gangion – Page 2 – NOAA Teacher at Sea Blog

August 19, 2013August 20, 2021

Liz Harrington: Let’s Go Fishing! August 17, 2013

NOAA Teacher At Sea
Liz Harrington
Aboard NOAA Ship Oregon II
August 10 – 25, 2013

Mission : Shark/Red Snapper Bottom Longline
Geographical area of cruise: Western Atlantic Ocean and Gulf of Mexico
Date: Aug 17, 2013

Weather: current conditions from the bridge:
Partly cloudy, scattered showers and thunder storms
Lat. 27.19 °N Lon. 84.38 °W
Temp. 92 °F ( 33.4° C)
Wind speed 10-15 knots
Barometer 30.1 in (1015 mb)
Visibility 10 mi
Sea temp 83 ° F (28.8 ° C)

Science and Technology Log

We have arrived at the survey sites, the fishing has begun and I’m having the time of my life! The process is a collaborative effort between the science team and the crew of the ship. In upcoming blogs I’ll focus on all the different people on board the ship and their roles, but I’d like to first tell you about the fishing from my perspective as part of the science team. The science team consists of four scientists and seven volunteers. We are divided into day shift (noon to midnight) and night shift (midnight to noon). I am assigned to the day shift.

I was told that about a mile of line with 100 hooks would be let out and weighted to stay close to the bottom. I was interested to see how they could let the line out and haul it back in again without all those hooks getting tangled. Well, I learned that the hooks are removable. The hooks are attached to one end of a 12 foot section of line. The other end holds a snap. This set up is called a gangion. The gangions are snapped onto the longline as it is let out and taken off the line as it is reeled in. They are stored in a very orderly way to avoid tangles, although an occasional tangle does occur. As the ship is approaching a designated site we prepare for setting the line. This is done from the rear of the ship, called the stern.

baited gangions — Gangions baited and ready to set

We bait the hooks and decide on job assignments. The jobs that need to be done while setting the line are “Data” (manning the computer to keep a count of the gangions that are put on the line); “High Flyer” (throwing out the buoys that will mark the beginning and end of the line); “Slinger” (throwing the baited hook over the edge of the ship and holding the other end of the gangion to receive a numbered tag); and “Numbers” (snapping numbered tags on to the gangions). The weather conditions and the speed of the current must be checked before the final approval is given to set the line. When the signal is given our team gets to work.

Skilled fisherman Chuck Godwin and I get ready to put out the high flyer

High Flyers mark each end of the longline

Lead scientist for this trip, Kristin Hannan, slinging while we set out the line. The bait is Atlantic Mackerel.

After the line is set and the work station is cleaned up (that bait can get a little messy!), a CTD is deployed to gather data on the water – Conductivity (a measure of salinity), Temperature and Depth. The CTD also measures the dissolved oxygen in the water – remember that fish breathe by absorbing oxygen from the water as it runs over their gills.

An hour after the last high flyer is set, the line is hauled in. This is done from the bow (the front deck of the ship). During this part of the process I am full of anticipation as we wait to see what each hook holds. It might be a light catch with a couple of fish or it might be a very busy catch. When the crew yells “fish on”, the action begins. Anything that is caught is brought on board and data is collected (more on this later). If it is too big to be pulled in, then it is lifted into a cradle and worked on along the side of the ship. The crew will determine if cradling is needed and will shout out “hard hats”, as we all need to be wearing hard hats when the crane is being used to move the cradle. In our first two days of fishing, the day shift has cradled five sharks. It is so exciting to be next to such a big, beautiful creature.

The final step to the fishing process is clean up. Our gear is put away, the deck is hosed down (using salt water, as fresh water is in precious on a ship), numbers are checked for proper order and damaged gangions are repaired. If there were fish caught that require dissection, this would be done now as well. In the meantime, Oregon II steams on to the next survey site. So, you can see that the ship is a busy place 24 hours a day.

repairing or replacing worn gangions — Members of the day shift science team repair gangions after a recent haul. Foreground- Micayla and Cliff, volunteers. Background – Amy Schmidt, scientist.

Personal Log

I am having so much fun on the Oregon II. The work is really interesting and the people have been fantastic. Not only has everyone on board been very friendly and helpful, but they have really made me feel like a member of the team. Right from the start we were trained for the various jobs and expected to do them, with lots of help and encouragement always available. I initially thought I’d be more of an observer, but that is not the case at all. All of the volunteers are actively involved in every aspect of the fishing routine.

sharpnose shark — Here I am taking measurements on a Sharpnose Shark

I find it fascinating that people from all over the country have come together to cross paths here aboard a ship in the Gulf of Mexico. In future blogs I’d like to highlight some of their stories, but for now there is work to be done (although I’m not to the point where I can call this work. It’s way too much fun!)

New Terms

Shark Burn – the abrasion received when a wiggling shark rubs against your skin.

Water Haul – nothing at all is caught during a set.

night shark — Daniel, volunteer, prepares to release a Night Shark

removing hook — Removing a hook from a cradled Sandbar shark

Micayla and Cliff stabilize the CTD during deployment.

data collection — Micayla logs hook numbers as line is let out.

July 30, 2012August 11, 2021

Steven Frantz: Training at Sea, July 30, 2012

NOAA Teacher at Sea
Steven Frantz
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.

Parts — From top to bottom: clips, hooks, AK snaps

Hooks on Bucket — 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.

August 18, 2011March 12, 2021

Jennifer Goldner: Shark Week- All day, every day!, August 16, 2011

NOAA Teacher at Sea
Jennifer Goldner
Aboard NOAA Ship Oregon II (NOAA Ship Tracker)
August 11 — August 24, 2011

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 Mackeral for the next station — Mark, Chief Scientist, and Adam, Scientist, preparing Atlantic mackerel for the next station

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
hooks.

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

Scientists getting the gangion ready to give to Jeff, Chief Boatswain

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.

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.

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.

Personal Log

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 dogfish shark — Me with a smooth dogfish

Adam, Scientist, getting ready to measure a tiger shark

Drew, Scientist, measuring a blacknose shark

Me touching a sandbar shark — Me touching a nurse shark