaller pollock and this has been seen in our harvest as some pollock come up from the net with smaller fish in their mouth or stomach contents.
Pollock larvae
What is plankton?
Plankton is a general word used to describe aquatic organisms that tend to drift with the current and are usually unable to swim against it. They are generally buoyant and found in the epipelagic zone (top of water receiving sun energy) although many species have serious vertical migration to feed and escape predators. Most folks think of plankton as being tiny but large seaweeds and jellyfish are considered plankton. Phytoplankton refers to algae and photosynthetic organisms that make food with the sun’s energy. Diatoms are important phytoplankton in the Bering Sea ecosystem an have amazing silicon patterns. Zooplankton includes many groups of animal-like organisms, including microscopic protozoa and tiny crustaceans such as daphnia and copepods. The copepods population seems like an important link in understanding survivorship of young pollock. Many benthic crustaceans and mollusks (oysters and clams) start their life cycle as free-swimming larvae high in the water column. Young fish such as pollock also start their life cycle as plankton-like larvae.
Methot net, flow meter, and emptying the plankton net
Observing and Measuring Pollock Food: Last night we did a Methot Trawl. This involves dragging a net with a finer mesh than our fish trawl to pick up plankton. This is important in understanding what the fish we study are eating. When we dissect the belly of a pollock we often find it full of zooplankton with the occasional small fish, such as smelts or young pollock. We correlate the mass of the plankton caught in the net with the flow rate to estimate population density. We estimated 44,000 critters in the 35,000 cubic meters of water that passed through the net, much of which consisted of Euphausiids and Amphipods. This works out to approximately 1.3 plankton organisms per cubic meter of water.
Euphausiid pictured left and Amphipod pictured right
Personal Log
The Bering Sea has been relatively calm with good visibility. We have seen our first boats in over 36 hours, some fishing boats and a Coast Guard Cutter. There have been some marine mammal sightings but nothing close enough to make an ID. I am settling into a bit of a routine, waking around 10:30 AM for lunch and then relaxing and working out before checking in for my shift at 4 pm. I spend a fair amount of my off time in our spacious bridge discovering new technological toys and looking out for wildlife. Each day I spend some time out on the deck above the bridge for fresh air.
Mature Female Pollock with visible eggs
After dinner we usually begin fishing and I don my foulies and safety equipment and observe operations from the back deck. I then photo anything new that comes in and try to process any bycatch to make sure it is returned to the water quickly and in good shape. The science team then works together, processing the pollock and helping with the clean up. Sometimes the fish schools are large so we have to stay in our gear and work back to back trawls. After trawling we often look at the data collected or deploy various test equipment and water quality checks. Nighttime is not best for trawling so the few hours between sunset and sunrise is reserved for special project applications designed to modify our methods. In between fishing I work on my Teacher-At-Sea writings and interviewing folks on the boat.
Mature Male Pollock; testis visible above
Question of the Day
Today’s question: How is the field of acoustics used in science?
Previous Question: How does one tell a male fish from a female fish in Pollock?
Male and female Pollock look the same from their exterior anatomy. Although we weigh and catalog all the fish we pull in, we sex a 300 fish sample batch from each trawl. This involves dissecting the fish to identify their gonads. We make a cut on the ventral surface from the gills towards the anus. We open the body cavity and move the liver to the side to expose the other internal organs. Gravid females are relatively simple to ID since they have large egg sacks with whitish eggs. A mature female will have a large ovary that tends to be reddish and lined with blood vessels. Immature females are more difficult to identify and have a less pronounced ovary that varies in color.
Mature males will have developed white coiled testis. For undeveloped males one looks for pink globular organs where the white testis should be. Immature males are more difficult to identify but when no ovary is visible we search for a thin membranous tissue running from the Uro-genital opening up into the body cavity towards the backbone.
NOAA Teacher at Sea
Scott Dickinson
Onboard Research Vessel Shearwater September 30 – October 11, 2006
Mission: Quantitative Finfish Abundance Geographical Area: Channel Islands Marine Protected Areas Date: September 30 – October 11, 2006
Santa Barbara, seen from the ship
Prologue
The cruise that I participated on was a multi-part project that spanned several weeks. I came on board for the final, and most interesting part of the project. Those parts you can read about in my log entries, however some background and technical information may be useful to better understand the operation.
The cruise took place onboard the NOAA R/V Shearwater. The project was called a Quantitative Finfish Abundance and Exploration of the Channel Islands Marine Protected Areas. A cooperative Remotely Operated Vehicle (ROV) study with the California Department of Fish and Game, Marine Applied Research and Exploration, and the Channel Islands National Marine Sanctuary.
When I arrived, the bulk of the work had been completed and it was time for the experimental portions of the project to take place. These experiments were designed to ensure the reliability, precision, and accuracy of the quantitative data collected by ROV survey. The basic operations involved live boating the ROV along predetermined track lines. That is, the RV Shearwater would proceed along a predetermined line on the surface that the ROV was also independently operating on at the ocean floor. The ROV had a range of 50 meters from the stern of the RV Shearwater. The ROV pilot had on-screen-display (OSD) from the video cameras mounted on the ROV, as well as an OSD that displayed the ROV position relative to the mother ship. This display is generated with the use of a sonar beacon mounted on the ROV and a sonar receiver lowered over the side of the mother ship.
On to the logs…
Deploying the ROV
Saturday 9/30
Arrive at the R/V Shearwater. Got the lay of the land.
Sunday 10/1
Head out of the Santa Barbara Harbor in transit to Santa Cruz Island to pick up the research crew. With the team of scientists on board, we head out for our destination of East Point on Santa Rosa Island for the first deployment of the ROV.
The weather turned on us, with the winds blowing and the rain pounding. The seas got rough and the going was slow. This being the first day out, the sea legs had yet to be adjusted. This was the cause for a quick retreat to the head…
Finally made it to our testing location. Weather was dismal as the ROV was launched. Today’s mission was to “paint” fish with lasers mounted along side the ROV camera. This was a very interesting procedure designed to measure fish length. Essentially capturing a fish on video and “painting” it with two laser dots at the known distance of 11 cm. Total fish length can then be calculated either by determining fish camera fish length and laser dot space, or by using the screen width and the fish length in comparison.
This day I became umbilical tender and hydraulic operator for launching and retrieving the ROV. I also observed the underwater video and fish painting process. This was a very interesting day becoming part of the crew and assisting in the work. Due to a couple of technical issues, we returned to Santa Barbara for the night.
Watching and operating the launch
Monday 10/2
While crewmembers were working on correcting the technical issues, I assisted others with setting up lines for the next set of experiments. This required setting up vinyl covered steel cables at a length of 110 meters and marking them with colored flags every 10 meters that would be easy to view through the ROV cameras. These cables were also set up with loops on each end for linking together, or for securing weights. The cables were then spooled for ease of deployment and stowed for later use.
The technical issues as well were repaired and again we set out to sea. This day’s destination was Anacapa Island. With some sonar scanning, a sight was selected for the next sets of experiments, to determine accuracy of transect distance precision across the spatial dimension.
For this experiment, the 110 meter cables were laid across the bottom with high relief profiles. This distance of cable would provide a length of 100 meters to run with the ROV. Divers also swam the line and took depth readings along the cable. The cable ran up and down over rocks and various substrates that are considered fish habitat. The concept being that there were more lineal feet of fish habitat in this relief than straight line distance. The ROV recorded this distance, but this was a means to determine if those recordings were an accurate measurement.
The sight we were working was spectacular. We were on the southern tip of Anacapa Island. The shoreline of the island was shear rocky cliffs. The cliffs are a major nesting and roosting sight for the endangered California Brown Pelicans, they were everywhere both on the cliffs and circling in the sky. The area was also populated with sea lions. They were very amusing swimming around the boat and with their barks echoing off the cliffs of the island. After the work here was done, we headed north for a protected cove to drop anchor for the night.
Brown pelican nesting area on the high cliffs
Tuesday 10/3
This day we headed back toward Anacapa to continue the track line experiments. Another shallow depth sight was selected toward the North end of the island. The same procedures were used here laying out the cable lengths that were then checked by divers and then run with the ROV.
The water was thick with small baitfish that was being fed on by schools of Bonita. This was a sight to see, and was particularly amusing to see the pelicans dive-bombing into the water also feeding on the baitfish. This went on for most of the day. Operations went well today and when complete the gear was collected and stowed. We headed off to another protected cove for the nights anchorage.
Wednesday 10/4
We continued the track line experiments today. Work was going well so we started preparations for the next upcoming experiment. The preparations consisted of setting up fish models of various sizes and securing weights to then to enable deployment of them floating various heights off the bottom. The fish models were constructed of a flat piece of neoprene with color copied pictures of the local significant fish species laminated and attached to the sides.
The sight of the day was a pod of dolphins leaping out of the water and splashing around in some sort of frenzy. We assumed the must have been feeding, but were not really close enough to tell exactly what was going on. Today’s tasks went well and I went out on the Avon to retrieve the cables and the divers. With all back onboard, we headed off to the nights anchorage.
On the zodiac
Thursday 10/5
Today we set out for a deep water site to continue the track line experiment. The previous sites had been in the 10 to 20 meter depth zones. Today we would run the track line experiment in a 50 meter depth zone. This posed a different set of circumstances. The tracking cable was spooled into a basket for deployment. It was then deployed skillfully and precisely by the well experienced deck officer. With the cable in place, the ROV was launched to run the line. This depth was to deep to send divers down, so the ROV did all the work. Tracking went well and the ROV was brought back on board.
Recovery of the gear was a bit more difficult. We had to haul back the cable and weights with a power winch as opposed to winding it back by hand in shallow water. After we got about half of the length back, it got jammed and snapped so fast my head spun. At least the experiment was completed.
After gathering and comparing the ROV data with the diver collected data it was apparent that the ROV collected nearly identical data to the diver collected data. This experiment seemed to be a success. ROV use and procedures seemed to be a reliable means to determine transect distance across the spatial dimension by my observations. Naturally the collected data would be reviewed later by the scientists on board to accurately determine the results.
Full moon rising
During the day we continued to prepare the fish models for deployment tonight. With the track line experiments complete, we headed for a location suitable for the fish model experiment. This experiment was conducted in the evening to simulate the light conditions in the typical habitat depth of 50 meters. The point of the experiment was to determine the accuracy of fish length as determined by ROV survey. The ROV survey used both paired lasers and distance sonar to determine fish length. When these procedures are utilized on fish models of known length, the scientists could determine if the process could be accurate when video capturing wild fish in the test zone.
As we arrived at the experiment location, the sun was setting and a most beautiful full moon was rising over a distant horizon. Divers were used to strategically deploy the models to simulate populations of wild fish. The ROV was deployed and ran the line of fish models while video capturing the images. Tonight I had an opportunity to pilot the ROV. I thoroughly enjoyed this opportunity and spent some time observing some flat fish scurrying about the bottom as I waited for the divers to collect the fish models. Soon all was complete, the divers came back on board, and we recovered the ROV safely. We remained at this location for the night, it was quite beautiful.
Friday 10/6…the final day.
Today was a public relations day. We returned to Anacapa and met up with the California Dept. of Fish and Game boat, the R/V Garibaldi. They had brought some local writers and reporters out to cover the project. We still went on with the normal operations of surveying fish populations. It was another great day on board the NOAA R/V Shearwater as a participant in the Teacher at Sea Program! Back to Santa Barbara we cruised.
