As soon as the day group’s shift started at noon we were right into sorting the catch and doing the work-up of weighing, measuring and taking samples.
It’s with a good bit of anticipation waiting to see what the net will reveal when its contents are emptied! There were some new fish for me to see today of which I was able to get some nice photos. I was asked today if I had a favorite fish. I enjoy seeing the variety of star fish that come down the conveyor belt as we sort through the catch even though they are not part of the survey. The Atlantic Mackerel (Scomber scombrus) are beautiful with their blue and black bands on their upper bodies and their shimmering scales. They are a schooling fish and today one catch consisted primarily of this species. I’m fascinated with the unusual looking fish such as the goosefish, the Atlantic wolffish (Anarchichas lupus) with its sharp protruding teeth, and some of the different crabs we have caught in the net. Another catch today, closer to land where the seafloor was more sandy, was full of Atlantic Scallops. Their shells consisted of a variety of interesting colors and patterns.
Today I also had a chance to have a conversation with the Commanding Officer of the Henry B. Bigelow, Commander Jeffrey Taylor. After serving as a medic in the air force, and with a degree in Biology with a concentration in marine zoology from the University of South Florida. What he enjoys about his job is teaching the younger NOAA officers in the operation of the ship. He is proud of his state-of-the-art ship with its advanced technology and engineering and its mission to protect, restore, and manage the marine, coastal and ocean resources. Some things that were touched upon in our conversation about the ship included the winch system for trawling. It is an advanced system that monitors the cable tension and adjusts to keep the net with its sensors open to specific measurements and to keep it on the bottom of the seafloor. This system also is more time efficient. The Hydrographic Winch System deploys the CTD’s before each trawl. CO Taylor also related how the quiet hull and the advanced SONAR systems help in their missions. What we discussed that I am most familiar with since I boarded the Henry B. Bigelow is the Wet Lab, which was especially engineered for the Henry B. Bigelow and its survey missions. This is where I spend a good bit of time during the survey. The ergonomically designed work stations interface with the computer system to record and store the data collected from the fish samples 100% digitally. I was pleased to hear what thought, skill and fine tuning had gone into designing this room as I had earlier on the trip mentally noted some of the interesting aspects of the layout of the room. Commanding Officer Taylor also had high praise for his dedicated NOAA Corps staff and the crew, engineers and scientists that work together as a team.
NOAA Teacher at Sea
Onboard NOAA Ship Oregon II
July 27 – August 8, 2012
Mission: Longline Shark Tagging Survey
Geographic area of cruise: Gulf of Mexico and Atlantic off the east coast of Florida
Date: July 29, 2012
TRAINING AT SEA
In my last blog I mentioned we would be at sea three days to get to where we will begin the longline survey. I thought I would take a little time to share some of the training before we ever start a longline survey. Everybody pitches in to make sure we have a safe, successful journey.
First we learned the different parts to the longline. The line starts with a high-flier buoy and a weight. Gangions (also known as a branch line or leader) are snapped to the line. Another weight is placed midway, with more gangions, then finally another high-flier buoy at the end. There are 100 gangions used for the NFMS Bottom Longline Survey. While there are several variations when using longline gear, the NFMS Bottom Longline Survey has used this standardized set-up in order to minimize variables. By using the same gear year after year they are able to compare fish catch data, minimizing any bias attributed to changing gear that may fish differently.
This just isn’t your average fishing trip! The longline itself is one nautical mile long! How long is this on land? In addition, each end is also calculated into the total length. This will vary depending on how deep the ocean floor is where we are fishing. The longline is left for one hour then retrieved.
Longline Diagram, courtesy Dr. Trey Driggers
Before we begin, everything needs to be ready and in place. Each gangion has to be placed in a barrel so they do not get tangled taking them out. A tangled bunch of gangions is a big problem. First, the AK snap of the gangion goes into the bucket. Next, let the line go into the bucket. Finally, place the hook in the notch in the bucket, making sure it points in toward the bucket. We certainly do not want anyone passing by caught by a hook.
From top to bottom: clips, hooks, AK snaps
How to place gangions in the bucket
There are many data scientists use in their research. We need to make sure we collect accurate data; consistent with the 18 years this study has been going on. First we learned how to measure the length (in millimeters) of a shark. We used an Atlantic Mackerel as a measurement example. There are three length measurements to be taken: Total Length (from tip or nose to tip of tail), Fork Length (from tip of nose to notch in tail), and Standard Length (from tip of nose to where body ends and tail begins). The shark is placed on a two meter long measuring board. If the shark is longer than two meters, a measuring tape is used to measure length. The three lengths are recorded.
In addition to the three length measurements, we must also identify the species of shark, measure weight, condition when caught, sex, maturity (for males), hook number, and any tag information if the shark had been tagged before. For some species, if the shark isn’t tagged, we will tag it. We also need to record which vessel we are on, which survey, which station, and the date. Data is also being collected on many aspects of the water. Other samples may be taken that will determine the age of the shark (vertebrae).
The last thing we learned was how to bait a hook. These hooks are big! Atlantic Mackerel are used for bait. We must be careful to double hook the bait or it will fall off.
There you have it. Tomorrow I will begin working the longline actually fishing for sharks!
After three days in the Gulf of Mexico we see land! We passed near enough to be able to see the coastline of Miami. It all seems so peaceful here aboard the Oregon II when looking out into what I know is the hustle and bustle of Miami, Florida.
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: August 16, 2011
Weather Data from the Bridge
Latitude: 25.15 N
Longitude: 82.48 W
Wind Speed: 2.09 kts
Surface Water Temperature: 29.20 C
Air Temperature: 30.10 C
Relative Humidity: 69.00%
Science and Technology Log
If there’s one thing I’ve learned since I’ve been on this trip it is that both science and technology are crucial for doing a shark survey. Keep in mind NOAA Ship Oregon II’s mission is not to fish for sharks, rather it is to survey them. In other words, it is to find out how the sharks are doing and where they like to hang out in the ocean. Thus, the ship doesn’t ONLY go to the “shark hot spots” so to speak. Instead, there are various locations the ship stops at to perform a survey. These are called stations. The stations vary greatly in depth, temperature, dissolved oxygen, etc. It would be similar to marketers taking a survey to see what restaurants people prefer.
With that being said, there is a certain science to performing a survey of the sharks. Here is how it is done. There is much preparation before leaving port to do a survey. NOAA Ship Oregon II cannot leave port without Atlantic mackerel, and lots of it. This is the bait that is used to catch the sharks. The hook of choice is a circle hook. The fishing line is monofilament and extremely strong. These are the basic items needed, but there are numerous other tools needed such as the cradle for larger sharks, tagging tools, vials for samples, and the list goes on. Suffice it to say, once the ship leaves from port, everything has to be on board in order to have a productive survey.
Anyone who fishes knows there are numerous ways to catch a fish. So how do you catch a shark? If you’ve ever seen the movie, “The Perfect Storm,” then you have a good idea. The method used is called longlining. As the name claims, this method makes use of a long line. The line must first be prepared. In order to do this the circle hooks are baited with Atlantic mackerel. There are 100 hooks in total to put on the line. The hooks are part of a unit called a gangion. A gangion consists of a leader, a monofilament line, and a circle hook. These are placed in a barrel. There are 50 gangions with bait per barrel, for a total of 2 barrels per fishing set.
Mark, Chief Scientist, and Adam, Scientist, preparing Atlantic mackerel for the next station
Preparing the bait
Hooks are baited and ready to go!
Gangion bucket- Notice when the line is set the bait is given out in a clockwise direction. When it is hauled back in, it is put in a counterclockwise direction.
Incidentally, there are 2 shifts: day shift (noon until midnight) and night shift (midnight until noon). I am on the day shift. Thus there are stations being worked 24 hours a day. The bridge will announce when we are coming on another station. Also, it is posted on the dry lab door so we can all be prepared for the next station. Knowing this, the shift gets the mackerel ready by thawing it out, then cutting it up to bait the
Once the ship is to the station, everyone gets in their places, and the OOD (Officer of the Deck) disconnects the engine. At this point the drift test begins. This takes into account both the wind and the current to determine what direction to set the line. If there is too much current, determined by the Field Party Chief and the OOD, the station is either canceled or moved closer to shore. Next the ship slowly moves forward (4 knots) and the line is fed from the ship. The line, which is 1 nautical mile, is let out at the stern (back) of the ship. The fishermen are responsible for feeding it through blocks (pulley) system. The 1st thing on the line is a high flyer. This is an orange flotation device put at the end of the line.
The next thing put on the line is a weight. This sinks the line to the bottom. At this point, the first of 50 baited gangions are handed to the fishermen to clip to the line, each being evenly distributed. It should be noted that each gangion has a hook number so that an accurate record can be kept. The hook numbers are taken off a line and clipped on the gangion as the bait is being fed over the deck to the fisherman. After the 50th gangion, another weight is put on the line, followed by 50 more gangions, another weight, and lastly, a high flyer. While all of this is going on, one person on the team records data on the computer which is instantly uploaded with such things as the latitude and longitude and real time of when each hook is deployed.
Longline Diagram, courtesy of Dr. Trey Driggers
100 hook number tags
Scientists getting the gangion ready to give to Jeff, Chief Boatswain
The night shift crew preparing the bait
Greg, Fisherman, clipping a gangion on the line
Chief Scientist, Mark Grace, records data
The longline is allowed to soak for 1 hour before it is brought back on board on the starboard (right) side of the well-deck, just aft of the bow (front). During this time the deck and buckets are cleaned up and the CTD is deployed (Conductivity Temperature Depth).
The CTD takes many measurements including temperature, salinity, turbidity, chlorophyll, depth, and dissolved oxygen. These measurements give the scientists valuable information for the habitats of the sharks. For example, any level of dissolved oxygen 2.0 mg/liter or lower is considered apoxic and causes physiological stress on an animal. Most animals live in an area between 2-7 mg/liter of dissolved oxygen. A reading of 7 would only be found in very cold water such as the Arctic.
Water color test
In addition to the CTD readings, the scientists report the water color along with the current weather conditions.
After the line has soaked, the team meets at the bow to haul in the line. The fishermen unclip the gangions from the line and hand it off to a scientist who records the hook number and the condition of the bait. If a fish is caught, it is brought aboard and morphometric (total length, fork length, sex, and weight) data is collected.
Travis, Scientist, taking measurements
In the event a larger fish is caught, it is placed in the cradle.What are the benefits of doing a longline survey? It gives the scientists presence/absence data from looking at what was caught and was not caught. It gets samples from the Gulf to compare with other areas.
Mark, Chief Scientist, taking measurements
One word: WOW! Let me say it backwards: WOW!!! This week is DEFINITELY making my “Top Ten Life Experiences” list!! Shark Week has absolutely nothing on this NOAA crew! It is evident they eat, sleep, and live sharks and other fish all year long. NOAA Ship Oregon II needs to have a camera follow them for a reality show called “Shark Year.” If they aren’t catching it, they are studying about it. I am amazed at the depth of knowledge of the entire crew, including each and every member on board, of the ocean. What impresses me even more is their enthusiasm and patience in teaching this teacher how it all works.
Now for your questions. . .
One of you asked about shark finning. According to the scientists and fishermen on board it is not a big problem off the coast of the United States like it is in Asia. Here it is regulated. In fact, when commercial fishermen bring in their sharks, the fins have to be attached, so that cuts down on this practice.
Another question that came up was in regards to tagging. On this ship the scientists mainly use passive tagging techniques. This requires the fish to be recaptured after it has been tagged. The tag has a phone number to call when the shark is caught as well as an identification number. Another method of tagging is active tagging, for instance satellite tags. Satellite tags are attached to animals to study migration. These are very expensive, ranging from $3,000-$5,000. They are set to pop off the animal at a predetermined time and date and transmit data to a satellite in order to plot the shark’s course. Many shark species are migratory so this type of tag is beneficial to see their migration patterns.
Also, a question was asked about how deep it needs to be to safely navigate. According to Cap, the draft for the ship is 15 feet. The ship can safely sail in 30 feet of water. That’s unbelievable for a ship of this size, huh? It makes Orgeon II a great vessel to do the shallow water surveys. Most other ships can’t go that shallow.
By the way, great job class on last blog’s poll! The correct answer was 70! You all aced the quiz!
My son, Hayden on his 1st day of 6th grade
I also have to share a picture of my son, Hayden. His 1st day of school was Monday. I can’t believe he is already in 6th grade! Hayden is a shark enthusiast and is following my blog at home with my parents. Cap has already told me he is welcome on the ship. Someday he can come study sharks, just like his Mom!
Shark Gallery Pictures
The next blog will be a lesson on specific sharks, but for now, enjoy the pictures!!
Me with a smooth dogfish
Adam, Scientist, getting ready to measure a tiger shark