NOAA Teacher at Sea
Adrienne Heim Onboard NOAA Ship Albatross IV August 7 – September 2, 2007
The CTD, recording information at depth
Mission: Sea Scallop Survey Geographic Region: Northeast U.S. Date: August 27, 2007
Science and Technology Log: CTD Casts
Immediately following the fire and abandon ship drills, we proceeded to have a debriefing regarding appropriate and professional behaviors, as well as, receiving information regarding shift schedules, meals, work expectations, etc. Our Chief Scientist, Victor Nordahl, informed us of the various duties and responsibilities each of us would have during the Sea Scallop Survey. I was paired with another volunteer, Shawn, to help with the measuring of the sea scallops once they were sorted and weighed. I was also assigned the role of performing CTD casts and collecting data from the inclinometer.CTD casts are performed at every third station. The acronym stands for conductivity, temperature, and depth. It is a hefty contraption that is hooked onto a cable and sent down, a vertical cast, into the water. Basically, while the CTD is sent down vertically, it records the temperature, depth, salinity, and pressure. The saltier the water, the more conductivity is generated. The cast first soaks for about one-two minutes at the surface of the water to record the salinity. It is then sent down, stops about 5-10 meters before reaching the bottom of the ocean floor and then is hauled back. Recording this data is essential for scientists, especially while conducting a Sea Scallop Survey; because the CTD casts helps to associate water temperature and salinity with sea scallop abundance. Scientists record the data to view it later and assess the casts with the other data collected from the work stations.
Computers and cameras recording information from the CTDThe winch at the back of the shipCommunicating with the winch operator
NOAA Teacher at Sea
Adrienne Heim Onboard NOAA Ship Albatross IV August 7 – September 2, 2007
Working at night
Mission: Sea Scallop Survey Geographic Region: Northeast U.S. Date: August 24, 2007
Science and Technology Log: Sample Sorting
It is then time to get to work. Each of us works in 12 hour shifts. We are either designated to a noon-midnight shift or visa-versa. First, the winch operator sends out the dredge. It trolls in 15 minute increments and collects everything that it encounters along the way. This includes various marine life, vegetation, and bottom sediment like rocks and sand. Once it is brought to surface the deck handler’s work with the winch operator to lower the dredge to the middle of the stern. The dredge is emptied of its contents and then it is our turn to sift through it. The marine life is sorted into blue buckets according to their species. Our Watch Chief teaches us how to identify them, especially when sorting Winter versus Little Skates or Winter versus Yellow-Tail Flounders. We put all of the scallops into large orange baskets. The species are then weighed and measured. We work in pairs and each pair is assigned to one of the three work stations. The data is recorded into the FSCS, which stands for Fisheries Scientific Computer System. Some of the scallops are frozen for further scientific investigation while the others, as well as the other marine life collected from the dredge are put back into the water. The buckets are washed and stored for the next tow, which occurs every 45 minutes as we wait to reach the following station.
Sorting baskets
I am learning so much and I can’t wait to bring all of this information back to my students. My next log will discuss the diversity of the marine life here along the Georges Bank and Nantucket Shoals, as well as, the purpose of the FDA sending employees to test for PSP (Paralytic Shellfish Poison) within the meat, viscera, and gonads of the sea scallops.
QUESTIONS OF THE WEEK FOR MY STUDENTS:
What preys upon sea scallops besides starfish?
How are the open and closed waters designated and determined?
What is the impact of scallop fishing on the overall ecosystem?
NOAA Teacher at Sea
Adrienne Heim Onboard NOAA Ship Albatross IV August 7 – September 2, 2007
Mission: Sea Scallop Survey Geographic Region: Northeast U.S. Date: August 16, 2007
Science Log: Beautiful Sunsets
The best thing about working 12 hour shifts are the sunsets! Sunsets along the Atlantic Ocean have been positively beautiful.
The weather has shifted drastically while on board the ALBATRSS IV. Initially in the voyage the weather was cold, foggy, damp, and windy. The visibility was difficult, as well as, balancing myself with the continuous rocking of the vessel. Quite a feat! Recently the weather has been gorgeous: fair skies, very warm, with a rewarding breeze. My partner, Shawn McPhee, and I have developed quite a rhythm for measuring the scallops and cleaning up. We have even “graduated” to measuring many other species in order to help expedite the process and allow enough time for our Watch Chiefs to focus, more importantly, on collecting other sorts of data during each tow.
NOAA Teacher at Sea
Adrienne Heim Onboard NOAA Ship Albatross IV August 7 – September 2, 2007
Woods Hole
Mission: Sea Scallop Survey Geographic Region: Northeast U.S. Date: August 7, 2007
Weather Data
Visibility: 10 miles or more
Latitude: 68° 27.5 W
Longitude: 41° 24.7 N
Wind Speed: 6.5-7 Knots
Wind Direction: N NE
Cloud Cover: 10-20% : Stratus
Seawater Temperature: 15.5 °C
Sea Level Pressure: 1013.2mb
Sea Wave Height: 1 foot
Sea Wave Swell: 2 feet
Science and Technology Log
Downtown shops
I arrived in Woods Hole, MA on Sunday August 5th, 2007. The ALBATROSS IV was scheduled to depart early Monday morning, but we were unfortunately delayed a couple of days as a result of waiting for some diesel oil and fresh water shipments to arrive. During our delay we took a tour of the NOAA Aquarium right there in Woods Hole, MA. We started to become more acquainted with some of the species we would encounter while on the survey. We set sail early Tuesday afternoon. I stood at the stern of the vessel watching the landscape fade away into the foggy mist.
Once on board and steadily sailing north bound, a few procedures and protocols were immediately rehearsed. The first procedure was a fire drill. As the alarm sounded, we quickly retrieved life jackets and a large orange tote containing a wet suit from our rooms and proceeded into the “wet lab” where we waited for the following instructions. Afterwards, an abandon ship drill was announced. The entire crew congregated at the stern of the vessel. Each individual had to rapidly unpack the survival suit from the large orange tote. We had to slip into the red immersion suits, which proved to be a bit difficult for me to maneuver. However, hopefully in the event of an actual abandon ship emergency, I would be much more successful at putting them on. They certainly provide enough protection in case of an emergency.
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)
