NOAA Teacher at Sea
Aboard NOAA Ship Oregon II
September 13 – 29, 2013
Mission: Shark and Red Snapper Bottom Longline Survey
Geographical Area of Cruise: Gulf of Mexico
Date: September 19, 2013
Weather Data from the Bridge:
Barometric Pressure: 1017.17mb
Sea Temperature: 28.8˚C
Air Temperature: 27˚C
Wind speed: 18.05 knots
Science and Technology Log:
Those of you following our progress on the NOAA Ship Tracker might have noticed some interesting movements of the ship. We had some rough weather that forced us to skip a station, and the current by the mouth of the Mississippi River also forced us to skip a station. The safety of everyone on board comes first so if the seas are too rough or the weather is bad we will skip a scheduled station and move to the next one. Now we are off the coast of Florida and hope we can get some good fishing done!
This survey is being done using longlines. Longlines are exactly as their name describes, long stretches of line with lots of hooks on them. The line we are using is 6,000 feet long, the length of one nautical mile. From that long line, there are 100 shorter lines called gangions hanging down with hooks on the end. Each gangion is 12 feet long.
When we arrive at a sampling station, everyone on our shift helps to set the line. In order to set the line, we have to bait each one of the hooks with mackerel.
Once the hooks are baited, we wait for the Officer of the Deck (OOD), driving the ship from the bridge, to let us know that we are in position at the station and ready to start setting the line. The first item deployed is a high flyer to announce the position of our line to other boats and to help us keep track of our line.
This is a bottom longline survey so after the high flyer is deployed, the first weight is deployed to help pull the line to the bottom of the ocean just above the seabed. After the first weight is deployed, it is time to put out the first 50 hooks. This is typically a three person job. One person slings the bait by pulling the gangion from the barrel and getting ready to pass it to the crew member. Another person adds a number tag to the gangion so each hook has its own number.
A member of the deck crew attaches each gangion to the main line and sends it over the side into the water. The gangions are placed 60 feet apart. The crew members are able to space them out just by sight! The bridge announces every tenth of a mile over the radio so they are able to double check themselves as they set the line. Another weight is deployed after the first 50 hooks. A final weight is placed after the last hook. The end of the line is marked with another high flyer. Once the line has been set, we scrub the gangion barrels and the deck. The line stays in the water for one hour.
Once the line has soaked for one hour, the fun begins! Haul back is definitely my favorite part! Sometimes it can be disappointing, like last night when there was absolutely nothing on the line. Other times we are kept busy trying to work up everything on the line. When the line is set and brought back in, everything is kept track of on a computer. The computer allows us to record the time and exact location that every part of the line was deployed or retrieved. The touchscreen makes it easy to record the data on the computer.
It is nice to be doing some fishing! There have been some long distances in between our stations so my shift has not gotten the opportunity to set the line as much as we would like. I’m hopeful that the weather holds out for us so we can get a few stations in on our shift today. Being able to see these sharks up close has been amazing. I am enjoying working with the people on my shift and learning from each one of them. Before we haul back the line, I ask everyone what their guess is for number of fish on the line. My number has been 45 the past few haul backs and I’ve been wrong every time! Christine was exactly right on one of our last haul backs when she guessed two. I know I’ll be right one of these stations. It is hard to get pictures of what comes up on the line because we get so busy processing everything. I’m going to try to get more pictures of our next stations.
The views out in the Gulf are gorgeous. I never get tired of them!
Did You Know?
When we arrive at a sampling station, the officer on watch must be aware of other ships and rigs in the area. At times the bridge watchstander will make the decision to adjust the location of our sampling station based on large ships or rigs in the area.