Mission: Alaska Walleye Pollock Survey
Geographical Area: Gulf of Alaska
Date: July 13, 2013
Location Data from the Bridge:
Longitude: 152.32 W
Ship speed: 10.7 kn
Weather Data from the Bridge:
Air temperature: 11 degrees centigrade
Surface water temperature: 11 degrees Centigrade
Wind speed: 7.14 kn
Wind direction: 90 degrees
Barometric pressure: 1018 mb
Science and Technology Log:
The scientists on the Oscar Dyson are using several different types of cameras and sensors. I have already mentioned the CamTrawl. This camera is attached to the trawl net and takes pictures as the net is being dragged behind the ship. The pictures are time stamped. These pictures help to identify at what time and depth things were entering the net. This is very helpful if you have a haul with a variety of different fish. Also attached to the net is the FS-70 Netsond sensor, also known as the third wire.
This third wire uses sound and its echo to see what is entering the net. One more sensor attached to the net reads temperature and depth this is the SeaBird Electronics SBE-39 Bathythermograph.
Sometimes sensors and cameras are dropped from the side of the ship. These are not attached to a net. Instead, these are on frames that are dropped over the side and lowered using thick cable wire on a winch. The CTD sensor measures water conductivity, temperature, and depth.
The Drop Camera also is dropped from the side of the ship and lowered using a winch. This also has a depth sensor and takes time stamped pictures. This device can help scientists identify fish present in areas that they are not able to trawl in.
The compilation of information gathered from these sensors, cameras, and haul data will help scientists get a good picture of what type and how many fish are present in different areas around Alaska and in varying ocean conditions. The analysis of this data will be used to help determine the quota for commercial fishermen looking for the Alaskan walleye pollock in different areas.
There are sensors on the hull of the ship that are always gathering information. On the NOAA website Ship Tracker you can see some of this information in real time.
Yesterday was an excellent day for whale watching. We spent our afternoon and evening surrounded by a pod of Humpback whales. At times they were so close that I could hear them breathing. They were much closer and more plentiful than the first whale sighting. Last night in the mess hall I got up to look out the porthole (window) and a whale came up less than 50 feet from me. It was amazing!
We continue to trawl pulling up on average 2 to 3 hauls an evening. In our hauls the majority of the fish are pollock. This week I have also seen, more capelin, rock fish, and lumpsuckers. We have also pulled up dog salmon, arrow tooth flat fish, krill, cod, and a spiny lumpsucker.
I was given a tour of the engine rooms below by the Chief Engineer. It was very loud. There is a lot of machinery on board to make the ship self-sustainable while at sea. One of the machines is called the “water maker”. This takes salt water and heats it to 140 degrees Fahrenheit. The machine then captures the steam, leaving behind salt and other non desired items in the water. The steam is then condensed to make all for the fresh water for the ship.