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.

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:

Scalloped hammerhead

Scalloped hammerhead

  • 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

 

 

Clearnose skate

Clearnose skate

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.

 

 

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