Karen Grady: Let’s Catch Some Sharks, April 7, 2017

NOAA Teacher at Sea

Karen Grady

Aboard NOAA Ship Oregon II

April 5 – 20, 2017

Mission: Experimental Longline Survey

Geographic Area of Cruise: Gulf of Mexico

Date: April 7, 2017

 

Weather Data

74 Degrees

Clear Skies

Calm Seas

Location

Latitude 2754.34N

Longitude 08905.93W

 

 Science and Technology Log

This is the second leg of the Oregon II’s experimental longline survey.  A longline is a type of fishing gear that will deploy one fishing line that is very long and very thick and has many hooks attached to it.  We will be doing a survey by collecting systematic samplings to assess fish populations.   This mission is an experimental one because the longline is being placed at depths deeper than they fish during the annual longline survey and are able to alter the bait type and leader material to see how it could affect catch rates.

The longlines are baited with pieces of squid. Squid live in deep water so it makes sense to use them to attract deep-sea sharks.  Squid also stays on the hooks better than the mackerel and these hooks have to make it a LONG way down on this survey. The lines are placed in the water and then allowed to soak for several hours.  This allows the squid bait to settle down into the deep water (aided by the weights attached) and for sharks to find the bait.  The fishing line with the hooks is a mile long, but the total line put out can be up to 3 miles long because of the scope needed to allow the 1 mile of gear to reach the deep bottom depths.

baiting hooks

Scientist Kevin Rademacher baiting hooks with squid

As we bring in the catch we will be gathering data on the species caught, sex, maturity stage for male sharks, and certain sharks will be tagged. There are different tags for different sizes of sharks and a small piece of fin is collected on all tagged sharks for genetic purposes. The weight and three or four different measurements will be taken on the all species. Photos of any uncommon species are also taken if time allows to help with identification processes in the future, and so everyone can see them if they weren’t on the watch when the catch occurred.

On my dayshift team is James Sulikowski, a scientist from the University of New England in Maine, who will be using an ultrasound on larger female sharks that we bring on board. Ideally, he and Trey Driggers, the night watchleader from the NOAA MS Labs, would like to catch some large female hammerhead or dusky sharks.  James will use the ultrasound to determine if the large females are pregnant. If they are pregnant, a satellite tag will be placed on the sharks that will stay on for approximately 30 days.  This is perfect as females could be giving birth over this time frame.  The tags will be used to track the sharks with the hope that important habitats where the adults give birth can be identified.  James (and Neil Hammerschlag) has conducted similar research on tiger sharks, but linking pregnancy to specific movements has not been conducted with sharks captured in the Gulf of Mexico.  Our experimental longline survey is happening at a perfect time to gather data for this research.

ultrasounding sharks

James Sulikowski ultra sounding some small pregnant sharks.

shark-ultrasound.jpg

How many baby sharks do you see? We saw THREE!

 

Personal Log

We are at sea now but since getting somewhere is half the fun…..isn’t that what they always say….I wanted to tell you a little about my trip to the ship. On Tuesday night as I was packing we had a storm and lost power for a few hours.  No big deal since I was on the ball and pretty much packed at this point. Wednesday morning, I leave for the airport and about 15 miles down the road I realize I left something I had to have. So, I made a quick turn around and retrieved it. It was a nice drizzling rain and some fog for the drive to the airport.  Now my luck continued when I arrived at airport. Long term parking was full so I had to park at the BACK of the economy lot.  I don’t mind a walk normally but it was raining and that made THREE parking lots to walk through.  Luckily the airport has a little shuttle van to pick up travelers in just such situations.  Oh wait…. This one just drove past us all and kept circling but never actually picked anyone up.  Hmmm.  I had a very bumpy ride to Dallas due to the weather and was relieved to make it to my gate for my connection in Dallas.  Then comes the announcement that they need to change a tire on our plane.  I was completely ok with this hour wait since I see the value in having tires when we land in Gulfport! So only an hour late I made it safely to my destination.

I had a great visit with the scientist who picked me up at the airport. I found out that he and his family intend a vacation in the future to canoe on the Buffalo River. I forget what an amazing state I live in sometimes when it comes to our state parks and outdoor adventures.   One of his areas of focus is Cownose Rays and we discussed how he uses networking to find opportunities to gather data.  My students know how important I feel networking can be.   You never know when that person you meet can help answer a question, provide guidance or solve a problem for you somewhere down the road.  He told me how he took the time just this week to meet some folks who are at NOAA from other countries and ask them to share his contact information because it could help him fill in some needed data for his research.

arriving at ship

Arriving at the Oregon II! Ready to get this adventure started.

Arriving the day before most everyone else made my first night a little bit of an adventure. I had a short tour of the boat and then was on my own.  I was talking with my son on the phone and he asked if it felt like an episode of Scooby Doo where they are on an abandoned ship.  Well.. a little like that.  There were lots of new noises to get used to. And for such a small ship there are lots of doors and rooms.  It is a definite culture shock from the cruise ship I was on during spring break just two weeks ago.

My students all wanted to know what the ship would be like. I will be posting some pics so you can get an idea of what it’s like. I will be sharing my cabin with someone else.  We will basically take turns using it about 12 hours apiece each day.  I knew it would be small but let’s just say I won’t be doing any workouts in my room.  But it has a place for everything and my bunk is comfortable.  There are metal stairs from level to level on the ship.  These are an adventure with my tri-level glasses.  One hand for the rail and I am good.  For those that know me well one of their concerns was that I wouldn’t be able to make it without going for a run.  Crisis averted…there is a rowing machine, weights, a stationary bike etc. onboard. So I guess I will not have to resort to running in place as some people thought.

stairs

The stairs require you to pay attention and use a hand rail..especially if your wearing tri-level glasses like I am

stern.jpg

A boat deck is a busy place with lots of equipment.

The first day onboard was spent getting ready to sail. I just stayed out of the way and introduced myself to the crew as they passed by. We were underway in the early afternoon and it was an adjustment getting used to the motion of the boat.  We had some very informative safety meetings and I got an overview of what we would be doing the next day.  Had a great dinner, our stewards really will keep us fed well!  Then we spent the evening talking and getting to know one another, watching tv, catching up on emails, going through data collection and trying to stay up till midnight so we could get our bodies started on our new schedule.

Day two and we are ready to rock and roll. I slept amazing and woke up to calmer seas.  I was up on deck enjoying the sunshine and getting to watch James ultrasound a few smaller sharks.   I have participated in ultrasounds on dogs, cows, and horses but never a shark.  It was a lot of fun trying to identify how many babies were inside and the best way to use the ultrasound on these smaller sharks.

The day continued to be gorgeous. We pulled one set and caught several sharks, red snapper, and a few eels.  After pulling one set we had several hours of downtime as we head to our next station.  The timing looks like we will get the next set out for the night crew to pull.  The downtime allows everyone to catch up on computer work, and emails.   You can also just sit out on the deck and enjoy the sunset.

 

sunset

Gorgeous sunset our first full day at sea.  Like working 12pm-12am because sunsets are my favorites.

 

Did You Know

  • The Gulf of Mexico has a broad range of ocean ecosystems from shallow reefs to sea forests and has both shallow coastlines and deep ocean waters reaching as deep as 14,300. There is an ample food supply and the perfect habitat for several species of sharks.
  • Sharks do not have swim bladders like bony fish.
  • Sharks store energy in their liver in the form of a viscous oil.   This means their liver is very large.

Elizabeth Eubanks, July 24, 2007

NOAA Teacher at Sea
Elizabeth Eubanks
Onboard NOAA Ship David Starr Jordan
July 22 – August 3, 2007

Mission: Relative Shark Abundance Survey and J vs. Circle Hook Comparison
Geographical Area: Pacific Ocean, West of San Diego
Date: July 24, 2007

Weather Data from the Bridge 
Visibility: 10nm
Air temperature: 19.8 degrees C
Sea Temperature at surface: 20.6 degrees C
Wind Direction: 250 W
Wind Speed:  09 kts
Cloud cover: partial Alto cumulus
Sea Level Pressure: 1011.4 mb
Sea Wave Height : 1 ft
Swell Wave Height : 2-3 ft

NOAA scientist Dr. Suzy Kohin (center places) two different satellite tags on a 197cm Mako shark.

NOAA scientist Dr. Suzy Kohin (center places) two different satellite tags on a 197cm Mako shark.

Science and Technology Log 

Today was absolutely beautiful, the sun was shining all day. We caught 3 sharks 2 Mako and 1 Blue in the first set and 1 Mako in the second set.  This isn’t a whole lot of sharks but for me, even one shark is great! The really cool thing about the day was that we got a Mako large enough to put satellite tags on. The tags are very expensive ~ $5,000, so they want make sure it is a big enough shark to wear the gear. One of the tags is called a P.A.T. and this stands for Pop Off Archival Tag. This tag collects data such as depth, temperature, light measurement, how far it is from the equator and rates of change. It can be set to record information during certain time periods. They only last up to 8 months and then they pop off. Dr. Kohin set this one to pop off in 6 months. The data is stored in the device so data cannot be retrieved until it comes off of the shark. It pops off of the shark floats to the top of the ocean surface and then transmits basic data to a central location. Hopefully someone will find the tag and mail it back to NOAA – Dr. Kohin and she will receive a more complete data report.  The other tag S.P.O.T. – Satellite Position Only Tag goes on the dorsal fin and as it implies, it only tracks satellites just like a GPS does allowing scientists to know the exact location of the shark.

P.A.T. (black tag) and S.P.O.T. (satellite tags)

P.A.T. (black tag) and S.P.O.T. (satellite tags)

Lauren Miko wanted to know what the Circular hook looked like, so here is a photo comparing the two. The circle is believed to cause less damage on the shark. The way that it is curved makes it harder for the shark to swallow, thus reducing the potential amount of internal damage. Also because of the curve sharks are most likely to get this type of hook stuck in its lip/jaw. These shark studies tag and release the shark and are conducted for the overall betterment of the shark, so they need to be kept healthy. Sharks are more likely swallow a J hook and could be damaged in ways that the scientist can’t view even if they remove the hook. Regardless if the shark appears to be in great condition it is possible that it has suffered internally and isn’t showing effects at the time. Does this make sense? Let me know if it doesn’t. FYI- the circular hook is harder to bait, so it is curved up just slightly to make it easier and not flat if you lay it on a table.

Circular Hook and J Hook size 16/0

Circular Hook and J Hook size 16/0

Personal Log 

This ship is so huge. We basically have about 5 hours a day we have to be on deck working. Besides that time I am free and just so you know I spend a lot of time on this log for my students and all who read. I also read, send out emails, take dog naps in the sun and wander around from deck to deck , it is amazing how you could go for hours on this large vessel and not cross paths with anyone and then all of sudden you will go to the top deck and run into two people relaxing. It is like walking through a maze. There are more likely places where you will find folks such as the Mess decks where you eat, snack, relax, watch the tube and of course make scientifically created milkshakes. You also may find people in the crew deck. This is where they have a huge TV, tons of books and lets see, about 500 movies to choose from. The more I think of it, the more I realize that most middle school kids would love this ship. Sean Maloney, it has your name written all over it! Of course although we have amazing food we don’t have your mom’s great banana bread – at least not yet! Lauren was my first student to send an email, then followed Karissa and Sean.

Thank you so much for reading and sending a note and questions. Lauren I believe I answered your question – do you now know what a circle hook looks like?

Question of the Day 

You will notice that at the top of my weather data I list visibility in nm that stands for nautical mile. I also use the term when I say that we put out 2 nautical miles of long line to fish from. What is the difference between a mile and a nautical mile? 

Question of the trip: Which hook, the J or Circle, will catch more sharks?

Please make a hypothesis. Utilize resources to justify your hypothesis.  ———Yes, you get extra credit for this.   

Grad students, Dovi Kacev, Heather Marshall and Lyndsay testing their ability to make the best milkshake – should you add brownies or Oreo cookies?

Grad students, Dovi Kacev, Heather Marshall and Lyndsay testing their ability to make the best milkshake – should you add brownies or Oreo cookies?

Brenton Burnett, July 1, 2006

NOAA Teacher at Sea
Brenton Burnett
Onboard NOAA Ship David Starr Jordan
June 26 – July 6, 2006

Mission: Shark Abundance Survey
Geographical Area: California Coast
Date: July 1, 2006

A hooked pelagic ray swims aside the DAVID STARR JORDAN.

A hooked pelagic ray swims aside the DAVID STARR JORDAN.

Weather Data from Bridge 
Visibility: 10 nautical miles (nm)
Wind direction: 315 degrees
Wind speed: 12 kts
Sea wave height: 1’
Swell wave height: 2-4’
Seawater temperature: 19.6 degrees C
Sea level pressure: 1012.5 mb
Cloud cover: Clear

Science and Technology Log 

Today’s first run was sharkless but instead we did catch eight pelagic stingrays. In the afternoon we caught two smaller makos and another ray. As I mentioned yesterday, chimera, skates and rays, and sharks make up Class Chondrichthyes.  The chimera are the most ancient grouping of these cartilaginous fish. Later came the skates, rays, and sharks in the Subclass Elasmobranch which make up 96% of the cartilaginous fish species. In general, the rays and skates are characterized by a flattened body with their pectoral fins fully attached to the head. This design is an adaptation to living on the seafloor.  Creatures that live here are described as benthic. This lifestyle is in contrast to sea life that lives in the open ocean, which is described as pelagic.

Which of the toy models is a ray and which is a skate?  Skates have dorsal fins located near the ends of their tails

Which of the toy models is a ray and which is a skate? Skates have dorsal fins located near the ends of their tails

The pelagic stingray is the only stingray that is not benthic. This behavior may be a relatively recent occurrence on evolutionary time scales, however, as it retains a number of characteristics best designed tails. Like all skates and rays, their mouths are located under their flattened body.  In this position, they can swim along the bottom and suck in prey off the seafloor. I recently witnessed such feeding as I fed a bat ray at SeaWorld last week.

The gills of skates and rays (collectively known as the batoids) are located underneath, or ventral, to the body. When resting on the bottom, water flow through the gills is limited and so obtaining oxygen would be a problem if it weren’t for another feature common in cartilaginous fish, the spiracle.  Most sharks also have spiracles, which are small holes on either side of their head. They have a respiratory function. In rays and skates these spiracles are located just behind the eyes up on the top of the head. When the pelagic rays are out of the water, the opening and closing of the spiracles as they breathed was obvious. There are two features most useful in distinguishing a skate from a ray.  Most skates have one or two dorsal fins located far back on their tails, and they never have spines that are typical of rays.

The spine of a ray is often toxic and used as a defense by the ray. When the pelagic rays were brought on board, the first priority was the safety of the humans.  The spine was snipped or if possible, the ray is placed upside down on foam that ultimately will take a spine “hit” and from then on cover the spine. The toxin of a ray’s spine is not delivered in the way a snake’s fangs might inject its poison.  A ray’s spine is serrated and acts like a harpoon or barbed hook, preventing removal in the opposite direction from which it was inserted.  The spine of a stingray has serrated edges but is in the form of a mucous that fills two that make it virtually impossible to remove a grooves on the underside of the spine.

The spiracles of a stingray are located just behind the eyes. The spine, sometimes two or three of them, is found near the base of the tail.

The spiracles of a stingray are located just behind the eyes. The spine, sometimes two or three of them, is found near the base of the tail.

A pelagic ray is on the shark platform belly up. Its spine is safely lodged into the foam. A puncture made by the spine that may then be infected by the toxic mucous. Telling shark from batoid is not always easy. The order of sharks known as angel sharks bear resemblance to batoids but their pectoral fins are clearly not fully attached to the head, and their mouths are at the front of the head and not underneath as it is in all rays and skates. Other kinds of sharks and rays that can be confused are the sawshark, which is a shark, and the sawfish, which is a ray. Both have a bizarre flattened snout from which teeth stick laterally, or sideways, outwards. They both have a thicker more sharklike body.  Both have two dorsal fins, a set of pectoral fins and a set of pelvic fins.  But they are no more closely related than any shark is to any ray. When two different types of animals (or plants, or other living thing) are faced with similar challenges, they can sometimes independently evolve in a way that arrives at a similar solution.  Bats, birds and butterflies each independently evolved flight.  Triceratops and rhinos evolved head horns.  Mako sharks and dolphins evolved sleek torpedo shaped bodies for rapid swimming.

A pelagic ray is on the shark platform belly up. Its spine is safely lodged into the foam.

A pelagic ray is on the shark platform belly
up. Its spine is safely lodged into the foam.

And sawsharks and sawfish have independently evolved a saw shaped snout.  Each is believed to use their snout to capture and kill prey.  But they also retain their sharkiness Angel sharks are flattened like a ray but their pectoral  fins are distinctly unattached from the head. Angel sharks have mouths at the front of the head while all batoids have mouths located ventrally, or under the body. There five known species of sawsharks.  They, like most  other sharks, have their gill slits on the sides of their head.  Also, their pectoral fins are not fully attached to the head. Sawsharks have a pair of barbels coming from the sides of their snouts, giving them a mustachioed  appearance. Sawsharks like other sharks have a sensitivity to the electrical disturbances created by moving fish and other prey. Their snout enhances this sensitivity. But the sawfish has no such electrical organ. The sawfish does have pectoral fins that attach fully to the head where the sawshark’s pectoral fins do not. Additionally, the pectoral and pelvic fins of the sawfish are flatter and more flush with the body.  And the gills of the sawfish are underneath the head, but they are found on the side of the head on the sawshark. Lastly, another feature that distinguishes the two are the sawshark barbels that stick out from the middles of their snouts like moustaches—sawfish do not have these.

The spine of a stingray has serrated edges that make it virtually impossible to remove a spine by simply pulling it out the way it went in.

The spine of a stingray has serrated edges that make it virtually impossible to remove a spine by simply pulling it out the way it went in.

I need to address a couple of student questions that I don’t believe I’ve yet answered:

Oxytetracycline (OTC), the dye used to stain the vertebrae for aging studies, is not known to do harm to the shark if given in excess.  However, a table of calculated dosages based on length is used because if too much OTC is used, growth layers other than just the present one will also become stained.

The J-hooks typically used are about four inches in length. The shark abundance survey has been going on since 1994, and to maintain consistent and scientifically comparable data, they continue to use these hooks.

Sharks have few enemies in the oceans.  They tend to be the top predators in their food webs, but as the vast majority of sharks are less than one meter (three feet) long, they can be come prey for other, larger sharks, or even whales like orca. By far the species that poses the largest threat to them are humans.  Mostly humans kill sharks when it is other types of fish that meant to be caught.  The shark would then be referred to as “by-catch”.  At other times sharks are intentionally caught for their meat or as sport—this is often the case for mako sharks.

Angel sharks are flattened like a ray but their pectoral fins are distinctly unattached from the head.

Angel sharks are flattened like a ray but their pectoral fins are distinctly unattached from the head.

Sawfish have their gills located underneath their head like all other batoids.

Oxytetracycline is light sensitive, meaning it reacts and breaks down when exposed to enough light.  For this reason the bottle is brown and kept in a bag, and loaded syringes are kept inside a glove for ready use.

The J-hook and somewhat smaller circle hook are used for mako  and thresher shark lines.

Personal Log 

I continue to have a good time here, if not for the sights and sounds but for the people I am working with.  Lots of interesting, friendly, and fun-loving folks.  And, happily, they have been quite tolerant, and even obliging of me walking around with my video camera catching this and that.

Angel sharks have mouths at the front of the head while all batoids have mouths located ventrally, or under the body.

Angel sharks have mouths at the front of the head while all batoids have mouths located ventrally, or under the body.

There five known species of sawsharks. They, like most other sharks, have their gill slits on the sides of their head. Also, their pectoral fins are not fully attached to the head.

There five known species of sawsharks. They, like most other sharks, have their gill slits on the sides of their head. Also, their pectoral fins are not fully attached to the head.

Sawsharks have a pair of barbels coming from the sides of their snouts, giving them a mustachioed appearance.

Sawsharks have a pair of barbels coming from the sides of their snouts, giving them a mustachioed appearance.

Sawfish have their gills located underneath their head like all other batoids.

Sawfish have their gills located underneath their head like all other batoids.

Oxytetracycline is light sensitive, meaning it reacts and breaks down when exposed to enough light. For this reason the bottle is brown and kept in a bag, and loaded syringes are kept inside a glove for ready use.

Oxytetracycline is light sensitive, meaning it reacts and breaks down when exposed to enough light. For this reason the bottle is brown and kept in a bag, and loaded syringes are kept inside a glove for ready use.

The J-hook and somewhat smaller circle hook are used for mako and thresher shark lines.

The J-hook (right) and somewhat smaller circle hook are used for mako and thresher shark lines.