Mission: Alaska Walleye Pollock Survey Geographical Area: Gulf of Alaska Date: July 6th, 2013
Location Data from the Bridge: Latitude: 55.29.300 N
Longitude: 156.25.200 W
Ship speed: 10.7 kn
Weather Data from the Bridge: Air temperature: 8.6 degrees Centigrade
Surface water temperature: 8.6 degrees Centigrade
Wind speed: 14 kn
Wind direction: 210 degrees
Barometric pressure: 1008.5 mb
Science and Technology Log:
The Oscar Dyson is equipped with several labs to accommodate the researchers on board. In this blog post I will describe to you what is happening in the wet/fish lab. This is where I have experienced quite a bit of hands-on data collection.
After a trawl, the crew dumps the load of fish into a bin. Inside the lab we can raise or lower this bin to control the amount of fish coming onto a conveyor belt. Once the fish are on the belt the scientists decide how they will be separated. We separate the pollock according to age into baskets. They are categorized by size; under 20 cm (age 1), under 30 cm (age 2), and any larger than 30 cm
At this time we also pull out any other sea creatures that are not pollock. So far we have pulled up quite a few jelly fish, la lumpsucker, shrimp, squid, eulachon, and capelin. These are also weighed, measured, and in some cases frozen per request of scientists not currently on board.
After organizing the pollock into appropriate age groups, we then measure and record their weight in bulk. Scientists are using a scale attached to a touch screen computer with a program called CLAMS to record this information. The pollock are then dumped into a stainless steel bin where their sex will be determined. In order to do this the fish must be cut open to look for “boy parts, or girl parts”. After the pollock are separated into female and male bins we begin to measure their length.
The tool used to measure length is called the Ichthystick. This tool is connected to the CLAMS computer system. The fish is placed on the Ichthystick and a pointer with a magnet in it is placed at the tail end of the fish. There are three different types of length measurement that can be done: fork length, standard length, and total length. When the magnetic pointer touches the Ichthystick it senses that length and sends the information to the CLAMS computer system.
One of these bins of fish is placed aside for individual weighing, length measurements, and removal of otoliths. You may recall that I mentioned otoliths in the last blog post. These ear bones are sent to a lab and analyzed to determine the age of each of these individually measured fish. The Alaska Fisheries Science Center has created a demonstration program where you can try to determine the age of different types of fish by looking at their otoliths. Click here to try it yourself! (I will add hyperlink to: http://www.afsc.noaa.gov/refm/age/interactive.htm)
One afternoon while waiting for the fishermen to bring up the trawl net, I watched a group of porpoises swimming behind the ship. Another day I was able to see whales from up on the bridge. These were pretty far out and required binoculars to see any detail. I observed many spouts, saw one breach, and some flukes as well.
There is quite a bit of downtime for me on the ship while I am waiting in between trawls. I get to read a lot and watch movies in my free time. I have had the opportunity to talk with different members of the crew and learn about their roles a bit. The chief engineer gave me a tour of the engine rooms (more about this with pictures in a future post.)
The 4th of July fireworks show on the Oscar Dyson was like no others I have ever experienced. Two of our crew, Ben & Brian, dressed in official fire gear shot expired flares off the ship into the sea. America themed music was played over the PA system. I have attached a video of our fireworks display. Happy Independence Day everyone!
NOAA Teacher at Sea Kathleen Harrison Aboard NOAA Ship Oscar Dyson July 4 — 22, 2011
Location: Gulf of Alaska Mission: Walleye Pollock Survey Date: July 9, 2011
Weather Data from the Bridge True wind direction: 59.9°, True wind speed: 11.44 knots
Sea Temperature: 9°C
Air Temperature: 8.9°C
Air pressure: 1009.74 mb
Foggy with 1 mile visibility
Ship heading: 88°, ship speed: 11 knots
Science and Technology Log
The Shumagin Islands are a group of about 20 islands in the Gulf of Alaska, southwest of Kodiak Island. They were named for Nikita Shumagin, a sailor on Vitus Bering’s Arctic voyage in 1741. They are volcanic in origin, composed mostly of basalt.
Several islands even exhibit hexagonal basaltic columns. There are about 1000 people who reside in the islands, mostly in the town of Sand Point, on Popof Island. According to the United States Coast Pilot (a book published by NOAA with extensive descriptions about coastlines for ship navigation), the islands extend out 60 miles from the Alaskan Peninsula. They are bold and mountainous.
The shores are broken in many places by inlets that afford good anchorages. The shores are rockbound close to. Fishing stations and camps are scattered throughout the group, and good fishing banks are off the islands. Fox and cattle raising are carried on to some extent.
Sea water quality is very important to the scientists on the Oscar Dyson. So important, that it is monitored 24 hours a day. This is called the Underway System. The sea water comes through an intake valve on the keel of the bow, and is pumped up and aft to the chem lab. There, it goes through 4 instruments: the fluorometer, the dissolved Oxygen unit, the Thermosalinograph (TSG), and the ISUS (nitrate concentration).
The fluorometer measures the amount of chlorophyll and turbidity in the sea water once every second. A light is passed through the water, and a sensor measures how much fluorescence (reflected light) the water has. The amount of chlorophyll is then calculated. The measurement was 6.97 µg/L when I observed the instrument. The amount of phytoplankton in the water can be interpreted from the amount of chlorophyll. Another sensor measures how much light passes through the water, which gives an indication of turbidity. Twice a day, a sample of water is filtered, and the chlorophyll is removed. The filter with the chlorophyll is preserved and sent to one of the NOAA labs on land for examination.
The next instrument that the water passes through will measure the amount of dissolved oxygen every 20 seconds. Oxygen is important, because aquatic organisms take in oxygen for cellular respiration. From plankton to white sharks, the method of underwater “breathing” varies, but the result is the same – oxygen into the body. The oxygen in the water is produced by aquatic plants and phytoplankton as they do photosynthesis, and the amount directly affects how much aquatic life can be supported.
The TSG will measure temperature, and conductivity (how much electricity passes through) every second, and from these 2 measurements, salinity (how much salt is in the water) can be calculated. The day that I observed the TSG temperature was 8.0° C, and the salinity was 31.85 psu (practical salinity units). Average sea water salinity is 35. The intense study of melting sea ice and glaciers involves sea water temperature measurements all over the world. A global data set can be accumulated and examined in order to understand changing temperature patterns.
The last instrument measures nitrate concentration in the sea water every couple of minutes. It is called ISUS, which stands for In Situ Ultraviolet Spectrophotometer. Nitrate comes from organic waste material, and tends to be low at the surface, since the wastes normally sink to the bottom. The normal value is .05 mg/L, at the surface, at 8°C. Values within the range of 0.00 to 25 mg/L are acceptable, although anything above 5 is reason for concern.
All of the data from these instruments is fed into a ship’s computer, and displayed as a graph on a monitor. The Survey Technician monitors the data, and the instruments, to make sure everything is working properly.
New Species Seen today:
Whale (unknown, but probably grey or humpback)
Living on a ship is quite different from living at home. For one thing, every item on the ship is bolted, strapped, taped, or hooked to the bulkhead (wall), or deck (floor). Most hatches (doors) have a hook behind them to keep them open(this reminds me of when I put hooks behind my doors at home to keep little children from slamming them and crushing fingers). Some hatches (around ladderways (stairwells)) are magnetically controlled, and stay open most of the time. They close automatically when there is a fire or abandon ship situation or drill. Every drawer and cabinet door clicks shut and requires moving a latch or lever to open it. For some cabinet doors that you want to stay open while you are working in the cabinet, there is a hook from the bulkhead to keep it open.
On every desk is a cup holder, wider on the bottom than the top, designed to hold a regular glass or a cup of coffee. If one of those is not handy, a roll of duct tape works well for a regular glass. All shelves and counters have a lip on the front, and book shelves have an extra bar to hold the books in. Trash cans and boxes are lashed to the bulkhead with an adjustable strap, and even the new copier machine has a special brace that is bolted to the deck to hold it in one place (I heard that the old copier fell over one time when there was a particularly huge wave). There are lots of great pictures on the bulkheads of the Oscar Dyson, and each one is fastened to the bulkhead with at least 4 screws, or velcro. There are hand rails everywhere – on the bulkhead in the passageway (hallway) (reminds me of Mom’s nursing home), and on the consoles of the bridge.
Desk chairs can be secured by a bungee cord, and the chairs in the mess (dining room) can be hooked to the deck.
Another thing that is different from home is the fact that the Oscar Dyson operates 24-7 (well, in my home, there could easily be someone awake any hour of the night, but the only thing they might operate is the TV). The lights in the passageways and mess are always on. The acoustics and water quality equipment are always collecting data. Different people work different shifts, so during any one hour, there is usually someone asleep. Most staterooms have 2 people, and they will probably be on opposite shifts. One might work 4 am to 4 pm, and the other would work 4 pm to 4 am. That way, only one person is in the room at a time (there is not really room for more than one). There is always someone on the bridge – at least the Officer of the Deck (OOD) – to monitor and steer the ship. During the day, there is usually a look out as well.
His job is to, well, look out – look for floating items in the water, whales, rocks, and other ships (called contacts or targets). This helps the OOD, because he or she can’t always keep their eyes on the horizon.
I have thoroughly enjoyed living on the Oscar Dyson (we have had calm seas so far), and talking with the NOAA staff and crew. They are ordinary people, who have chosen an extraordinary life – aboard a ship. It has challenges, but also great rewards – seeing the land from a different perspective, being up close to sea life, and forging close relationships with shipmates, as well as participating in the science that helps us understand the world’s oceans.
NOAA Teacher at Sea Richard Chewning Onboard NOAA Ship Oscar Dyson June 4 – 24, 2010
NOAA Ship Oscar Dyson Mission: Pollock Survey Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor) Date: June 18, 2010
Weather Data from the Bridge
Position: Bering Sea, north of Dutch Harbor Time: 1600 hours Latitude: N 55 06.120 Longitude: W 166 33.450 Cloud Cover: Mostly cloudy Wind: 10 knots from the west Temperature: 7.1 C Barometric Pressure: 1010.8
Science and Technology Log
In order to manage a public resource such as pollock, fisheries managers must develop a stock assessment. A stock assessment is a big picture overview of a certain population of fish. Fisheries managers use stock assessments to determine opening and closing dates for fishing seasons, catch limits (the number of fish that can be caught by a particular fisherman or boat), and the total allowable catch for the season. Stock assessments are developed from a combination of fishery dependant and independent data. Fishery dependant data includes catch records from commercial fishing boats and reports from processors dockside that prepare and package the fish for market. Combined with this information is fishery independent data. This information is gathered from sources not involved with commercial fishing.
The Dyson’s acoustic trawl survey is one of the primary sources of fishery independent data for the pollock stock assessment. The Dyson’s transducers provide a wealth of acoustic data from each transect. These acoustic returns must first be identified or deciphered before being used in the stock assessment. Just like you need a key to decode the symbols on a road map or need a scale to interpret the colors on a weather map, the acoustic returns also need to be referenced with actual pollock specimens collected by trawling. By matching up the characteristics of the fish caught in the trawl with their acoustic returns, researchers can interpret all the acoustic data from the entire survey area.
Pollock specimens are collected with Aleutian wing trawls, or AWTs for short. An Aleutian wing trawl is a single large net deployed off the stern of the Dyson. Large metal fishbuster doors are used to open the mouth of the net in the water. The catch is collected in a bag located at the end of the net called the cod end. The cod end’s mesh size prevents anything larger than 0.5 inches from escaping. Once the net is hauled back on deck, the cod end is emptied in the wet lab, and the entire catch is sorted. Fish are identified, counted, weighed, and measured. The gender and maturity of a subsample of pollock are also recorded. Stomachs are collected to determine what the pollock are eating. Finally, otoliths, the ear bones of fish, are collected. Just like counting the rings of a tree, researchers will count the number of rings in the otolith to determine the age of the pollock. Notable bycatch (fish that were not targeted) include eulachon, arrowtooth flounder, Pacific cod, sturgeon poacher, and yellowfin sole. Misha told me Russians used to dry out eulachon whole and use them as candles because of their high oil content. In fact I learned that one of common names in the US for eulachon is candlefish!
Why gather so much information on a single species of fish like pollock? Fisheries managers are responsible for the sustainable use of public resources. Without careful monitoring, fishing pressure, natural predation, and disease might remove pollock from the population faster than they can replace themselves. There is great demand for pollock both commercially and in the Bering Sea ecosystem. Walleye pollock is the largest US fishery by volume and third largest by value. Annual US catches can average 2.5 billion pounds. Pollock is also an important food source for Stellar sea lion, other marine mammals, birds, and other fish.
On Thursday, I had the pleasure of joining two members of the deck crew, Joel Kellogg and Glen Whitney, to pick up a new addition of the science party in Dutch Harbor. Mike Sigler, a fish biologist with NOAA, is a project leader and principal investigator with the North Pacific Research Board’s Bering Sea Integrated Ecosystem Research Program (BSIERP). He is joining the Dyson for the last week of our survey. BSIERP is a six year long collaborative study with the National Science Foundation’s Bering Ecosystem Study (BEST). More than a hundred scientists from these two groups are investigating the organisms and physical forces that make up and influence life in the Bering Sea ecosystem.
To pick up Mike, the Dyson launched the Peggy D. Named for wife of Oscar Dyson, the Peggy D. is a small power boat used to ferry people to and from shore. Peggy Dyson is a famous Alaskan in her own right, serving as a National Weather Service ship to shore weather broadcaster. Her voice brought vital information and reassurance to Alaskan fisherman. She diligently performed these duties twice a day, seven days a week for 25 years. I really enjoyed having the opportunity to see the Dyson from the water as my only vantage point for the last two weeks has been from the Dyson looking out. I was surprised how quickly the Dyson shrunk on the horizon as we sped away and traveled into Dutch Harbor. Dutch Harbor felt like a true frontier town. The vehicles seemed to reflect the character of the town. While looking rough and weathered on the outside, the beat-up cars and trucks of Dutch Harbor revealed a resilience and gritty determination to keep moving forward and press on against an unforgiving environment. I loved hearing the cry of the bald eagles that were spotted everywhere you looked. While I enjoyed having solid ground under my feet for a few short minutes, I appreciated the sense of familiarity and belonging I felt upon returning to the Dyson.
Scute, the Georgia Sea Turtle Center Mascot, was spotted visiting the Bering Sea today! Scute, a loggerhead sea turtle, travels the world promoting awareness of sea turtles. We know Scute was only visiting the Bering Sea as these waters are too cold for loggerhead sea turtles. Loggerhead sea turtles are the most abundant sea turtles in US coastal waters. Scute’s home is the Georgia Sea Turtle Center (GSTC) located on Jekyll Island, Georgia. The GSTC is a research, rehabilitation, and education center dedicated to helping sea turtles along the GA coast and around the world. Sea turtles released from the GSTC will often have a satellite transmitter attached to their shell just like Scute. The transmitters allow researchers to track their movements at sea. Only one of the seven species of sea turtles found worldwide can survive this far north – the leatherback sea turtle. The leatherback sea turtle is the largest species of sea turtle reaching six and a half feet in length and weighing as much as 2000 pounds! Leatherbacks have several adaptations such as high oil content in their large bodies that help them tolerate the cold waters of the southern Bering Sea. Leatherback sea turtles feed on jellyfish and can dive to great depths because the protection provided by their leathery shell (a hard shell would crack under the high pressure of the water). For more information about Scute and sea turtles, check out the GSTC website at http://www.georgiaseaturtlecenter.org !