esprowls2017

April 13, 2017April 13, 2017

Emily Sprowls: Whirlwind Return to Shore, April 11, 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: April 11, 2017

Weather Data

The weather on the last scheduled day of the cruise was so bad (12 ft. seas! 30 knot winds!) that the ship came into port early on Sunday. The strong winds and waves kicked up and a string of severe storms and tornadoes swept through the area just after my flight home left on Monday morning.

Science and Technology Log

The last few days of the cruise brought in a lot of sharks, fish and data. We were kept pretty busy, putting in and hauling out 3 or 4 lines each shift. In total between both shifts we set 53 stations and caught 679 vertebrate specimens (not counting the invertebrates: sea stars, sea cucumbers and all those isopods)! There were points when this was totally exhausting and repetitive, but then there were moments when we were holding sharks and it was all worth it! We caught some amazing creatures, and some just floated or flew by for a visit like jellyfish and migrant birds.

In between stations the scientists worked to collect and label tissue samples from the specimens needed by different research labs, including fin clips, parasites, muscles, and eye lenses.

Migrating songbird visitor

Portuguese man-o-war jelly

Tissue specimens from bony fish

Personal Log

To be completely honest, there was a point about two-thirds through the cruise when I felt pretty tired, a little bit nauseous, and like I had already seen and learned so much that I was ready to go home. That happened to be a day when another thunderstorm blew in, and we had to take a break from sampling. That terrific weather break (during which we lounged with popcorn and a not-so-terrific movie) also coincided with the forecast suggesting a possible early end to the cruise. Suddenly, it seemed like my trip was almost over — I realized that I had so many more questions for my new scientist friends and not enough time to learn everything!

Fortunately, the scientists on board were very kind and eager to answer my students’ questions with the best information they could find. We had several engaging discussions while answering the kids’ questions… in fact, at one point we were so engrossed in a conversation about dogfish life history that we were suddenly interrupted by radio calls from the deck and bridge that we had missed hauling in our line! We grabbed all our gear: boots, gloves, life jackets, hardhats, clipboards, cameras, laptop; and ran out on deck as fast as we could muster. We had all forgotten it was April Fool’s Day! Ha!

Oregon2 crew — NOAA Corps Officers LCDR Lecia Salerno, LT Reni Rydlewicz and ENS Chelsea Parrish

I am so grateful to the entire crew for their hospitality and their willingness to teach me about their jobs. They shared not only their homes on the boat, but also their own stories and knowledge about the work we were doing. I was lucky to share my first boat experience with Ensign Parrish, who was on her first cruise as a newly minted NOAA officer. Her infectious smile and clear love for being at sea, all while learning the ropes of the Oregon II, helped pull me right along with her enthusiasm.

The main person responsible for my excellent experience aboard was the Field Party Chief.

Baby tiger shark — The amazing shark wrangler Kristin Hannan with a young tiger shark!

Kristin Hannan was friendly and generous with her time, all while coordinating stations with the bridge, managing the scientific crew, and preparing for the next research trip. She was also indefatigable! By the time I would get my baiting gloves off, catch my breath, and get ready to help clean up, she had already finished scrubbing the barrels and decks! Most endearing, however, were her encyclopedic knowledge of shark anatomy and population ecology, and her love of all things shark (even the movie JAWS), tempered by a clear, rational, scientific perspective on issues facing the Gulf of Mexico.

Eventually, the trip drew to a close. As we approached the final sampling stations, there were many species I had hoped to see that hadn’t come up yet. It was as if all I had to do was wish for them and they appeared in the final hauls: Stingrays – CHECK! Big bull shark – CHECK! Beautiful baby tiger shark — CHECK! Adorable spinner shark — CHECK!

I started to see why this work was so addictive and attractive to the crew. But, at the end, I was definitely ready to be on stable land and order whatever I wanted from a restaurant. Going home to my incredibly spacious queen-sized bed and enormous 50 square foot bathroom was also quite nice! I loved my adventure at sea, while I also so admire the tenacity and grit that the scientists and crew on the Oregon II have for living the boat life for much, much longer than two fun weeks. Thank you!

Kids’ Questions

What types of sharks will you catch in the Gulf?

On our leg, we caught the following shark species:

Blacknose shark , CARCHARHINUS ACRONOTUS
Spinner shark, CARCHARHINUS BREVIPINNA
Blacktip shark, CARCHARHINUS LIMBATUS
Sandbar shark, CARCHARHINUS PLUMBEUS
Gulper shark, CENTROPHORUS GRANULOSUS
Little gulper shark, CENTROPHORUS UYATO
Tiger shark, GALEOCERDO CUVIERI
Dusky smoothhound shark, MUSTELUS CANIS
Gulf smoothhound, MUSTELUS SINUSMEXICANUS
Sharpnose shark, RHIZOPRIONODON TERRAENOVAE
Scalloped hammerhead shark, SPHYRNA LEWINI
Cuban dogfish shark, SQUALUS CUBENSIS

We also caught the following batoid species:

Southern stingray, DASYATIS AMERICANA
Roughtail stingray, DASYATIS CENTROURA
Bullnose ray, MYLIOBATIS FREMINVILLII
Clearnose skate, RAJA EGLANTERIA

What is the most populous type of shark in the Gulf of Mexico?

Sharpnose sharks were the most common in our sampling (we caught 247!) Bonnethead sharks are the more common species closer to shore, and blacktip sharks tend to be more common out farther to sea.

Are some shark species more or less sensitive to pollution?

Bull sharks are tolerant of extremes in water conditions (they have been found in the Mississippi River!), so they may be less sensitive to pollution. In general, hammerhead species are more sensitive and younger sharks are also in sensitive life stages, so they might be more sensitive. This is exactly the kind of questions that scientists might be able to answer more definitively someday using the large amounts of data collected by the Oregon II.

What are sharks’ lifespans?

Each shark species is different, but generally they live a long time. Small sharpnose sharks can live about 10 years. Dogfish can live up to 70 years. Other sharks average about 30 years. There is speculation that a Greenland shark has lived over 100 years! These long lifespans are part of the reason many shark populations are vulnerable because it takes them a long time to reach maturity and they do not reproduce quickly. Life history information about sharks is important to know as the NOAA scientists help manage fisheries.

April 1, 2017April 1, 2017

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.

April 1, 2017April 1, 2017

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.

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.

March 27, 2017April 4, 2017

Emily Sprowls: Tag, you’re it! March 26, 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 26, 2017

Weather Data from the Bridge

13:00 hours

28°12.1’ N 89°23.8’W

Visibility 6 nm, Haze

Wind 15 kts 170°E

Sea wave height 4-5 ft.

Seawater temp 23.4°C

Science and Technology Log

I learn to measure my first (little) shark!

The ship has completed our deep-water sampling and we are now headed to more shallow areas, where there are likely to be more sharks and hopefully even some that have been tagged in the past. With each shark we catch, we record in a database their measurements and exactly where they were caught. If things are going well with the shark out of water, we also take a fin clip, a blood sample, and attach a tag.

Tag-and-recapture is one way for wildlife biologists to estimate population size. You can compare the number of tagged sharks to newly caught sharks, and then extrapolate using that ratio to the total number of sharks in the area.

P1050255 — Volunteers help enter data into the “Toughbook” computer.

Recapturing a tagged shark also helps scientists determine the age of a shark, as well as its rate of growth. In bony fish, it is possible to examine the otoliths (bony structures in the ear) to determine the age of a fish. However, since sharks do not have bones, scientists must use other ways to determine their ages and track their growth. One of the scientists on board (my roommate) is collecting shark vertebrae so that her lab can use growth rings in the vertebrae to assess their age, sort of like counting the rings on a tree stump.

Personal Log

The past few days have put all my seasickness remedies to the test with waves over 6 feet and plenty of rolling on the ship. The good news is that they have been working pretty well for the most part – I’ve only lost my lunch once so far! One “cure” for seasickness is to stay busy, which has been difficult to do because the high winds and lightning have made it unsafe to do any sampling.

Fortunately, the crew’s lounge is well-stocked with movies, so I have watched quite a few while we wait for the waves to calm down and the thunderstorm to pass. The lounge has some cushioned benches long enough to stretch out on, which is key because being horizontal is the best way for me to minimize my seasickness.

Kids’ Questions

How do you put the tag on?
Data collection sheet and shark tagging tool.

The tag for smaller sharks is a bit like a plastic earring, but on the shark’s dorsal fin. First you have to “pierce” the fin with a tool like a paper hole-punch, and then use another tool to snap in the tag — making sure that the ID numbers are facing out. If the shark is a species that will outgrow a plastic roto tag, they get a skinny floating tag inserted just under their dorsal fin.

How does the tag stay on the shark?

The shark heals the wound made by the tag, and the scar tissue holds the tag in place. Because the tags are made of plastic and stainless steel, they do not rust or deteriorate in the ocean.

P1050391 — Tagged dorsal fin of *Mustelus sinusmexicanus.*

How do they make the tags?

The NOAA fisheries lab orders tags from manufacturing companies, and are similar to tags used on domestic animals like cows. Each tag includes a phone number and the word “REWARD,” so that if fishermen catch a tagged shark they can report it.

What are they doing with the shark tagging data?

Tagging the sharks in the Gulf of Mexico allows us to figure out how fast they are growing and how far they are traveling. Measuring all the sharks also helps scientists understand how the populations of different species might be changing. Some clues to changing populations include catching smaller or fewer sharks of one species.

March 24, 2017March 28, 2017

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

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.

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.