Karen Grady: Sometimes You Find A Little Something Extra, April 16, 2017

NOAA Teacher at Sea

Karen Grady

Aboard NOAA Ship Oregon II

April 5 – April 20, 2017

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: April 16, 2017

 Weather Data

Latitude 2848.37 N
Longitude 09247.66 W
76 degrees
Sunny
No precipitation
Winds at 11 KTS
Waves at 2-4 FT

Science and Technology Log

Sometimes when a shark or fish is brought on board it has a “hitchhiker’ attached. We caught a blacknose shark that had a common remora, often referred to as a sucker fish, or shark sucker, attached to it. Scientist Kevin Rademacher placed this sharksucker (Echeneis naucrates) on my arm. I couldn’t really feel it but he was stuck there until I peeled him off. It was like peeling a piece of tape off. You can see from the photo how he is designed to attach to host species. Their head is actually a modified dorsal fin that has an oval shaped sucking disk with slat-like structures that open and close to create suction and take a firm hold against the skin of its host animal such as a shark, turtle, whale, or ray. By sliding backward, the remora can increase its suction, or it can release itself by swimming forward. They can be small like the one attached to my arm or they can grow to over two feet in length. The remora can move around on the host, removing parasites while at the same time gaining protection provided by the host. This relationship is often looked at as one of commensalism where both the host and the remora benefit.

Photos of the remora that was attached to a black-nosed shark.

When one hears that this is an experimental long-line survey of sharks and reef fish, all you think of is catching these creatures and collecting data. However, scientists are collecting data about the environment as well. It is very useful to obtain information about the water where they catch large numbers of a species and areas where they may not catch anything. One way they can do this is by using a Conductivity Temperature Depth Profiler (CTD).

The CTD gives scientists a profile of the water column where we just put out our line. The CTD has sensors that collects information on oxygen levels, temperature, water clarity, chlorophyll concentration, and salinity. The CTD is placed in the water and allowed to sit for three minutes to let the oxygen sensors soak and adjust from being on the deck and lowered into the water. The crew lowers it to a depth that is decided based upon the depth to the ocean floor. They like to take it as close to the bottom as possible in order for the information they gather to be as complete as possible. It is allowed to settle, run its scans and then is brought back up to the surface and the sensors are flushed with fresh water. The data is automatically loaded into the database. This information is collected at each station. It takes a joint effort of the deck, science and bridge crews to place the CTD in the water. Walkie talkies are utilized for communicating between all the crew involved in the operation.

Personal Log

Being at sea with Easter approaching had its moments when I thought of family and friends. We have our Easter traditions and I would be missing them this year. The Easter Bunny (Field Party Chief, Kristin Hannan) decided we needed an early visit this year. I think she was right. The surprise and the treats perked all the science staff up.

TAS Karen Grady 4-16-17 Easter basket

FPC Kristin Hannan asks me often if I have any questions about what they are doing or anything in general. I will be honest… I have gotten so caught up in what we are doing, trying to do my best at whatever job I am working on, and being in awe that I am actually out here that I forget to ask questions about the details. I love the anticipation of what might be on the next hook, I am mesmerized by the sleek lines of the sharks when we have them on board.

TAS Karen Grady 4-16-17 shark liver

Shark liver

When we had one come onboard that was dead due to low oxygen levels in the water where we caught it, we did a dissection on the deck while we waited to put out another line. The animal science nerd in me came to life!   I had no idea the liver was the largest organ inside a shark. Think about it …these creatures have no body fat and they store their energy in the liver. Then we looked at the intestines. There is not a lot of room in there so the shark we looked at the intestines are rolled up like you would roll a piece of paper. This gives them maximum absorption area but takes up a limited space.

 

 

 

One thing I think of as we are catching these species is that very few people stop and think about the actual research scientists do to help understand what is needed to maintain healthy populations. It is necessary to do these surveys, catch the species, tag some, draw blood, take fin clips, keep whole specimens, and dissect some. On our cruise we were lucky enough to ultrasound a few pregnant sharks and see the pups inside.

TAS Karen Grady 4-16-17 shark ultrasound

Baby sharks visible on ultrasound

Now stop and think about all those things I just listed that we do at times. When a hook comes up and there is a fish or shark on it is handed off to one of the science crew.  It is noted in the computer that there was a something caught. The science crew member will take measurements and weight of the fish or shark. If it is a shark, the sex will be noted and some species may be tagged, have a fin clip taken and blood drawn. While all of these activities are taking place, the next hooks keep being brought up. The deck can get pretty crazy if there are several hooks in a row with something on them. The data collector has to keep tag numbers, species, measurements, samples and weights all written in the correct spot while having two or three people calling them out for different fish and or sharks. I had experience working cattle which would mean filling syringes, writing down tag numbers, filling taggers, etc. But this is even crazier than that could get at times. And everything stops if someone calls “hardhats” because that means we have one big enough for the cradle. Working back writing down data or taking measurements you can’t see what is on the next line so you sneak up for a peak when they say it’s a big one then you get out of the way.   One of the best experiences so far was almost getting a big tiger shark in the cradle. I was lucky enough to get a video of her, so stay tuned! Unfortunately, when the big shark brushed against the cradle she snapped the line and was gone with a huge spray of water.

This second leg of the experimental long-line survey is winding down. There have been long days but they are filled with laughter, giggles, anticipation, excitement, teachable moments (I can finally get the circle hooks out by myself…sometimes) , and the dreaded words “snapper.” I mean nothing against the Red Snapper, they are a bright colorful and tasty fish, but when you are hoping for a shark to be on the hook…. let’s just say the sets where we get 12 snapper and two sharks are not our favorites.

Photos: “Shark!” or “Fish on!” means a busy deck.

TAS Karen Grady 4-16-17 hammerhead cradle

Scalloped hammerhead shark

When the guys at the rail grab the hard hats it means it is time for the cradle and we get to see things like this gorgeous scalloped hammerhead. Things move very quickly when one is in the cradle. Safety for those on deck comes first and everyone is focused on getting measurements, fin clip and a tag on the shark and getting it safely back in the water as quickly as possible.

TAS Karen Grady 4-16-17 baby tiger shark

Baby tiger shark

Baby tiger shark in the cradle. They warned me that they were cute and they were so right. Yes, a shark can be “cute” when your referring to baby tiger sharks and baby hammerheads!

Did You Know

Sharks store energy in their liver. It is the largest organ in their body. The heart on the other hand is extremely small in comparison to the size of the shark.

TAS Karen Grady 4-16-17 hammerhead dissection

Dissected scalloped hammerhead with liver visible

Look at the liver of this scalloped hammerhead. It is amazing how big it is in relation to the body of the shark. This is just one way these amazing creatures are designed to be efficient and survive in their underwater world.

Sharks have a nictitating membrane that they can close over their eye for protection. When a shark is brought on deck you can touch near the eye and the membrane will automatically move to close.

TAS Karen Grady 4-16-17 nictitating membrane

Nictitating membrane partially closed on the eye of a scalloped hammerhead

Karen Grady: One Fish Two Fish Red Fish …… Weird Fish, April 10, 2017

NOAA Teacher at Sea

Karen Grady

Aboard NOAA Ship Oregon II

April 5 – April 20, 2017

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: April 10, 2017

Weather Data

Latitude 2827.10
Longitude 09148.6
75 degrees
Sunny
No precipitation
Winds at 10 KTS
Waves at 2-4 FT

Science and Technology Log

We have continued to move between deep stations setting the baited line and hoping to catch deep water fish and sharks. These deep sets require longer soaking time to allow the hooks to reach the bottom.   The downside is that we have been retrieving one set of gear and putting out one set of gear in a 12 hour period of time. Some sets have a few fish and some we get a big goose egg.   There is always anticipation though as the 100 hooks are brought up. Everyone stands in their spots waiting to hear either “fish on,” “shark” or everyone’s favorite, “hard hats!” which means there is a big shark and it’s time for the sling. Below you will see the awesome Great Hammerhead (Sphyrna lewini) we caught.

TAS Karen Grady 4-13-17 great hammerhead

Great Hammerhead Shark

The first few days we have been fishing deep in the Mississippi Canyon. The Mississippi Canyon is a geological formation in the Gulf of Mexico. It is located in an area which is part of the territorial waters of the United States. We put out some deep lines with the deepest at 1900 feet. These lines soaked four hours once fully deployed.  They soak longer because they have so far to sink to get to the depth the scientists want to fish at. When we deploy a line the first thing in the water is the High Flyer, which stands like a beacon and bobs in the water marking the start of our fishing line. The next thing over the side of the ship is a weight that helps carry the line to the desired depth. Halfway through, another weight is deployed, and after the 100th hook, the third weight goes in.   The last thing over is another High Flyer to mark the end of the line. If it is dark outside, the High Flyers have lights attached on top that flash so that they can be seen.

TAS Karen Grady launching high flyer

“High Flyers” mark the beginning and the end of the long line set.

At our last deep station we caught a Mexican Grenadier, Coryphaenoides mexicanus. This fish is very unusual in color and appearance. If you feel the scales on the fish you find that they are very unique. Each scale has tiny sharp, thin spinules. As you run your hand over the fish you can feel these scale modifications. The eyes are bulged due to the pressure change of coming up from such deep depths. The scientists determined the sex of the Grenadier and then it was frozen for future study.

TAS Karen Grady 4-13-17 grenadier

Mexican Grenadier

We also caught two Cutthroat Eels, from the family Synaphobranchidae, that were both females. Synaphobranch means unified gill… the two gill slits join together making it look like a cut throat. They are bottom-dwelling fish, found in deep waters. The eels were weighed, measured, and the scientists determined the sex and maturity of each eel. It is important that they make accurate identification of specimens and collect data. The scientists work together using personal knowledge and books when necessary. There are times on deck when the scientists will stop to examine a species and will take multiple pictures of certain identifying parts so that they can look at them closely later.

 

Personal Log

One of the great things during a watch is being able to talk with the scientists. I am an avid listener and observer. This is what they do year in and year out and they love what they do. I am a quiet observer a lot of the time. I listen and then ask questions later. It’s not exactly easy to carry around paper and pencil to take notes. But during the transit portions or soak times I ask more questions and gather information to share in my blog posts or for the lesson plan I will be writing when I get home.

The food has been great here on the ship. Our stewards have fresh salads, and menus that include two main course options, a daily soup, dessert and multiple side choices.   There are snacks available 24/7 so you are never hungry. Because the meals are so great you see most people trying to fit in a workout during the day. I have been introduced to the Jacob’s ladder for workouts. I never liked hills and now I can say I don’t like climbing ladder rungs either. That machine is evil!! However, I will continue to do cardio on it as the food is excellent and keeping food in your stomach helps prevent sea sickness. I will happily eat more than I usually do if it means I don’t get seasick. An example of a typical lunch would be today when we had choices of salad, reuben, tuna melt, french fries, sweet potato fries, cookies and several other sides.

Today started with us catching two Cutthroat Eels and a Mexican Grenadier. You can see from the pictures I have posted that they look very different from most fish that you see. They really are that color. It was a shock after the sleek sharks and the bright orange Red Snapper I had seen on previous sets. I was busy watching the scientists using their books and personal knowledge to identify each species accurately.   After we finished the work up on the fish we caught we headed for the next station. Now we are back to shallower fishing and expect to catch sharks, red snapper, and a variety of other fish.

TAS Karen Grady 4-13-17 grenadier and eels

Two cutthroat eels (top) and Mexican grenadier (bottom)

I can honestly say that the 12 hour shifts start wearing you down, and sleeping is not an issue once you climb under the covers. The waves will wake you up now and then. And some mornings I wake up and can smell them cooking breakfast but sleep overrides the smell of food because I know how long it will be till I get to bed again. Walking out on deck each morning to views like this does lead to a smile on your face, that and the music that is playing loudly on the deck. Yesterday it was Hair Nation…. taking me back to the 80’s.

TAS Karen Grady 4-13-17 blue water

View from the deck of NOAA Ship Oregon II

Did You Know?

The Gulf of Mexico is roughly 995 miles along its longer, east-west axis. It has a surface area of about 600,000 square miles.

A wide variety of physical adaptations allow sharks to thrive in the Gulf of Mexico. They have powerful smell receptors. The sensory organs lining their prominent snouts, called ampullae of Lorenzini, can detect movement of potential prey even if the sharks cannot see it. These sensory organs assist in trailing injured marine animals from great distances. They help sharks locate all sort of other things, too– shrimp boats, other sharks, birds, turtles (tiger sharks a big turtle eaters!), even boats that are dumping trash.

The skin on a shark is smooth if you run your hand head to tail and rough like sandpaper if you run your hand from tail to head. At one time, sharks skin was used as a form of sandpaper. The dermal denticles, or skin teeth, can be different from species to species and can sometimes be used as a character to look at when trying to identify one species from another.

Emily Sprowls: Gulpers of the Gulf, March 31, 2017

 

NOAA Teacher at Sea

Emily Sprowls

Aboard NOAA Ship Oregon II

March 20 – April 3, 2017

 

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: March 31, 2017

 

Weather Data from the Bridge

12:00 hours

29°36.7’ N, 87°43.7’ W

Visibility 10 nm,

Wind 6 kts 350°N

Sea wave height 2-3 ft.

Seawater temp 22.9°C

 

Science and Technology Log

GulperEye

Gulper shark from 800 meters under the sea!

On the deep longlines we sampled many gulper sharks (Centrophorus spp.). Gulper sharks have cool anatomical adaptations, including their huge reflective eyes, buccal folds for gulping their food, and the ability to excrete huge amounts of slime from their skin. Gulpers also have very large eggs, which is of particular interest to my crewmate Lydia Crawford, a scientist from Tulane University that is studying shark reproduction and evolution.

LydiaDissects

Lydia dissects a shark specimen to study its eggs.

Lydia is collecting eggs from as many different kinds of sharks as she can in order to understand more about how sharks evolved a variety of reproductive strategies. Oviparous sharks and skates lay egg cases, also knows as “mermaids purses.” Oviviparous sharks let their eggs hatch internally and the babies are born swimming. Some embryos eat other eggs or even their siblings as they develop in their mother! Placental viviparous sharks are also born alive, but the embryos are fed via umbilical cords, similar to us humans.

Lydia will examine the microscopic structures of the shark ovaries she collected when she gets back to her lab. She hypothesizes that certain features of the ovaries have allowed sharks to evolve the ability to give birth to large babies, ready to act like the apex predators they are!

 

Personal Log

Last night we caught a blacktip shark (Carcharhinus limbatus) that my data sheet says measured 1.4 meters, but my memory says it was MUCH BIGGER because he lunged and snapped at us! Most of the sharks we have collected have been rather stunned by their brief trip out of the ocean onto the deck, but this guy acted like a shark still in the water! He and his biting jaws were clear reminders of what incredible predators sharks are. He put a healthy dose of fear back in me, along with a lot of respect for the science team who managed to measure him despite his aggressive activity!

 

Kids’ Questions

  • Why don’t sharks have swim bladders?

Sharks maintain neutral buoyancy by having very large, oily livers. We confirmed this by throwing the dissected lobes of the liver overboard and they floated!

  • Is there a shark that glows in the dark?

The eyes of some of the deep sea sharks that what we caught appear to be glowing because they are so big and have very reflective layers (called tapeta lucida) that shines back the boat lights. However some sharks, including the lantern shark, have special organs called photophores that glow!

Lydia Tilefish

Marine biologist Lydia with tilefish (Lopholatilus chamaeleonticeps)

  • How would you recommend reversing the sense of fear people associate with sharks?

Lydia’s response:

As a scientist, you shouldn’t try to reverse people’s fears because you can’t rationalize away a feeling. Also, we should have a respectful fear of sharks. They are amazing predators! Instead we should convince people why sharks are important in the ocean ecosystem as keystone species.

Emily Sprowls: Shark Bait, March 28, 2017

NOAA Teacher at Sea

Emily Sprowls

Aboard NOAA Ship Oregon II

March 20 – April 3, 2017

 

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: March 28, 2017

 

Weather Data from the Bridge

RedSnapper

Red snapper (Lutjanus campechanus)

13:00 hours

29°09.3’ N 88°35.2’W

Visibility 10 nm, Scattered clouds

Wind 8 kts 170°E

Sea wave height <1 ft.

Seawater temp 22.9°C

 

Science and Technology Log

In addition to experimenting by sampling deeper, we are varying the fishing gear and using different kinds of bait. We have switched to hooks on a steel leader so that even a strong, big shark cannot bite through the line. We are rotating through squid and mackerel as bait in order to see which species are more attracted to different bait. In addition to many species of sharks, we have also caught and measured eels, large fish and rays.

Nick hooks

Nick prepares hooks for longline gangions.

One of the scientists on board specializes in fishing gear, and helps keep maintain all our gear after it gets twisted by eels or looped up on itself. He also works on turtle exclusion devices for trawling gear.

 

Personal Log

Last night the line pulled in a huge tangle of “ghost gear.” This was fishing line and hooks that had been lost and sunk. It would have been much easier to just cut the line and let the mess sink back to where it came from, but everybody worked together to haul it out so it won’t sit at the bottom tangling up other animals.

Ghost gear

Lost or “ghost” gear that tangled in our lines.

This is just one example of the dedication the scientists and crew have to ocean stewardship. I have been so impressed by the care and speed with which everybody handles the sharks in order to get them back in the water safely.

 

Kids’ Questions

  • Is there any bycatch of dolphins?
Deep seastar

A few seastars come up with uneaten bait as bycatch.

Today we saw dolphins for the first time! They were only a few of them pretty far from the boat, so they did not affect our sampling. Had they decided to come play by riding in our wake, we would have postponed our sampling to avoid any interactions between the dolphins and the gear. One of the reasons that we only deploy the fishing gear for one hour is in case an air-breathing turtle or mammal gets tangled (they can hold their breath for over an hour). However, since dolphins hunt live fish, they don’t try to eat the dead bait we are using.

  • Can sharks use echolocation? How do they find their food?

Sharks do not use echolocation like marine mammals, but they do have an “extra” sense to help them find their food. They can detect electrical current using special sense organs called ampullae of Lorenzini.

  • What are the chances of getting hurt? Why don’t they bite?

While there is a chance of the sharks accidentally biting us as we handle them, we are very careful to hold them on the backs of their heads and not to put our fingers near their mouths! “Shark burn” is a more likely injury, which occurs when a shark wiggles and their rough skin scrapes the person handling them. Sharks do not have scales, but are covered in tiny, abrasive denticles that feel like sandpaper.

 

 

 

Emily Sprowls: The pressure is on! March 23, 2017

 

NOAA Teacher at Sea

Emily Sprowls

Aboard Oregon II

March 20 – April 3,2017

Mission: Experimental Longline Survey

Oregon2

NOAA Ship Oregon II

Geographic Area of Cruise: Gulf of Mexico

Date: March 23, 2017

Weather Data from the Bridge

13:00 hours

28°03.9’ N 89°08.3’W

Visibility 10 nm, Haze

Wind 3kts 100°E

Sea wave height <1 ft.

Seawater temp 25.1°C

 Science and Technology Log

The past two days have been devoted to setting extremely deep longlines. Each of these sampling lines take many hours, as we have to slowly reel out over 3 miles of line, give it time to sink, soak, and then reel it back in.   The line that we put out today is even a bit longer than usual, because I got to be in charge of “slinging” the hooks onto the line and I was not very fast at getting the four different sizes of hooks ready

Grenadier fish Kevin.jpg

A Mexican grenadier fish

. Have I mentioned how patient everyone is with the “Teach” aboard?

This morning we pulled up 97 empty hooks from 1250 meters before we caught the amazing grenadier fish! It suffered barotrauma, which is a nicer way of saying that its eyes and swim bladder inflated like balloons from the inside as it was hauled up from the high pressure depths.

One of the scientists onboard studies ocean food chains by examining the contents of fish stomachs. The stomach of the Mexican grenadier fish contained a fully intact armored shrimp!

Personal Log

Today I took advantage of the calm, calm seas to try the workout equipment onboard. They have all kinds of gear to help folks stay active and work off the delicious food in the galley. There is a rowing machine, stationary bike, weight bench, Jacob’s ladder, and elliptical. I used the elliptical machine because it was way too hot on the upper decks to use the exercise bike. Even with the very calm seas, there is a little bit of rolling, which made it an extra challenge for me keep it going!

Kids’ Questions of the Day

These questions about the Oregon II are from Harmony elementary students:

  • How big is the boat?       How tall? How long?

The boat is 175 feet long and 80 feet tall.

  • How much does the boat weigh?      

The boat weight is 800 tons. This is not how much the boat would weigh if you put it on a scale, but how

survival suit.jpg

TAS Emily Sprowls dons a survival suit

much weight the boat can carry if it were loaded full of cargo. We are not carrying nearly that much weight because a lot of the space on the boat is for equipment and for scientists and crew to live aboard.

  • How fast can it go?

Typically, the boat can go about 10 nautical miles per hour using both engines. She can go a little faster if the wind and current conditions are just right.

  • What is the boat made of?

The boat is made of steel and aluminum.

  • What are the white balloon things on top of the boat?

The white domes cover satellite dishes for the internet and phone.

  • What are the poles on the boat for? Are there sails?

The two yellow poles on either side of the boat are the outriggers used to

CTD sensor.jpg

This array houses the Conductivity, Temperature, and Depth probe.

pull a wide trawling net, much like a shrimp boat. Scientists trawl the bottom to study benthic organisms, including shrimp, but also sponges, crabs and bottom-dwelling sharks.

  • What new technologies does the boat have?

The Oregon II turns 50 years old this year!   It has been sailing the Atlantic Ocean since before I was born, but the crew is constantly fixing and replacing equipment on the boat. Even though she is old, she is very safe and reliable. Nevertheless, we still have to prepare for emergencies, including the possibility of needing to abandon ship while wearing the goofy-looking, but life-saving survival suits.

 

StyrofoamCup

Styrofoam Cup Test!

Scientists have brought new technology on board, including plenty of computers to collect, sort, store and analyze all the data we collect. One of the computers is connected to a device called the “CTD” with a set of sensors for Conductivity, Temperature, Depth and Dissolved Oxygen. Today the CTD went all the way to about 1100 meters (3700 ft.), and we tethered some styrofoam cups to the outside to subject them to the extreme pressure at that depth.

 

Emily Sprowls: It’s a shark eat shark world down there! March 22, 2017

NOAA Teacher at Sea

Emily Sprowls

Aboard Oregon II

March 20 – April 3, 2017

 

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: March 22, 2017

Science and Technology Log

This first leg of the Oregon II’s research for the season is an experimental longline survey. This is an exciting cruise for everybody, as we are all anxious to see what comes in on each line, and we hope to find some rare and little-studied species.

longline.jpg

               Reeling in a shark caught on one of the longline hooks 

A longline is a type of fishing gear that deploys one very long and very thick fishing line with many hooks attached. A fisheries survey is a systematic sampling of the ocean to assess fish populations. This mission is experimental because we are testing the longline at extreme depths and we are using different kinds of hooks in order to catch as wide a variety of species as possible.

Things have been busy onboard from the very first day, as we have been setting out and hauling longlines around the clock. We are headed deeper and deeper into the Mississippi canyon of the Gulf of Mexico with each station, starting at 100m and have worked our way down to 750 m, where we currently have a line “soaking” before we haul it up to record what we caught.

Personal Log

Life on the ship is divided into night and day watch. I’m “on days,” which means I work noon to midnight. I am so lucky to be a cruise with a lot of seasoned marine scientists and a great, hard-working crew. Shark scientist Kristin Hannan is the Field Party Chief and has taken me under her wing to get me settled and teach me as much as she can (without making me feel like the newbie that I am)!

oilrigs.jpg

Oil rigs on the horizon

The seas have been calm and the water is the most beautiful color of blue! We are pretty far out to sea, and I have been amazed to see so many oil rigs off in the distance. They glow like small cities at night, and I think they look like strange robots walking on the horizon during the day.

 

Kids’ Questions of the Day

These questions are from the 1st-2nd grade and multi-age classes at Harmony School.

  •  How do you catch the sharks?

We catch the sharks by setting out 100 baited hooks at a time on a very long fishing line. A winch reels in the 3 miles of line after a couple of hours, and we record what is on every single hook.

  • How do you find the sharks?

We rely on the sharks finding our baited hooks. We put weights on the line so that it will sink all the way down to the bottom. We are fishing so deep that it takes almost an hour just for the line to sink! The sharks find the bait using their incredible sense of smell.

  •  What do sharks eat? Fish? Squid? Cookies? Other sharks?

We are baiting the hooks with pieces of squid. The process of baiting hundreds of hooks has left my clothes covered with squid ink!

sharkbait.jpg

Hooks baited with pieces of squid

Sometimes they catch sharks with fish (mackerel), but squid bait stays better on the hooks, and deep-sea sharks clearly like squid, which also live in deep water. While this mission is experimental, the scientists onboard do not think we will have much luck baiting a hook with a cookie – it will just dissolve in the sea (besides the cookies in the galley are so delicious that there are no leftovers)! One type of deep-sea shark makes their own cookies… cookie-cutter sharks (Isistius) bite “cookies” out of other fish with their amazing jaws. Maybe we’ll catch one!?!

Last night we hauled in one hook with only a shark head on it…. What do you think happened to the rest of the shark?

 

Denise Harrington: A Shark A Day, September 29, 2016

NOAA Teacher at Sea

Denise Harrington

Aboard NOAA Ship Oregon II

September 16-30, 2016

Mission: Longline Survey

Geographic Area: Gulf of Mexico

Date: Thursday, September 29, 2016

Science Log

The cruise is coming to a close. Looking back at my three experiences with NOAA, hydrography (mapping the ocean), fisheries lab work, or shark and snapper surveys,  I couldn’t decide which was my favorite.  Like the facets of a diamond, each experience gave me another perspective on our one world ocean.

Just like different geographic locations and work, each shark species give me a lens through which I can appreciate the mysteries of the ocean.  Every day, I held, measured, kissed, or released a different species of shark. In the Gulf of Mexico, there are 44 shark species frequently caught.  Fortunately, I saw quite a few, and will share some, in the order in which I met them.

Our first night fishing, we caught many Atlantic sharpnose sharks (Rhizoprionodon terraenovae).  They are named for their long flat snout and sharp nose. It seemed whenever we caught one, a bunch more followed. They were abundant and kept us busy.

p1080163

Paul Felts, Fisheries Biologist, records measurements while Kevin Rademacher, Fisheries Biologist, wrestles and measures the shark. Matt Ellis, NOAA Science Writer, took amazing pictures throughout the cruise.

Day two, we caught a deep water Cuban dogfish (Squalus cubensis).  

 

p1090143

The Cuban dogfish’s huge iridescent eyes were entrancing.

On September 2o, we almost caught a bull shark (Carcharhinus leucas).  We brought the cradle down, but the shark thrashed its way off, refusing to be studied. The bull shark, along with the tiger shark, are “one of the top three sharks implicated in unprovoked fatal attacks around the world.”

Within a couple days of catching the Cuban dogfish, we caught another shark with iridescent eyes. It turns out this similar looking shark was not a Cuban dogfish, but a rare roughskin spiny dogfish (Cirrhigaleus asper).  

p1080318

Dr. Trey Driggers, Field Party Chief, and prolific shark researcher, surprised us all when he reported this was the first roughskin spiny dogfish he had ever caught!

The beautifully mottled, sleek, immature tiger shark (Galeocerdo cuvier) caught on September 23 had remarkable skin patterns that apparently fade as the shark ages. Adult sharks can get as large as 18 feet and 2,000 pounds.  Along with the bull shark, it is one of the top three species implicated in unprovoked, fatal attacks worldwide.

September 24 we caught a fascinating scalloped hammerhead (Sphyrna lewini).  The flat extended head of this hammerhead is wavy, giving it the “scalloped” part of its name.  Its populations in the Gulf have drastically decreased since 1981, making it a species of concern.

 

img_0430

Here, Kevin measures one of several scalloped hammerhead sharks we caught on Leg IV of the survey.

We also caught a silky shark (Carcharhinus falciformis). Like other Carcharhinus sharks, the silky shark has a sharp “Carchar,” nose “hinus” (Greek derivation), but also has a silky appearance due to its closely spaced dermal denticles.

img_2294

I instantly felt the silky was the most beautiful shark I’d seen. Photo: Matt Ellis/NOAA Fisheries

 

We  saw two of the three smoothhound species present in the Gulf.  On September 25, we caught a Gulf smoothhound, (Mustelus sinusmexicanus), a species named less than 20 years ago. Much is left to learn about the ecology and biology of this recently discovered shark.

img_2575

Getting ready to weigh the gulf smoothhound, Kevin Rademacher, Fisheries Biologist, stops for a photo.                                                      Photo: Matt Ellis/NOAA Fisheries

Then, I watched the night crew catch, measure and tag a dusky shark (Carcharhinus obscurus).

OLYMPUS DIGITAL CAMERA

Photo: NOAA Fisheries

On September 26, we caught a sandbar shark (Carcharhinus plumbeus).  Despite its size,  the sandbar shark poses little threat to man.

img_2889

The sandbar shark’s large fin to body ratio and size make them a prime target for commercial fisheries. Photo: Matt Ellis/NOAA Fisheries

Due to over-fishing, sandbar shark populations are said to have dropped by as much as 2/3 between the 1970’s and the 1990’s. They are now making a comeback, whether it be from fishing regulations, or the decreased populations of larger sharks feeding on juvenile sandbar sharks.

img_3128

This sandbar shark attacked a blacknose shark that had taken our bait. Photo: Matt Ellis/NOAA Fisheries

We tagged many sharks during my two weeks on the Oregon II.  If you never catch one of those sharks again, the tag doesn’t mean anything.  But this week, we also caught a previously tagged sandbar shark!  Recapturing a wild marine animal is phenomenal.  You can learn about its migration patterns, statistically estimate population sizes, and learn much more. The many years of NOAA’s work with this species in particular demonstrates that thoughtful, long term management of a species works.

 

On September 27, we almost caught a nurse shark (Ginglymostoma cirratum). The barbels coming from its mouth reminded me of a catfish or exotic man with a mustache.

Today, September 29, was our last day of fishing, a bittersweet day for me.  That nurse shark that got away, or more likely, another one like it, came up in our cradle.

Every day we caught sharks, including a few other species not mentioned here.  Only once our line came back without a fish.  The diverse characteristics and adaptations that allow each of these species to survive in a challenging marine environment inspire biologists as they try to categorize and understand the species they research.   While catching so many different species of sharks gives me hope, many members of the crew reminisce about times gone by when fish were more abundant than they are now.

Personal Log

I am the kind of person who always struggles to return from an adventure.  I have learned so much, I don’t want to leave.  Yet I know my class at South Prairie is waiting patiently for my return. I hope to share these many marine species  with my class so that we all may view every moment with curiosity and amazement.